Libraries: Create top level directory for libraries.

Things were getting a little crowded in the project root, so this patch
moves the Lib*/ directories into Libraries/.

44 files changed, 2815 insertions, 0 deletions

diff --git a/Libraries/LibCore/CArgsParser.cpp b/Libraries/LibCore/CArgsParser.cpp
new file mode 100644
index 0000000000..12ce7c90b4
--- /dev/null
+++ b/Libraries/LibCore/CArgsParser.cpp
@@ -0,0 +1,237 @@
+#include "CArgsParser.h"
+#include <AK/StringBuilder.h>
+
+#include <stdio.h>
+
+bool CArgsParserResult::is_present(const String& arg_name) const
+{
+    return m_args.contains(arg_name);
+}
+
+String CArgsParserResult::get(const String& arg_name) const
+{
+    return m_args.get(arg_name);
+}
+
+const Vector<String>& CArgsParserResult::get_single_values() const
+{
+    return m_single_values;
+}
+
+CArgsParser::Arg::Arg(const String& name, const String& description, bool required)
+    : name(name)
+    , description(description)
+    , required(required)
+{
+}
+
+CArgsParser::Arg::Arg(const String& name, const String& value_name, const String& description, bool required)
+    : name(name)
+    , description(description)
+    , value_name(value_name)
+    , required(required)
+{
+}
+
+CArgsParser::CArgsParser(const String& program_name)
+    : m_program_name(program_name)
+    , m_prefix("-")
+{
+}
+
+CArgsParserResult CArgsParser::parse(int argc, char** argv)
+{
+    CArgsParserResult res;
+
+    // We should have at least one parameter
+    if (argc < 2)
+        return {};
+
+    // We parse the first parameter at the index 1
+    if (parse_next_param(1, argv, argc - 1, res) != 0)
+        return {};
+
+    if (!check_required_args(res))
+        return {};
+
+    return res;
+}
+
+int CArgsParser::parse_next_param(int index, char** argv, const int params_left, CArgsParserResult& res)
+{
+    if (params_left == 0)
+        return 0;
+
+    String param = argv[index];
+
+    // We check if the prefix is found at the beginning of the param name
+    if (is_param_valid(param)) {
+        auto prefix_length = m_prefix.length();
+        String param_name = param.substring(prefix_length, param.length() - prefix_length);
+
+        auto arg = m_args.find(param_name);
+        if (arg == m_args.end()) {
+            printf("Unknown arg \"");
+            if (!param_name.is_null())
+                printf("%s", param_name.characters());
+            printf("\"\n");
+            return -1;
+        }
+
+        // If this parameter must be followed by a value, we look for it
+        if (!arg->value.value_name.is_null()) {
+            if (params_left < 1) {
+                printf("Missing value for argument %s\n", arg->value.name.characters());
+                return -1;
+            }
+
+            String next = String(argv[index + 1]);
+
+            if (is_param_valid(next)) {
+                printf("Missing value for argument %s\n", arg->value.name.characters());
+                return -1;
+            }
+
+            res.m_args.set(arg->value.name, next);
+            return parse_next_param(index + 2, argv, params_left - 2, res);
+        }
+
+        // Single argument, not followed by a value
+        res.m_args.set(arg->value.name, "");
+        return parse_next_param(index + 1, argv, params_left - 1, res);
+    }
+
+    // Else, it's a value alone, a file name parameter for example
+    res.m_single_values.append(param);
+    return parse_next_param(index + 1, argv, params_left - 1, res);
+}
+
+bool CArgsParser::is_param_valid(const String& param_name)
+{
+    return param_name.substring(0, m_prefix.length()) == m_prefix;
+}
+
+bool CArgsParser::check_required_args(const CArgsParserResult& res)
+{
+    for (auto& it : m_args) {
+        if (it.value.required) {
+            if (!res.is_present(it.value.name))
+                return false;
+        }
+    }
+
+    int required_arguments = 0;
+    for (const auto& a : m_single_args) {
+        if (a.required) {
+            required_arguments++;
+        }
+    }
+
+    if (required_arguments != 0) {
+        if (res.m_single_values.size() < required_arguments)
+            return false;
+    }
+
+    return true;
+}
+
+void CArgsParser::add_required_arg(const String& name, const String& description)
+{
+    m_args.set(name, Arg(name, description, true));
+}
+
+void CArgsParser::add_required_arg(const String& name, const String& value_name, const String& description)
+{
+    m_args.set(name, Arg(name, value_name, description, true));
+}
+
+void CArgsParser::add_arg(const String& name, const String& description)
+{
+    m_args.set(name, Arg(name, description, false));
+}
+
+void CArgsParser::add_arg(const String& name, const String& value_name, const String& description)
+{
+    m_args.set(name, Arg(name, value_name, description, false));
+}
+
+void CArgsParser::add_single_value(const String& name)
+{
+    m_single_args.append(SingleArg { name, false });
+}
+
+void CArgsParser::add_required_single_value(const String& name)
+{
+    if (m_single_args.size() != 0) {
+        // adding required arguments after non-required arguments would be nonsensical
+        ASSERT(m_single_args.last().required);
+    }
+    m_single_args.append(SingleArg { name, true });
+}
+
+String CArgsParser::get_usage() const
+{
+    StringBuilder sb;
+
+    sb.append("usage : ");
+    sb.append(m_program_name);
+    sb.append(" ");
+
+    for (auto& it : m_args) {
+        if (it.value.required)
+            sb.append("<");
+        else
+            sb.append("[");
+
+        sb.append(m_prefix);
+        sb.append(it.value.name);
+
+        if (!it.value.value_name.is_null()) {
+            sb.append(" ");
+            sb.append(it.value.value_name);
+        }
+
+        if (it.value.required)
+            sb.append("> ");
+        else
+            sb.append("] ");
+    }
+
+    for (auto& arg : m_single_args) {
+        if (arg.required)
+            sb.append("<");
+        else
+            sb.append("[");
+
+        sb.append(arg.name);
+
+        if (arg.required)
+            sb.append("> ");
+        else
+            sb.append("] ");
+    }
+
+    sb.append("\n");
+
+    for (auto& it : m_args) {
+        sb.append("    ");
+        sb.append(m_prefix);
+        sb.append(it.value.name);
+
+        if (!it.value.value_name.is_null()) {
+            sb.append(" ");
+            sb.append(it.value.value_name);
+        }
+
+        sb.append(" : ");
+        sb.append(it.value.description);
+        sb.append("\n");
+    }
+
+    return sb.to_string();
+}
+
+void CArgsParser::print_usage() const
+{
+    printf("%s\n", get_usage().characters());
+}
diff --git a/Libraries/LibCore/CArgsParser.h b/Libraries/LibCore/CArgsParser.h
new file mode 100644
index 0000000000..6a696054e2
--- /dev/null
+++ b/Libraries/LibCore/CArgsParser.h
@@ -0,0 +1,69 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/HashMap.h>
+#include <AK/Vector.h>
+
+/*
+  The class ArgsParser provides a way to parse arguments by using a given list that describes the possible
+  types of arguments (name, description, required or not, must be followed by a value...).
+  Call the add_arg() functions to describe your arguments.
+
+  The class ArgsParserResult is used to manipulate the arguments (checking if an arg has been provided,
+  retrieve its value...). In case of error (missing required argument) an empty structure is returned as result.
+*/
+
+class CArgsParserResult {
+public:
+    bool is_present(const String& arg_name) const;
+    String get(const String& arg_name) const;
+    const Vector<String>& get_single_values() const;
+
+private:
+    HashMap<String, String> m_args;
+    Vector<String> m_single_values;
+
+    friend class CArgsParser;
+};
+
+class CArgsParser {
+public:
+    CArgsParser(const String& program_name);
+
+    CArgsParserResult parse(int argc, char** argv);
+
+    void add_required_arg(const String& name, const String& description);
+    void add_required_arg(const String& name, const String& value_name, const String& description);
+    void add_arg(const String& name, const String& description);
+    void add_arg(const String& name, const String& value_name, const String& description);
+    void add_single_value(const String& name);
+    void add_required_single_value(const String& name);
+    String get_usage() const;
+    void print_usage() const;
+
+private:
+    struct Arg {
+        inline Arg() {}
+        Arg(const String& name, const String& description, bool required);
+        Arg(const String& name, const String& value_name, const String& description, bool required);
+
+        String name;
+        String description;
+        String value_name;
+        bool required;
+    };
+
+    int parse_next_param(int index, char** argv, const int params_left, CArgsParserResult& res);
+    bool is_param_valid(const String& param_name);
+    bool check_required_args(const CArgsParserResult& res);
+
+    String m_program_name;
+    String m_prefix;
+
+    struct SingleArg {
+        String name;
+        bool required;
+    };
+    Vector<SingleArg> m_single_args;
+    HashMap<String, Arg> m_args;
+};
diff --git a/Libraries/LibCore/CConfigFile.cpp b/Libraries/LibCore/CConfigFile.cpp
new file mode 100644
index 0000000000..2f1fec736a
--- /dev/null
+++ b/Libraries/LibCore/CConfigFile.cpp
@@ -0,0 +1,233 @@
+#include <AK/StringBuilder.h>
+#include <LibCore/CConfigFile.h>
+#include <LibCore/CFile.h>
+#include <LibCore/CUserInfo.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <unistd.h>
+
+NonnullRefPtr<CConfigFile> CConfigFile::get_for_app(const String& app_name)
+{
+    String home_path = get_current_user_home_path();
+    if (home_path == "/")
+        home_path = String::format("/tmp");
+    auto path = String::format("%s/%s.ini", home_path.characters(), app_name.characters());
+    return adopt(*new CConfigFile(path));
+}
+
+NonnullRefPtr<CConfigFile> CConfigFile::get_for_system(const String& app_name)
+{
+    auto path = String::format("/etc/%s.ini", app_name.characters());
+    return adopt(*new CConfigFile(path));
+}
+
+CConfigFile::CConfigFile(const String& file_name)
+    : m_file_name(file_name)
+{
+    reparse();
+}
+
+CConfigFile::~CConfigFile()
+{
+    sync();
+}
+
+void CConfigFile::reparse()
+{
+    m_groups.clear();
+
+    CFile file(m_file_name);
+    if (!file.open(CIODevice::OpenMode::ReadOnly))
+        return;
+
+    HashMap<String, String>* current_group = nullptr;
+
+    while (file.can_read_line()) {
+        auto line = file.read_line(BUFSIZ);
+        auto* cp = (const char*)line.pointer();
+
+        while (*cp && (*cp == ' ' || *cp == '\t' || *cp == '\n'))
+            ++cp;
+
+        switch (*cp) {
+        case '\0': // EOL...
+        case '#':  // Comment, skip entire line.
+        case ';':  // -||-
+            continue;
+        case '[': { // Start of new group.
+            StringBuilder builder;
+            ++cp; // Skip the '['
+            while (*cp && (*cp != ']'))
+                builder.append(*(cp++));
+            current_group = &m_groups.ensure(builder.to_string());
+            break;
+        }
+        default: { // Start of key{
+            StringBuilder key_builder;
+            StringBuilder value_builder;
+            while (*cp && (*cp != '='))
+                key_builder.append(*(cp++));
+            ++cp; // Skip the '='
+            while (*cp && (*cp != '\n'))
+                value_builder.append(*(cp++));
+            if (!current_group) {
+                // We're not in a group yet, create one with the name ""...
