yuzu/src/core/hle/kernel/semaphore.cpp
2018-01-07 16:52:23 -05:00

66 lines
1.8 KiB
C++

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include "common/assert.h"
#include "core/hle/kernel/errors.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/object_address_table.h"
#include "core/hle/kernel/semaphore.h"
#include "core/hle/kernel/thread.h"
namespace Kernel {
Semaphore::Semaphore() {}
Semaphore::~Semaphore() {}
ResultVal<SharedPtr<Semaphore>> Semaphore::Create(VAddr guest_addr, VAddr mutex_addr,
std::string name) {
SharedPtr<Semaphore> semaphore(new Semaphore);
// When the semaphore is created, some slots are reserved for other threads,
// and the rest is reserved for the caller thread;
semaphore->available_count = Memory::Read32(guest_addr);
semaphore->name = std::move(name);
semaphore->guest_addr = guest_addr;
semaphore->mutex_addr = mutex_addr;
// Semaphores are referenced by guest address, so track this in the kernel
g_object_address_table.Insert(guest_addr, semaphore);
return MakeResult<SharedPtr<Semaphore>>(std::move(semaphore));
}
bool Semaphore::ShouldWait(Thread* thread) const {
return available_count <= 0;
}
void Semaphore::Acquire(Thread* thread) {
if (available_count <= 0)
return;
--available_count;
UpdateGuestState();
}
ResultCode Semaphore::Release(s32 target) {
++available_count;
UpdateGuestState();
if (target == -1) {
// When -1, wake up all waiting threads
WakeupAllWaitingThreads();
} else {
// Otherwise, wake up just a single thread
WakeupWaitingThread(GetHighestPriorityReadyThread());
}
return RESULT_SUCCESS;
}
void Semaphore::UpdateGuestState() {
Memory::Write32(guest_addr, available_count);
}
} // namespace Kernel