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 */
29 #ifndef __BIONIC_PRIVATE_BIONIC_TLS_H_
30 #define __BIONIC_PRIVATE_BIONIC_TLS_H_
32 #include <sys/cdefs.h>
33 #include <sys/limits.h>
34 #include "bionic_macros.h"
35 #include "__get_tls.h"
37 __BEGIN_DECLS
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 **/
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,
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,
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,
67 TLS_SLOT_STACK_GUARD = 5, // GCC requires this specific slot for x86.
68 TLS_SLOT_DLERROR,
70 TLS_SLOT_FIRST_USER_SLOT // Must come last!
71 };
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 * Following are current pthread keys used internally:
79 * basename libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
80 * dirname libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
81 * uselocale libc
82 * getmntent_mntent libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
83 * getmntent_strings libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
84 * ptsname libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
85 * ttyname libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
86 * strerror libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
87 * strsignal libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
88 * stubs libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
89 * _res_key libc
90 * je_thread_allocated_tsd jemalloc
91 * je_arenas_tsd jemalloc
92 * je_tcache_tsd jemalloc
93 * je_tcache_enabled_tsd jemalloc
94 * je_quarantine_tsd jemalloc
95 *
96 */
98 #define LIBC_TLS_RESERVED_SLOTS 11
100 #if defined(USE_JEMALLOC)
101 /* jemalloc uses 5 keys for itself. */
102 #define BIONIC_TLS_RESERVED_SLOTS (LIBC_TLS_RESERVED_SLOTS + 5)
103 #else
104 #define BIONIC_TLS_RESERVED_SLOTS LIBC_TLS_RESERVED_SLOTS
105 #endif
107 /*
108 * Maximum number of elements in the TLS array.
109 * This includes space for pthread keys and our own internal slots.
110 */
111 #define BIONIC_TLS_SLOTS (PTHREAD_KEYS_MAX + TLS_SLOT_FIRST_USER_SLOT + BIONIC_TLS_RESERVED_SLOTS)
113 __END_DECLS
115 #if defined(__cplusplus)
116 class KernelArgumentBlock;
117 extern __LIBC_HIDDEN__ void __libc_init_tls(KernelArgumentBlock& args);
118 #endif
120 #endif /* __BIONIC_PRIVATE_BIONIC_TLS_H_ */