+                current_group = &m_groups.ensure("");
+            }
+            current_group->set(key_builder.to_string(), value_builder.to_string());
+        }
+        }
+    }
+}
+
+String CConfigFile::read_entry(const String& group, const String& key, const String& default_value) const
+{
+    if (!has_key(group, key)) {
+        const_cast<CConfigFile&>(*this).write_entry(group, key, default_value);
+        return default_value;
+    }
+    auto it = m_groups.find(group);
+    auto jt = it->value.find(key);
+    return jt->value;
+}
+
+int CConfigFile::read_num_entry(const String& group, const String& key, int default_value) const
+{
+    if (!has_key(group, key)) {
+        const_cast<CConfigFile&>(*this).write_num_entry(group, key, default_value);
+        return default_value;
+    }
+
+    bool ok;
+    int value = read_entry(group, key).to_uint(ok);
+    if (!ok)
+        return default_value;
+    return value;
+}
+
+Color CConfigFile::read_color_entry(const String& group, const String& key, Color default_value) const
+{
+    if (!has_key(group, key)) {
+        const_cast<CConfigFile&>(*this).write_color_entry(group, key, default_value);
+        return default_value;
+    }
+
+    auto shades = read_entry(group, key).split(',');
+    if (shades.size() < 3)
+        return default_value;
+    bool ok1 = true,
+         ok2 = true,
+         ok3 = true,
+         ok4 = true;
+    Color value;
+    if (shades.size() == 3) {
+        value = Color(shades[0].to_uint(ok1),
+            shades[1].to_uint(ok2),
+            shades[2].to_uint(ok3));
+    } else {
+        value = Color(shades[0].to_uint(ok1),
+            shades[1].to_uint(ok2),
+            shades[2].to_uint(ok3),
+            shades[3].to_uint(ok4));
+    }
+    if (!(ok1 && ok2 && ok3 && ok4))
+        return default_value;
+    return value;
+}
+
+bool CConfigFile::read_bool_entry(const String& group, const String& key, bool default_value) const
+{
+    return read_entry(group, key, default_value ? "1" : "0") == "1";
+}
+
+void CConfigFile::write_entry(const String& group, const String& key, const String& value)
+{
+    m_groups.ensure(group).ensure(key) = value;
+    m_dirty = true;
+}
+
+void CConfigFile::write_num_entry(const String& group, const String& key, int value)
+{
+    write_entry(group, key, String::number(value));
+}
+void CConfigFile::write_bool_entry(const String& group, const String& key, bool value)
+{
+    write_entry(group, key, value ? "1" : "0");
+}
+void CConfigFile::write_color_entry(const String& group, const String& key, Color value)
+{
+    write_entry(group, key, String::format("%d,%d,%d,%d", value.red(), value.green(), value.blue(), value.alpha()));
+}
+
+bool CConfigFile::sync()
+{
+    if (!m_dirty)
+        return true;
+
+    FILE* fp = fopen(m_file_name.characters(), "wb");
+    if (!fp)
+        return false;
+
+    for (auto& it : m_groups) {
+        fprintf(fp, "[%s]\n", it.key.characters());
+        for (auto& jt : it.value)
+            fprintf(fp, "%s=%s\n", jt.key.characters(), jt.value.characters());
+        fprintf(fp, "\n");
+    }
+
+    fclose(fp);
+
+    m_dirty = false;
+    return true;
+}
+
+void CConfigFile::dump() const
+{
+    for (auto& it : m_groups) {
+        printf("[%s]\n", it.key.characters());
+        for (auto& jt : it.value)
+            printf("%s=%s\n", jt.key.characters(), jt.value.characters());
+        printf("\n");
+    }
+}
+
+Vector<String> CConfigFile::groups() const
+{
+    return m_groups.keys();
+}
+
+Vector<String> CConfigFile::keys(const String& group) const
+{
+    auto it = m_groups.find(group);
+    if (it == m_groups.end())
+        return {};
+    return it->value.keys();
+}
+
+bool CConfigFile::has_key(const String& group, const String& key) const
+{
+    auto it = m_groups.find(group);
+    if (it == m_groups.end())
+        return {};
+    return it->value.contains(key);
+}
+
+bool CConfigFile::has_group(const String& group) const
+{
+    return m_groups.contains(group);
+}
+
+void CConfigFile::remove_group(const String& group)
+{
+    m_groups.remove(group);
+    m_dirty = true;
+}
+
+void CConfigFile::remove_entry(const String& group, const String& key)
+{
+    auto it = m_groups.find(group);
+    if (it == m_groups.end())
+        return;
+    it->value.remove(key);
+    m_dirty = true;
+}
diff --git a/Libraries/LibCore/CConfigFile.h b/Libraries/LibCore/CConfigFile.h
new file mode 100644
index 0000000000..1816ba53c9
--- /dev/null
+++ b/Libraries/LibCore/CConfigFile.h
@@ -0,0 +1,51 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/HashMap.h>
+#include <AK/RefPtr.h>
+#include <AK/RefCounted.h>
+#include <AK/Vector.h>
+#include <SharedGraphics/Color.h>
+
+class CConfigFile : public RefCounted<CConfigFile> {
+public:
+    static NonnullRefPtr<CConfigFile> get_for_app(const String& app_name);
+    static NonnullRefPtr<CConfigFile> get_for_system(const String& app_name);
+    ~CConfigFile();
+
+    bool has_group(const String&) const;
+    bool has_key(const String& group, const String& key) const;
+
+    Vector<String> groups() const;
+    Vector<String> keys(const String& group) const;
+
+    String read_entry(const String& group, const String& key, const String& default_vaule = String()) const;
+    int read_num_entry(const String& group, const String& key, int default_value = 0) const;
+    bool read_bool_entry(const String& group, const String& key, bool default_value = false) const;
+    Color read_color_entry(const String& group, const String& key, Color default_value) const;
+
+    void write_entry(const String& group, const String& key, const String& value);
+    void write_num_entry(const String& group, const String& key, int value);
+    void write_bool_entry(const String& group, const String& key, bool value);
+    void write_color_entry(const String& group, const String& key, Color value);
+
+    void dump() const;
+
+    bool is_dirty() const { return m_dirty; }
+
+    bool sync();
+
+    void remove_group(const String& group);
+    void remove_entry(const String& group, const String& key);
+
+    String file_name() const { return m_file_name; }
+
+private:
+    explicit CConfigFile(const String& file_name);
+
+    void reparse();
+
+    String m_file_name;
+    HashMap<String, HashMap<String, String>> m_groups;
+    bool m_dirty { false };
+};
diff --git a/Libraries/LibCore/CDirIterator.cpp b/Libraries/LibCore/CDirIterator.cpp
new file mode 100644
index 0000000000..d76d52970d
--- /dev/null
+++ b/Libraries/LibCore/CDirIterator.cpp
@@ -0,0 +1,67 @@
+#include "CDirIterator.h"
+#include <cerrno>
+
+CDirIterator::CDirIterator(const StringView& path, Flags flags)
+    : m_flags(flags)
+{
+    m_dir = opendir(path.characters());
+    if (m_dir == nullptr) {
+        m_error = errno;
+    }
+}
+
+CDirIterator::~CDirIterator()
+{
+    if (m_dir != nullptr) {
+        closedir(m_dir);
+        m_dir = nullptr;
+    }
+}
+
+bool CDirIterator::advance_next()
+{
+    if (m_dir == nullptr)
+        return false;
+
+    bool keep_advancing = true;
+    while (keep_advancing) {
+        errno = 0;
+        auto* de = readdir(m_dir);
+        if (de) {
+            m_next = de->d_name;
+        } else {
+            m_error = errno;
+            m_next = String();
+        }
+
+        if (m_next.is_null()) {
+            keep_advancing = false;
+        } else if (m_flags & Flags::SkipDots) {
+            if (m_next.length() < 1 || m_next[0] != '.') {
+                keep_advancing = false;
+            }
+        } else {
+            keep_advancing = false;
+        }
+    }
+
+    return m_next.length() > 0;
+}
+
+bool CDirIterator::has_next()
+{
+    if (!m_next.is_null())
+        return true;
+
+    return advance_next();
+}
+
+String CDirIterator::next_path()
+{
+    if (m_next.is_null())
+        advance_next();
+
+    auto tmp = m_next;
+    m_next = String();
+    return tmp;
+}
diff --git a/Libraries/LibCore/CDirIterator.h b/Libraries/LibCore/CDirIterator.h
new file mode 100644
index 0000000000..08c9040b48
--- /dev/null
+++ b/Libraries/LibCore/CDirIterator.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <dirent.h>
+
+class CDirIterator {
+public:
+    enum Flags {
+        NoFlags = 0x0,
+        SkipDots = 0x1,
+    };
+
+    CDirIterator(const StringView& path, Flags = Flags::NoFlags);
+    ~CDirIterator();
+
+    bool has_error() const { return m_error != 0; }
+    int error() const { return m_error; }
+    const char* error_string() const { return strerror(m_error); }
+    bool has_next();
+    String next_path();
+
+private:
+    DIR* m_dir = nullptr;
+    int m_error = 0;
+    String m_next;
+    int m_flags;
+
+    bool advance_next();
+};
diff --git a/Libraries/LibCore/CElapsedTimer.cpp b/Libraries/LibCore/CElapsedTimer.cpp
new file mode 100644
index 0000000000..4e8902d348
--- /dev/null
+++ b/Libraries/LibCore/CElapsedTimer.cpp
@@ -0,0 +1,20 @@
+#include <AK/Assertions.h>
+#include <AK/Time.h>
+#include <LibCore/CElapsedTimer.h>
+#include <sys/time.h>
+
+void CElapsedTimer::start()
+{
+    m_valid = true;
+    gettimeofday(&m_start_time, nullptr);
+}
+
+int CElapsedTimer::elapsed() const
+{
+    ASSERT(is_valid());
+    struct timeval now;
+    gettimeofday(&now, nullptr);
+    struct timeval diff;
+    timeval_sub(now, m_start_time, diff);
+    return diff.tv_sec * 1000 + diff.tv_usec / 1000;
+}
diff --git a/Libraries/LibCore/CElapsedTimer.h b/Libraries/LibCore/CElapsedTimer.h
new file mode 100644
index 0000000000..76fa304478
--- /dev/null
+++ b/Libraries/LibCore/CElapsedTimer.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <sys/time.h>
+
+class CElapsedTimer {
+public:
+    CElapsedTimer() {}
+
+    bool is_valid() const { return m_valid; }
+    void start();
+    int elapsed() const;
+
+private:
+    bool m_valid { false };
+    struct timeval m_start_time {
+        0, 0
+    };
+};
diff --git a/Libraries/LibCore/CEvent.cpp b/Libraries/LibCore/CEvent.cpp
new file mode 100644
index 0000000000..eacce964c2
--- /dev/null
+++ b/Libraries/LibCore/CEvent.cpp
