* Headers/Additions/GNUstepBase/GSObjCRuntime.h/m

(GSAllocateMutexAt): New function.
        (_GSObjCRuntimeInitializer): Define local support class.

        * Headers/Additions/GNUstepBase/objc-gnu2next.h: Fixed minor
        whitespace issues.
        (objc_mutex_t, objc_mutex_allocate, objc_mutex_deallocate)
        (objc_mutex_lock, objc_mutex_unlock, objc_mutex_trylock):
        Declare
        for the NeXT runtime.
        * Source/Additions/GSNextRuntime.m
        (objc_mutex_allocate, objc_mutex_deallocate)
        (objc_mutex_lock, objc_mutex_unlock, objc_mutex_trylock):
        Implement for NeXT runtime.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@19249 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,19 @@
+2004-05-06  David Ayers  <d.ayers@inode.at>
+
+	* Headers/Additions/GNUstepBase/GSObjCRuntime.h/m
+	(GSAllocateMutexAt): New function.
+	(_GSObjCRuntimeInitializer): Define local support class.
+
+	* Headers/Additions/GNUstepBase/objc-gnu2next.h: Fixed minor
+	whitespace issues.
+	(objc_mutex_t, objc_mutex_allocate, objc_mutex_deallocate)
+	(objc_mutex_lock, objc_mutex_unlock, objc_mutex_trylock): Declare
+	for the NeXT runtime.
+	* Source/Additions/GSNextRuntime.m 
+	(objc_mutex_allocate, objc_mutex_deallocate)
+	(objc_mutex_lock, objc_mutex_unlock, objc_mutex_trylock):
+	Implement for NeXT runtime.
+	
 2004-05-06 Mateu Batle
 
 	* Tools/gdomap.c: mingw fixes.

Headers/Additions/GNUstepBase/GSObjCRuntime.h

@@ -468,6 +468,31 @@ GSObjCZone(NSObject *obj);
 GS_EXPORT void *
 GSAutoreleasedBuffer(unsigned size);
 
+/**
+ * Allocate a new objc_mutex_t and store it in the location
+ * pointed to by request.  A mutex is only created if the value
+ * pointed to by request is NULL.  This function is thread safe
+ * in the sense that multiple threads my call this function with the same
+ * value of request and only one will actually set the mutex.
+ * It is the users responsibility that no one else attempts to set
+ * the mutex pointed to.  This function should be
+ * used with objc_mutex_t variables which were statically initialized
+ * to NULL like:
+ * <example>
+ * void function (void)
+ * {
+ *   static objc_mutex_t my_lock = NULL;
+ *   if (my_lock == NULL)
+ *     GSAllocateMutexAt(&my_lock);
+ *   objc_mutex_lock(my_lock);
+ *   do_work ();
+ *   objc_mutex_unlock(my_lock);
+ * }
+ * </example>
+ */
+GS_EXPORT void
+GSAllocateMutexAt(objc_mutex_t *request);
+
 /** Returns a system error message on a variety of systems
  */
 GS_EXPORT const char *

Headers/Additions/GNUstepBase/objc-gnu2next.h

@@ -36,8 +36,8 @@
 #include <ctype.h>
 #include <stdio.h>
 
-/* Disable builtin functions for gcc < 3.x since it triggers a bad bug (even some 3.x versions may have this
-   bug) */
+/* Disable builtin functions for gcc < 3.x since it triggers a bad bug 
+   (even some 3.x versions may have this bug).  */
 #if __GNUC__ < 3
 #define __builtin_apply(a,b,c) 0
 #define __builtin_apply_args() 0
@@ -192,6 +192,16 @@ extern void *(*_objc_realloc)(void *, size_t);
 extern void *(*_objc_calloc)(size_t, size_t);
 extern void (*_objc_free)(void *);
 
+
+/* threading functions */
+typedef void *objc_mutex_t;
+
+objc_mutex_t objc_mutex_allocate (void);
+int objc_mutex_deallocate (objc_mutex_t mutex);
+int objc_mutex_lock (objc_mutex_t mutex);
+int objc_mutex_unlock (objc_mutex_t mutex);
+int objc_mutex_trylock (objc_mutex_t mutex);
+
 /* encoding functions */
 extern int objc_sizeof_type(const char* type);
 extern int objc_alignof_type(const char* type);

Source/Additions/GSNextRuntime.m

@@ -593,3 +593,59 @@ objc_set_error_handler(objc_error_handler func)
   return temp;
 }
 
+/*
+ * Functions for threading support.
+ */
+
+/* This currently assumes that the NeXT Runtime is using pthreads
+   as the underlying thread support.  This is true for 'modern' NeXT
+   Runtime implementations but it may not be for older versions.  */
+
+#include <pthread.h>
+
+objc_mutex_t
+objc_mutex_allocate(void)
+{
+  pthread_mutex_t *p;
+  p = (pthread_mutex_t *)calloc(1, sizeof(pthread_mutex_t));
+  if (pthread_mutex_init(p, NULL) != 0)
+    {
+      abort();
+    }
+  return (objc_mutex_t)p;
+}
+
+int
+objc_mutex_deallocate(objc_mutex_t mutex)
+{
+  int ret;
+  pthread_mutex_t *p = (pthread_mutex_t *)mutex;
+  ret = pthread_mutex_destroy(p);
+  if (ret == 0)
+    {
+      free(p);
+    }
+  return ret;
+}
+
+int
+objc_mutex_lock(objc_mutex_t mutex)
+{
+  pthread_mutex_t *p = (pthread_mutex_t *)mutex;
+  return pthread_mutex_lock(p);  
+}
+
+int
+objc_mutex_unlock (objc_mutex_t mutex)
+{
+  pthread_mutex_t *p = (pthread_mutex_t *)mutex;
+  return pthread_mutex_unlock(p);  
+}
+
+int
+objc_mutex_trylock (objc_mutex_t mutex)
+{
+  pthread_mutex_t *p = (pthread_mutex_t *)mutex;
+  return pthread_mutex_trylock(p);  
+}
+

Source/Additions/GSObjCRuntime.m

@@ -59,6 +59,59 @@
 @end
 #endif
 
+static objc_mutex_t local_lock = NULL;
+
+/* This class it intended soley for thread safe / +load safe
+   initialization of the local lock.
+   It's a root class so it won't trigger the initialization
+   of any other class.  */
+@interface _GSObjCRuntimeInitializer /* Root Class */
+{
+  Class isa;
+}
++ (Class)class;
+@end
+@implementation _GSObjCRuntimeInitializer
++ (void)initialize
+{
+  if (local_lock == NULL)
+    {
+      local_lock = objc_mutex_allocate();
+    }
+}
++ (Class)class
+{
+  return self;
+}
+@end
+
+void
+GSAllocateMutexAt(objc_mutex_t *request)
+{
+  if (request == NULL)
+    {
+      /* This could be called very early in process 
+	 initialization so many things may not have 
+	 been setup correctly yet.  */
+      fprintf(stderr, 
+	      "Error: GSAllocateMutexAt() called with NULL pointer.\n");
+      abort();
+    }
+
+  if (local_lock == NULL)
+    {
+      /* Initialize in a thread safe way.  */
+      [_GSObjCRuntimeInitializer class];
+    }
+
+  objc_mutex_lock(local_lock);
+  if (*request == NULL)
+    {
+      *request = objc_mutex_allocate();
+    }
+  objc_mutex_unlock(local_lock);
+}
+
 /**  Deprecated ... use GSObjCFindVariable() */
 BOOL
 GSFindInstanceVariable(id obj, const char *name,