Make gst_proxy thread safe

Author: mathk

configure.ac

@@ -27,7 +27,7 @@ GST_HAVE_GMP
 
 _AM_DEPENDENCIES(OBJC)
 AC_CANONICAL_HOST
-LDFLAGS=-module
+LDFLAGS="-module -lpthread -no-undefined"
 case $host in
      *-*-darwin*) OBJCLIBS='-framework Cocoa' ;;
      *)		  AC_CHECK_TOOL(GNUSTEP_CONFIG, [gnustep-config], 
@@ -43,8 +43,7 @@ case $host in
 		 *i386*) AC_DEFINE([__i386__]) ;;
 		 *x86_64*) AC_DEFINE([__x86_64__]) ;;
 esac
-		 
-LDFLAGS+=" -no-undefined"
+
 AC_SUBST(OBJC, [$CC])
 AC_SUBST(OBJCFLAGS, [$CFLAGS])
 AC_SUBST(GNUSTEP_CFLAGS)

gst-objc-ext.h

@@ -15,6 +15,9 @@ typedef struct gst_objc_object
 }
  *gst_objc_object;
 
+/* Initialize threading object */
+void gst_initThreading ();
+
 /* Initialize ffi type */
 void gst_initFFIType ();
 

gst-objc-ext.m

@@ -1,7 +1,8 @@
 #include <ffi.h>
 #import "gst-objc-ext.h"
 
-//extern VMProxy* gst_proxy;
+pthread_mutex_t gstProxyMutex;
+
 ffi_type *ffi_type_cgfloat;
 ffi_type ffi_type_nspoint;
 ffi_type ffi_type_nsrect;
@@ -20,6 +21,11 @@
 }
   objc_ffi_closure;
 
+void gst_initThreading ()
+{
+  pthread_mutex_init (&gstProxyMutex, NULL);
+} 
+
 void gst_initFFIType ()
 {
   ffi_type_cgfloat = (sizeof(CGFloat) == sizeof(double)) ? &ffi_type_double : &ffi_type_float;
@@ -524,7 +530,9 @@ void gst_initFFIType ()
       gst_boxValue (args[i+2], argsOOP+i, [sig getArgumentTypeAtIndex: i+2]);
     }
   argsOOP[i] = NULL;
+  GST_LOCK_PROXY;
   resultOOP = gst_proxy->vmsgSend (receiver, selector, argsOOP);
+  GST_UNLOCK_PROXY;
   gst_unboxValue (resultOOP, result, [sig methodReturnType]);
 
 }

gst-objc.h

@@ -1,9 +1,17 @@
 #include <gstpub.h>
+#include <pthread.h>
 #import "gst-objc-ext.h"
 #import <Foundation/Foundation.h>
 //#import "LKInterpreterRuntime.h"
 #ifndef GNU_RUNTIME
 #include <objc/objc-runtime.h>
 #endif
 
+/* Smallltalk proxy */
 extern VMProxy* gst_proxy;
+
+/* Mutex to prevent gst_proxy race access */
+extern pthread_mutex_t gstProxyMutex;
+
+#define GST_LOCK_PROXY (pthread_mutex_lock (&gstProxyMutex))
+#define GST_UNLOCK_PROXY (pthread_mutex_unlock (&gstProxyMutex))

gst-objc.m

@@ -17,8 +17,9 @@
 #endif  // __APPLE__
 
   gst_initFFIType ();
+  gst_initThreading ();
   proxy->defineCFunc ("objc_sendMsg", gst_sendMessage);
-   proxy->defineCFunc ("objc_sizeofCGFloat", gst_sizeofCGFloat);
+  proxy->defineCFunc ("objc_sizeofCGFloat", gst_sizeofCGFloat);
   proxy->defineCFunc ("objc_sendReturnSize", gst_sendMessageReturnSize);
   proxy->defineCFunc ("objc_sendReturnType", gst_sendMessageReturnType);
   proxy->defineCFunc ("objc_setIvarOOP", gst_setIvarOOP);

objc-proxy.m

@@ -41,8 +41,11 @@ - (void) forwardInvocation: (NSInvocation*) anInvocation
       gst_boxValue (argumentBuffer, args+i, [sig getArgumentTypeAtIndex: i+2]);
     }
   args[i] = NULL;
-
+  
+  GST_LOCK_PROXY;
   OOP returnOOP = gst_proxy->vmsgSend (stObject, selector, args);
+  GST_UNLOCK_PROXY;
+
   gst_unboxValue (returnOOP, (void*)returnBuffer, [sig methodReturnType]);
   [anInvocation setReturnValue: (void*)returnBuffer];
 }