@@ -0,0 +1,12 @@
+#include <LibCore/CEvent.h>
+#include <LibCore/CObject.h>
+
+CChildEvent::CChildEvent(Type type, CObject& child)
+    : CEvent(type)
+    , m_child(child.make_weak_ptr())
+{
+}
+
+CChildEvent::~CChildEvent()
+{
+}
diff --git a/Libraries/LibCore/CEvent.h b/Libraries/LibCore/CEvent.h
new file mode 100644
index 0000000000..9d262c4a76
--- /dev/null
+++ b/Libraries/LibCore/CEvent.h
@@ -0,0 +1,74 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/Function.h>
+#include <AK/Types.h>
+#include <AK/WeakPtr.h>
+
+class CObject;
+
+class CEvent {
+public:
+    enum Type {
+        Invalid = 0,
+        Quit,
+        Timer,
+        DeferredDestroy,
+        DeferredInvoke,
+        ChildAdded,
+        ChildRemoved,
+    };
+
+    CEvent() {}
+    explicit CEvent(unsigned type)
+        : m_type(type)
+    {
+    }
+    virtual ~CEvent() {}
+
+    unsigned type() const { return m_type; }
+
+private:
+    unsigned m_type { Type::Invalid };
+};
+
+class CDeferredInvocationEvent : public CEvent {
+    friend class CEventLoop;
+
+public:
+    CDeferredInvocationEvent(Function<void(CObject&)> invokee)
+        : CEvent(CEvent::Type::DeferredInvoke)
+        , m_invokee(move(invokee))
+    {
+    }
+
+private:
+    Function<void(CObject&)> m_invokee;
+};
+
+class CTimerEvent final : public CEvent {
+public:
+    explicit CTimerEvent(int timer_id)
+        : CEvent(CEvent::Timer)
+        , m_timer_id(timer_id)
+    {
+    }
+    ~CTimerEvent() {}
+
+    int timer_id() const { return m_timer_id; }
+
+private:
+    int m_timer_id;
+};
+
+class CChildEvent final : public CEvent {
+public:
+    CChildEvent(Type, CObject& child);
+    ~CChildEvent();
+
+    CObject* child() { return m_child.ptr(); }
+    const CObject* child() const { return m_child.ptr(); }
+
+private:
+    WeakPtr<CObject> m_child;
+};
diff --git a/Libraries/LibCore/CEventLoop.cpp b/Libraries/LibCore/CEventLoop.cpp
new file mode 100644
index 0000000000..e38c2b2154
--- /dev/null
+++ b/Libraries/LibCore/CEventLoop.cpp
@@ -0,0 +1,302 @@
+#include <AK/Time.h>
+#include <LibCore/CEvent.h>
+#include <LibCore/CEventLoop.h>
+#include <LibCore/CLock.h>
+#include <LibCore/CNotifier.h>
+#include <LibCore/CObject.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+
+//#define CEVENTLOOP_DEBUG
+//#define DEFERRED_INVOKE_DEBUG
+
+static CEventLoop* s_main_event_loop;
+static Vector<CEventLoop*>* s_event_loop_stack;
+HashMap<int, OwnPtr<CEventLoop::EventLoopTimer>>* CEventLoop::s_timers;
+HashTable<CNotifier*>* CEventLoop::s_notifiers;
+int CEventLoop::s_next_timer_id = 1;
+
+CEventLoop::CEventLoop()
+{
+    if (!s_event_loop_stack) {
+        s_event_loop_stack = new Vector<CEventLoop*>;
+        s_timers = new HashMap<int, OwnPtr<CEventLoop::EventLoopTimer>>;
+        s_notifiers = new HashTable<CNotifier*>;
+    }
+
+    if (!s_main_event_loop) {
+        s_main_event_loop = this;
+        s_event_loop_stack->append(this);
+    }
+
+#ifdef CEVENTLOOP_DEBUG
+    dbgprintf("(%u) CEventLoop constructed :)\n", getpid());
+#endif
+}
+
+CEventLoop::~CEventLoop()
+{
+}
+
+CEventLoop& CEventLoop::main()
+{
+    ASSERT(s_main_event_loop);
+    return *s_main_event_loop;
+}
+
+CEventLoop& CEventLoop::current()
+{
+    return *s_event_loop_stack->last();
+}
+
+void CEventLoop::quit(int code)
+{
+    m_exit_requested = true;
+    m_exit_code = code;
+}
+
+struct CEventLoopPusher {
+public:
+    CEventLoopPusher(CEventLoop& event_loop)
+        : m_event_loop(event_loop)
+    {
+        if (&m_event_loop != s_main_event_loop) {
+            m_event_loop.take_pending_events_from(CEventLoop::current());
+            s_event_loop_stack->append(&event_loop);
+        }
+    }
+    ~CEventLoopPusher()
+    {
+        if (&m_event_loop != s_main_event_loop) {
+            s_event_loop_stack->take_last();
+            CEventLoop::current().take_pending_events_from(m_event_loop);
+        }
+    }
+
+private:
+    CEventLoop& m_event_loop;
+};
+
+int CEventLoop::exec()
+{
+    CEventLoopPusher pusher(*this);
+    for (;;) {
+        if (m_exit_requested)
+            return m_exit_code;
+        pump();
+    }
+    ASSERT_NOT_REACHED();
+}
+
+void CEventLoop::pump(WaitMode mode)
+{
+    // window server event processing...
+    do_processing();
+
+    if (m_queued_events.is_empty()) {
+        wait_for_event(mode);
+        do_processing();
+    }
+    decltype(m_queued_events) events;
+    {
+        LOCKER(m_lock);
+        events = move(m_queued_events);
+    }
+
+    for (auto& queued_event : events) {
+        auto* receiver = queued_event.receiver.ptr();
+        auto& event = *queued_event.event;
+#ifdef CEVENTLOOP_DEBUG
+        dbgprintf("CEventLoop: %s{%p} event %u\n", receiver->class_name(), receiver, (unsigned)event.type());
+#endif
+        if (!receiver) {
+            switch (event.type()) {
+            case CEvent::Quit:
+                ASSERT_NOT_REACHED();
+                return;
+            default:
+                dbgprintf("Event type %u with no receiver :(\n", event.type());
+            }
+        } else if (event.type() == CEvent::Type::DeferredInvoke) {
+#ifdef DEFERRED_INVOKE_DEBUG
+            printf("DeferredInvoke: receiver=%s{%p}\n", receiver->class_name(), receiver);
+#endif
+            static_cast<CDeferredInvocationEvent&>(event).m_invokee(*receiver);
+        } else {
+            receiver->event(event);
+        }
+
+        if (m_exit_requested) {
+            LOCKER(m_lock);
+            auto rejigged_event_queue = move(events);
+            rejigged_event_queue.append(move(m_queued_events));
+            m_queued_events = move(rejigged_event_queue);
+        }
+    }
+}
+
+void CEventLoop::post_event(CObject& receiver, OwnPtr<CEvent>&& event)
+{
+    LOCKER(m_lock);
+#ifdef CEVENTLOOP_DEBUG
+    dbgprintf("CEventLoop::post_event: {%u} << receiver=%p, event=%p\n", m_queued_events.size(), &receiver, event.ptr());
+#endif
+    m_queued_events.append({ receiver.make_weak_ptr(), move(event) });
+}
+
+void CEventLoop::wait_for_event(WaitMode mode)
+{
+    fd_set rfds;
+    fd_set wfds;
+    FD_ZERO(&rfds);
+    FD_ZERO(&wfds);
+
+    int max_fd = 0;
+    auto add_fd_to_set = [&max_fd](int fd, fd_set& set) {
+        FD_SET(fd, &set);
+        if (fd > max_fd)
+            max_fd = fd;
+    };
+
+    int max_fd_added = -1;
+    add_file_descriptors_for_select(rfds, max_fd_added);
+    max_fd = max(max_fd, max_fd_added);
+    for (auto& notifier : *s_notifiers) {
+        if (notifier->event_mask() & CNotifier::Read)
+            add_fd_to_set(notifier->fd(), rfds);
+        if (notifier->event_mask() & CNotifier::Write)
+            add_fd_to_set(notifier->fd(), wfds);
+        if (notifier->event_mask() & CNotifier::Exceptional)
+            ASSERT_NOT_REACHED();
+    }
+
+    bool queued_events_is_empty;
+    {
+        LOCKER(m_lock);
+        queued_events_is_empty = m_queued_events.is_empty();
+    }
+
+    timeval now;
+    struct timeval timeout = { 0, 0 };
+    bool should_wait_forever = false;
+    if (mode == WaitMode::WaitForEvents) {
+        if (!s_timers->is_empty() && queued_events_is_empty) {
+            gettimeofday(&now, nullptr);
+            get_next_timer_expiration(timeout);
+            timeval_sub(timeout, now, timeout);
+        } else {
+            should_wait_forever = true;
+        }
+    } else {
+        should_wait_forever = false;
+    }
+
+    int marked_fd_count = select(max_fd + 1, &rfds, &wfds, nullptr, should_wait_forever ? nullptr : &timeout);
+    if (marked_fd_count < 0) {
+        ASSERT_NOT_REACHED();
+    }
+
+    if (!s_timers->is_empty()) {
+        gettimeofday(&now, nullptr);
+    }
+
+    for (auto& it : *s_timers) {
+        auto& timer = *it.value;
+        if (!timer.has_expired(now))
+            continue;
+#ifdef CEVENTLOOP_DEBUG
+        dbgprintf("CEventLoop: Timer %d has expired, sending CTimerEvent to %p\n", timer.timer_id, timer.owner);
+#endif
+        post_event(*timer.owner, make<CTimerEvent>(timer.timer_id));
+        if (timer.should_reload) {
+            timer.reload(now);
+        } else {
+            // FIXME: Support removing expired timers that don't want to reload.
+            ASSERT_NOT_REACHED();
+        }
+    }
+
+    if (!marked_fd_count)
+        return;
+
+    for (auto& notifier : *s_notifiers) {
+        if (FD_ISSET(notifier->fd(), &rfds)) {
+            if (notifier->on_ready_to_read)
+                notifier->on_ready_to_read();
+        }
+        if (FD_ISSET(notifier->fd(), &wfds)) {
+            if (notifier->on_ready_to_write)
+                notifier->on_ready_to_write();
+        }
+    }
+
+    process_file_descriptors_after_select(rfds);
+}
+
+bool CEventLoop::EventLoopTimer::has_expired(const timeval& now) const
+{
+    return now.tv_sec > fire_time.tv_sec || (now.tv_sec == fire_time.tv_sec && now.tv_usec >= fire_time.tv_usec);
+}
+
+void CEventLoop::EventLoopTimer::reload(const timeval& now)
+{
+    fire_time = now;
+    fire_time.tv_sec += interval / 1000;
+    fire_time.tv_usec += (interval % 1000) * 1000;
+}
+
+void CEventLoop::get_next_timer_expiration(timeval& soonest)
+{
+    ASSERT(!s_timers->is_empty());
+    bool has_checked_any = false;
+    for (auto& it : *s_timers) {
+        auto& fire_time = it.value->fire_time;
+        if (!has_checked_any || fire_time.tv_sec < soonest.tv_sec || (fire_time.tv_sec == soonest.tv_sec && fire_time.tv_usec < soonest.tv_usec))
+            soonest = fire_time;
+        has_checked_any = true;
+    }
+}
+
+int CEventLoop::register_timer(CObject& object, int milliseconds, bool should_reload)
+{
+    ASSERT(milliseconds >= 0);
+    auto timer = make<EventLoopTimer>();
+    timer->owner = object.make_weak_ptr();
+    timer->interval = milliseconds;
+    timeval now;
+    gettimeofday(&now, nullptr);
+    timer->reload(now);
+    timer->should_reload = should_reload;
+    int timer_id = ++s_next_timer_id; // FIXME: This will eventually wrap around.
+    ASSERT(timer_id);                 // FIXME: Aforementioned wraparound.
