aboutsummaryrefslogtreecommitdiffstats
path: root/libc/private/bionic_tls.h
blob: 852b9aebc6fb70b4b15b6582ba925a85ff186be4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/*
 * 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 __BIONIC_PRIVATE_BIONIC_TLS_H_
#define __BIONIC_PRIVATE_BIONIC_TLS_H_

#include <locale.h>
#include <mntent.h>
#include <stdio.h>
#include <sys/cdefs.h>
#include <sys/param.h>

#include "bionic_macros.h"
#include "__get_tls.h"
#include "grp_pwd.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).
 **/

// 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,

  // These two aren't used by bionic itself, but allow the graphics code to
  // access TLS directly rather than using the pthread API.
  TLS_SLOT_OPENGL_API = 3,
  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 that isn't needed during libc startup.
  TLS_SLOT_BIONIC_PREINIT = TLS_SLOT_OPENGL_API,

  TLS_SLOT_STACK_GUARD = 5, // GCC requires this specific slot for x86.
  TLS_SLOT_DLERROR,

  // Fast storage for Thread::Current() in ART.
  TLS_SLOT_ART_THREAD_SELF,

  // Lets TSAN avoid using pthread_getspecific for finding the current thread
  // state.
  TLS_SLOT_TSAN,

  BIONIC_TLS_SLOTS // Must come last!
};

// ~3 pages.
struct bionic_tls {
  locale_t locale;

  char basename_buf[MAXPATHLEN];
  char dirname_buf[MAXPATHLEN];

  mntent mntent_buf;
  char mntent_strings[BUFSIZ];

  char ptsname_buf[32];
  char ttyname_buf[64];

  char strerror_buf[NL_TEXTMAX];
  char strsignal_buf[NL_TEXTMAX];

  group_state_t group;
  passwd_state_t passwd;
};

#define BIONIC_TLS_SIZE (BIONIC_ALIGN(sizeof(bionic_tls), PAGE_SIZE))

/*
 * Bionic uses some pthread keys internally. All pthread keys used internally
 * should be created in constructors, except for keys that may be used in or
 * before constructors.
 *
 * We need to manually maintain the count of pthread keys used internally, but
 * pthread_test should fail if we forget.
 *
 * These are the pthread keys currently used internally by libc:
 *  _res_key               libc (constructor in BSD code)
 */

#define LIBC_PTHREAD_KEY_RESERVED_COUNT 1

/* Internally, jemalloc uses a single key for per thread data. */
#define JEMALLOC_PTHREAD_KEY_RESERVED_COUNT 1
#define BIONIC_PTHREAD_KEY_RESERVED_COUNT (LIBC_PTHREAD_KEY_RESERVED_COUNT + JEMALLOC_PTHREAD_KEY_RESERVED_COUNT)

/*
 * Maximum number of pthread keys allocated.
 * This includes pthread keys used internally and externally.
 */
#define BIONIC_PTHREAD_KEY_COUNT (BIONIC_PTHREAD_KEY_RESERVED_COUNT + PTHREAD_KEYS_MAX)

__END_DECLS

#if defined(__cplusplus)
class KernelArgumentBlock;
extern void __libc_init_main_thread(KernelArgumentBlock&);
#endif

#endif /* __BIONIC_PRIVATE_BIONIC_TLS_H_ */