Imported ObjectiveC2 framework.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@29625 72102866-910b-0410-8b05-ffd578937521

Source/ObjectiveC2/sync.m

@@ -0,0 +1,107 @@
+#include "runtime.h"
+
+/* Ensure Unix98 compatible pthreads for glibc */
+#if defined __GLIBC__
+	#define __USE_UNIX98 1
+#endif
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+@interface Fake
++ (void)dealloc;
+@end
+
+static pthread_mutex_t at_sync_init_lock = PTHREAD_MUTEX_INITIALIZER;
+static unsigned long long lockClassId;
+
+IMP objc_msg_lookup(id, SEL);
+
+static void deallocLockClass(id obj, SEL _cmd);
+
+static inline Class findLockClass(id obj)
+{
+	struct objc_object object = { obj->isa };
+	SEL dealloc = @selector(dealloc);
+	// Find the first class where this lookup is correct
+	if (objc_msg_lookup((id)&object, dealloc) != (IMP)deallocLockClass)
+	{
+		do {
+			object.isa = class_getSuperclass(object.isa);
+		} while (Nil != object.isa && 
+				objc_msg_lookup((id)&object, dealloc) != (IMP)deallocLockClass);
+	}
+	if (Nil == object.isa) { return Nil; }
+	// object->isa is now either the lock class, or a class which inherits from
+	// the lock class
+	Class lastClass;
+	do {
+		lastClass = object.isa;
+		object.isa = class_getSuperclass(object.isa);
+	} while (Nil != object.isa &&
+		   objc_msg_lookup((id)&object, dealloc) == (IMP)deallocLockClass);
+	return lastClass;
+}
+
+static inline Class initLockObject(id obj)
+{
+	char nameBuffer[40];
+	snprintf(nameBuffer, 39, "hiddenlockClass%lld", lockClassId++);
+	Class lockClass = objc_allocateClassPair(obj->isa, nameBuffer,
+			sizeof(pthread_mutex_t));
+	const char *types =
+		method_getTypeEncoding(class_getInstanceMethod(obj->isa,
+					@selector(dealloc)));
+	class_addMethod(lockClass, @selector(dealloc), (IMP)deallocLockClass,
+			types);
+	objc_registerClassPair(lockClass);
+
+	pthread_mutex_t *lock = object_getIndexedIvars(lockClass);
+	pthread_mutexattr_t attr;
+	pthread_mutexattr_init(&attr);
+	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+	pthread_mutex_init(lock, &attr);
+	pthread_mutexattr_destroy(&attr);
+
+	obj->isa = lockClass;
+	return lockClass;
+}
+
+static void deallocLockClass(id obj, SEL _cmd)
+{
+	Class lockClass = findLockClass(obj);
+	Class realClass = class_getSuperclass(lockClass);
+	// Free the lock
+	pthread_mutex_t *lock = object_getIndexedIvars(lockClass);
+	pthread_mutex_destroy(lock);
+	// Free the class
+	objc_disposeClassPair(lockClass);
+	// Reset the class then call the real -dealloc
+	obj->isa = realClass;
+	[obj dealloc];
+}
+
+void objc_sync_enter(id obj)
+{
+	Class lockClass = findLockClass(obj);
+	if (Nil == lockClass)
+	{
+		pthread_mutex_lock(&at_sync_init_lock);
+		// Test again in case two threads call objc_sync_enter at once
+		lockClass = findLockClass(obj);
+		if (Nil == lockClass)
+		{
+			lockClass = initLockObject(obj);
+		}
+		pthread_mutex_unlock(&at_sync_init_lock);
+	}
+	pthread_mutex_t *lock = object_getIndexedIvars(lockClass);
+	pthread_mutex_lock(lock);
+}
+void objc_sync_exit(id obj)
+{
+	Class lockClass = findLockClass(obj);
+	pthread_mutex_t *lock = object_getIndexedIvars(lockClass);
+	pthread_mutex_unlock(lock);
+}