+    timer->timer_id = timer_id;
+    s_timers->set(timer->timer_id, move(timer));
+    return timer_id;
+}
+
+bool CEventLoop::unregister_timer(int timer_id)
+{
+    auto it = s_timers->find(timer_id);
+    if (it == s_timers->end())
+        return false;
+    s_timers->remove(it);
+    return true;
+}
+
+void CEventLoop::register_notifier(Badge<CNotifier>, CNotifier& notifier)
+{
+    s_notifiers->set(&notifier);
+}
+
+void CEventLoop::unregister_notifier(Badge<CNotifier>, CNotifier& notifier)
+{
+    s_notifiers->remove(&notifier);
+}
diff --git a/Libraries/LibCore/CEventLoop.h b/Libraries/LibCore/CEventLoop.h
new file mode 100644
index 0000000000..8cab0bbe99
--- /dev/null
+++ b/Libraries/LibCore/CEventLoop.h
@@ -0,0 +1,89 @@
+#pragma once
+
+#include <AK/Badge.h>
+#include <AK/HashMap.h>
+#include <AK/OwnPtr.h>
+#include <AK/Vector.h>
+#include <AK/WeakPtr.h>
+#include <LibCore/CLock.h>
+#include <sys/select.h>
+#include <sys/time.h>
+#include <time.h>
+
+class CEvent;
+class CObject;
+class CNotifier;
+
+class CEventLoop {
+public:
+    CEventLoop();
+    virtual ~CEventLoop();
+
+    int exec();
+
+    enum class WaitMode {
+        WaitForEvents,
+        PollForEvents,
+    };
+
+    // processe events, generally called by exec() in a loop.
+    // this should really only be used for integrating with other event loops
+    void pump(WaitMode = WaitMode::WaitForEvents);
+
+    void post_event(CObject& receiver, OwnPtr<CEvent>&&);
+
+    static CEventLoop& main();
+    static CEventLoop& current();
+
+    bool was_exit_requested() const { return m_exit_requested; }
+
+    static int register_timer(CObject&, int milliseconds, bool should_reload);
+    static bool unregister_timer(int timer_id);
+
+    static void register_notifier(Badge<CNotifier>, CNotifier&);
+    static void unregister_notifier(Badge<CNotifier>, CNotifier&);
+
+    void quit(int);
+
+    virtual void take_pending_events_from(CEventLoop& other)
+    {
+        m_queued_events.append(move(other.m_queued_events));
+    }
+
+protected:
+    virtual void add_file_descriptors_for_select(fd_set&, int& max_fd) { UNUSED_PARAM(max_fd); }
+    virtual void process_file_descriptors_after_select(const fd_set&) {}
+    virtual void do_processing() {}
+
+private:
+    void wait_for_event(WaitMode);
+    void get_next_timer_expiration(timeval&);
+
+    struct QueuedEvent {
+        WeakPtr<CObject> receiver;
+        OwnPtr<CEvent> event;
+    };
+
+    Vector<QueuedEvent, 64> m_queued_events;
+
+    bool m_exit_requested { false };
+    int m_exit_code { 0 };
+
+    CLock m_lock;
+
+    struct EventLoopTimer {
+        int timer_id { 0 };
+        int interval { 0 };
+        timeval fire_time;
+        bool should_reload { false };
+        WeakPtr<CObject> owner;
+
+        void reload(const timeval& now);
+        bool has_expired(const timeval& now) const;
+    };
+
+    static HashMap<int, OwnPtr<EventLoopTimer>>* s_timers;
+    static int s_next_timer_id;
+
+    static HashTable<CNotifier*>* s_notifiers;
+};
diff --git a/Libraries/LibCore/CFile.cpp b/Libraries/LibCore/CFile.cpp
new file mode 100644
index 0000000000..09d209d4b4
--- /dev/null
+++ b/Libraries/LibCore/CFile.cpp
@@ -0,0 +1,51 @@
+#include <LibCore/CFile.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+CFile::CFile(const StringView& filename)
+    : m_filename(filename)
+{
+}
+
+CFile::~CFile()
+{
+    if (m_should_close_file_descriptor == ShouldCloseFileDescription::Yes && mode() != NotOpen)
+        close();
+}
+
+bool CFile::open(int fd, CIODevice::OpenMode mode, ShouldCloseFileDescription should_close)
+{
+    set_fd(fd);
+    set_mode(mode);
+    m_should_close_file_descriptor = should_close;
+    return true;
+}
+
+bool CFile::open(CIODevice::OpenMode mode)
+{
+    int flags = 0;
+    if ((mode & CIODevice::ReadWrite) == CIODevice::ReadWrite) {
+        flags |= O_RDWR | O_CREAT;
+    } else if (mode & CIODevice::ReadOnly) {
+        flags |= O_RDONLY;
+    } else if (mode & CIODevice::WriteOnly) {
+        flags |= O_WRONLY | O_CREAT;
+    }
+    if (mode & CIODevice::Append)
+        flags |= O_APPEND;
+    if (mode & CIODevice::Truncate)
+        flags |= O_TRUNC;
+    if (mode & CIODevice::MustBeNew)
+        flags |= O_EXCL;
+    int fd = ::open(m_filename.characters(), flags, 0666);
+    if (fd < 0) {
+        set_error(errno);
+        return false;
+    }
+
+    set_fd(fd);
+    set_mode(mode);
+    return true;
+}
diff --git a/Libraries/LibCore/CFile.h b/Libraries/LibCore/CFile.h
new file mode 100644
index 0000000000..976d5718d9
--- /dev/null
+++ b/Libraries/LibCore/CFile.h
@@ -0,0 +1,28 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <LibCore/CIODevice.h>
+
+class CFile final : public CIODevice {
+public:
+    CFile() {}
+    explicit CFile(const StringView&);
+    virtual ~CFile() override;
+
+    String filename() const { return m_filename; }
+    void set_filename(const StringView& filename) { m_filename = filename; }
+
+    virtual bool open(CIODevice::OpenMode) override;
+
+    enum class ShouldCloseFileDescription {
+        No = 0,
+        Yes
+    };
+    bool open(int fd, CIODevice::OpenMode, ShouldCloseFileDescription);
+
+    virtual const char* class_name() const override { return "CFile"; }
+
+private:
+    String m_filename;
+    ShouldCloseFileDescription m_should_close_file_descriptor { ShouldCloseFileDescription::Yes };
+};
diff --git a/Libraries/LibCore/CHttpJob.cpp b/Libraries/LibCore/CHttpJob.cpp
new file mode 100644
index 0000000000..a3b00b9175
--- /dev/null
+++ b/Libraries/LibCore/CHttpJob.cpp
@@ -0,0 +1,118 @@
+#include <LibCore/CHttpJob.h>
+#include <LibCore/CHttpResponse.h>
+#include <LibCore/CTCPSocket.h>
+#include <stdio.h>
+#include <unistd.h>
+
+CHttpJob::CHttpJob(const CHttpRequest& request)
+    : m_request(request)
+{
+}
+
+CHttpJob::~CHttpJob()
+{
+}
+
+void CHttpJob::on_socket_connected()
+{
+    auto raw_request = m_request.to_raw_request();
+#if 0
+    printf("raw_request:\n%s\n", String::copy(raw_request).characters());
+#endif
+
+    bool success = m_socket->send(raw_request);
+    if (!success)
+        return deferred_invoke([this](auto&) { did_fail(CNetworkJob::Error::TransmissionFailed); });
+
+    Vector<u8> buffer;
+    while (m_socket->is_connected()) {
+        if (m_state == State::InStatus) {
+            while (!m_socket->can_read_line())
+                usleep(1);
+            ASSERT(m_socket->can_read_line());
+            auto line = m_socket->read_line(PAGE_SIZE);
+            if (line.is_null()) {
+                printf("Expected HTTP status\n");
+                return deferred_invoke([this](auto&) { did_fail(CNetworkJob::Error::TransmissionFailed); });
+            }
+            auto parts = String::copy(line, Chomp).split(' ');
+            if (parts.size() < 3) {
+                printf("Expected 3-part HTTP status, got '%s'\n", line.pointer());
+                return deferred_invoke([this](auto&) { did_fail(CNetworkJob::Error::ProtocolFailed); });
+            }
+            bool ok;
+            m_code = parts[1].to_uint(ok);
+            if (!ok) {
+                printf("Expected numeric HTTP status\n");
+                return deferred_invoke([this](auto&) { did_fail(CNetworkJob::Error::ProtocolFailed); });
+            }
+            m_state = State::InHeaders;
+            continue;
+        }
+        if (m_state == State::InHeaders) {
+            while (!m_socket->can_read_line())
+                usleep(1);
+            auto line = m_socket->read_line(PAGE_SIZE);
+            if (line.is_null()) {
+                printf("Expected HTTP header\n");
+                return did_fail(CNetworkJob::Error::ProtocolFailed);
+            }
+            auto chomped_line = String::copy(line, Chomp);
+            if (chomped_line.is_empty()) {
+                m_state = State::InBody;
+                continue;
+            }
+            auto parts = chomped_line.split(':');
+            if (parts.is_empty()) {
+                printf("Expected HTTP header with key/value\n");
+                return deferred_invoke([this](auto&) { did_fail(CNetworkJob::Error::ProtocolFailed); });
+            }
+            auto name = parts[0];
+            if (chomped_line.length() < name.length() + 2) {
+                printf("Malformed HTTP header: '%s' (%d)\n", chomped_line.characters(), chomped_line.length());
+                return deferred_invoke([this](auto&) { did_fail(CNetworkJob::Error::ProtocolFailed); });
+            }
+            auto value = chomped_line.substring(name.length() + 2, chomped_line.length() - name.length() - 2);
+            m_headers.set(name, value);
+            printf("[%s] = '%s'\n", name.characters(), value.characters());
+            continue;
+        }
+        ASSERT(m_state == State::InBody);
+        while (!m_socket->can_read())
+            usleep(1);
+        ASSERT(m_socket->can_read());
+        auto payload = m_socket->receive(PAGE_SIZE);
+        if (!payload) {
+            if (m_socket->eof()) {
+                m_state = State::Finished;
+                break;
+            }
+            return deferred_invoke([this](auto&) { did_fail(CNetworkJob::Error::ProtocolFailed); });
+        }
+        buffer.append(payload.pointer(), payload.size());
+
+        bool ok;
+        if (buffer.size() >= m_headers.get("Content-Length").to_int(ok) && ok) {
+            m_state = State::Finished;
+            break;
+        }
+    }
+
+    auto response = CHttpResponse::create(m_code, move(m_headers), ByteBuffer::copy(buffer.data(), buffer.size()));
+    deferred_invoke([this, response](auto&) {
+        did_finish(move(response));
+    });
+}
+
+void CHttpJob::start()
+{
+    ASSERT(!m_socket);
+    m_socket = new CTCPSocket(this);
+    m_socket->on_connected = [this] {
+        printf("Socket on_connected callback\n");
+        on_socket_connected();
+    };
+    bool success = m_socket->connect(m_request.hostname(), m_request.port());
+    if (!success)
+        return did_fail(CNetworkJob::Error::ConnectionFailed);
+}
diff --git a/Libraries/LibCore/CHttpJob.h b/Libraries/LibCore/CHttpJob.h
new file mode 100644
index 0000000000..5b714a7f77
--- /dev/null
+++ b/Libraries/LibCore/CHttpJob.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <AK/HashMap.h>
+#include <LibCore/CHttpRequest.h>
+#include <LibCore/CNetworkJob.h>
