I want to be able to log messages (and preferably interrupt the debugger) every time a certain object is allocated, saved, freed or freed CFType(for my current purposes - CGPDFDocument).
Since for CGPDFDocumentthere is no method Create...()that accepts CFAllocatorRef, I am trying to temporarily change the default allocator as follows:
void MyPDFDocumentCreate()
{
CFAllocatorRef defaultAllocator = CFAllocatorGetDefault();
CFAllocatorSetDefault(MyLogAllocator());
CGPDFDocumentRef documentRef = CGPDFDocumentCreateWithProvider(provider);
CFAllocatorSetDefault(defaultAllocator);
}
where is MyLogAllocator()defined as follows:
static void *(*DefaultAllocate)(CFIndex size, CFOptionFlags hint, void *info);
static const void *(*DefaultRetain)(const void *info);
static void (*DefaultRelease)(const void *info);
void *LogAllocate(CFIndex size, CFOptionFlags hint, void *info)
{
fprintf(stderr, "LogAllocate %p", info);
if (DefaultAllocate)
return DefaultAllocate(size, hint, info);
else
return NULL;
}
const void *LogRetain(const void *info)
{
fprintf(stderr, "LogRetain");
if (DefaultRetain)
return DefaultRetain(info);
else
return info;
}
void LogRelease(const void *info)
{
fprintf(stderr, "LogRelease");
if (DefaultRelease)
DefaultRelease(info);
}
static CFAllocatorRef MyLogAllocator()
{
static CFAllocatorRef theLogAllocator = NULL;
if (!theLogAllocator)
{
CFAllocatorContext context;
CFAllocatorRef defaultAllocator = CFAllocatorGetDefault();
CFAllocatorGetContext(defaultAllocator, &context);
DefaultAllocate = context.allocate;
DefaultRetain = context.retain;
DefaultRelease = context.release;
context.allocate = LogAllocate;
context.retain = LogRetain;
context.release = LogRelease;
theLogAllocator = CFAllocatorCreate(kCFAllocatorUseContext, &context);
}
return theLogAllocator;
}
, , (kCFAllocatorSystemDefault, ) NULL context.retain context.release, . , , , :
#0 0x357ded12 in CFRetain ()
#1 0x357dcb68 in _CFRuntimeCreateInstance ()
#2 0x303fe35e in CGTypeCreateInstanceWithAllocator ()
#3 0x303fe34c in CGTypeCreateInstance ()
#4 0x304b32f4 in CGPDFDocumentCreateWithProvider ()
#5 0x000293f4 in MyPDFDocumentCreate ([...]) at [...]
XCode , , , :
(gdb) continue
Continuing.
Program received signal SIGTRAP, Trace/breakpoint trap.
0x357ded12 in CFRetain ()
(gdb) continue
Continuing.
Program received signal SIGTRAP, Trace/breakpoint trap.
0x357ded12 in CFRetain ()
(gdb)
, SIGTRAP. , ; , , objc_exception_throw.
, LogRetain() LogAllocate() ( ) CFAllocatorCreate():
#0 LogRetain (info=0x1a8000) at [...]
#1 0x358086f2 in CFAllocatorCreate ()
#2 0x00028d58 in MyLogAllocator () at [...]
#3 0x000293e0 in MyPDFDocumentCreate ([...]) at [...]
#0 LogAllocate (size=104, hint=0, info=0x1a8000) at [...]
#1 0x3580882e in CFAllocatorCreate ()
#2 0x00028d58 in MyLogAllocator () at [...]
#3 0x000293e0 in MyPDFDocumentCreate ([...]) at [...]
LogAllocate() CFAllocatorAllocate():
#0 LogAllocate (size=64, hint=1024, info=0x1a8000) at [...]
#1 0x357dcc06 in CFAllocatorAllocate ()
#2 0x357dcb04 in _CFRuntimeCreateInstance ()
#3 0x303fe35e in CGTypeCreateInstanceWithAllocator ()
#4 0x303fe34c in CGTypeCreateInstance ()
#5 0x304b32f4 in CGPDFDocumentCreateWithProvider ()
#6 0x000293f4 in MyPDFDocumentCreate ([...]) at [...]
, _CFRuntimeCreateInstance() # 2 CFRetain(), .
-, , , (, , SIGTRAP); ; , ?
( , , DTrace CFRetain() CFRelease(), CFTypeID CGPDFDocument, , ( , , CGPDFDocumentCreateWithProvider()). , , keep/release/deallocate, , , DTrace. )
: CFRelease. , context.retain context.release - context.info. , . , , DTrace/Instruments - - ?!