gecko-dev/other-licenses/android/bionic_tls.h

114 строки
4.2 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _SYS_TLS_H
#define _SYS_TLS_H
#include <sys/cdefs.h>
__BEGIN_DECLS
/** WARNING WARNING WARNING
**
** This header file is *NOT* part of the public Bionic ABI/API
** and should not be used/included by user-serviceable parts of
** the system (e.g. applications).
**
** It is only provided here for the benefit of the system dynamic
** linker and the OpenGL sub-system (which needs to access the
** pre-allocated slot directly for performance reason).
**/
/* maximum number of elements in the TLS array */
#define BIONIC_TLS_SLOTS 64
/* note that slot 0, called TLS_SLOT_SELF must point to itself.
* this is required to implement thread-local storage with the x86
* Linux kernel, that reads the TLS from fs:[0], where 'fs' is a
* thread-specific segment descriptor...
*/
/* Well known TLS slots */
#define TLS_SLOT_SELF 0
#define TLS_SLOT_THREAD_ID 1
#define TLS_SLOT_ERRNO 2
#define TLS_SLOT_OPENGL_API 3
#define TLS_SLOT_OPENGL 4
/* this slot is only used to pass information from the dynamic linker to
* libc.so when the C library is loaded in to memory. The C runtime init
* function will then clear it. Since its use is extremely temporary,
* we reuse an existing location.
*/
#define TLS_SLOT_BIONIC_PREINIT (TLS_SLOT_ERRNO+1)
/* small technical note: it is not possible to call pthread_setspecific
* on keys that are <= TLS_SLOT_MAX_WELL_KNOWN, which is why it is set to
* TLS_SLOT_ERRNO.
*
* later slots like TLS_SLOT_OPENGL are pre-allocated through the use of
* TLS_DEFAULT_ALLOC_MAP. this means that there is no need to use
* pthread_key_create() to initialize them. on the other hand, there is
* no destructor associated to them (we might need to implement this later)
*/
#define TLS_SLOT_MAX_WELL_KNOWN TLS_SLOT_ERRNO
#define TLS_DEFAULT_ALLOC_MAP 0x0000001F
/* set the Thread Local Storage, must contain at least BIONIC_TLS_SLOTS pointers */
extern void __init_tls(void** tls, void* thread_info);
/* syscall only, do not call directly */
extern int __set_tls(void *ptr);
/* get the TLS */
#ifdef __arm__
/* Linux kernel helpers for its TLS implementation */
/* For performance reasons, avoid calling the kernel helper
* Note that HAVE_ARM_TLS_REGISTER is build-specific
* (it must match your kernel configuration)
*/
# ifdef HAVE_ARM_TLS_REGISTER
# define __get_tls() \
({ register unsigned int __val asm("r0"); \
asm ("mrc p15, 0, r0, c13, c0, 3" : "=r"(__val) ); \
(volatile void*)__val; })
# else /* !HAVE_ARM_TLS_REGISTER */
# define __get_tls() ( *((volatile void **) 0xffff0ff0) )
# endif
#else
extern void* __get_tls( void );
#endif
/* return the stack base and size, used by our malloc debugger */
extern void* __get_stack_base(int *p_stack_size);
__END_DECLS
#endif /* _SYS_TLS_H */