1/*
2 * Copyright (C) 2012 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_THREAD_LOCAL_BUFFER_H_included
30#define _BIONIC_THREAD_LOCAL_BUFFER_H_included
31
32#include <malloc.h>
33#include <pthread.h>
34
35// libstdc++ currently contains __cxa_guard_acquire and __cxa_guard_release,
36// so we make do with macros instead of a C++ class.
37// TODO: move __cxa_guard_acquire and __cxa_guard_release into libc.
38
39// We used to use pthread_once to initialize the keys, but life is more predictable
40// if we allocate them all up front when the C library starts up, via __constructor__.
41
42#define GLOBAL_INIT_THREAD_LOCAL_BUFFER(name) \
43  static pthread_key_t __bionic_tls_ ## name ## _key; \
44  static void __bionic_tls_ ## name ## _key_destroy(void* buffer) { \
45    free(buffer); \
46  } \
47  __attribute__((constructor)) static void __bionic_tls_ ## name ## _key_init() { \
48    pthread_key_create(&__bionic_tls_ ## name ## _key, __bionic_tls_ ## name ## _key_destroy); \
49  }
50
51// Leaves "name_tls_buffer" and "name_tls_buffer_size" defined and initialized.
52#define LOCAL_INIT_THREAD_LOCAL_BUFFER(type, name, byte_count) \
53  type name ## _tls_buffer = \
54      reinterpret_cast<type>(pthread_getspecific(__bionic_tls_ ## name ## _key)); \
55  if (name ## _tls_buffer == NULL) { \
56    name ## _tls_buffer = reinterpret_cast<type>(calloc(1, byte_count)); \
57    pthread_setspecific(__bionic_tls_ ## name ## _key, name ## _tls_buffer); \
58  } \
59  const size_t name ## _tls_buffer_size __attribute__((unused)) = byte_count
60
61#endif // _BIONIC_THREAD_LOCAL_BUFFER_H_included
62