Commit e411b74e by Ben Straub

Posix synchronized init, prototype win32 version

parent cfd192b0
......@@ -18,6 +18,7 @@ git_mutex git__mwindow_mutex;
git_global_shutdown_fn git__shutdown_callbacks[MAX_SHUTDOWN_CB];
git_atomic git__n_shutdown_callbacks;
git_atomic git__n_inits;
void git__on_shutdown(git_global_shutdown_fn callback)
{
......@@ -73,47 +74,99 @@ static void git__shutdown(void)
#if defined(GIT_THREADS) && defined(GIT_WIN32)
static DWORD _tls_index;
static int _tls_init = 0;
static HANDLE _init_mutex = NULL;
static HANDLE _initialized_event = NULL;
int git_threads_init(void)
static int synchronized_init_and_claim_mutex(volatile HANDLE *m)
{
if (*m == NULL) {
HANDLE nm = CreateMutex(NULL, FALSE, NULL);
if (InterlockedCompareExchangePointer(m, nm, NULL) != NULL) {
CloseHandle(nm);
}
}
return WaitForSingleObject(*m, INFINITE) == WAIT_FAILED;
}
static int synchronized_threads_init()
{
int error;
if (_tls_init)
return 0;
if (synchronized_init_and_claim_mutex(&_init_mutex) != WAIT_OBJECT_0) {
giterr_set(GITERR_OS, "git_threads_init: WaitForSingleObject failed");
return -1;
}
if (!_initialized_event) {
_initialized_event = CreateEvent(NULL, TRUE, FALSE, NULL);
}
_tls_index = TlsAlloc();
if (git_mutex_init(&git__mwindow_mutex))
return -1;
/* Initialize any other subsystems that have global state */
if ((error = git_hash_global_init()) >= 0 &&
(error = git_futils_dirs_global_init()) >= 0)
_tls_init = 1;
GIT_MEMORY_BARRIER;
if ((error = git_hash_global_init()) >= 0)
error = git_futils_dirs_global_init();
win32_pthread_initialize();
SetEvent(_initialized_event);
ReleaseMutex(_init_mutex);
return error;
}
int git_threads_init(void)
{
int error = -1,
n_inits = git_atomic_inc(&git__n_inits);
if (n_inits == 1)
error = synchronized_threads_init();
else {
while (!_initialized_event); /* SPIN */
error = (WaitForSingleObject(_initialized_event, INFINITE) == WAIT_OBJECT_0) ? 0 : -1;
}
GIT_MEMORY_BARRIER;
return error;
}
void git_threads_shutdown(void)
static void synchronized_threads_shutdown()
{
if (WaitForSingleObject(_init_mutex, INFINITE) != WAIT_OBJECT_0) {
giterr_set(GITERR_OS, "git_threads_shutdown: WaitForSingleObject failed");
return;
}
if (git__n_inits.val != 0) {
/* Someone else initialized while we were waiting */
ReleaseMutex(_init_mutex);
return;
}
ResetEvent(_initialized_event);
/* Shut down any subsystems that have global state */
git__shutdown();
TlsFree(_tls_index);
_tls_init = 0;
git_mutex_free(&git__mwindow_mutex);
ReleaseMutex(_init_mutex);
}
void git_threads_shutdown(void)
{
int n_inits = git_atomic_dec(&git__n_inits);
if (n_inits == 0)
synchronized_threads_shutdown();
GIT_MEMORY_BARRIER;
}
git_global_st *git__global_state(void)
{
void *ptr;
assert(_tls_init);
assert(git__n_inits.val);
if ((ptr = TlsGetValue(_tls_index)) != NULL)
return ptr;
......@@ -130,55 +183,57 @@ git_global_st *git__global_state(void)
#elif defined(GIT_THREADS) && defined(_POSIX_THREADS)
static pthread_key_t _tls_key;
static int _tls_init = 0;
static pthread_once_t _once_init = PTHREAD_ONCE_INIT;
int init_error = 0;
static void cb__free_status(void *st)
{
git__free(st);
}
int git_threads_init(void)
static void init_once(void)
{
int error = 0;
if (_tls_init)
return 0;
if (git_mutex_init(&git__mwindow_mutex))
return -1;
if ((init_error = git_mutex_init(&git__mwindow_mutex)) != 0)
return;
pthread_key_create(&_tls_key, &cb__free_status);
/* Initialize any other subsystems that have global state */
if ((error = git_hash_global_init()) >= 0 &&
(error = git_futils_dirs_global_init()) >= 0)
_tls_init = 1;
if ((init_error = git_hash_global_init()) >= 0)
init_error = git_futils_dirs_global_init();
GIT_MEMORY_BARRIER;
}
return error;
int git_threads_init(void)
{
pthread_once(&_once_init, init_once);
git_atomic_inc(&git__n_inits);
return init_error;
}
void git_threads_shutdown(void)
{
pthread_once_t new_once = PTHREAD_ONCE_INIT;
if (git_atomic_dec(&git__n_inits) > 0) return;
/* Shut down any subsystems that have global state */
git__shutdown();
if (_tls_init) {
void *ptr = pthread_getspecific(_tls_key);
pthread_setspecific(_tls_key, NULL);
git__free(ptr);
}
void *ptr = pthread_getspecific(_tls_key);
pthread_setspecific(_tls_key, NULL);
git__free(ptr);
pthread_key_delete(_tls_key);
_tls_init = 0;
git_mutex_free(&git__mwindow_mutex);
_once_init = new_once;
}
git_global_st *git__global_state(void)
{
void *ptr;
assert(_tls_init);
assert(git__n_inits.val);
if ((ptr = pthread_getspecific(_tls_key)) != NULL)
return ptr;
......
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