Add pthread_once() equivalent support.

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1357 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/pulsecore/thread-posix.c

@@ -30,6 +30,7 @@
 #include <atomic_ops.h>
 
 #include <pulse/xmalloc.h>
+#include <pulsecore/mutex.h>
 
 #include "thread.h"
 
@@ -52,6 +53,9 @@ struct pa_tls {
 static pa_tls *thread_tls;
 static pthread_once_t thread_tls_once = PTHREAD_ONCE_INIT;
 
+static pa_mutex *once_mutex;
+static pthread_once_t thread_once_once = PTHREAD_ONCE_INIT;
+
 static void thread_tls_once_func(void) {
     thread_tls = pa_tls_new(NULL);
     assert(thread_tls);
@@ -125,6 +129,27 @@ void pa_thread_yield(void) {
 #endif
 }
 
+static void thread_once_once_func(void) {
+    once_mutex = pa_mutex_new();
+    assert(once_mutex);
+}
+
+void pa_thread_once(pa_thread_once_t *control, pa_thread_once_func_t once_func) {
+    assert(control);
+    assert(once_func);
+
+    ASSERT_SUCCESS(pthread_once(&thread_once_once, thread_once_once_func));
+
+    pa_mutex_lock(once_mutex);
+
+    if (*control == PA_THREAD_ONCE_INIT) {
+        *control = ~PA_THREAD_ONCE_INIT;
+        pa_mutex_unlock(once_mutex);
+        once_func();
+    } else
+        pa_mutex_unlock(once_mutex);
+}
+
 pa_tls* pa_tls_new(pa_free_cb_t free_cb) {
     pa_tls *t;
 

src/pulsecore/thread-win32.c

@@ -49,35 +49,21 @@ struct pa_tls_monitor {
     void *data;
 };
 
-static pa_tls *thread_tls = NULL;
+static pa_tls *thread_tls;
-static pa_tls *monitor_tls = NULL;
+static pa_thread_once_t thread_tls_once = PA_THREAD_ONCE_INIT;
+static pa_tls *monitor_tls;
+static pa_thread_once_t monitor_tls_once = PA_THREAD_ONCE_INIT;
 
 static void thread_tls_once_func(void) {
-    HANDLE mutex;
-    char name[64];
-
-    sprintf(name, "pulse%d", (int)GetCurrentProcessId());
-
-    mutex = CreateMutex(NULL, FALSE, name);
-    assert(mutex);
-
-    WaitForSingleObject(mutex, INFINITE);
-
-    if (thread_tls == NULL) {
     thread_tls = pa_tls_new(NULL);
     assert(thread_tls);
-    }
-
-    ReleaseMutex(mutex);
-
-    CloseHandle(mutex);
 }
 
 static DWORD WINAPI internal_thread_func(LPVOID param) {
     pa_thread *t = param;
     assert(t);
 
-    thread_tls_once_func();
+    pa_thread_once(&thread_tls_once, thread_tls_once_func);
     pa_tls_set(thread_tls, t);
 
     t->thread_func(t->userdata);
@@ -133,7 +119,7 @@ int pa_thread_join(pa_thread *t) {
 }
 
 pa_thread* pa_thread_self(void) {
-    thread_tls_once_func();
+    pa_thread_once(&thread_tls_once, thread_tls_once_func);
     return pa_tls_get(thread_tls);
 }
 
@@ -141,10 +127,13 @@ void pa_thread_yield(void) {
     Sleep(0);
 }
 
-static void monitor_tls_once_func(void) {
+void pa_thread_once(pa_thread_once_t *control, pa_thread_once_func_t once_func) {
     HANDLE mutex;
     char name[64];
 
+    assert(control);
+    assert(once_func);
+
     sprintf(name, "pulse%d", (int)GetCurrentProcessId());
 
     mutex = CreateMutex(NULL, FALSE, name);
@@ -152,17 +141,22 @@ static void monitor_tls_once_func(void) {
 
     WaitForSingleObject(mutex, INFINITE);
 
-    if (monitor_tls == NULL) {
+    if (*control == PA_THREAD_ONCE_INIT) {
-        monitor_tls = pa_tls_new(NULL);
+        *control = ~PA_THREAD_ONCE_INIT;
-        assert(monitor_tls);
+        ReleaseMutex(mutex);
-        pa_tls_set(monitor_tls, NULL);
+        once_func();
-    }
+    } else
-
         ReleaseMutex(mutex);
 
     CloseHandle(mutex);
 }
 
+static void monitor_tls_once_func(void) {
+    monitor_tls = pa_tls_new(NULL);
+    assert(monitor_tls);
+    pa_tls_set(monitor_tls, NULL);
+}
+
 static DWORD WINAPI monitor_thread_func(LPVOID param) {
     struct pa_tls_monitor *m = param;
     assert(m);
@@ -218,7 +212,7 @@ void *pa_tls_set(pa_tls *t, void *userdata) {
     if (t->free_func) {
         struct pa_tls_monitor *m;
 
-        monitor_tls_once_func();
+        pa_thread_once(&monitor_tls_once, monitor_tls_once_func);
 
         m = pa_tls_get(monitor_tls);
         if (!m) {

src/pulsecore/thread.h

@@ -24,9 +24,13 @@
 
 #include <pulse/def.h>
 
+#define PA_THREAD_ONCE_INIT 0
+
 typedef struct pa_thread pa_thread;
 
 typedef void (*pa_thread_func_t) (void *userdata);
+typedef void (*pa_thread_once_func_t) (void);
+typedef unsigned int pa_thread_once_t;
 
 pa_thread* pa_thread_new(pa_thread_func_t thread_func, void *userdata);
 void pa_thread_free(pa_thread *t);
@@ -34,6 +38,7 @@ int pa_thread_join(pa_thread *t);
 int pa_thread_is_running(pa_thread *t);
 pa_thread *pa_thread_self(void);
 void pa_thread_yield(void);
+void pa_thread_once(pa_thread_once_t *control, pa_thread_once_func_t once_func);
 
 typedef struct pa_tls pa_tls;