+
+class CTCPSocket;
+
+class CHttpJob final : public CNetworkJob {
+public:
+    explicit CHttpJob(const CHttpRequest&);
+    virtual ~CHttpJob() override;
+
+    virtual void start() override;
+
+    virtual const char* class_name() const override { return "CHttpJob"; }
+
+private:
+    void on_socket_connected();
+
+    enum class State {
+        InStatus,
+        InHeaders,
+        InBody,
+        Finished,
+    };
+
+    CHttpRequest m_request;
+    CTCPSocket* m_socket { nullptr };
+    State m_state { State::InStatus };
+    int m_code { -1 };
+    HashMap<String, String> m_headers;
+};
diff --git a/Libraries/LibCore/CHttpRequest.cpp b/Libraries/LibCore/CHttpRequest.cpp
new file mode 100644
index 0000000000..93cbc6987d
--- /dev/null
+++ b/Libraries/LibCore/CHttpRequest.cpp
@@ -0,0 +1,44 @@
+#include <AK/StringBuilder.h>
+#include <LibCore/CHttpJob.h>
+#include <LibCore/CHttpRequest.h>
+
+CHttpRequest::CHttpRequest()
+{
+}
+
+CHttpRequest::~CHttpRequest()
+{
+}
+
+CNetworkJob* CHttpRequest::schedule()
+{
+    auto* job = new CHttpJob(*this);
+    job->start();
+    return job;
+}
+
+String CHttpRequest::method_name() const
+{
+    switch (m_method) {
+    case Method::GET:
+        return "GET";
+    case Method::HEAD:
+        return "HEAD";
+    case Method::POST:
+        return "POST";
+    default:
+        ASSERT_NOT_REACHED();
+    }
+}
+
+ByteBuffer CHttpRequest::to_raw_request() const
+{
+    StringBuilder builder;
+    builder.append(method_name());
+    builder.append(' ');
+    builder.append(m_path);
+    builder.append(" HTTP/1.0\r\nHost: ");
+    builder.append(m_hostname);
+    builder.append("\r\n\r\n");
+    return builder.to_byte_buffer();
+}
diff --git a/Libraries/LibCore/CHttpRequest.h b/Libraries/LibCore/CHttpRequest.h
new file mode 100644
index 0000000000..c5a39c9ffd
--- /dev/null
+++ b/Libraries/LibCore/CHttpRequest.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <AK/AKString.h>
+
+class CNetworkJob;
+
+class CHttpRequest {
+public:
+    enum Method {
+        Invalid,
+        HEAD,
+        GET,
+        POST
+    };
+
+    CHttpRequest();
+    ~CHttpRequest();
+
+    String hostname() const { return m_hostname; }
+    int port() const { return m_port; }
+    String path() const { return m_path; }
+    Method method() const { return m_method; }
+
+    void set_hostname(const String& hostname) { m_hostname = hostname; }
+    void set_port(int port) { m_port = port; }
+    void set_path(const String& path) { m_path = path; }
+    void set_method(Method method) { m_method = method; }
+
+    String method_name() const;
+    ByteBuffer to_raw_request() const;
+
+    CNetworkJob* schedule();
+
+private:
+    String m_hostname;
+    String m_path;
+    int m_port { 80 };
+    Method m_method { GET };
+};
diff --git a/Libraries/LibCore/CHttpResponse.cpp b/Libraries/LibCore/CHttpResponse.cpp
new file mode 100644
index 0000000000..07fef16ee0
--- /dev/null
+++ b/Libraries/LibCore/CHttpResponse.cpp
@@ -0,0 +1,12 @@
+#include <LibCore/CHttpResponse.h>
+
+CHttpResponse::CHttpResponse(int code, HashMap<String, String>&& headers, ByteBuffer&& payload)
+    : CNetworkResponse(move(payload))
+    , m_code(code)
+    , m_headers(move(headers))
+{
+}
+
+CHttpResponse::~CHttpResponse()
+{
+}
diff --git a/Libraries/LibCore/CHttpResponse.h b/Libraries/LibCore/CHttpResponse.h
new file mode 100644
index 0000000000..3feaa6bfd2
--- /dev/null
+++ b/Libraries/LibCore/CHttpResponse.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/HashMap.h>
+#include <LibCore/CNetworkResponse.h>
+
+class CHttpResponse : public CNetworkResponse {
+public:
+    virtual ~CHttpResponse() override;
+    static NonnullRefPtr<CHttpResponse> create(int code, HashMap<String, String>&& headers, ByteBuffer&& payload)
+    {
+        return adopt(*new CHttpResponse(code, move(headers), move(payload)));
+    }
+
+    int code() const { return m_code; }
+    const HashMap<String, String>& headers() const { return m_headers; }
+
+private:
+    CHttpResponse(int code, HashMap<String, String>&&, ByteBuffer&&);
+
+    int m_code { 0 };
+    HashMap<String, String> m_headers;
+};
diff --git a/Libraries/LibCore/CIODevice.cpp b/Libraries/LibCore/CIODevice.cpp
new file mode 100644
index 0000000000..86393f6888
--- /dev/null
+++ b/Libraries/LibCore/CIODevice.cpp
@@ -0,0 +1,242 @@
+#include <AK/PrintfImplementation.h>
+#include <LibCore/CIODevice.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/select.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+CIODevice::CIODevice(CObject* parent)
+    : CObject(parent)
+{
+}
+
+CIODevice::~CIODevice()
+{
+}
+
+const char* CIODevice::error_string() const
+{
+    return strerror(m_error);
+}
+
+ByteBuffer CIODevice::read(int max_size)
+{
+    if (m_fd < 0)
+        return {};
+    if (!max_size)
+        return {};
+    auto buffer = ByteBuffer::create_uninitialized(max_size);
+    auto* buffer_ptr = (char*)buffer.pointer();
+    int remaining_buffer_space = buffer.size();
+    int taken_from_buffered = 0;
+    if (!m_buffered_data.is_empty()) {
+        taken_from_buffered = min(remaining_buffer_space, m_buffered_data.size());
+        memcpy(buffer_ptr, m_buffered_data.data(), taken_from_buffered);
+        Vector<u8> new_buffered_data;
+        new_buffered_data.append(m_buffered_data.data() + taken_from_buffered, m_buffered_data.size() - taken_from_buffered);
+        m_buffered_data = move(new_buffered_data);
+        remaining_buffer_space -= taken_from_buffered;
+        buffer_ptr += taken_from_buffered;
+    }
+    if (!remaining_buffer_space)
+        return buffer;
+    int nread = ::read(m_fd, buffer_ptr, remaining_buffer_space);
+    if (nread < 0) {
+        if (taken_from_buffered) {
+            buffer.trim(taken_from_buffered);
+            return buffer;
+        }
+        set_error(errno);
+        return {};
+    }
+    if (nread == 0) {
+        set_eof(true);
+        if (taken_from_buffered) {
+            buffer.trim(taken_from_buffered);
+            return buffer;
+        }
+        return {};
+    }
+    buffer.trim(taken_from_buffered + nread);
+    return buffer;
+}
+
+bool CIODevice::can_read_from_fd() const
+{
+    // FIXME: Can we somehow remove this once CSocket is implemented using non-blocking sockets?
+    fd_set rfds;
+    FD_ZERO(&rfds);
+    FD_SET(m_fd, &rfds);
+    struct timeval timeout {
+        0, 0
+    };
+    int rc = select(m_fd + 1, &rfds, nullptr, nullptr, &timeout);
+    if (rc < 0) {
+        // NOTE: We don't set m_error here.
+        perror("CIODevice::can_read: select");
+        return false;
+    }
+    return FD_ISSET(m_fd, &rfds);
+}
+
+bool CIODevice::can_read_line()
+{
+    if (m_eof && !m_buffered_data.is_empty())
+        return true;
+    if (m_buffered_data.contains_slow('\n'))
+        return true;
+    if (!can_read_from_fd())
+        return false;
+    populate_read_buffer();
+    return m_buffered_data.contains_slow('\n');
+}
+
+bool CIODevice::can_read() const
+{
+    return !m_buffered_data.is_empty() || can_read_from_fd();
+}
+
+ByteBuffer CIODevice::read_all()
+{
+    ByteBuffer buffer;
+    if (!m_buffered_data.is_empty()) {
+        buffer = ByteBuffer::copy(m_buffered_data.data(), m_buffered_data.size());
+        m_buffered_data.clear();
+    }
+
+    while (can_read_from_fd()) {
+        char read_buffer[4096];
+        int nread = ::read(m_fd, read_buffer, sizeof(read_buffer));
+        if (nread < 0) {
+            set_error(nread);
+            return buffer;
+        }
+        if (nread == 0) {
+            set_eof(true);
+            break;
+        }
+        buffer.append(read_buffer, nread);
+    }
+    return buffer;
+}
+
+ByteBuffer CIODevice::read_line(int max_size)
+{
+    if (m_fd < 0)
+        return {};
+    if (!max_size)
+        return {};
+    if (!can_read_line())
+        return {};
+    if (m_eof) {
+        if (m_buffered_data.size() > max_size) {
+            dbgprintf("CIODevice::read_line: At EOF but there's more than max_size(%d) buffered\n", max_size);
+            return {};
+        }
+        auto buffer = ByteBuffer::copy(m_buffered_data.data(), m_buffered_data.size());
+        m_buffered_data.clear();
+        return buffer;
+    }
+    auto line = ByteBuffer::create_uninitialized(max_size + 1);
+    int line_index = 0;
+    while (line_index < max_size) {
+        u8 ch = m_buffered_data[line_index];
+        line[line_index++] = ch;
+        if (ch == '\n') {
+            Vector<u8> new_buffered_data;
+            new_buffered_data.append(m_buffered_data.data() + line_index, m_buffered_data.size() - line_index);
+            m_buffered_data = move(new_buffered_data);
+            line[line_index] = '\0';
+            line.trim(line_index + 1);
+            return line;
+        }
+    }
+    return {};
+}
+
+bool CIODevice::populate_read_buffer()
+{
+    if (m_fd < 0)
+        return false;
+    u8 buffer[1024];
+    int nread = ::read(m_fd, buffer, sizeof(buffer));
+    if (nread < 0) {
+        set_error(errno);
+        return false;
+    }
+    if (nread == 0) {
+        set_eof(true);
+        return false;
+    }
+    m_buffered_data.append(buffer, nread);
+    return true;
+}
+
+bool CIODevice::close()
+{
+    if (fd() < 0 || mode() == NotOpen)
+        return false;
+    int rc = ::close(fd());
+    if (rc < 0) {
+        set_error(rc);
+        return false;
+    }
+    set_fd(-1);
+    set_mode(CIODevice::NotOpen);
+    return true;
+}
+
+bool CIODevice::seek(i64 offset, SeekMode mode, off_t* pos)
+{
+    int m = SEEK_SET;
+    switch (mode) {
+    case SeekMode::SetPosition:
+        m = SEEK_SET;
+        break;
+    case SeekMode::FromCurrentPosition:
+        m = SEEK_CUR;
+        break;
+    case SeekMode::FromEndPosition:
+        m = SEEK_END;
+        break;
+    }
+    off_t rc = lseek(m_fd, offset, m);
+    if (rc < 0) {
+        set_error(errno);
+        if (pos)
+            *pos = -1;
+        return false;
+    }
+    m_buffered_data.clear();
+    m_eof = false;
+    if (pos)
+        *pos = rc;
+    return true;
+}
+
+bool CIODevice::write(const u8* data, int size)
+{
+    int rc = ::write(m_fd, data, size);
+    if (rc < 0) {
+        perror("CIODevice::write: write");
+        set_error(errno);
+        return false;
+    }
+    return rc == size;
+}
+
+int CIODevice::printf(const char* format, ...)
