/* Routine to get the thread-specific error variable */
SDL_error *
SDL_GetErrBuf(void)
{
static SDL_SpinLock tls_lock;
static SDL_bool tls_being_created;
static SDL_TLSID tls_errbuf;
static SDL_error SDL_global_errbuf;
const SDL_error *ALLOCATION_IN_PROGRESS = (SDL_error *)-1;
SDL_error *errbuf;
/* tls_being_created is there simply to prevent recursion if SDL_TLSCreate() fails.
It also means it's possible for another thread to also use SDL_global_errbuf,
but that's very unlikely and hopefully won't cause issues.
*/
if (!tls_errbuf && !tls_being_created) {
SDL_AtomicLock(&tls_lock);
if (!tls_errbuf) {
SDL_TLSID slot;
tls_being_created = SDL_TRUE;
slot = SDL_TLSCreate();
tls_being_created = SDL_FALSE;
SDL_MemoryBarrierRelease();
tls_errbuf = slot;
}
SDL_AtomicUnlock(&tls_lock);
}
if (!tls_errbuf) {
return &SDL_global_errbuf;
}
SDL_MemoryBarrierAcquire();
errbuf = (SDL_error *)SDL_TLSGet(tls_errbuf);
if (errbuf == ALLOCATION_IN_PROGRESS) {
return &SDL_global_errbuf;
}
if (!errbuf) {
/* Mark that we're in the middle of allocating our buffer */
SDL_TLSSet(tls_errbuf, ALLOCATION_IN_PROGRESS, NULL);
errbuf = (SDL_error *)SDL_malloc(sizeof(*errbuf));
if (!errbuf) {
SDL_TLSSet(tls_errbuf, NULL, NULL);
return &SDL_global_errbuf;
}
SDL_zerop(errbuf);
SDL_TLSSet(tls_errbuf, errbuf, SDL_free);
}
return errbuf;
}
SDL_TLSData *
SDL_Generic_GetTLSData()
{
SDL_threadID thread = SDL_ThreadID();
SDL_TLSEntry *entry;
SDL_TLSData *storage = NULL;
#if !SDL_THREADS_DISABLED
if (!SDL_generic_TLS_mutex) {
static SDL_SpinLock tls_lock;
SDL_AtomicLock(&tls_lock);
if (!SDL_generic_TLS_mutex) {
SDL_mutex *mutex = SDL_CreateMutex();
SDL_MemoryBarrierRelease();
SDL_generic_TLS_mutex = mutex;
if (!SDL_generic_TLS_mutex) {
SDL_AtomicUnlock(&tls_lock);
return NULL;
}
}
SDL_AtomicUnlock(&tls_lock);
}
#endif /* SDL_THREADS_DISABLED */
SDL_MemoryBarrierAcquire();
SDL_LockMutex(SDL_generic_TLS_mutex);
for (entry = SDL_generic_TLS; entry; entry = entry->next) {
if (entry->thread == thread) {
storage = entry->storage;
break;
}
}
#if !SDL_THREADS_DISABLED
SDL_UnlockMutex(SDL_generic_TLS_mutex);
#endif
return storage;
}
SDL_TLSData *
SDL_SYS_GetTLSData()
{
if (thread_local_storage == TLS_OUT_OF_INDEXES && !generic_local_storage) {
static SDL_SpinLock lock;
SDL_AtomicLock(&lock);
if (thread_local_storage == TLS_OUT_OF_INDEXES && !generic_local_storage) {
DWORD storage = TlsAlloc();
if (storage != TLS_OUT_OF_INDEXES) {
SDL_MemoryBarrierRelease();
thread_local_storage = storage;
} else {
generic_local_storage = SDL_TRUE;
}
}
SDL_AtomicUnlock(&lock);
}
if (generic_local_storage) {
return SDL_Generic_GetTLSData();
}
SDL_MemoryBarrierAcquire();
return (SDL_TLSData *)TlsGetValue(thread_local_storage);
}
SDL_TLSData *
SDL_SYS_GetTLSData()
{
if (thread_local_storage == INVALID_PTHREAD_KEY && !generic_local_storage) {
static SDL_SpinLock lock;
SDL_AtomicLock(&lock);
if (thread_local_storage == INVALID_PTHREAD_KEY && !generic_local_storage) {
pthread_key_t storage;
if (pthread_key_create(&storage, NULL) == 0) {
SDL_MemoryBarrierRelease();
thread_local_storage = storage;
} else {
generic_local_storage = SDL_TRUE;
}
}
SDL_AtomicUnlock(&lock);
}
if (generic_local_storage) {
return SDL_Generic_GetTLSData();
}
SDL_MemoryBarrierAcquire();
return (SDL_TLSData *)pthread_getspecific(thread_local_storage);
}
