OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Makefile.in (OBJC_SOURCE_FILES): Added accessors.m.

Browse Source 
2010-10-24  Nicola Pero  <nicola.pero@meta-innovation.com>

        * Makefile.in (OBJC_SOURCE_FILES): Added accessors.m.
        * accessors.m: New.
        * init.c: Include objc-private/accessors.h.
        (__objc_exec_class): Call __objc_accessors_init.
        * objc-private/accessors.h: New.

From-SVN: r165903
This commit is contained in:
Nicola Pero 2010-10-24 17:23:19 +00:00 committed by Nicola Pero
parent 0f237806af
commit 682e805aaf
5 changed files with 330 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
libobjc/ChangeLog
View File

@ -1,3 +1,11 @@
2010-10-24 Nicola Pero <nicola.pero@meta-innovation.com>
* Makefile.in (OBJC_SOURCE_FILES): Added accessors.m.
* accessors.m: New.
* init.c: Include objc-private/accessors.h.
(__objc_exec_class): Call __objc_accessors_init.
* objc-private/accessors.h: New.
2010-10-17 Nicola Pero <nicola.pero@meta-innovation.com>
* objc/message.h: Moved initial includes outside of extern "C".

1
libobjc/Makefile.in
View File

@ -163,6 +163,7 @@ OBJC_SOURCE_FILES = \
NXConstStr.m \
Object.m \
Protocol.m \
accessors.m \
linking.m
# C source files to compile