+{
+    va_list ap;
+    va_start(ap, format);
+    // FIXME: We're not propagating write() failures to client here!
+    int ret = printf_internal([this](char*&, char ch) {
+        int rc = write((const u8*)&ch, 1);
+        if (rc < 0)
+            dbgprintf("CIODevice::printf: write: %s\n", strerror(errno));
+    },
+        nullptr, format, ap);
+    va_end(ap);
+    return ret;
+}
diff --git a/Libraries/LibCore/CIODevice.h b/Libraries/LibCore/CIODevice.h
new file mode 100644
index 0000000000..e6de17b46d
--- /dev/null
+++ b/Libraries/LibCore/CIODevice.h
@@ -0,0 +1,74 @@
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/StringView.h>
+#include <LibCore/CObject.h>
+
+class CIODevice : public CObject {
+public:
+    enum OpenMode {
+        NotOpen = 0,
+        ReadOnly = 1,
+        WriteOnly = 2,
+        ReadWrite = 3,
+        Append = 4,
+        Truncate = 8,
+        MustBeNew = 16,
+    };
+
+    virtual ~CIODevice() override;
+
+    int fd() const { return m_fd; }
+    unsigned mode() const { return m_mode; }
+    bool eof() const { return m_eof; }
+
+    int error() const { return m_error; }
+    const char* error_string() const;
+
+    bool has_error() const { return m_error != 0; }
+
+    ByteBuffer read(int max_size);
+    ByteBuffer read_line(int max_size);
+    ByteBuffer read_all();
+
+    bool write(const u8*, int size);
+    bool write(const AK::StringView& v) { return write((const u8*)v.characters(), v.length()); }
+
+    // FIXME: I would like this to be const but currently it needs to call populate_read_buffer().
+    bool can_read_line();
+
+    bool can_read() const;
+
+    enum class SeekMode {
+        SetPosition,
+        FromCurrentPosition,
+        FromEndPosition,
+    };
+
+    bool seek(i64, SeekMode = SeekMode::SetPosition, off_t* = nullptr);
+
+    virtual bool open(CIODevice::OpenMode) = 0;
+    virtual bool close();
+
+    int printf(const char*, ...);
+
+    virtual const char* class_name() const override { return "CIODevice"; }
+
+protected:
+    explicit CIODevice(CObject* parent = nullptr);
+
+    void set_fd(int fd) { m_fd = fd; }
+    void set_mode(OpenMode mode) { m_mode = mode; }
+    void set_error(int error) { m_error = error; }
+    void set_eof(bool eof) { m_eof = eof; }
+
+private:
+    bool populate_read_buffer();
+    bool can_read_from_fd() const;
+
+    int m_fd { -1 };
+    int m_error { 0 };
+    bool m_eof { false };
+    OpenMode m_mode { NotOpen };
+    Vector<u8> m_buffered_data;
+};
diff --git a/Libraries/LibCore/CLock.h b/Libraries/LibCore/CLock.h
new file mode 100644
index 0000000000..2c31751f92
--- /dev/null
+++ b/Libraries/LibCore/CLock.h
@@ -0,0 +1,125 @@
+#pragma once
+
+#ifdef __serenity__
+
+#include <AK/Assertions.h>
+#include <AK/Types.h>
+#include <unistd.h>
+
+#define memory_barrier() asm volatile("" :: \
+                                          : "memory")
+
+static inline u32 CAS(volatile u32* mem, u32 newval, u32 oldval)
+{
+    u32 ret;
+    asm volatile(
+        "cmpxchgl %2, %1"
+        : "=a"(ret), "+m"(*mem)
+        : "r"(newval), "0"(oldval)
+        : "cc", "memory");
+    return ret;
+}
+
+class CLock {
+public:
+    CLock() {}
+    ~CLock() {}
+
+    void lock();
+    void unlock();
+
+private:
+    volatile u32 m_lock { 0 };
+    u32 m_level { 0 };
+    int m_holder { -1 };
+};
+
+class CLocker {
+public:
+    [[gnu::always_inline]] inline explicit CLocker(CLock& l)
+        : m_lock(l)
+    {
+        lock();
+    }
+    [[gnu::always_inline]] inline ~CLocker() { unlock(); }
+    [[gnu::always_inline]] inline void unlock() { m_lock.unlock(); }
+    [[gnu::always_inline]] inline void lock() { m_lock.lock(); }
+
+private:
+    CLock& m_lock;
+};
+
+[[gnu::always_inline]] inline void CLock::lock()
+{
+    int tid = gettid();
+    for (;;) {
+        if (CAS(&m_lock, 1, 0) == 0) {
+            if (m_holder == -1 || m_holder == tid) {
+                m_holder = tid;
+                ++m_level;
+                memory_barrier();
+                m_lock = 0;
+                return;
+            }
+            m_lock = 0;
+        }
+        donate(m_holder);
+    }
+}
+
+inline void CLock::unlock()
+{
+    for (;;) {
+        if (CAS(&m_lock, 1, 0) == 0) {
+            ASSERT(m_holder == gettid());
+            ASSERT(m_level);
+            --m_level;
+            if (m_level) {
+                memory_barrier();
+                m_lock = 0;
+                return;
+            }
+            m_holder = -1;
+            memory_barrier();
+            m_lock = 0;
+            return;
+        }
+        donate(m_holder);
+    }
+}
+
+#define LOCKER(lock) CLocker locker(lock)
+
+template<typename T>
+class CLockable {
+public:
+    CLockable() {}
+    CLockable(T&& resource)
+        : m_resource(move(resource))
+    {
+    }
+    CLock& lock() { return m_lock; }
+    T& resource() { return m_resource; }
+
+    T lock_and_copy()
+    {
+        LOCKER(m_lock);
+        return m_resource;
+    }
+
+private:
+    T m_resource;
+    CLock m_lock;
+};
+
+#else
+
+class CLock {
+public:
+    CLock() { }
+    ~CLock() { }
+};
+
+#define LOCKER(x)
+
+#endif
diff --git a/Libraries/LibCore/CNetworkJob.cpp b/Libraries/LibCore/CNetworkJob.cpp
new file mode 100644
index 0000000000..67d02d5d73
--- /dev/null
+++ b/Libraries/LibCore/CNetworkJob.cpp
@@ -0,0 +1,43 @@
+#include <LibCore/CNetworkJob.h>
+#include <LibCore/CNetworkResponse.h>
+#include <stdio.h>
+
+CNetworkJob::CNetworkJob()
+{
+}
+
+CNetworkJob::~CNetworkJob()
+{
+}
+
+void CNetworkJob::did_finish(NonnullRefPtr<CNetworkResponse>&& response)
+{
+    m_response = move(response);
+    printf("%s{%p} job did_finish!\n", class_name(), this);
+    ASSERT(on_finish);
+    on_finish(true);
+    delete_later();
+}
+
+void CNetworkJob::did_fail(Error error)
+{
+    m_error = error;
+    dbgprintf("%s{%p} job did_fail! error: %u (%s)\n", class_name(), this, (unsigned)error, to_string(error));
+    ASSERT(on_finish);
+    on_finish(false);
+    delete_later();
+}
+
+const char* to_string(CNetworkJob::Error error)
+{
+    switch (error) {
+    case CNetworkJob::Error::ProtocolFailed:
+        return "ProtocolFailed";
+    case CNetworkJob::Error::ConnectionFailed:
+        return "ConnectionFailed";
+    case CNetworkJob::Error::TransmissionFailed:
+        return "TransmissionFailed";
+    default:
+        return "(Unknown error)";
+    }
+}
diff --git a/Libraries/LibCore/CNetworkJob.h b/Libraries/LibCore/CNetworkJob.h
new file mode 100644
index 0000000000..b68dba5670
--- /dev/null
+++ b/Libraries/LibCore/CNetworkJob.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <AK/Function.h>
+#include <LibCore/CObject.h>
+
+class CNetworkResponse;
+
+class CNetworkJob : public CObject {
+public:
+    enum class Error {
+        None,
+        ConnectionFailed,
+        TransmissionFailed,
+        ProtocolFailed,
+    };
+    virtual ~CNetworkJob() override;
+
+    Function<void(bool success)> on_finish;
+
+    bool has_error() const { return m_error != Error::None; }
+    Error error() const { return m_error; }
+    CNetworkResponse* response() { return m_response.ptr(); }
+    const CNetworkResponse* response() const { return m_response.ptr(); }
+
+    virtual void start() = 0;
+
+    virtual const char* class_name() const override { return "CNetworkJob"; }
+
+protected:
+    CNetworkJob();
+    void did_finish(NonnullRefPtr<CNetworkResponse>&&);
+    void did_fail(Error);
+
+private:
+    RefPtr<CNetworkResponse> m_response;
+    Error m_error { Error::None };
+};
+
+const char* to_string(CNetworkJob::Error);
diff --git a/Libraries/LibCore/CNetworkResponse.cpp b/Libraries/LibCore/CNetworkResponse.cpp
new file mode 100644
index 0000000000..1550d8ac69
--- /dev/null
+++ b/Libraries/LibCore/CNetworkResponse.cpp
@@ -0,0 +1,10 @@
+#include <LibCore/CNetworkResponse.h>
+
+CNetworkResponse::CNetworkResponse(ByteBuffer&& payload)
+    : m_payload(payload)
+{
+}
+
+CNetworkResponse::~CNetworkResponse()
+{
+}
diff --git a/Libraries/LibCore/CNetworkResponse.h b/Libraries/LibCore/CNetworkResponse.h
new file mode 100644
index 0000000000..c637f6a514
--- /dev/null
+++ b/Libraries/LibCore/CNetworkResponse.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/RefCounted.h>
+
+class CNetworkResponse : public RefCounted<CNetworkResponse> {
+public:
+    virtual ~CNetworkResponse();
+
+    bool is_error() const { return m_error; }
+    const ByteBuffer& payload() const { return m_payload; }
+
+protected:
+    explicit CNetworkResponse(ByteBuffer&&);
+
+    bool m_error { false };
+    ByteBuffer m_payload;
+};
diff --git a/Libraries/LibCore/CNotifier.cpp b/Libraries/LibCore/CNotifier.cpp
new file mode 100644
index 0000000000..c124191ac1
--- /dev/null
+++ b/Libraries/LibCore/CNotifier.cpp
@@ -0,0 +1,15 @@
+#include <LibCore/CEvent.h>
+#include <LibCore/CEventLoop.h>
+#include <LibCore/CNotifier.h>
+
+CNotifier::CNotifier(int fd, unsigned event_mask)
+    : m_fd(fd)
+    , m_event_mask(event_mask)
+{
+    CEventLoop::register_notifier({}, *this);
+}
+
+CNotifier::~CNotifier()
+{
+    CEventLoop::unregister_notifier({}, *this);
+}
diff --git a/Libraries/LibCore/CNotifier.h b/Libraries/LibCore/CNotifier.h
new file mode 100644
index 0000000000..196cad8388
--- /dev/null
+++ b/Libraries/LibCore/CNotifier.h
@@ -0,0 +1,26 @@
+#pragma once
+
+#include <AK/Function.h>
+
+class CNotifier {
+public:
+    enum Event {
+        None = 0,
+        Read = 1,
+        Write = 2,
+        Exceptional = 4,
+    };
+    CNotifier(int fd, unsigned event_mask);
+    ~CNotifier();
+
+    Function<void()> on_ready_to_read;
+    Function<void()> on_ready_to_write;
+
+    int fd() const { return m_fd; }
+    unsigned event_mask() const { return m_event_mask; }
+    void set_event_mask(unsigned event_mask) { m_event_mask = event_mask; }
+
+private:
+    int m_fd { -1 };
+    unsigned m_event_mask { 0 };
+};
diff --git a/Libraries/LibCore/CObject.cpp b/Libraries/LibCore/CObject.cpp
new file mode 100644
index 0000000000..bbee4501dd
--- /dev/null
+++ b/Libraries/LibCore/CObject.cpp
@@ -0,0 +1,113 @@
+#include <AK/Assertions.h>
+#include <AK/kstdio.h>
+#include <LibCore/CEvent.h>
+#include <LibCore/CEventLoop.h>
+#include <LibCore/CObject.h>
+#include <stdio.h>
+
+CObject::CObject(CObject* parent, bool is_widget)
+    : m_parent(parent)
+    , m_widget(is_widget)
+{
+    if (m_parent)
+        m_parent->add_child(*this);
+}
+
+CObject::~CObject()
+{
+    stop_timer();
+    if (m_parent)
+        m_parent->remove_child(*this);
+    auto children_to_delete = move(m_children);
+    for (auto* child : children_to_delete)
+        delete child;
+}
+
+void CObject::event(CEvent& event)
+{
+    switch (event.type()) {
+    case CEvent::Timer:
+        return timer_event(static_cast<CTimerEvent&>(event));
+    case CEvent::DeferredDestroy:
+        delete this;
+        break;
+    case CEvent::ChildAdded:
+    case CEvent::ChildRemoved:
+        return child_event(static_cast<CChildEvent&>(event));
+    case CEvent::Invalid:
+        ASSERT_NOT_REACHED();
+        break;
+    default:
+        break;
+    }
+}
+
+void CObject::add_child(CObject& object)
+{
+    // FIXME: Should we support reparenting objects?
