/* AngelCode Scripting Library Copyright (c) 2003-2014 Andreas Jonsson This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution. The original version of this library can be located at: http://www.angelcode.com/angelscript/ Andreas Jonsson andreas@angelcode.com */ // // as_thread.cpp // // Functions for multi threading support // #include "as_config.h" #include "as_thread.h" #include "as_atomic.h" BEGIN_AS_NAMESPACE //======================================================================= // Singleton static asCThreadManager *threadManager = 0; //====================================================================== // Global API functions extern "C" { AS_API int asThreadCleanup() { return asCThreadManager::CleanupLocalData(); } AS_API asIThreadManager *asGetThreadManager() { return threadManager; } AS_API int asPrepareMultithread(asIThreadManager *externalThreadMgr) { return asCThreadManager::Prepare(externalThreadMgr); } AS_API void asUnprepareMultithread() { asCThreadManager::Unprepare(); } AS_API void asAcquireExclusiveLock() { if( threadManager ) { ACQUIREEXCLUSIVE(threadManager->appRWLock); } } AS_API void asReleaseExclusiveLock() { if( threadManager ) { RELEASEEXCLUSIVE(threadManager->appRWLock); } } AS_API void asAcquireSharedLock() { if( threadManager ) { ACQUIRESHARED(threadManager->appRWLock); } } AS_API void asReleaseSharedLock() { if( threadManager ) { RELEASESHARED(threadManager->appRWLock); } } } //====================================================================== #if !defined(AS_NO_THREADS) && defined(_MSC_VER) && defined(AS_WINDOWS_THREADS) && (WINAPI_FAMILY & WINAPI_FAMILY_PHONE_APP) __declspec(thread) asCThreadLocalData *asCThreadManager::tld = 0; #endif asCThreadManager::asCThreadManager() { // We're already in the critical section when this function is called #ifdef AS_NO_THREADS tld = 0; #else // Allocate the thread local storage #if defined AS_POSIX_THREADS pthread_key_t pKey; pthread_key_create(&pKey, 0); tlsKey = (asDWORD)pKey; #elif defined AS_WINDOWS_THREADS #if defined(_MSC_VER) && (WINAPI_FAMILY & WINAPI_FAMILY_PHONE_APP) tld = 0; #else tlsKey = (asDWORD)TlsAlloc(); #endif #endif #endif refCount = 1; } int asCThreadManager::Prepare(asIThreadManager *externalThreadMgr) { // Don't allow an external thread manager if there // is already a thread manager defined if( externalThreadMgr && threadManager ) return asINVALID_ARG; // The critical section cannot be declared globally, as there is no // guarantee for the order in which global variables are initialized // or uninitialized. // For this reason it's not possible to prevent two threads from calling // AddRef at the same time, so there is a chance for a race condition here. // To avoid the race condition when the thread manager is first created, // the application must make sure to call the global asPrepareForMultiThread() // in the main thread before any other thread creates a script engine. if( threadManager == 0 && externalThreadMgr == 0 ) threadManager = asNEW(asCThreadManager); else { // If an application uses different dlls each dll will get it's own memory // space for global variables. If multiple dlls then uses AngelScript's // global thread support functions it is then best to share the thread // manager to make sure all dlls use the same critical section. if( externalThreadMgr ) threadManager = reinterpret_cast(externalThreadMgr); ENTERCRITICALSECTION(threadManager->criticalSection); threadManager->refCount++; LEAVECRITICALSECTION(threadManager->criticalSection); } // Success return 0; } void asCThreadManager::Unprepare() { asASSERT(threadManager); if( threadManager == 0 ) return; // It's necessary to protect this section so no // other thread