279
libobjc/accessors.m Normal file
View File

@ -0,0 +1,279 @@
/* GNU Objective C Runtime accessors functions
Copyright (C) 2010 Free Software Foundation, Inc.
Contributed by Nicola Pero
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
GCC 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 General Public License for more
details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "objc-private/common.h"
#include "objc/objc.h"
#include "objc/thr.h"
#include <string.h> /* For memcpy */
/* This file contains functions that the compiler uses when
synthesizing accessors (getters/setters) for properties. The
functions are part of the ABI, but are meant to be used by the
compiler and not by users; for this reason, they are not declared
in public header files. The compiler automatically generates
declarations for these functions. */
/* Properties can be "atomic", which requires protecting them from
concurrency issues using a lock. Unfortunately, we can't have a
lock for each property, so we'll go with a small pool of locks.
Any time a property is accessed in an "atomic" way, we pick a
random lock from the pool (random, but always the same one for the
same property of the same object) and use it to protect access to
the property.
The size of the pool is currently 16. A bigger pool can help
reduce contention, ie, reduce the chances that two threads,
operating on unrelated properties, will have to wait for each other
because the properties use the same lock. 16 seems big enough at
the moment. */
#define ACCESSORS_NUMBER_OF_LOCKS 16
#define ACCESSORS_HASH(POINTER) ((((size_t)POINTER >> 8) ^ (size_t)POINTER) & (ACCESSORS_NUMBER_OF_LOCKS - 1))
static objc_mutex_t accessors_locks[ACCESSORS_NUMBER_OF_LOCKS];
/* This is called at startup to setup the locks. */
void
__objc_accessors_init (void)
{
int i;
for (i = 0; i < ACCESSORS_NUMBER_OF_LOCKS; i++)
accessors_locks[i] = objc_mutex_allocate ();
}
/* The property accessors automatically call various methods from the
Foundation library (eg, GNUstep-base). These methods are not
implemented here, but we need to declare them so we can compile the
runtime. The Foundation library will need to provide
implementations of these methods (most likely in the root class,
eg, NSObject) as the accessors only work with objects of classes
that implement these methods. */
@interface _libobjcNSObject
- (id) copyWithZone: (void *)zone;
- (id) mutableCopyWithZone: (void *)zone;
@end
#define COPY(X) [((_libobjcNSObject *)(X)) copyWithZone: NULL]
#define MUTABLE_COPY(X) [((_libobjcNSObject *)(X)) mutableCopyWithZone: NULL]
#if OBJC_WITH_GC
# define AUTORELEASE(X) (X)
# define RELEASE(X)
# define RETAIN(X) (X)
#else
@interface _libobjcNSObject (RetainReleaseMethods)
- (id) autorelease;
- (oneway void) release;
- (id) retain;
@end
# define AUTORELEASE(X) [((_libobjcNSObject *)(X)) autorelease]
# define RELEASE(X) [((_libobjcNSObject *)(X)) release]
# define RETAIN(X) [((_libobjcNSObject *)(X)) retain]
#endif
/* The compiler uses this function when implementing some synthesized
getters for properties of type 'id'. */
id
objc_getProperty (id self, SEL __attribute__((unused)) _cmd, ptrdiff_t offset, BOOL is_atomic)
{
if (self != nil)
{
id *pointer_to_ivar = (id *)((char *)self + offset);
if (is_atomic == NO)
return AUTORELEASE (RETAIN (*pointer_to_ivar));
else
{
objc_mutex_t lock = accessors_locks[ACCESSORS_HASH (pointer_to_ivar)];
id result;
objc_mutex_lock (lock);
result = RETAIN (*(pointer_to_ivar));
objc_mutex_unlock (lock);
return AUTORELEASE (result);
}
}
return nil;
}
/* The compiler uses this function when implementing some synthesized
setters for properties of type 'id'.
PS: Note how 'should_copy' is declared 'BOOL' but then actually
takes values from 0 to 2. This hack was introduced by Apple; we
do the same for compatibility reasons. */
void
objc_setProperty (id self, SEL __attribute__((unused)) _cmd, ptrdiff_t offset, id new_value, BOOL is_atomic, BOOL should_copy)
{
if (self != nil)
{
id *pointer_to_ivar = (id *)((char *)self + offset);
id retained_value;
#if !OBJC_WITH_GC
id old_value;
#endif
switch (should_copy)
{
case 0: /* retain */
{
if (*pointer_to_ivar == new_value)
return;
retained_value = RETAIN (new_value);
break;
}
case 2: /* mutable copy */
{
retained_value = MUTABLE_COPY (new_value);
break;
}
case 1: /* copy */
default:
{
retained_value = COPY (new_value);
break;
}
}
if (is_atomic == NO)
{
#if !OBJC_WITH_GC
old_value = *pointer_to_ivar;
#endif
*pointer_to_ivar = retained_value;
}
else
{
objc_mutex_t lock = accessors_locks[ACCESSORS_HASH (pointer_to_ivar)];
objc_mutex_lock (lock);
#if !OBJC_WITH_GC
old_value = *pointer_to_ivar;
#endif
*pointer_to_ivar = retained_value;
objc_mutex_unlock (lock);
}
#if !OBJC_WITH_GC
RELEASE (old_value);
#endif
}
}
/* The compiler uses this function when implementing some synthesized
getters for properties of arbitrary C types. The data is just
copied. Compatibility Note: this function does not exist in the
Apple/NeXT runtime. */
void
objc_getPropertyStruct (void *destination, const void *source, ptrdiff_t size, BOOL is_atomic, BOOL __attribute__((unused)) has_strong)
{
if (is_atomic == NO)
memcpy (destination, source, size);
else
{
objc_mutex_t lock = accessors_locks[ACCESSORS_HASH (source)];
objc_mutex_lock (lock);
memcpy (destination, source, size);
objc_mutex_unlock (lock);
}
}
/* The compiler uses this function when implementing some synthesized
setters for properties of arbitrary C types. The data is just
copied. Compatibility Note: this function does not exist in the
Apple/NeXT runtime. */
void
objc_setPropertyStruct (void *destination, const void *source, ptrdiff_t size, BOOL is_atomic, BOOL __attribute__((unused)) has_strong)
{
if (is_atomic == NO)
memcpy (destination, source, size);
else
{
objc_mutex_t lock = accessors_locks[ACCESSORS_HASH (destination)];
objc_mutex_lock (lock);
memcpy (destination, source, size);
objc_mutex_unlock (lock);
}
}
/* This is the function that the Apple/NeXT runtime has instead of
objc_getPropertyStruct and objc_setPropertyStruct. We include it
for API compatibility (just for people who may have used
objc_copyStruct on the NeXT runtime thinking it was a public API);
the compiler never generates calls to it with the GNU runtime.
This function is clumsy because it requires two locks instead of
one. */
void
objc_copyStruct (void *destination, const void *source, ptrdiff_t size, BOOL is_atomic, BOOL __attribute__((unused)) has_strong)
{
if (is_atomic == NO)
memcpy (destination, source, size);
else
{
/* We don't know which one is the property, so we have to lock
both. One of them is most likely a temporary buffer in the
local stack and we really wouldn't want to lock it (our
objc_getPropertyStruct and objc_setPropertyStruct functions
don't lock it). Note that if we're locking more than one
accessor lock at once, we need to always lock them in the
same order to avoid deadlocks. */
objc_mutex_t first_lock;
objc_mutex_t second_lock;
if (ACCESSORS_HASH (source) == ACCESSORS_HASH (destination))
{
/* A lucky collision. */
first_lock = accessors_locks[ACCESSORS_HASH (source)];
objc_mutex_lock (first_lock);
memcpy (destination, source, size);
objc_mutex_unlock (first_lock);
return;
}
if (ACCESSORS_HASH (source) > ACCESSORS_HASH (destination))
{
first_lock = accessors_locks[ACCESSORS_HASH (source)];
second_lock = accessors_locks[ACCESSORS_HASH (destination)];
}
else
{
first_lock = accessors_locks[ACCESSORS_HASH (destination)];
second_lock = accessors_locks[ACCESSORS_HASH (source)];
}
objc_mutex_lock (first_lock);
objc_mutex_lock (second_lock);
memcpy (destination, source, size);
objc_mutex_unlock (second_lock);
objc_mutex_unlock (first_lock);
}
}

2
libobjc/init.c
View File

@ -35,6 +35,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
#include "objc-private/protocols.h" /* For __objc_protocols_init(),
__objc_protocols_add_protocol()
__objc_protocols_register_selectors() */
#include "objc-private/accessors.h" /* For __objc_accessors_init() */
/* The version number of this runtime. This must match the number
defined in gcc (objc-act.c). */
@ -582,6 +583,7 @@ __objc_exec_class (Module_t module)
(hash_func_type)objc_hash_ptr,
objc_compare_ptrs);
__objc_protocols_init ();
__objc_accessors_init ();
__objc_sync_init ();
previous_constructors = 1;
}

40
libobjc/objc-private/accessors.h Normal file
View File

@ -0,0 +1,40 @@
/* GNU Objective C Runtime accessors - Private Declarations
Copyright (C) 2010 Free Software Foundation, Inc.
Contributed by Nicola Pero <nicola.pero@meta-innovation.com>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
GCC 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 General Public License for more
details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifndef __objc_private_accessors_INCLUDE_GNU
#define __objc_private_accessors_INCLUDE_GNU
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/* This function needs to be called at startup by init.c. */
void
__objc_accessors_init (void);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* not __objc_private_accessors_INCLUDE_GNU */