rework memory management for ffi

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@30611 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,16 @@
+2010-06-07  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/GSInvocation.h:
+	* Source/GSFFIInvocation.m:
+	* Source/NSInvocation.m:
+	* Source/cifframe.h:
+	* Source/cifframe.m:
+	Rework memory management for frame used in FFI invocation so that
+	the memory has a retain count and multiple invocations can use the
+	same frame since it looks like the way FFI works, if you cache the
+	method implementation of a proxy, the same frame memory is re-used
+	in multiple invocations.
+
 2010-06-07  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/GSFFIInvocation.m: Fix breakage caused by David's changes.

Source/GSFFIInvocation.m

@@ -141,6 +141,7 @@ gs_find_by_receiver_best_typed_sel (id receiver, SEL sel)
 
 static IMP gs_objc_msg_forward2 (id receiver, SEL sel)
 {
+  void			*frame;
   cifframe_t            *cframe;
   ffi_closure           *cclosure;
   NSMethodSignature     *sig;
@@ -183,7 +184,6 @@ static IMP gs_objc_msg_forward2 (id receiver, SEL sel)
 	    "receiver, or you must be using an old/faulty version of the "
 	    "Objective-C runtime library.\n", sel_get_name(sel));
 #endif
-
 	  /*
 	   * Default signature is for a method returning an object.
 	   */
@@ -198,10 +198,15 @@ static IMP gs_objc_msg_forward2 (id receiver, SEL sel)
   NSCAssert1(sig, @"No signature for selector %@", NSStringFromSelector(sel));
 
   /* Construct the frame and closure. */
-  /* Note: We malloc cframe here, but it's passed to GSFFIInvocationCallback
+  /* Note: We obtain cframe here, but it's passed to GSFFIInvocationCallback
      where it becomes owned by the callback invocation, so we don't have to
-     worry about freeing it */
-  cframe = cifframe_from_signature(sig);
+     worry about ownership */
+  frame = cifframe_from_signature(sig);
+#if	GS_WITH_GC
+  cframe = frame;
+#else
+  cframe = [(NSMutableData*)frame mutableBytes];
+#endif
   /* Autorelease the closure through GSAutoreleasedBuffer */
 
   memory = [GSCodeBuffer memoryWithSize: sizeof(ffi_closure)];
@@ -211,7 +216,7 @@ static IMP gs_objc_msg_forward2 (id receiver, SEL sel)
       [NSException raise: NSMallocException format: @"Allocating closure"];
     }
   if (ffi_prep_closure(cclosure, &(cframe->cif),
-    GSFFIInvocationCallback, cframe) != FFI_OK)
+    GSFFIInvocationCallback, frame) != FFI_OK)
     {
       [NSException raise: NSGenericException format: @"Preping closure"];
     }
@@ -328,7 +333,14 @@ static id gs_objc_proxy_lookup(id receiver, SEL op)
   _sig = RETAIN(aSignature);
   _numArgs = [aSignature numberOfArguments];
   _info = [aSignature methodInfo];
+#if	GS_WITH_GC
+  _frame = nil;
   _cframe = cifframe_from_signature(_sig);
+#else
+  _frame = (NSMutableData*)cifframe_from_signature(_sig);
+  [_frame retain];
+  _cframe = [_frame mutableBytes];
+#endif
 
   /* Make sure we have somewhere to store the return value if needed.
    */
@@ -354,7 +366,7 @@ static id gs_objc_proxy_lookup(id receiver, SEL op)
    but we own it now so we can free it */
 - (id) initWithCallback: (ffi_cif *)cif
 		 values: (void **)vals
-		  frame: (cifframe_t *)frame
+		  frame: (void *)frame
 	      signature: (NSMethodSignature*)aSignature
 {
   cifframe_t *f;
@@ -363,7 +375,14 @@ static id gs_objc_proxy_lookup(id receiver, SEL op)
   _sig = RETAIN(aSignature);
   _numArgs = [aSignature numberOfArguments];
   _info = [aSignature methodInfo];
+#if	GS_WITH_GC
+  _frame = nil;
   _cframe = frame;
+#else
+  _frame = (NSMutableData*)frame;
+  [_frame retain];
+  _cframe = [_frame mutableBytes];
+#endif
   f = (cifframe_t *)_cframe;
   f->cif = *cif;
 
