/* * Copyright (c) 2018-2020 Atmosphère-NX * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <stratosphere.hpp> #include "impl/os_waitable_object_list.hpp" #include "impl/os_timeout_helper.hpp" namespace ams::os { void InitializeSemaphore(SemaphoreType *sema, s32 count, s32 max_count) { AMS_ASSERT(max_count >= 1); AMS_ASSERT(count >= 0); /* Setup objects. */ new (GetPointer(sema->cs_sema)) impl::InternalCriticalSection; new (GetPointer(sema->cv_not_zero)) impl::InternalConditionVariable; /* Setup wait lists. */ new (GetPointer(sema->waitlist)) impl::WaitableObjectList; /* Set member variables. */ sema->count = count; sema->max_count = max_count; /* Mark initialized. */ sema->state = SemaphoreType::State_Initialized; } void FinalizeSemaphore(SemaphoreType *sema) { AMS_ASSERT(sema->state = SemaphoreType::State_Initialized); AMS_ASSERT(GetReference(sema->waitlist).IsEmpty()); /* Mark uninitialized. */ sema->state = SemaphoreType::State_NotInitialized; /* Destroy wait lists. */ GetReference(sema->waitlist).~WaitableObjectList(); /* Destroy objects. */ GetReference(sema->cv_not_zero).~InternalConditionVariable(); GetReference(sema->cs_sema).~InternalCriticalSection(); } void AcquireSemaphore(SemaphoreType *sema) { AMS_ASSERT(sema->state == SemaphoreType::State_Initialized); { std::scoped_lock lk(GetReference(sema->cs_sema)); while (sema->count == 0) { GetReference(sema->cv_not_zero).Wait(GetPointer(sema->cs_sema)); } --sema->count; } } bool TryAcquireSemaphore(SemaphoreType *sema) { AMS_ASSERT(sema->state == SemaphoreType::State_Initialized); { std::scoped_lock lk(GetReference(sema->cs_sema)); if (sema->count == 0) { return false; } --sema->count; } return true; } bool TimedAcquireSemaphore(SemaphoreType *sema, TimeSpan timeout) { AMS_ASSERT(sema->state == SemaphoreType::State_Initialized); AMS_ASSERT(timeout.GetNanoSeconds() >= 0); { impl::TimeoutHelper timeout_helper(timeout); std::scoped_lock lk(GetReference(sema->cs_sema)); while (sema->count == 0) { if (timeout_helper.TimedOut()) { return false; } GetReference(sema->cv_not_zero).TimedWait(GetPointer(sema->cs_sema), timeout_helper); } --sema->count; } return true; } void ReleaseSemaphore(SemaphoreType *sema) { AMS_ASSERT(sema->state == SemaphoreType::State_Initialized); { std::scoped_lock lk(GetReference(sema->cs_sema)); AMS_ASSERT(sema->count + 1 <= sema->max_count); ++sema->count; GetReference(sema->cv_not_zero).Signal(); GetReference(sema->waitlist).SignalAllThreads(); } } void ReleaseSemaphore(SemaphoreType *sema, s32 count) { AMS_ASSERT(sema->state == SemaphoreType::State_Initialized); { std::scoped_lock lk(GetReference(sema->cs_sema)); AMS_ASSERT(sema->count + count <= sema->max_count); sema->count += count; GetReference(sema->cv_not_zero).Signal(); GetReference(sema->waitlist).SignalAllThreads(); } } s32 GetCurrentSemaphoreCount(const SemaphoreType *sema) { AMS_ASSERT(sema->state == SemaphoreType::State_Initialized); return sema->count; } // void InitializeWaitableHolder(WaitableHolderType *waitable_holder, SemaphoreType *sema); }