Added support for @synchronize. Still testing this change.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/libobjc/trunk@26826 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,9 @@
+2008-08-31 11:13-EDT Gregory John Casamento <greg_casamento@yahoo.com>
+
+	* GNUmakefile
+	* synchronization.m: Added objc_sync_exit and objc_sync_enter.  Support for
+	@synchronize.
+
 2007-04-21  Andrew Ruder  <andy@aeruder.net>
 
 	* sendmsg.c (__objc_get_forward_imp): Call

GNUmakefile

@@ -85,6 +85,7 @@ libobjc_HEADER_FILES = \
 libobjc_OBJC_FILES = \
 	Object.m	\
 	Protocol.m	\
+	synchronization.m \
 	linking.m
 
 ifeq ($(GNUSTEP_TARGET_OS), cygwin)

synchronization.m

@@ -0,0 +1,243 @@
+/* 
+   The implementation of synchronization primitives for Objective-C.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   Gregory Casamento <greg.casamento@gmail.com>
+   
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by the
+   Free Software Foundation; either version 2, or (at your option) any
+   later version.
+   
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING.  If not, write to
+   the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  
+*/
+
+/* 
+   As a special exception, if you link this library with files compiled
+   with GCC to produce an executable, this does not cause the resulting
+   executable to be covered by the GNU General Public License.  This
+   exception does not however invalidate any other reasons why the
+   executable file might be covered by the GNU General Public License. 
+*/
+
+#include <stdlib.h>
+#include "objc/objc.h"
+#include "objc/objc-api.h"
+#include "objc/thr.h"
+
+/*
+ * Node structure...
+ */
+typedef struct lock_node {
+  id obj;
+  objc_mutex_t lock;
+  struct lock_node *next;
+  struct lock_node *prev;
+} lock_node_t;
+
+/*
+ * Return types for the locks...
+ */
+typedef enum { 
+  OBJC_SYNC_SUCCESS = 0,
+  OBJC_SYNC_NOT_OWNING_THREAD_ERROR = -1,
+  OBJC_SYNC_TIMED_OUT = -2,
+  OBJC_SYNC_NOT_INITIALIZED = -3		
+} sync_return_t;
+
+static lock_node_t *lock_list = NULL;
+static objc_mutex_t table_lock = NULL; 
+
+/**
+ * Initialize the table lock.
+ */
+static void sync_lock_init()
+{
+ if(table_lock == NULL)
+    {
+      table_lock = objc_mutex_allocate();
+    }
+}
+
+/**
+ * Find the node in the list.
+ */
+lock_node_t* objc_sync_find_node(id obj)
+{
+  lock_node_t *current = NULL;
+
+  if(lock_list != NULL)
+    {
+      // iterate over the list looking for the end...
+      while(current != NULL)
+	{
+	  // if the current object is the one, breal and
+	  // return that node.
+	  if(current->obj == obj)
+	    {
+	      break;
+	    }
+
+	  // get the next one...
+	  current = current->next;
+	}
+    }
+  return current;
+}
+
+/**
+ * Add a node for the object, if one doesn't already exist.
+ */
+lock_node_t* objc_sync_add_node(id obj)
+{
+  lock_node_t *current = NULL;
+
+  // get the lock...
+  sync_lock_init();
+  
+  // restrict access to the table....
+  objc_mutex_lock(table_lock);
+
+  // if the list hasn't been initialized, initialize it.
+  if(lock_list == NULL)
+    {
+      // instantiate the new node and set the list...
+      lock_list = malloc(sizeof(lock_node_t));
+
+      // set the current node to the last in the list...
+      current = lock_list;
+
+      // set next and prev...
+      current->prev = NULL;
+      current->next = NULL;
+    }
+  else 
+    {
+      lock_node_t *new_node = NULL;
+      current = lock_list;
+
+      // look for the end of the list.
+      while(current->next)
+	{
+	  current = current->next;
+	}
+
+      // instantiate the new node...
+      new_node = malloc(sizeof(lock_node_t));
+
+      if(new_node != NULL)
+	{
+	  // set next and prev...
+	  current->next = new_node;
+	  new_node->prev = current;
+	  new_node->next = NULL;
+	  
+	  // set the current node to the last in the list...
+	  current = new_node;
+	}
+    }
+
+  if(current != NULL)
+    {
+      // add the object and it's lock
+      current->obj = obj;
+      current->lock = objc_mutex_allocate();
+    }
+
+  // release access to the table...
+  objc_mutex_unlock(table_lock);
+
+  return current;
+}
+
+/**
+ * Remove the node for the object if one does exist.
+ */
+lock_node_t* objc_sync_remove_node(id obj)
+{
+  lock_node_t *curr = NULL;
+
+  // find the node...
+  curr = objc_sync_find_node(obj);
+
+  // if the node is not null, proceed...
+  if(curr != NULL)
+    {
+      // skip the current node in 
+      // the list and remove it from the
+      // prev and next nodes.
+      lock_node_t *prev = NULL;
+      lock_node_t *next = NULL;
+
+      prev = curr->prev;
+      next = curr->next;
+
+      next->prev = prev;
+      prev->next = next;
+    }
+  
+  // return the removed node...
+  return curr;
+}
+
+/**
+ * Add a lock for the object.
+ */ 
+int objc_sync_enter(id obj)
+{
+  lock_node_t *node = NULL;
+  int status = 0;
+
+  node = objc_sync_find_node(obj);
+  if(node == NULL)
+    {
+      node = objc_sync_add_node(obj);
+      if(node == NULL)
+	{
+	  return OBJC_SYNC_NOT_INITIALIZED;
+	}
+    }
+
+  status = objc_mutex_lock(node->lock);
+  if(status < 1)
+    {
+      return OBJC_SYNC_NOT_OWNING_THREAD_ERROR;
+    }
+
+  return OBJC_SYNC_SUCCESS;
+}
+
+/**
+ * Remove a lock for the object.
+ */
+int objc_sync_exit(id obj)
+{
+  lock_node_t *node = NULL;
+  int status = 0;
+
+  node = objc_sync_remove_node(obj);
+  if(node == NULL)
+    {
+      return OBJC_SYNC_NOT_INITIALIZED;
+    }
+
+  status = objc_mutex_unlock(node->lock);
+  if(status < 1)
+    {
+      return OBJC_SYNC_NOT_OWNING_THREAD_ERROR;      
+    }
+ 
+  // dealloc the node and return success.
+  free(node);
+  return OBJC_SYNC_SUCCESS;  
+}