@@ -548,7 +567,8 @@ GSFFIInvocationCallback(ffi_cif *cif, void *retp, void **args, void *user)
   obj      = *(id *)args[0];
   selector = *(SEL *)args[1];
 
-  if (!class_respondsToSelector(obj->class_pointer, @selector(forwardInvocation:)))
+  if (!class_respondsToSelector(obj->class_pointer,
+    @selector(forwardInvocation:)))
     {
       [NSException raise: NSInvalidArgumentException
 		   format: @"GSFFIInvocation: Class '%s'(%s) does not respond"

Source/GSInvocation.h

@@ -27,6 +27,8 @@
 
 #include <Foundation/NSInvocation.h>
 
+@class	NSMutableData;
+
 typedef struct	{
   int		offset;
   unsigned	size;
@@ -39,7 +41,9 @@ typedef struct	{
 
 @interface GSFFIInvocation : NSInvocation
 {
+@public
   uint8_t	_retbuf[32];	// Store return values of up to 32 bytes here.
+  NSMutableData	*_frame;
 }
 @end
 

Source/NSInvocation.m

@@ -334,7 +334,11 @@ _arg_addr(NSInvocation *inv, int index)
 #if	defined(USE_LIBFFI)
   if (_cframe)
     {
-      NSZoneFree(NSDefaultMallocZone(), _cframe);
+      /* If we get here then we are not using GC, so the _frame instance
+       * variable points to a mutable data object containing _cframe and
+       * we can release it.
+       */
+      [((GSFFIInvocation*)self)->_frame release];
     }
 #elif defined(USE_FFCALL)
   if (_cframe)

Source/cifframe.h

@@ -50,7 +50,7 @@ typedef struct _cifframe_t {
   void **values;
 } cifframe_t;
 
-extern cifframe_t *cifframe_from_signature (NSMethodSignature *info);
+extern void *cifframe_from_signature (NSMethodSignature *info);
 
 extern void cifframe_set_arg(cifframe_t *cframe, int index, void *buffer, 
 			     int size);

Source/cifframe.m

@@ -122,13 +122,14 @@ cifframe_guess_struct_size(ffi_type *stype)
 }
 
 
-cifframe_t *
+void *
 cifframe_from_signature (NSMethodSignature *info)
 {
   unsigned      size = sizeof(cifframe_t);
   unsigned      align = __alignof(double);
   unsigned      type_offset = 0;
   unsigned      offset = 0;
+  void		*result;
   void          *buf;
   int           i;
   int		numargs = [info numberOfArguments];
@@ -180,9 +181,11 @@ cifframe_from_signature (NSMethodSignature *info)
     }
 
 #if	GS_WITH_GC
-  cframe = buf = NSAllocateCollectable(size, NSScannedOption);
+  cframe = buf = result = NSAllocateCollectable(size, NSScannedOption);
 #else
-  cframe = buf = NSZoneCalloc(NSDefaultMallocZone(), size, 1);
+  result = (void*)[NSMutableData dataWithCapacity: size];
+  [(NSMutableData*)result setLength: size];
+  cframe = buf = [(NSMutableData*)result mutableBytes];
 #endif
 
   if (cframe)
@@ -196,8 +199,7 @@ cifframe_from_signature (NSMethodSignature *info)
   if (ffi_prep_cif (&cframe->cif, FFI_DEFAULT_ABI, cframe->nargs,
 		   rtype, cframe->arg_types) != FFI_OK)
     {
-      objc_free(cframe);
-      cframe = NULL;
+      cframe = result = NULL;
     }
 
   if (cframe)
@@ -222,7 +224,7 @@ cifframe_from_signature (NSMethodSignature *info)
         }
     }
 
-  return cframe;
+  return result;
 }
 
 void