+    ASSERT(!object.parent() || object.parent() == this);
+    object.m_parent = this;
+    m_children.append(&object);
+    event(*make<CChildEvent>(CEvent::ChildAdded, object));
+}
+
+void CObject::remove_child(CObject& object)
+{
+    for (ssize_t i = 0; i < m_children.size(); ++i) {
+        if (m_children[i] == &object) {
+            m_children.remove(i);
+            event(*make<CChildEvent>(CEvent::ChildRemoved, object));
+            return;
+        }
+    }
+}
+
+void CObject::timer_event(CTimerEvent&)
+{
+}
+
+void CObject::child_event(CChildEvent&)
+{
+}
+
+void CObject::start_timer(int ms)
+{
+    if (m_timer_id) {
+        dbgprintf("CObject{%p} already has a timer!\n", this);
+        ASSERT_NOT_REACHED();
+    }
+
+    m_timer_id = CEventLoop::register_timer(*this, ms, true);
+}
+
+void CObject::stop_timer()
+{
+    if (!m_timer_id)
+        return;
+    bool success = CEventLoop::unregister_timer(m_timer_id);
+    ASSERT(success);
+    m_timer_id = 0;
+}
+
+void CObject::delete_later()
+{
+    CEventLoop::current().post_event(*this, make<CEvent>(CEvent::DeferredDestroy));
+}
+
+void CObject::dump_tree(int indent)
+{
+    for (int i = 0; i < indent; ++i) {
+        printf(" ");
+    }
+    printf("%s{%p}\n", class_name(), this);
+
+    for_each_child([&](auto& child) {
+        child.dump_tree(indent + 2);
+        return IterationDecision::Continue;
+    });
+}
+
+void CObject::deferred_invoke(Function<void(CObject&)> invokee)
+{
+    CEventLoop::current().post_event(*this, make<CDeferredInvocationEvent>(move(invokee)));
+}
diff --git a/Libraries/LibCore/CObject.h b/Libraries/LibCore/CObject.h
new file mode 100644
index 0000000000..392a94e189
--- /dev/null
+++ b/Libraries/LibCore/CObject.h
@@ -0,0 +1,94 @@
+#pragma once
+
+#include <AK/Function.h>
+#include <AK/StdLibExtras.h>
+#include <AK/Vector.h>
+#include <AK/Weakable.h>
+
+class CEvent;
+class CChildEvent;
+class CTimerEvent;
+
+class CObject : public Weakable<CObject> {
+public:
+    CObject(CObject* parent = nullptr, bool is_widget = false);
+    virtual ~CObject();
+
+    virtual const char* class_name() const { return "CObject"; }
+
+    virtual void event(CEvent&);
+
+    Vector<CObject*>& children() { return m_children; }
+    const Vector<CObject*>& children() const { return m_children; }
+
+    template<typename Callback>
+    void for_each_child(Callback callback)
+    {
+        for (auto* child : m_children) {
+            if (callback(*child) == IterationDecision::Break)
+                return;
+        }
+    }
+
+    template<typename T, typename Callback>
+    void for_each_child_of_type(Callback callback);
+
+    CObject* parent() { return m_parent; }
+    const CObject* parent() const { return m_parent; }
+
+    void start_timer(int ms);
+    void stop_timer();
+    bool has_timer() const { return m_timer_id; }
+
+    void add_child(CObject&);
+    void remove_child(CObject&);
+
+    void delete_later();
+
+    void dump_tree(int indent = 0);
+
+    void deferred_invoke(Function<void(CObject&)>);
+
+    bool is_widget() const { return m_widget; }
+    virtual bool is_window() const { return false; }
+
+protected:
+    virtual void timer_event(CTimerEvent&);
+    virtual void child_event(CChildEvent&);
+
+private:
+    CObject* m_parent { nullptr };
+    int m_timer_id { 0 };
+    bool m_widget { false };
+    Vector<CObject*> m_children;
+};
+
+template<typename T>
+inline bool is(const CObject&) { return false; }
+
+template<>
+inline bool is<CObject>(const CObject&) { return true; }
+
+template<typename T>
+inline T& to(CObject& object)
+{
+    ASSERT(is<typename RemoveConst<T>::Type>(object));
+    return static_cast<T&>(object);
+}
+
+template<typename T>
+inline const T& to(const CObject& object)
+{
+    ASSERT(is<typename RemoveConst<T>::Type>(object));
+    return static_cast<const T&>(object);
+}
+
+template<typename T, typename Callback>
+inline void CObject::for_each_child_of_type(Callback callback)
+{
+    for_each_child([&](auto& child) {
+        if (is<T>(child))
+            return callback(to<T>(child));
+        return IterationDecision::Continue;
+    });
+}
diff --git a/Libraries/LibCore/CProcessStatisticsReader.cpp b/Libraries/LibCore/CProcessStatisticsReader.cpp
new file mode 100644
index 0000000000..7f0456d53e
--- /dev/null
+++ b/Libraries/LibCore/CProcessStatisticsReader.cpp
@@ -0,0 +1,58 @@
+#include <AK/JsonArray.h>
+#include <AK/JsonObject.h>
+#include <AK/JsonValue.h>
+#include <LibCore/CFile.h>
+#include <LibCore/CProcessStatisticsReader.h>
+#include <pwd.h>
+#include <stdio.h>
+
+CProcessStatisticsReader::CProcessStatisticsReader()
+{
+    setpwent();
+    while (auto* passwd = getpwent())
+        m_usernames.set(passwd->pw_uid, passwd->pw_name);
+    endpwent();
+}
+
+HashMap<pid_t, CProcessStatistics> CProcessStatisticsReader::get_map()
+{
+    HashMap<pid_t, CProcessStatistics> res;
+    update_map(res);
+    return res;
+}
+
+void CProcessStatisticsReader::update_map(HashMap<pid_t, CProcessStatistics>& map)
+{
+    CFile file("/proc/all");
+    if (!file.open(CIODevice::ReadOnly)) {
+        fprintf(stderr, "CProcessHelper : failed to open /proc/all: %s\n", file.error_string());
+        return;
+    }
+
+    auto file_contents = file.read_all();
+    auto json = JsonValue::from_string({ file_contents.data(), file_contents.size() });
+    json.as_array().for_each([&](auto& value) {
+        const JsonObject& process_object = value.as_object();
+        CProcessStatistics process;
+        process.pid = process_object.get("pid").to_u32();
+        process.nsched = process_object.get("times_scheduled").to_u32();
+        process.uid = process_object.get("uid").to_u32();
+        process.username = get_username_from_uid(process.uid);
+        process.priority = process_object.get("priority").to_string();
+        process.syscalls = process_object.get("syscall_count").to_u32();
+        process.state = process_object.get("state").to_string();
+        process.name = process_object.get("name").to_string();
+        process.virtual_size = process_object.get("amount_virtual").to_u32();
+        process.physical_size = process_object.get("amount_resident").to_u32();
+        map.set(process.pid, process);
+    });
+}
+
+String CProcessStatisticsReader::get_username_from_uid(const uid_t uid)
+{
+    auto it = m_usernames.find(uid);
+    if (it != m_usernames.end())
+        return (*it).value;
+    else
+        return String::number(uid);
+}
diff --git a/Libraries/LibCore/CProcessStatisticsReader.h b/Libraries/LibCore/CProcessStatisticsReader.h
new file mode 100644
index 0000000000..adb96f39ad
--- /dev/null
+++ b/Libraries/LibCore/CProcessStatisticsReader.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/HashMap.h>
+
+struct CProcessStatistics {
+    pid_t pid;
+    unsigned nsched;
+    String name;
+    String state;
+    String username;
+    uid_t uid;
+    String priority;
+    size_t virtual_size;
+    size_t physical_size;
+    unsigned syscalls;
+};
+
+class CProcessStatisticsReader {
+public:
+    CProcessStatisticsReader();
+    HashMap<pid_t, CProcessStatistics> get_map();
+
+private:
+    void update_map(HashMap<pid_t, CProcessStatistics>& map);
+    String get_username_from_uid(const uid_t uid);
+
+    HashMap<uid_t, String> m_usernames;
+};
diff --git a/Libraries/LibCore/CSocket.cpp b/Libraries/LibCore/CSocket.cpp
new file mode 100644
index 0000000000..4479969c40
--- /dev/null
+++ b/Libraries/LibCore/CSocket.cpp
@@ -0,0 +1,93 @@
+#include <LibCore/CNotifier.h>
+#include <LibCore/CSocket.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+
+CSocket::CSocket(Type type, CObject* parent)
+    : CIODevice(parent)
+    , m_type(type)
+{
+}
+
+CSocket::~CSocket()
+{
+}
+
+bool CSocket::connect(const String& hostname, int port)
+{
+    auto* hostent = gethostbyname(hostname.characters());
+    if (!hostent) {
+        dbgprintf("CSocket::connect: Unable to resolve '%s'\n", hostname.characters());
+        return false;
+    }
+
+    IPv4Address host_address((const u8*)hostent->h_addr_list[0]);
+    dbgprintf("CSocket::connect: Resolved '%s' to %s\n", hostname.characters(), host_address.to_string().characters());
+    return connect(host_address, port);
+}
+
+bool CSocket::connect(const CSocketAddress& address, int port)
+{
+    ASSERT(!is_connected());
+    ASSERT(address.type() == CSocketAddress::Type::IPv4);
+    ASSERT(port > 0 && port <= 65535);
+
+    struct sockaddr_in addr;
+    memset(&addr, 0, sizeof(addr));
+    auto ipv4_address = address.ipv4_address();
+    memcpy(&addr.sin_addr.s_addr, &ipv4_address, sizeof(IPv4Address));
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(port);
+
+    m_destination_address = address;
+    m_destination_port = port;
+
+    dbgprintf("Connecting to %s...", address.to_string().characters());
+    fflush(stdout);
+    int rc = ::connect(fd(), (struct sockaddr*)&addr, sizeof(addr));
+    if (rc < 0) {
+        if (errno == EINPROGRESS) {
+            dbgprintf("in progress.\n");
+            m_notifier = make<CNotifier>(fd(), CNotifier::Event::Write);
+            m_notifier->on_ready_to_write = [this] {
+                dbgprintf("%s{%p} connected!\n", class_name(), this);
