CrashDaemon+CrashReporter: Streamline crash reporting a little bit

Before this patch, this is what would happen after something crashed:

1. CrashDaemon finds a new coredump in /tmp
2. CrashDaemon compresses the new coredump (gzip)
3. CrashDaemon parses the uncompressed coredump and prints a backtrace
4. CrashDaemon launches CrashReporter
5. CrashReporter parses the uncompressed coredump (again)
6. CrashReporter unlinks the uncompressed coredump
7. CrashReporter displays a GUI

This was taking quite a long time when dealing with large programs
crashing (like Browser's WebContent processes.)

The new flow:

1. CrashDaemon finds a new coredump in /tmp
2. CrashDaemon mmap()'s the (uncompressed) coredump
3. CrashDaemon launches CrashReporter
4. CrashDaemon goes to sleep for 3 seconds (hack alert!)
5. CrashReporter parses the (uncompressed) coredump
6. CrashReporter unlinks the (uncompressed) coredump
7. CrashReporter displays a GUI
8. CrashDaemon wakes up (after step 4)
9. CrashDaemon compresses the coredump (gzip)

TL;DR: we no longer parse the coredumps twice, and we also prioritize
launching the CrashReporter GUI immediately when a new coredump shows
up, instead of compressing and parsing it in CrashDaemon first.

The net effect of this is that you get a backtrace on screen much
sooner. That's pretty nice. :^)

1 files changed, 8 insertions, 0 deletions

diff --git a/Userland/Applications/CrashReporter/main.cpp b/Userland/Applications/CrashReporter/main.cpp
index cde7062ad3..01c4c04903 100644
--- a/Userland/Applications/CrashReporter/main.cpp
+++ b/Userland/Applications/CrashReporter/main.cpp
@@ -38,9 +38,12 @@ struct TitleAndText {
 
 static TitleAndText build_backtrace(Coredump::Reader const& coredump, ELF::Core::ThreadInfo const& thread_info, size_t thread_index)
 {
+    auto timer = Core::ElapsedTimer::start_new();
     Coredump::Backtrace backtrace(coredump, thread_info);
     auto metadata = coredump.metadata();
 
+    dbgln("Generating backtrace took {} ms", timer.elapsed());
+
     StringBuilder builder;
 
     auto prepend_metadata = [&](auto& key, StringView fmt) {
@@ -73,6 +76,11 @@ static TitleAndText build_backtrace(Coredump::Reader const& coredump, ELF::Core:
         builder.append(entry.to_string());
     }
 
+    dbgln("--- Backtrace for thread #{} (TID {}) ---", thread_index, thread_info.tid);
+    for (auto& entry : backtrace.entries()) {
+        dbgln("{}", entry.to_string(true));
+    }
+
     return {
         String::formatted("Thread #{} (TID {})", thread_index, thread_info.tid),
         builder.build()