Author: paullanders
Date: Fri Nov 11 19:19:32 2016
New Revision: 40217
URL: http://svn.gna.org/viewcvs/gnustep?rev=40217&view=rev
Log:
Merge NSObject changes from trunk instead of my previous commit. Fixes retain
and release compatibility with libobjc2 in a platform safe way.
Modified:
libs/base/branches/gnustep_testplant_branch/Source/NSObject.m
Modified: libs/base/branches/gnustep_testplant_branch/Source/NSObject.m
URL:
http://svn.gna.org/viewcvs/gnustep/libs/base/branches/gnustep_testplant_branch/Source/NSObject.m?rev=40217&r1=40216&r2=40217&view=diff
==============================================================================
--- libs/base/branches/gnustep_testplant_branch/Source/NSObject.m
(original)
+++ libs/base/branches/gnustep_testplant_branch/Source/NSObject.m Fri Nov
11 19:19:32 2016
@@ -1,26 +1,20 @@
/** Implementation of NSObject for GNUStep
Copyright (C) 1994-2010 Free Software Foundation, Inc.
-
Written by: Andrew Kachites McCallum <mccal...@gnu.ai.mit.edu>
Date: August 1994
-
This file is part of the GNUstep Base Library.
-
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
-
This library 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
Library General Public License for more details.
-
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02111 USA.
-
<title>NSObject class reference</title>
$Date$ $Revision$
*/
@@ -113,11 +107,10 @@
- (id) initWithObject: (id)anObject;
@end
-/*
- * allocationLock is needed when running multi-threaded for
- * protecting the map table of zombie information.
- */
-static NSLock *allocationLock;
+/* allocationLock is needed when for protecting the map table of zombie
+ * information and if atomic operations are not available.
+ */
+static NSLock *allocationLock = nil;
BOOL NSZombieEnabled = NO;
BOOL NSDeallocateZombies = NO;
@@ -187,15 +180,28 @@
#endif
+/* Traditionally, GNUstep has been using a 32bit reference count in front
+ * of the object. The automatic reference counting implementation in
+ * libobjc2 uses an intptr_t instead, so NSObject will only be compatible
+ * with ARC if either of the following apply:
+ *
+ * a) sizeof(intptr_t) == sizeof(int32_t)
+ * b) we can provide atomic operations on pointer sized values, allowing
+ * us to extend the refcount to intptr_t.
+ */
+#ifdef GS_ARC_COMPATIBLE
+#undef GS_ARC_COMPATIBLE
+#endif
#if defined(__llvm__) || (defined(USE_ATOMIC_BUILTINS) && (__GNUC__ > 4 ||
(__GNUC__ == 4 && __GNUC_MINOR__ >= 1)))
/* Use the GCC atomic operations with recent GCC versions */
-typedef int32_t volatile *gsatomic_t;
+typedef intptr_t volatile *gsatomic_t;
+typedef intptr_t gsrefcount_t;
#define GSATOMICREAD(X) (*(X))
#define GSAtomicIncrement(X) __sync_add_and_fetch(X, 1)
#define GSAtomicDecrement(X) __sync_sub_and_fetch(X, 1)
-
+#define GS_ARC_COMPATIBLE 1
#elif defined(_WIN32)
@@ -203,7 +209,7 @@
*/
typedef int32_t volatile *gsatomic_t;
-
+typedef int32_t gsrefcount_t;
#ifndef _WIN64
#undef InterlockedIncrement
#undef InterlockedDecrement
@@ -221,6 +227,7 @@
*/
typedef int32_t volatile *gsatomic_t;
+typedef int32_t gsrefcount_t;
#define GSATOMICREAD(X) (*(X))
@@ -254,6 +261,7 @@
#elif defined(__PPC__) || defined(__POWERPC__)
typedef int32_t volatile *gsatomic_t;
+typedef int32_t gsrefcount_t;
#define GSATOMICREAD(X) (*(X))
@@ -292,6 +300,7 @@
#elif defined(__m68k__)
typedef int32_t volatile *gsatomic_t;
+typedef int32_t gsrefcount_t;
#define GSATOMICREAD(X) (*(X))
@@ -316,6 +325,7 @@
#elif defined(__mips__)
typedef int32_t volatile *gsatomic_t;
+typedef int32_t gsrefcount_t;
#define GSATOMICREAD(X) (*(X))
@@ -356,8 +366,7 @@
#if !defined(GSATOMICREAD)
-/*
- * Having just one allocationLock for all leads to lock contention
+/* Having just one allocationLock for all leads to lock contention
* if there are lots of threads doing lots of retain/release calls.
