/* * Copyright (c) 2006-2007 Apple Inc. All Rights Reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ #import <string.h> #import <stddef.h> #import <libkern/OSAtomic.h> #import "objc-accessors.h" #import <objc/objc-auto.h> #import <objc/runtime.h> #import "../objc-private.h" #import "/usr/local/include/auto_zone.h" #import "objc-accessors-table.h" // stub interface declarations to make compiler happy. @interface __NSCopyable - (id)copyWithZone:(void *)zone; @end @interface __NSRetained - (id)retain; - (oneway void)release; - (id)autorelease; @end static /*inline*/ IMP optimized_getter_for_gc(id self, SEL name, ptrdiff_t offset) { // replace this method with a faster version that does no message sends, and fewer tests. IMP getter = GETPROPERTY_IMP(offset); if (getter != NULL) { // HACK ALERT: replaces the IMP in the cache! Class cls = self->isa; Method method = class_getInstanceMethod(cls, name); if (method_getImplementation(method) != getter) method_setImplementation(method, getter); } return getter; } static /*inline*/ IMP optimized_setter_for_gc(id self, SEL name, ptrdiff_t offset) { // replace this method with a faster version that does no message sends. IMP setter = SETPROPERTY_IMP(offset); if (setter != NULL) { // HACK ALERT: replaces the IMP in the cache! Class cls = self->isa; Method method = class_getInstanceMethod(cls, name); if (method_getImplementation(method) != setter) method_setImplementation(method, setter); } return setter; } // ATOMIC entry points typedef uintptr_t spin_lock_t; extern void _spin_lock(spin_lock_t *lockp); extern int _spin_lock_try(spin_lock_t *lockp); extern void _spin_unlock(spin_lock_t *lockp); /* need to consider cache line contention - space locks out XXX */ #define GOODPOWER 7 #define GOODMASK ((1<<GOODPOWER)-1) #define GOODHASH(x) (((long)x >> 5) & GOODMASK) static spin_lock_t PropertyLocks[1 << GOODPOWER] = { 0 }; id objc_getProperty(id self, SEL _cmd, ptrdiff_t offset, BOOL atomic) { if (UseGC) { // FIXME: we could optimize getters when a class is first initialized, then KVO won't get confused. if (false) { IMP getter = optimized_getter_for_gc(self, _cmd, offset); if (getter) return getter(self, _cmd); } return *(id*) ((char*)self + offset); } // Retain release world id *slot = (id*) ((char*)self + offset); if (!atomic) return *slot; // Atomic retain release world spin_lock_t *slotlock = &PropertyLocks[GOODHASH(slot)]; _spin_lock(slotlock); id value = [*slot retain]; _spin_unlock(slotlock); // for performance, we (safely) issue the autorelease OUTSIDE of the spinlock. return [value autorelease]; } void objc_setProperty(id self, SEL _cmd, ptrdiff_t offset, id newValue, BOOL atomic, BOOL shouldCopy) { if (UseGC) { if (shouldCopy) { newValue = [newValue copyWithZone:NULL]; } else if (false) { IMP setter = optimized_setter_for_gc(self, _cmd, offset); if (setter) { setter(self, _cmd, newValue); return; } } objc_assign_ivar_internal(newValue, self, offset); return; } // Retain release world id oldValue, *slot = (id*) ((char*)self + offset); // atomic or not, if slot would be unchanged, do nothing. if (!shouldCopy && *slot == newValue) return; newValue = (shouldCopy ? [newValue copyWithZone:NULL] : [newValue retain]); if (!atomic) { oldValue = *slot; *slot = newValue; } else { spin_lock_t *slotlock = &PropertyLocks[GOODHASH(slot)]; _spin_lock(slotlock); oldValue = *slot; *slot = newValue; _spin_unlock(slotlock); } [oldValue release]; } __private_extern__ auto_zone_t *gc_zone; // This entry point was designed wrong. When used as a getter, src needs to be locked so that // if simultaneously used for a setter then there would be contention on src. // So we need two locks - one of which will be contended. void objc_copyStruct(void *dest, const void *src, ptrdiff_t size, BOOL atomic, BOOL hasStrong) { static spin_lock_t StructLocks[1 << GOODPOWER] = { 0 }; spin_lock_t *lockfirst = NULL; spin_lock_t *locksecond = NULL; if (atomic) { lockfirst = &StructLocks[GOODHASH(src)]; locksecond = &StructLocks[GOODHASH(dest)]; // order the locks by address so that we don't deadlock if (lockfirst > locksecond) { lockfirst = locksecond; locksecond = &StructLocks[GOODHASH(src)]; } else if (lockfirst == locksecond) { // lucky - we only need one lock locksecond = NULL; } _spin_lock(lockfirst); if (locksecond) _spin_lock(locksecond); } if (UseGC && hasStrong) { auto_zone_write_barrier_memmove(gc_zone, dest, src, size); } else { memmove(dest, src, size); } if (atomic) { _spin_unlock(lockfirst); if (locksecond) _spin_unlock(locksecond); } } // PRE-ATOMIC entry points id <NSCopying> object_getProperty_bycopy(id self, SEL _cmd, ptrdiff_t offset) { if (UseGC) { IMP getter = optimized_getter_for_gc(self, _cmd, offset); if (getter) return getter(self, _cmd); } id *slot = (id*) ((char*)self + offset); return *slot; } void object_setProperty_bycopy(id self, SEL _cmd, id <NSCopying> value, ptrdiff_t offset) { id *slot = (id*) ((char*)self + offset); id oldValue = *slot; objc_assign_ivar_internal([value copyWithZone:NULL], self, offset); [oldValue release]; } id object_getProperty_byref(id self, SEL _cmd, ptrdiff_t offset) { if (UseGC) { IMP getter = optimized_getter_for_gc(self, _cmd, offset); if (getter) return getter(self, _cmd); } id *slot = (id*) ((char*)self + offset); return *slot; } void object_setProperty_byref(id self, SEL _cmd, id value, ptrdiff_t offset) { if (UseGC) { IMP setter = optimized_setter_for_gc(self, _cmd, offset); if (setter) { setter(self, _cmd, value); return; } } id *slot = (id*) ((char*)self + offset); id oldValue = *slot; if (oldValue != value) { objc_assign_ivar_internal([value retain], self, offset); [oldValue release]; } }