platform_bionic/libc/private/bionic_tls.h
Elliott Hughes ad59322ae4 Pull the pthread_key_t functions out of pthread.c.
This was originally motivated by noticing that we were setting the
wrong bits for the well-known tls entries. That was a harmless bug
because none of the well-known tls entries has a destructor, but
it's best not to leave land mines lying around.

Also add some missing POSIX constants, a new test, and fix
pthread_key_create's return value when we hit the limit.

Change-Id: Ife26ea2f4b40865308e8410ec803b20bcc3e0ed1
2013-02-11 12:00:48 -08:00

141 lines
5.1 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
/* Well-known TLS slots. What data goes in which slot is arbitrary unless otherwise noted. */
enum {
TLS_SLOT_SELF = 0, /* The kernel requires this specific slot for x86. */
TLS_SLOT_THREAD_ID,
TLS_SLOT_ERRNO,
TLS_SLOT_OPENGL_API = 3,
TLS_SLOT_OPENGL = 4,
TLS_SLOT_STACK_GUARD = 5, /* GCC requires this specific slot for x86. */
TLS_SLOT_DLERROR,
TLS_SLOT_FIRST_USER_SLOT /* Must come last! */
};
/* 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 that isn't needed during libc startup.
*/
#define TLS_SLOT_BIONIC_PREINIT TLS_SLOT_OPENGL_API
/* 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__
/* The standard way to get the TLS is to call a kernel helper
* function (i.e. a function provided at a fixed address in a
* "magic page" mapped in all user-space address spaces ), which
* contains the most appropriate code path for the target device.
*
* However, for performance reasons, we're going to use our own
* machine code for the system's C shared library.
*
* We cannot use this optimization in the static version of the
* C library, because we don't know where the corresponding code
* is going to run.
*/
# ifdef LIBC_STATIC
/* Use the kernel helper in static C library. */
typedef volatile void* (__kernel_get_tls_t)(void);
# define __get_tls() (*(__kernel_get_tls_t *)0xffff0fe0)()
# else /* !LIBC_STATIC */
/* Use optimized code path.
* Note that HAVE_ARM_TLS_REGISTER is build-specific
* (it must match your kernel configuration)
*/
# ifdef HAVE_ARM_TLS_REGISTER
/* We can read the address directly from a coprocessor
* register, which avoids touching the data cache
* completely.
*/
# 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 */
/* The kernel provides the address of the TLS at a fixed
* address of the magic page too.
*/
# define __get_tls() ( *((volatile void **) 0xffff0ff0) )
# endif
# endif /* !LIBC_STATIC */
#elif defined(__mips__)
# define __get_tls() \
({ register unsigned int __val asm("v1"); \
asm ( \
" .set push\n" \
" .set mips32r2\n" \
" rdhwr %0,$29\n" \
" .set pop\n" \
: "=r"(__val) \
); \
(volatile void*)__val; })
#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
#if defined(__cplusplus)
struct KernelArgumentBlock;
extern void __libc_init_tls(KernelArgumentBlock& args);
#endif
#endif /* _SYS_TLS_H */