* To alleviate this, instead of a single
* allocationLock for all objects, we divide the object space into
@@ -382,6 +391,17 @@
#endif
+#ifndef GS_ARC_COMPATIBLE
+/*
+ * If we haven't previously declared that we can work in fast-ARC mode,
+ * check whether a point is 32bit (4 bytes) wide, which also enables ARC
+ * integration.
+ */
+# if __SIZEOF_POINTER__ == 4
+# define GS_ARC_COMPATIBLE 1
+# endif
+#endif
+
#if defined(__GNUC__) && __GNUC__ < 4
#define __builtin_offsetof(s, f) (uintptr_t)(&(((s*)0)->f))
#endif
@@ -392,7 +412,7 @@
* (before the start) in each object.
*/
typedef struct obj_layout_unpadded {
- uintptr_t retained;
+ gsrefcount_t retained;
} unp;
#define UNP sizeof(unp)
@@ -412,7 +432,7 @@
struct obj_layout {
char padding[__BIGGEST_ALIGNMENT__ - ((UNP % __BIGGEST_ALIGNMENT__)
? (UNP % __BIGGEST_ALIGNMENT__) : __BIGGEST_ALIGNMENT__)];
- uintptr_t retained;
+ gsrefcount_t retained;
};
typedef struct obj_layout *obj;
@@ -423,7 +443,7 @@
* (and hence whether the extra reference count was decremented).<br />
* This function is used by the [NSObject-release] method.
*/
-BOOL
+inline BOOL
NSDecrementExtraRefCountWasZero(id anObject)
{
if (double_release_check_enabled)
@@ -435,58 +455,45 @@
[NSException raise: NSGenericException
format: @"Release would release object too many times."];
}
- if (allocationLock != 0)
- {
+ {
#if defined(GSATOMICREAD)
- int32_t result;
-
- result = GSAtomicDecrement((gsatomic_t)&(((obj)anObject)[-1].retained));
- if (result < 0)
- {
- if (result != -1)
- {
- [NSException raise: NSInternalInconsistencyException
- format: @"NSDecrementExtraRefCount() decremented too far"];
- }
- /* The counter has become negative so it must have been zero.
- * We reset it and return YES ... in a correctly operating
- * process we know we can safely reset back to zero without
- * worrying about atomicity, since there can be no other
- * thread accessing the object (or its reference count would
- * have been greater than zero)
- */
- (((obj)anObject)[-1].retained) = 0;
- return YES;
- }
+ gsrefcount_t result;
+
+ result = GSAtomicDecrement((gsatomic_t)&(((obj)anObject)[-1].retained));
+ if (result < 0)
+ {
+ if (result != -1)
+ {
+ [NSException raise: NSInternalInconsistencyException
+ format: @"NSDecrementExtraRefCount() decremented too far"];
+ }
+ /* The counter has become negative so it must have been zero.
+ * We reset it and return YES ... in a correctly operating
+ * process we know we can safely reset back to zero without
+ * worrying about atomicity, since there can be no other
+ * thread accessing the object (or its reference count would
+ * have been greater than zero)
+ */
+ (((obj)anObject)[-1].retained) = 0;
+ return YES;
+ }
#else /* GSATOMICREAD */
- NSLock *theLock = GSAllocationLockForObject(anObject);
-
- [theLock lock];
- if (((obj)anObject)[-1].retained == 0)
- {
- [theLock unlock];
- return YES;
- }
- else
- {
- ((obj)anObject)[-1].retained--;
- [theLock unlock];
- return NO;
- }
+ NSLock *theLock = GSAllocationLockForObject(anObject);
+
+ [theLock lock];
+ if (((obj)anObject)[-1].retained == 0)
+ {
+ [theLock unlock];
+ return YES;
+ }
+ else
+ {
+ ((obj)anObject)[-1].retained--;
+ [theLock unlock];
+ return NO;
+ }
#endif /* GSATOMICREAD */
- }
- else
- {
- if (((obj)anObject)[-1].retained == 0)
- {
- return YES;
- }
- else
- {
- ((obj)anObject)[-1].retained--;
- return NO;
- }
- }
+ }
return NO;
}
@@ -510,42 +517,30 @@
inline void
NSIncrementExtraRefCount(id anObject)
{
- if (allocationLock != 0)
- {
#if defined(GSATOMICREAD)
- /* I've seen comments saying that some platforms only support up to
- * 24 bits in atomic locking, so raise an exception if we try to
- * go beyond 0xfffffe.
