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