make sure that backend initialization is done only once

ChangeLog

@@ -1,8 +1,14 @@
+2006-12-20  Aleksey Demakov  <ademakov@gmail.com>
+
+	* jit/jit-thread.h, jit/jit-thread.c: add _jit_global_lock mutex.
+	* jit/jit-init.c (jit_init): make sure that initialization is done
+	  only once.
+
 2006-12-17  Klaus Treichel  <ktreichel@web.de>
 
 	* include/jit/jit-function.h, jit/jit-function.c: Add the function
-	jit_function_from_vtable_pointer to convert a vtable pointer back to the
-	jit_function_t.
+	jit_function_from_vtable_pointer to convert a vtable pointer back to
+	the jit_function_t.
 
 2006-11-29  Aleksey Demakov  <ademakov@gmail.com>
 

jit/jit-init.c

@@ -37,9 +37,20 @@
 @*/
 void jit_init(void)
 {
+	static int init_done = 0;
+
 	/* Make sure that the thread subsystem is initialized */
 	_jit_thread_init();
 
+	/* Make sure that the initialization is done only once
+	   (requires the global lock initialized above) */
+	jit_mutex_lock(&_jit_global_lock);
+	if(init_done)
+	{
+		goto done;
+	}
+	init_done = 1;
+
 #ifdef JIT_USE_SIGNALS
 	/* Initialize the signal handlers */
 	_jit_signal_init();
@@ -47,6 +58,9 @@ void jit_init(void)
 
 	/* Initialize the backend */
 	_jit_init_backend();
+
+done:
+	jit_mutex_unlock(&_jit_global_lock);
 }
 
 /*@

jit/jit-thread.c

@@ -34,6 +34,11 @@
 #endif
 #include <errno.h>
 
+/*
+ * Mutex that synchronizes global data initialization.
+ */
+jit_mutex_t _jit_global_lock;
+
 #if defined(JIT_THREADS_PTHREAD)
 
 /*
@@ -46,6 +51,8 @@ static pthread_key_t control_key;
  */
 static void init_pthread(void)
 {
+	jit_mutex_create(&_jit_global_lock);
+
 	/* Allocate a thread-specific variable for the JIT's thread
 	   control object, and arrange for it to be freed when the
 	   thread exits or is otherwise terminated */
@@ -64,6 +71,8 @@ static DWORD control_key;
  */
 static void init_win32_thread(void)
 {
+	jit_mutex_create(&_jit_global_lock);
+
 	control_key = TlsAlloc();
 }
 

jit/jit-thread.h

@@ -115,6 +115,11 @@ typedef int jit_mutex_t;
 
 #endif
 
+/*
+ * Mutex that synchronizes global data initialization.
+ */
+extern jit_mutex_t _jit_global_lock;
+
 /*
  * Define the primitive monitor operations.
  */