Merge pull request #2108 from libgit2/rb/threadsafe-index-iterator

Make index iterator thread safe

1 files changed, 10 insertions, 10 deletions

diff --git a/src/global.c b/src/global.c
index c26b4b311..15baf1eb8 100644
--- a/src/global.c
+++ b/src/global.c
@@ -16,8 +16,9 @@ git_mutex git__mwindow_mutex;
 
 #define MAX_SHUTDOWN_CB 8
 
-git_global_shutdown_fn git__shutdown_callbacks[MAX_SHUTDOWN_CB];
-git_atomic git__n_shutdown_callbacks;
+static git_global_shutdown_fn git__shutdown_callbacks[MAX_SHUTDOWN_CB];
+static git_atomic git__n_shutdown_callbacks;
+static git_atomic git__n_inits;
 
 void git__on_shutdown(git_global_shutdown_fn callback)
 {
@@ -74,7 +75,6 @@ static void git__shutdown(void)
 
 static DWORD _tls_index;
 static DWORD _mutex = 0;
-static DWORD _n_inits = 0;
 
 static int synchronized_threads_init()
 {
@@ -101,7 +101,7 @@ int git_threads_init(void)
 	while (InterlockedCompareExchange(&_mutex, 1, 0)) { Sleep(0); }
 
 	/* Only do work on a 0 -> 1 transition of the refcount */
-	if (1 == ++_n_inits)
+	if (1 == git_atomic_inc(&git__n_inits))
 		error = synchronized_threads_init();
 
 	/* Exit the lock */
@@ -124,7 +124,7 @@ void git_threads_shutdown(void)
 	while (InterlockedCompareExchange(&_mutex, 1, 0)) { Sleep(0); }
 
 	/* Only do work on a 1 -> 0 transition of the refcount */
-	if (0 == --_n_inits)
+	if (0 == git_atomic_dec(&git__n_inits))
 		synchronized_threads_shutdown();
 
 	/* Exit the lock */
@@ -135,7 +135,7 @@ git_global_st *git__global_state(void)
 {
 	void *ptr;
 
-	assert(_n_inits);
+	assert(git_atomic_get(&git__n_inits) > 0);
 
 	if ((ptr = TlsGetValue(_tls_index)) != NULL)
 		return ptr;
@@ -153,7 +153,6 @@ git_global_st *git__global_state(void)
 
 static pthread_key_t _tls_key;
 static pthread_once_t _once_init = PTHREAD_ONCE_INIT;
-static git_atomic git__n_inits;
 int init_error = 0;
 
 static void cb__free_status(void *st)
@@ -204,7 +203,7 @@ git_global_st *git__global_state(void)
 {
 	void *ptr;
 
-	assert(git__n_inits.val);
+	assert(git_atomic_get(&git__n_inits) > 0);
 
 	if ((ptr = pthread_getspecific(_tls_key)) != NULL)
 		return ptr;
@@ -224,14 +223,15 @@ static git_global_st __state;
 
 int git_threads_init(void)
 {
-	/* noop */
+	git_atomic_inc(&git__n_inits);
 	return 0;
 }
 
 void git_threads_shutdown(void)
 {
 	/* Shut down any subsystems that have global state */
-	git__shutdown();
+	if (0 == git_atomic_dec(&git__n_inits))
+		git__shutdown();
 }
 
 git_global_st *git__global_state(void)