7e2903cb74
This handle manager more closely mirrors the behaviour of the CTR-OS one. In addition object ref-counts and support for DuplicateHandle have been added. Note that support for DuplicateHandle is still experimental, since parts of the kernel still use Handles internally, which will likely cause troubles if two different handles to the same object are used to e.g. wait on a synchronization primitive.
96 lines
3.3 KiB
C++
96 lines
3.3 KiB
C++
// Copyright 2014 Citra Emulator Project
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// Licensed under GPLv2 or any later version
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// Refer to the license.txt file included.
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#include <queue>
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#include "common/common.h"
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#include "core/hle/kernel/kernel.h"
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#include "core/hle/kernel/semaphore.h"
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#include "core/hle/kernel/thread.h"
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namespace Kernel {
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class Semaphore : public Object {
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public:
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std::string GetTypeName() const override { return "Semaphore"; }
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std::string GetName() const override { return name; }
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static const HandleType HANDLE_TYPE = HandleType::Semaphore;
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HandleType GetHandleType() const override { return HANDLE_TYPE; }
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s32 max_count; ///< Maximum number of simultaneous holders the semaphore can have
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s32 available_count; ///< Number of free slots left in the semaphore
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std::queue<Handle> waiting_threads; ///< Threads that are waiting for the semaphore
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std::string name; ///< Name of semaphore (optional)
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/**
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* Tests whether a semaphore still has free slots
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* @return Whether the semaphore is available
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*/
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bool IsAvailable() const {
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return available_count > 0;
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}
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ResultVal<bool> WaitSynchronization() override {
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bool wait = !IsAvailable();
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if (wait) {
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Kernel::WaitCurrentThread(WAITTYPE_SEMA, GetHandle());
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waiting_threads.push(GetCurrentThreadHandle());
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} else {
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--available_count;
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}
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return MakeResult<bool>(wait);
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}
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};
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////////////////////////////////////////////////////////////////////////////////////////////////////
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ResultCode CreateSemaphore(Handle* handle, s32 initial_count,
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s32 max_count, const std::string& name) {
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if (initial_count > max_count)
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return ResultCode(ErrorDescription::InvalidCombination, ErrorModule::Kernel,
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ErrorSummary::WrongArgument, ErrorLevel::Permanent);
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Semaphore* semaphore = new Semaphore;
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// TOOD(yuriks): Fix error reporting
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*handle = g_handle_table.Create(semaphore).ValueOr(INVALID_HANDLE);
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// When the semaphore is created, some slots are reserved for other threads,
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// and the rest is reserved for the caller thread
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semaphore->max_count = max_count;
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semaphore->available_count = initial_count;
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semaphore->name = name;
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return RESULT_SUCCESS;
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}
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ResultCode ReleaseSemaphore(s32* count, Handle handle, s32 release_count) {
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Semaphore* semaphore = g_handle_table.Get<Semaphore>(handle);
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if (semaphore == nullptr)
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return InvalidHandle(ErrorModule::Kernel);
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if (semaphore->max_count - semaphore->available_count < release_count)
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return ResultCode(ErrorDescription::OutOfRange, ErrorModule::Kernel,
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ErrorSummary::InvalidArgument, ErrorLevel::Permanent);
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*count = semaphore->available_count;
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semaphore->available_count += release_count;
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// Notify some of the threads that the semaphore has been released
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// stop once the semaphore is full again or there are no more waiting threads
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while (!semaphore->waiting_threads.empty() && semaphore->IsAvailable()) {
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Kernel::ResumeThreadFromWait(semaphore->waiting_threads.front());
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semaphore->waiting_threads.pop();
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--semaphore->available_count;
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}
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return RESULT_SUCCESS;
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}
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} // namespace
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