#include "Thread.h"

#include <windows.h>

extern "C" void thread_func();

void Scheduler::Loop()

{

while (true)

{

auto next = GetNextThread();

if (next)

{

this->next = next;

yield(this, ThreadStatus::READY);

if (next->status == ThreadStatus::ZOMBIE)

{

free_list_.emplace_back(next);

}

}

else

{

//TODO: wait for IOCP

printf("No thread to schedule\n");

return;

}

}

}

Thread* Scheduler::GetNextThread()

{

for (int i = 0, len = thread_list_.size(); i < len; ++i)

{

auto ret = thread_list_[last_pos_++];

last_pos_ = last_pos_ % len;

if (ret->status == ThreadStatus::READY)

return ret;

}

return nullptr;

}

Scheduler::Scheduler() :

monitor_(this, GetCurrentThreadId())

{

switch_count_ = 0;

monitor_.Start();

}

Thread* Scheduler::CreateThread(Func func, void* arg)

{

constexpr int DEFAULT_STACK_SIZE = 4 << 20;

Thread* new_thread;

if (free_list_.empty())

{

new_thread = new Thread;

new_thread->stack_data = VirtualAlloc(0, DEFAULT_STACK_SIZE, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);

new_thread->next = this;

thread_list_.push_back(new_thread);

}

else

{

new_thread = free_list_.back();

free_list_.pop_back();

}

void** p = (void**)(int(new_thread->stack_data) + DEFAULT_STACK_SIZE);

*--p = new_thread;

*--p = arg;

*--p = func;

*--p = &thread_func;

new_thread->stack = (void*)p;

new_thread->status = ThreadStatus::READY;

new_thread->switch_count_ = 0;

return new_thread;

}