1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #ifndef __BIONIC_PRIVATE_BIONIC_TLS_H_ 30 #define __BIONIC_PRIVATE_BIONIC_TLS_H_ 31 32 #include <sys/cdefs.h> 33 #include <sys/limits.h> 34 #include "bionic_macros.h" 35 #include "__get_tls.h" 36 37 __BEGIN_DECLS 38 39 /** WARNING WARNING WARNING 40 ** 41 ** This header file is *NOT* part of the public Bionic ABI/API 42 ** and should not be used/included by user-serviceable parts of 43 ** the system (e.g. applications). 44 ** 45 ** It is only provided here for the benefit of the system dynamic 46 ** linker and the OpenGL sub-system (which needs to access the 47 ** pre-allocated slot directly for performance reason). 48 **/ 49 50 // Well-known TLS slots. What data goes in which slot is arbitrary unless otherwise noted. 51 enum { 52 TLS_SLOT_SELF = 0, // The kernel requires this specific slot for x86. 53 TLS_SLOT_THREAD_ID, 54 TLS_SLOT_ERRNO, 55 56 // These two aren't used by bionic itself, but allow the graphics code to 57 // access TLS directly rather than using the pthread API. 58 TLS_SLOT_OPENGL_API = 3, 59 TLS_SLOT_OPENGL = 4, 60 61 // This slot is only used to pass information from the dynamic linker to 62 // libc.so when the C library is loaded in to memory. The C runtime init 63 // function will then clear it. Since its use is extremely temporary, 64 // we reuse an existing location that isn't needed during libc startup. 65 TLS_SLOT_BIONIC_PREINIT = TLS_SLOT_OPENGL_API, 66 67 TLS_SLOT_STACK_GUARD = 5, // GCC requires this specific slot for x86. 68 TLS_SLOT_DLERROR, 69 70 TLS_SLOT_FIRST_USER_SLOT // Must come last! 71 }; 72 73 /* 74 * There are two kinds of slot used internally by bionic --- there are the well-known slots 75 * enumerated above, and then there are those that are allocated during startup by calls to 76 * pthread_key_create; grep for GLOBAL_INIT_THREAD_LOCAL_BUFFER to find those. We need to manually 77 * maintain that second number, but pthread_test will fail if we forget. 78 */ 79 #define GLOBAL_INIT_THREAD_LOCAL_BUFFER_COUNT 5 80 81 #if defined(USE_JEMALLOC) 82 /* jemalloc uses 5 keys for itself. */ 83 #define BIONIC_TLS_RESERVED_SLOTS (GLOBAL_INIT_THREAD_LOCAL_BUFFER_COUNT + 5) 84 #else 85 #define BIONIC_TLS_RESERVED_SLOTS GLOBAL_INIT_THREAD_LOCAL_BUFFER_COUNT 86 #endif 87 88 /* 89 * Maximum number of elements in the TLS array. 90 * This includes space for pthread keys and our own internal slots. 91 * We need to round up to maintain stack alignment. 92 */ 93 #define BIONIC_TLS_SLOTS BIONIC_ALIGN(PTHREAD_KEYS_MAX + TLS_SLOT_FIRST_USER_SLOT + BIONIC_TLS_RESERVED_SLOTS, 4) 94 95 __END_DECLS 96 97 #if defined(__cplusplus) 98 class KernelArgumentBlock; 99 extern __LIBC_HIDDEN__ void __libc_init_tls(KernelArgumentBlock& args); 100 #endif 101 102 #endif /* __BIONIC_PRIVATE_BIONIC_TLS_H_ */ 103