+                m_connected = true;
+                m_notifier->set_event_mask(CNotifier::Event::None);
+                if (on_connected)
+                    on_connected();
+            };
+            return true;
+        }
+        perror("connect");
+        exit(1);
+    }
+    dbgprintf("ok!\n");
+    m_connected = true;
+    return true;
+}
+
+ByteBuffer CSocket::receive(int max_size)
+{
+    auto buffer = read(max_size);
+    if (eof()) {
+        dbgprintf("CSocket{%p}: Connection appears to have closed in receive().\n", this);
+        m_connected = false;
+    }
+    return buffer;
+}
+
+bool CSocket::send(const ByteBuffer& data)
+{
+    int nsent = ::send(fd(), data.pointer(), data.size(), 0);
+    if (nsent < 0) {
+        set_error(nsent);
+        return false;
+    }
+    ASSERT(nsent == data.size());
+    return true;
+}
diff --git a/Libraries/LibCore/CSocket.h b/Libraries/LibCore/CSocket.h
new file mode 100644
index 0000000000..587f80f290
--- /dev/null
+++ b/Libraries/LibCore/CSocket.h
@@ -0,0 +1,48 @@
+#pragma once
+
+#include <LibCore/CIODevice.h>
+#include <LibCore/CSocketAddress.h>
+
+class CNotifier;
+
+class CSocket : public CIODevice {
+public:
+    enum class Type {
+        Invalid,
+        TCP,
+        UDP
+    };
+    virtual ~CSocket() override;
+
+    bool connect(const String& hostname, int port);
+    bool connect(const CSocketAddress&, int port);
+
+    ByteBuffer receive(int max_size);
+    bool send(const ByteBuffer&);
+
+    bool is_connected() const { return m_connected; }
+
+    CSocketAddress source_address() const { return m_source_address; }
+    int source_port() const { return m_source_port; }
+
+    CSocketAddress destination_address() const { return m_source_address; }
+    int destination_port() const { return m_destination_port; }
+
+    Function<void()> on_connected;
+
+    virtual const char* class_name() const override { return "CSocket"; }
+
+protected:
+    CSocket(Type, CObject* parent);
+
+    CSocketAddress m_source_address;
+    CSocketAddress m_destination_address;
+    int m_source_port { -1 };
+    int m_destination_port { -1 };
+    bool m_connected { false };
+
+private:
+    virtual bool open(CIODevice::OpenMode) override { ASSERT_NOT_REACHED(); }
+    Type m_type { Type::Invalid };
+    OwnPtr<CNotifier> m_notifier;
+};
diff --git a/Libraries/LibCore/CSocketAddress.h b/Libraries/LibCore/CSocketAddress.h
new file mode 100644
index 0000000000..019a0869fb
--- /dev/null
+++ b/Libraries/LibCore/CSocketAddress.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <AK/IPv4Address.h>
+
+class CSocketAddress {
+public:
+    enum class Type {
+        Invalid,
+        IPv4,
+        Local
+    };
+
+    CSocketAddress() {}
+    CSocketAddress(const IPv4Address& address)
+        : m_type(Type::IPv4)
+        , m_ipv4_address(address)
+    {
+    }
+
+    Type type() const { return m_type; }
+    bool is_valid() const { return m_type != Type::Invalid; }
+    IPv4Address ipv4_address() const { return m_ipv4_address; }
+
+    String to_string() const
+    {
+        switch (m_type) {
+        case Type::IPv4:
+            return m_ipv4_address.to_string();
+        default:
+            return "[CSocketAddress]";
+        }
+    }
+
+private:
+    Type m_type { Type::Invalid };
+    IPv4Address m_ipv4_address;
+};
diff --git a/Libraries/LibCore/CTCPSocket.cpp b/Libraries/LibCore/CTCPSocket.cpp
new file mode 100644
index 0000000000..5f3702a482
--- /dev/null
+++ b/Libraries/LibCore/CTCPSocket.cpp
@@ -0,0 +1,19 @@
+#include <LibCore/CTCPSocket.h>
+#include <sys/socket.h>
+
+CTCPSocket::CTCPSocket(CObject* parent)
+    : CSocket(CSocket::Type::TCP, parent)
+{
+    int fd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
+    if (fd < 0) {
+        set_error(fd);
+    } else {
+        set_fd(fd);
+        set_mode(CIODevice::ReadWrite);
+        set_error(0);
+    }
+}
+
+CTCPSocket::~CTCPSocket()
+{
+}
diff --git a/Libraries/LibCore/CTCPSocket.h b/Libraries/LibCore/CTCPSocket.h
new file mode 100644
index 0000000000..fe4f3ffb3a
--- /dev/null
+++ b/Libraries/LibCore/CTCPSocket.h
@@ -0,0 +1,9 @@
+#include <LibCore/CSocket.h>
+
+class CTCPSocket final : public CSocket {
+public:
+    explicit CTCPSocket(CObject* parent = nullptr);
+    virtual ~CTCPSocket() override;
+
+private:
+};
diff --git a/Libraries/LibCore/CTimer.cpp b/Libraries/LibCore/CTimer.cpp
new file mode 100644
index 0000000000..fb55ad7e63
--- /dev/null
+++ b/Libraries/LibCore/CTimer.cpp
@@ -0,0 +1,61 @@
+#include <LibCore/CTimer.h>
+
+CTimer::CTimer(CObject* parent)
+    : CObject(parent)
+{
+}
+
+CTimer::CTimer(int interval, Function<void()>&& timeout_handler, CObject* parent)
+    : CObject(parent)
+    , on_timeout(move(timeout_handler))
+{
+    start(interval);
+}
+
+CTimer::~CTimer()
+{
+}
+
+void CTimer::start()
+{
+    start(m_interval);
+}
+
+void CTimer::start(int interval)
+{
+    if (m_active)
+        return;
+    m_interval = interval;
+    start_timer(interval);
+    m_active = true;
+}
+
+void CTimer::restart(int interval)
+{
+    if (m_active)
+        stop();
+    start(interval);
+}
+
+void CTimer::stop()
+{
+    if (!m_active)
+        return;
+    stop_timer();
+    m_active = false;
+}
+
+void CTimer::timer_event(CTimerEvent&)
+{
+    if (m_single_shot)
+        stop();
+    else {
+        if (m_interval_dirty) {
+            stop();
+            start(m_interval);
+        }
+    }
+
+    if (on_timeout)
+        on_timeout();
+}
diff --git a/Libraries/LibCore/CTimer.h b/Libraries/LibCore/CTimer.h
new file mode 100644
index 0000000000..b6c1c2005f
--- /dev/null
+++ b/Libraries/LibCore/CTimer.h
@@ -0,0 +1,41 @@
+#pragma once
+
+#include <AK/Function.h>
+#include <LibCore/CObject.h>
+
+class CTimer final : public CObject {
+public:
+    explicit CTimer(CObject* parent = nullptr);
+    CTimer(int interval, Function<void()>&& timeout_handler, CObject* parent = nullptr);
+    virtual ~CTimer() override;
+
+    void start();
+    void start(int interval);
+    void restart(int interval);
+    void stop();
+
+    bool is_active() const { return m_active; }
+    int interval() const { return m_interval; }
+    void set_interval(int interval)
+    {
+        if (m_interval == interval)
+            return;
+        m_interval = interval;
+        m_interval_dirty = true;
+    }
+
+    bool is_single_shot() const { return m_single_shot; }
+    void set_single_shot(bool single_shot) { m_single_shot = single_shot; }
+
+    Function<void()> on_timeout;
+
+    virtual const char* class_name() const override { return "CTimer"; }
+
+private:
+    virtual void timer_event(CTimerEvent&) override;
+
+    bool m_active { false };
+    bool m_single_shot { false };
+    bool m_interval_dirty { false };
+    int m_interval { 0 };
+};
diff --git a/Libraries/LibCore/CUserInfo.cpp b/Libraries/LibCore/CUserInfo.cpp
new file mode 100644
index 0000000000..d5308d454e
--- /dev/null
+++ b/Libraries/LibCore/CUserInfo.cpp
@@ -0,0 +1,17 @@
+#include "CUserInfo.h"
+#include <pwd.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+const char* get_current_user_home_path()
+{
+    if (auto* home_env = getenv("HOME"))
+        return home_env;
+
+    auto d = "/";
+    uid_t uid = getuid();
+    if (auto* pwd = getpwuid(uid))
+        return pwd->pw_dir;
+
+    return d;
+}
diff --git a/Libraries/LibCore/CUserInfo.h b/Libraries/LibCore/CUserInfo.h
new file mode 100644
index 0000000000..b47cec4af1
--- /dev/null
+++ b/Libraries/LibCore/CUserInfo.h
@@ -0,0 +1 @@
+const char* get_current_user_home_path();
diff --git a/Libraries/LibCore/Makefile b/Libraries/LibCore/Makefile
new file mode 100644
index 0000000000..1f88103724
--- /dev/null
+++ b/Libraries/LibCore/Makefile
@@ -0,0 +1,49 @@
+include ../../Makefile.common
+
+OBJS = \
+    CArgsParser.o \
+    CIODevice.o \
+    CFile.o \
+    CSocket.o \
+    CTCPSocket.o \
+    CElapsedTimer.o \
+    CNotifier.o \
+    CHttpRequest.o \
+    CHttpResponse.o \
+    CHttpJob.o \
+    CNetworkJob.o \
+    CNetworkResponse.o \
+    CObject.o \
+    CTimer.o \
+    CEventLoop.o \
+    CConfigFile.o \
+    CEvent.o \
+    CProcessStatisticsReader.o \
+    CDirIterator.o \
+    CUserInfo.o
+
+LIBRARY = libcore.a
+DEFINES += -DUSERLAND
+
+all: $(LIBRARY)
+
+$(LIBRARY): $(OBJS)
+	@echo "LIB $@"; $(AR) rcs $@ $(OBJS) $(LIBS)
+
+.cpp.o:
+	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
+
+-include $(OBJS:%.o=%.d)
+
+clean:
+	@echo "CLEAN"; rm -f $(LIBRARY) $(OBJS) *.d
+
+install: $(LIBRARY)
+	mkdir -p ../Root/usr/include/LibCore
+	mkdir -p ../Root/usr/include/AK
+	mkdir -p ../Root/usr/lib
+	# Copy headers
+	rsync -r -a --include '*/' --include '*.h' --exclude '*' . ../Root/usr/include/LibCore
+	rsync -r -a --include '*/' --include '*.h' --exclude '*' ../AK/ ../Root/usr/include/AK
+	# Install the library
+	cp $(LIBRARY) ../Root/usr/lib
diff --git a/Libraries/LibCore/install.sh b/Libraries/LibCore/install.sh
new file mode 100755
index 0000000000..fedc4b73fb
--- /dev/null
+++ b/Libraries/LibCore/install.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+
+mkdir -p ../Root/usr/include/LibCore/
+cp *.h ../Root/usr/include/LibCore/
+cp libcore.a ../Root/usr/lib/