acadia/zion/scheduler/scheduler.cpp

85 lines
1.6 KiB
C++

#include "scheduler/scheduler.h"
#include "debug/debug.h"
namespace sched {
namespace {
// Simple linked list class with the intent of eventually replacing this with a
// map.
class ProcList {
public:
ProcList() {}
// Takes ownership.
void InsertProcess(Process* proc) {
if (front_ == nullptr) {
front_ = new ProcEntry{
.proc = proc,
.next = nullptr,
};
return;
}
ProcEntry* back = front_;
while (back->next != nullptr) {
back = back->next;
}
back->next = new ProcEntry{
.proc = proc,
.next = nullptr,
};
}
private:
struct ProcEntry {
Process* proc;
ProcEntry* next;
};
ProcEntry* front_ = nullptr;
};
class Scheduler {
public:
Scheduler() {
Process* root = Process::RootProcess();
current_thread_ = root->GetThread(0);
proc_list_.InsertProcess(Process::RootProcess());
}
void Enable() { enabled_ = true; }
Process& CurrentProcess() { return current_thread_->process(); }
Thread& CurrentThread() { return *current_thread_; }
void Yield() {}
private:
bool enabled_ = false;
ProcList proc_list_;
Thread* current_thread_;
};
static Scheduler* gScheduler = nullptr;
Scheduler& GetScheduler() {
if (!gScheduler) {
panic("Scheduler not initialized");
}
return *gScheduler;
}
} // namespace
void InitScheduler() { gScheduler = new Scheduler(); }
void EnableScheduler() { GetScheduler().Enable(); }
void Yield() { GetScheduler().Yield(); }
Process& CurrentProcess() { return GetScheduler().CurrentProcess(); }
Thread& CurrentThread() { return GetScheduler().CurrentThread(); }
} // namespace sched