attempts to call AddRef or Release // while clean up is in progress. ENTERCRITICALSECTION(threadManager->criticalSection); if( --threadManager->refCount == 0 ) { // Make sure the local data is destroyed, at least for the current thread CleanupLocalData(); // As the critical section will be destroyed together // with the thread manager we must first clear the global // variable in case a new thread manager needs to be created; asCThreadManager *mgr = threadManager; threadManager = 0; // Leave the critical section before it is destroyed LEAVECRITICALSECTION(mgr->criticalSection); asDELETE(mgr,asCThreadManager); } else LEAVECRITICALSECTION(threadManager->criticalSection); } asCThreadManager::~asCThreadManager() { #ifndef AS_NO_THREADS // Deallocate the thread local storage #if defined AS_POSIX_THREADS pthread_key_delete((pthread_key_t)tlsKey); #elif defined AS_WINDOWS_THREADS #if defined(_MSC_VER) && (WINAPI_FAMILY & WINAPI_FAMILY_PHONE_APP) tld = 0; #else TlsFree((DWORD)tlsKey); #endif #endif #else if( tld ) { asDELETE(tld,asCThreadLocalData); } tld = 0; #endif } #if defined(AS_STD_THREADS) thread_local asCThreadLocalData *std_tld; #endif int asCThreadManager::CleanupLocalData() { if( threadManager == 0 ) return 0; #ifndef AS_NO_THREADS #if defined AS_POSIX_THREADS asCThreadLocalData *tld = (asCThreadLocalData*)pthread_getspecific((pthread_key_t)threadManager->tlsKey); #elif defined AS_WINDOWS_THREADS #if !defined(_MSC_VER) || !(WINAPI_FAMILY & WINAPI_FAMILY_PHONE_APP) asCThreadLocalData *tld = (asCThreadLocalData*)TlsGetValue((DWORD)threadManager->tlsKey); #endif #elif defined(AS_STD_THREADS) auto tld = std_tld; #endif if( tld == 0 ) return 0; if( tld->activeContexts.GetLength() == 0 ) { asDELETE(tld,asCThreadLocalData); #if defined AS_POSIX_THREADS pthread_setspecific((pthread_key_t)threadManager->tlsKey, 0); #elif defined AS_WINDOWS_THREADS #if defined(_MSC_VER) && (WINAPI_FAMILY & WINAPI_FAMILY_PHONE_APP) tld = 0; #else TlsSetValue((DWORD)threadManager->tlsKey, 0); #endif #endif return 0; } else return asCONTEXT_ACTIVE; #else if( threadManager->tld ) { if( threadManager->tld->activeContexts.GetLength() == 0 ) { asDELETE(threadManager->tld,asCThreadLocalData); threadManager->tld = 0; } else return asCONTEXT_ACTIVE; } return 0; #endif } asCThreadLocalData *asCThreadManager::GetLocalData() { if( threadManager == 0 ) return 0; #ifndef AS_NO_THREADS #if defined AS_POSIX_THREADS asCThreadLocalData *tld = (asCThreadLocalData*)pthread_getspecific((pthread_key_t)threadManager->tlsKey); if( tld == 0 ) { tld = asNEW(asCThreadLocalData)(); pthread_setspecific((pthread_key_t)threadManager->tlsKey, tld); } #elif defined AS_WINDOWS_THREADS #if defined(_MSC_VER) && (WINAPI_FAMILY & WINAPI_FAMILY_PHONE_APP) if( tld == 0 ) tld = asNEW(asCThreadLocalData)(); #else asCThreadLocalData *tld = (asCThreadLocalData*)TlsGetValue((DWORD)threadManager->tlsKey); if( tld == 0 ) { tld = asNEW(asCThreadLocalData)(); TlsSetValue((DWORD)threadManager->tlsKey, tld); } #endif #elif defined(AS_STD_THREADS) if(std_tld == nullptr) { std_tld = asNEW(asCThreadLocalData)(); } auto tld = std_tld; #endif return tld; #else if( threadManager->tld == 0 ) threadManager->tld = asNEW(asCThreadLocalData)(); return threadManager->tld; #endif } //========================================================================= asCThreadLocalData::asCThreadLocalData() { } asCThreadLocalData::~asCThreadLocalData() { } //========================================================================= #ifndef AS_NO_THREADS asCThreadCriticalSection::asCThreadCriticalSection() { #if defined AS_POSIX_THREADS pthread_mutex_init(&cs, 0); #elif defined AS_WINDOWS_THREADS #if defined(_MSC_VER) && (WINAPI_FAMILY & WINAPI_FAMILY_PHONE_APP) // Only the Ex version is available on Windows Store InitializeCriticalSectionEx(&cs, 4000, 0); #else // Only the non-Ex version is available on WinXP and older // MinGW also only defines this version InitializeCriticalSection(&cs); #endif #endif } asCThreadCriticalSection::~asCThreadCriticalSection() { #if defined AS_POSIX_THREADS pthread_mutex_destroy(&cs); #elif defined AS_WINDOWS_THREADS DeleteCriticalSection(&cs); #endif } void asCThreadCriticalSection::Enter() { #if defined AS_POSIX_THREADS pthread_mutex_lock(&cs); #elif defined AS_WINDOWS_THREADS EnterCriticalSection(&cs); #elif defined(AS_STD_THREADS) _mutex.lock(); #endif } void asCThreadCriticalSection::Leave() { #if defined AS_POSIX_THREADS pthread_mutex_unlock(&cs); #elif defined AS_WINDOWS_THREADS LeaveCriticalSection(&cs); #elif defined(AS_STD_THREADS) _mutex.unlock(); #endif } bool asCThreadCriticalSection::TryEnter() { #if defined AS_POSIX_THREADS return !pthread_mutex_trylock(&cs); #elif defined AS_WINDOWS_THREADS return TryEnterCriticalSection(&cs) ? true : false; #elif defined(AS_STD_THREADS) return _mutex.try_lock(); #else return true; #endif } asCThreadReadWriteLock::asCThreadReadWriteLock() { #if defined AS_POSIX_THREADS int r = pthread_rwlock_init(&lock, 0); asASSERT( r == 0 ); UNUSED_VAR(r); #elif defined AS_WINDOWS_THREADS #if defined(_MSC_VER) && (WINAPI_FAMILY & WINAPI_FAMILY_PHONE_APP) // Only the Ex versions are available on Windows Store // Create a semaphore to allow up to maxReaders simultaneous readers readLocks = CreateSemaphoreExW(NULL, maxReaders, maxReaders, 0, 0, 0); // Create a critical section to synchronize writers InitializeCriticalSectionEx(&writeLock, 4000, 0); #else readLocks = CreateSemaphoreW(NULL, maxReaders, maxReaders, 0); InitializeCriticalSection(&writeLock); #endif #endif } asCThreadReadWriteLock::~asCThreadReadWriteLock() { #if defined AS_POSIX_THREADS pthread_rwlock_destroy(&lock); #elif defined AS_WINDOWS_THREADS DeleteCriticalSection(&writeLock); CloseHandle(readLocks); #endif } void asCThreadReadWriteLock::AcquireExclusive() { #if defined AS_POSIX_THREADS pthread_rwlock_wrlock(&lock); #elif defined AS_WINDOWS_THREADS // Synchronize writers, so only one tries to lock out the readers EnterCriticalSection(&writeLock); // Lock all reader out from the semaphore. Do this one by one, // so the lock doesn't have to wait until there are no readers at all. // If we try to lock all at once it is quite possible the writer will // never succeed. for( asUINT n = 0; n < maxReaders; n++ ) WaitForSingleObjectEx(readLocks, INFINITE, FALSE); // Allow another writer to lock. It will only be able to // lock the readers when this writer releases them anyway. LeaveCriticalSection(&writeLock); #elif defined(AS_STD_THREADS) _mutex.lock(); #endif } void asCThreadReadWriteLock::ReleaseExclusive() { #if defined AS_POSIX_THREADS pthread_rwlock_unlock(&lock); #elif defined AS_WINDOWS_THREADS // Release all readers at once ReleaseSemaphore(readLocks, maxReaders, 0); #elif defined(AS_STD_THREADS) _mutex.unlock(); #endif } void asCThreadReadWriteLock::AcquireShared() { #if defined AS_POSIX_THREADS pthread_rwlock_rdlock(&lock); #elif defined AS_WINDOWS_THREADS // Lock a reader slot WaitForSingleObjectEx(readLocks, INFINITE, FALSE); #elif defined(AS_STD_THREADS) _mutex.lock_shared(); #endif } void asCThreadReadWriteLock::ReleaseShared() { #if defined AS_POSIX_THREADS pthread_rwlock_unlock(&lock); #elif defined AS_WINDOWS_THREADS // Release the reader slot ReleaseSemaphore(readLocks, 1, 0); #elif defined(AS_STD_THREADS) _mutex.unlock_shared(); #endif } #endif //======================================================================== END_AS_NAMESPACE