94 lines
3.3 KiB
C++
94 lines
3.3 KiB
C++
// Copyright 2014 Citra Emulator Project
|
|
// Licensed under GPLv2 or any later version
|
|
// Refer to the license.txt file included.
|
|
|
|
#include <queue>
|
|
|
|
#include "common/common.h"
|
|
|
|
#include "core/hle/kernel/kernel.h"
|
|
#include "core/hle/kernel/semaphore.h"
|
|
#include "core/hle/kernel/thread.h"
|
|
|
|
namespace Kernel {
|
|
|
|
class Semaphore : public Object {
|
|
public:
|
|
std::string GetTypeName() const override { return "Semaphore"; }
|
|
std::string GetName() const override { return name; }
|
|
|
|
static Kernel::HandleType GetStaticHandleType() { return Kernel::HandleType::Semaphore; }
|
|
Kernel::HandleType GetHandleType() const override { return Kernel::HandleType::Semaphore; }
|
|
|
|
s32 max_count; ///< Maximum number of simultaneous holders the semaphore can have
|
|
s32 available_count; ///< Number of free slots left in the semaphore
|
|
std::queue<Handle> waiting_threads; ///< Threads that are waiting for the semaphore
|
|
std::string name; ///< Name of semaphore (optional)
|
|
|
|
/**
|
|
* Tests whether a semaphore still has free slots
|
|
* @return Whether the semaphore is available
|
|
*/
|
|
bool IsAvailable() const {
|
|
return available_count > 0;
|
|
}
|
|
|
|
ResultVal<bool> WaitSynchronization() override {
|
|
bool wait = !IsAvailable();
|
|
|
|
if (wait) {
|
|
Kernel::WaitCurrentThread(WAITTYPE_SEMA, GetHandle());
|
|
waiting_threads.push(GetCurrentThreadHandle());
|
|
} else {
|
|
--available_count;
|
|
}
|
|
|
|
return MakeResult<bool>(wait);
|
|
}
|
|
};
|
|
|
|
////////////////////////////////////////////////////////////////////////////////////////////////////
|
|
|
|
ResultCode CreateSemaphore(Handle* handle, s32 initial_count,
|
|
s32 max_count, const std::string& name) {
|
|
|
|
if (initial_count > max_count)
|
|
return ResultCode(ErrorDescription::InvalidCombination, ErrorModule::Kernel,
|
|
ErrorSummary::WrongArgument, ErrorLevel::Permanent);
|
|
|
|
Semaphore* semaphore = new Semaphore;
|
|
*handle = g_handle_table.Create(semaphore);
|
|
|
|
// When the semaphore is created, some slots are reserved for other threads,
|
|
// and the rest is reserved for the caller thread
|
|
semaphore->max_count = max_count;
|
|
semaphore->available_count = initial_count;
|
|
semaphore->name = name;
|
|
|
|
return RESULT_SUCCESS;
|
|
}
|
|
|
|
ResultCode ReleaseSemaphore(s32* count, Handle handle, s32 release_count) {
|
|
Semaphore* semaphore = g_handle_table.Get<Semaphore>(handle);
|
|
if (semaphore == nullptr)
|
|
return InvalidHandle(ErrorModule::Kernel);
|
|
|
|
if (semaphore->max_count - semaphore->available_count < release_count)
|
|
return ResultCode(ErrorDescription::OutOfRange, ErrorModule::Kernel,
|
|
ErrorSummary::InvalidArgument, ErrorLevel::Permanent);
|
|
|
|
*count = semaphore->available_count;
|
|
semaphore->available_count += release_count;
|
|
|
|
// Notify some of the threads that the semaphore has been released
|
|
// stop once the semaphore is full again or there are no more waiting threads
|
|
while (!semaphore->waiting_threads.empty() && semaphore->IsAvailable()) {
|
|
Kernel::ResumeThreadFromWait(semaphore->waiting_threads.front());
|
|
semaphore->waiting_threads.pop();
|
|
--semaphore->available_count;
|
|
}
|
|
|
|
return RESULT_SUCCESS;
|
|
}
|
|
|
|
} // namespace
|