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#pragma once 30 31#include <pthread.h> 32#include <stdatomic.h> 33 34#include "private/bionic_lock.h" 35#include "private/bionic_tls.h" 36 37// Has the thread been detached by a pthread_join or pthread_detach call? 38#define PTHREAD_ATTR_FLAG_DETACHED 0x00000001 39 40// Has the thread been joined by another thread? 41#define PTHREAD_ATTR_FLAG_JOINED 0x00000002 42 43// Used for pthread_attr_setinheritsched. We need two flags for this apparent 44// boolean because our historical behavior matches neither of the POSIX choices. 45#define PTHREAD_ATTR_FLAG_INHERIT 0x00000004 46#define PTHREAD_ATTR_FLAG_EXPLICIT 0x00000008 47 48class pthread_key_data_t { 49 public: 50 uintptr_t seq; // Use uintptr_t just for alignment, as we use pointer below. 51 void* data; 52}; 53 54enum ThreadJoinState { 55 THREAD_NOT_JOINED, 56 THREAD_EXITED_NOT_JOINED, 57 THREAD_JOINED, 58 THREAD_DETACHED 59}; 60 61class thread_local_dtor; 62 63class pthread_internal_t { 64 public: 65 class pthread_internal_t* next; 66 class pthread_internal_t* prev; 67 68 pid_t tid; 69 70 private: 71 pid_t cached_pid_; 72 73 public: 74 pid_t invalidate_cached_pid() { 75 pid_t old_value; 76 get_cached_pid(&old_value); 77 set_cached_pid(0); 78 return old_value; 79 } 80 81 void set_cached_pid(pid_t value) { 82 cached_pid_ = value; 83 } 84 85 bool get_cached_pid(pid_t* cached_pid) { 86 *cached_pid = cached_pid_; 87 return (*cached_pid != 0); 88 } 89 90 pthread_attr_t attr; 91 92 _Atomic(ThreadJoinState) join_state; 93 94 __pthread_cleanup_t* cleanup_stack; 95 96 void* (*start_routine)(void*); 97 void* start_routine_arg; 98 void* return_value; 99 100 void* alternate_signal_stack; 101 102 Lock startup_handshake_lock; 103 104 size_t mmap_size; 105 106 thread_local_dtor* thread_local_dtors; 107 108 void* tls[BIONIC_TLS_SLOTS]; 109 110 pthread_key_data_t key_data[BIONIC_PTHREAD_KEY_COUNT]; 111 112 /* 113 * The dynamic linker implements dlerror(3), which makes it hard for us to implement this 114 * per-thread buffer by simply using malloc(3) and free(3). 115 */ 116#define __BIONIC_DLERROR_BUFFER_SIZE 512 117 char dlerror_buffer[__BIONIC_DLERROR_BUFFER_SIZE]; 118 119 bionic_tls* bionic_tls; 120}; 121 122__LIBC_HIDDEN__ int __init_thread(pthread_internal_t* thread); 123__LIBC_HIDDEN__ bool __init_tls(pthread_internal_t* thread); 124__LIBC_HIDDEN__ void __init_thread_stack_guard(pthread_internal_t* thread); 125__LIBC_HIDDEN__ void __init_alternate_signal_stack(pthread_internal_t*); 126 127__LIBC_HIDDEN__ pthread_t __pthread_internal_add(pthread_internal_t* thread); 128__LIBC_HIDDEN__ pthread_internal_t* __pthread_internal_find(pthread_t pthread_id); 129__LIBC_HIDDEN__ void __pthread_internal_remove(pthread_internal_t* thread); 130__LIBC_HIDDEN__ void __pthread_internal_remove_and_free(pthread_internal_t* thread); 131 132// Make __get_thread() inlined for performance reason. See http://b/19825434. 133static inline __always_inline pthread_internal_t* __get_thread() { 134 void** tls = __get_tls(); 135 if (__predict_true(tls)) { 136 return reinterpret_cast<pthread_internal_t*>(tls[TLS_SLOT_THREAD_ID]); 137 } 138 139 // This happens when called during libc initialization before TLS has been initialized. 140 return nullptr; 141} 142 143static inline __always_inline bionic_tls& __get_bionic_tls() { 144 return *__get_thread()->bionic_tls; 145} 146 147__LIBC_HIDDEN__ void pthread_key_clean_all(void); 148 149// Address space is precious on LP32, so use the minimum unit: one page. 150// On LP64, we could use more but there's no obvious advantage to doing 151// so, and the various media processes use RLIMIT_AS as a way to limit 152// the amount of allocation they'll do. 153#define PTHREAD_GUARD_SIZE PAGE_SIZE 154 155// SIGSTKSZ (8KiB) is not big enough. 156// An snprintf to a stack buffer of size PATH_MAX consumes ~7KiB of stack. 157// Also, on 64-bit, logging uses more than 8KiB by itself: 158// https://code.google.com/p/android/issues/detail?id=187064 159#define SIGNAL_STACK_SIZE_WITHOUT_GUARD (16 * 1024) 160 161// Traditionally we gave threads a 1MiB stack. When we started 162// allocating per-thread alternate signal stacks to ease debugging of 163// stack overflows, we subtracted the same amount we were using there 164// from the default thread stack size. This should keep memory usage 165// roughly constant. 166#define PTHREAD_STACK_SIZE_DEFAULT ((1 * 1024 * 1024) - SIGNAL_STACK_SIZE_WITHOUT_GUARD) 167 168// Leave room for a guard page in the internally created signal stacks. 169#define SIGNAL_STACK_SIZE (SIGNAL_STACK_SIZE_WITHOUT_GUARD + PTHREAD_GUARD_SIZE) 170 171// Needed by fork. 172__LIBC_HIDDEN__ extern void __bionic_atfork_run_prepare(); 173__LIBC_HIDDEN__ extern void __bionic_atfork_run_child(); 174__LIBC_HIDDEN__ extern void __bionic_atfork_run_parent(); 175