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authorAndreas Kling <awesomekling@gmail.com>2018-11-07 23:13:38 +0100
committerAndreas Kling <awesomekling@gmail.com>2018-11-07 23:14:56 +0100
commit43f40a305067745ed15891d8d02f12c0764004e4 (patch)
tree8be1eeebd4c77326caa96f643048f116c3f354c8 /Kernel/Scheduler.cpp
parent440029c9d17726da9776f35e66da869e843e2faf (diff)
downloadserenity-43f40a305067745ed15891d8d02f12c0764004e4.zip
Finally unbreak the colonel process and make it the true idle process.
Diffstat (limited to 'Kernel/Scheduler.cpp')
-rw-r--r--Kernel/Scheduler.cpp78
1 files changed, 40 insertions, 38 deletions
diff --git a/Kernel/Scheduler.cpp b/Kernel/Scheduler.cpp
index 338490f632..1f8384e965 100644
--- a/Kernel/Scheduler.cpp
+++ b/Kernel/Scheduler.cpp
@@ -10,6 +10,12 @@ static const dword time_slice = 5; // *10 = 50ms
Process* current;
static Process* s_colonel_process;
+struct TaskRedirectionData {
+ word selector;
+ TSS32 tss;
+};
+static TaskRedirectionData s_redirection;
+
bool Scheduler::pick_next()
{
ASSERT_INTERRUPTS_DISABLED();
@@ -50,6 +56,16 @@ bool Scheduler::pick_next()
return true;
}
+ if (process.state() == Process::ExecPhase1) {
+ process.set_state(Process::ExecPhase2);
+ return true;
+ }
+
+ if (process.state() == Process::ExecPhase2) {
+ process.set_state(Process::Runnable);
+ return true;
+ }
+
// Forgive dead orphans.
if (process.state() == Process::Dead) {
if (!Process::from_pid(process.ppid()))
@@ -57,11 +73,11 @@ bool Scheduler::pick_next()
}
// Release the forgiven.
- Process::for_each_in_state(Process::Forgiven, [] (auto& process) {
+ if (process.state() == Process::Forgiven) {
g_processes->remove(&process);
g_dead_processes->append(&process);
return true;
- });
+ };
return true;
});
@@ -104,25 +120,13 @@ bool Scheduler::pick_next()
if (process->state() == Process::Runnable || process->state() == Process::Running) {
#ifdef SCHEDULER_DEBUG
- dbgprintf("switch to %s(%u)\n", process->name().characters(), process->pid());
+ dbgprintf("switch to %s(%u) @ %w:%x\n", process->name().characters(), process->pid(), process->tss().cs, process->tss().eip);
#endif
return context_switch(*process);
}
if (process == prevHead) {
- // Back at process_head, nothing wants to run.
- kprintf("Nothing wants to run!\n");
- kprintf("PID OWNER STATE NSCHED NAME\n");
- for (auto* process = g_processes->head(); process; process = process->next()) {
- kprintf("%w %w:%w %b %w %s\n",
- process->pid(),
- process->uid(),
- process->gid(),
- process->state(),
- process->timesScheduled(),
- process->name().characters());
- }
- kprintf("Switch to kernel process @ %w:%x\n", s_colonel_process->tss().cs, s_colonel_process->tss().eip);
+ // Back at process_head, nothing wants to run. Send in the colonel!
return context_switch(*s_colonel_process);
}
}
@@ -214,38 +218,34 @@ int sched_yield()
return Scheduler::yield();
}
-static void redo_colonel_process_tss()
+static void initialize_redirection()
{
- if (!s_colonel_process->selector())
- s_colonel_process->setSelector(gdt_alloc_entry());
-
- auto& tssDescriptor = getGDTEntry(s_colonel_process->selector());
-
- tssDescriptor.setBase(&s_colonel_process->tss());
- tssDescriptor.setLimit(0xffff);
- tssDescriptor.dpl = 0;
- tssDescriptor.segment_present = 1;
- tssDescriptor.granularity = 1;
- tssDescriptor.zero = 0;
- tssDescriptor.operation_size = 1;
- tssDescriptor.descriptor_type = 0;
- tssDescriptor.type = 9;
-
+ auto& descriptor = getGDTEntry(s_redirection.selector);
+ descriptor.setBase(&s_redirection.tss);
+ descriptor.setLimit(0xffff);
+ descriptor.dpl = 0;
+ descriptor.segment_present = 1;
+ descriptor.granularity = 1;
+ descriptor.zero = 0;
+ descriptor.operation_size = 1;
+ descriptor.descriptor_type = 0;
+ descriptor.type = 9;
flushGDT();
}
void Scheduler::prepare_for_iret_to_new_process()
{
- redo_colonel_process_tss();
- s_colonel_process->tss().backlink = current->selector();
- load_task_register(s_colonel_process->selector());
+ auto& descriptor = getGDTEntry(s_redirection.selector);
+ descriptor.type = 9;
+ s_redirection.tss.backlink = current->selector();
+ load_task_register(s_redirection.selector);
}
void Scheduler::prepare_to_modify_own_tss()
{
// This ensures that a process modifying its own TSS in order to yield()
// and end up somewhere else doesn't just end up right after the yield().
- load_task_register(s_colonel_process->selector());
+ load_task_register(s_redirection.selector);
}
static void hlt_loop()
@@ -257,8 +257,10 @@ static void hlt_loop()
void Scheduler::initialize()
{
+ memset(&s_redirection, 0, sizeof(s_redirection));
+ s_redirection.selector = gdt_alloc_entry();
+ initialize_redirection();
s_colonel_process = Process::create_kernel_process(hlt_loop, "colonel");
current = nullptr;
- redo_colonel_process_tss();
- load_task_register(s_colonel_process->selector());
+ load_task_register(s_redirection.selector);
}