- */
- if (GSAtomicIncrement((gsatomic_t)&(((obj)anObject)[-1].retained))
- > 0xfffffe)
- {
- [NSException raise: NSInternalInconsistencyException
- format: @"NSIncrementExtraRefCount() asked to increment too far"];
- }
+ /* I've seen comments saying that some platforms only support up to
+ * 24 bits in atomic locking, so raise an exception if we try to
+ * go beyond 0xfffffe.
+ */
+ if (GSAtomicIncrement((gsatomic_t)&(((obj)anObject)[-1].retained))
+ > 0xfffffe)
+ {
+ [NSException raise: NSInternalInconsistencyException
+ format: @"NSIncrementExtraRefCount() asked to increment too far"];
+ }
#else /* GSATOMICREAD */
- NSLock *theLock = GSAllocationLockForObject(anObject);
-
- [theLock lock];
- if (((obj)anObject)[-1].retained > 0xfffffe)
- {
- [theLock unlock];
- [NSException raise: NSInternalInconsistencyException
- format: @"NSIncrementExtraRefCount() asked to increment too far"];
- }
- ((obj)anObject)[-1].retained++;
+ NSLock *theLock = GSAllocationLockForObject(anObject);
+
+ [theLock lock];
+ if (((obj)anObject)[-1].retained > 0xfffffe)
+ {
[theLock unlock];
+ [NSException raise: NSInternalInconsistencyException
+ format: @"NSIncrementExtraRefCount() asked to increment too far"];
+ }
+ ((obj)anObject)[-1].retained++;
+ [theLock unlock];
#endif /* GSATOMICREAD */
- }
- else
- {
- if (((obj)anObject)[-1].retained > 0xfffffe)
- {
- [NSException raise: NSInternalInconsistencyException
- format: @"NSIncrementExtraRefCount() asked to increment too far"];
- }
- ((obj)anObject)[-1].retained++;
- }
}
#ifndef NDEBUG
@@ -597,6 +592,8 @@
* the start of each object.
*/
+// FIXME rewrite object allocation to use class_createInstance when we
+// are using libobjc2.
inline id
NSAllocateObject (Class aClass, NSUInteger extraBytes, NSZone *zone)
{
@@ -735,23 +732,9 @@
* </p>
*/
@implementation NSObject
+#if defined(GS_ARC_COMPATIBLE)
- (void)_ARCCompliantRetainRelease {}
-
-+ (void) _becomeMultiThreaded: (NSNotification *)aNotification
-{
- if (allocationLock == 0)
- {
-#if !defined(GSATOMICREAD)
- NSUInteger i;
-
- for (i = 0; i < LOCKCOUNT; i++)
- {
- allocationLocks[i] = [NSLock new];
- }
-#endif
- allocationLock = [NSLock new];
- }
-}
+#endif
/**
* Semi-private function in libobjc2 that initialises the classes used for
@@ -849,6 +832,21 @@
# endif
#endif
+ /* Create the lock for NSZombie and for allocation when atomic
+ * operations are not available.
+ */
+ allocationLock = [NSLock new];
+#if !defined(GSATOMICREAD)
+ {
+ NSUInteger i;
+
+ for (i = 0; i < LOCKCOUNT; i++)
+ {
+ allocationLocks[i] = [NSLock new];
+ }
+ }
+#endif
+
/* Create the global lock.
* NB. Ths is one of the first things we do ... setting up a new lock
* must not call any other Objective-C classes and must not involve
@@ -897,15 +895,6 @@
* object, and that class hasn't been initialized yet ...
*/
zombieClass = objc_lookUpClass("NSZombie");
-
- /* Now that we have a working autorelease system and working string
- * classes we are able to set up notifications.
- */
- [[NSNotificationCenter defaultCenter]
- addObserver: self
- selector: @selector(_becomeMultiThreaded:)
- name: NSWillBecomeMultiThreadedNotification
- object: nil];
}
return;
}
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