BacktraceThread.h revision db44538387b08f367fc2419653639866f4c2fbd6 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef _LIBBACKTRACE_BACKTRACE_THREAD_H
18#define _LIBBACKTRACE_BACKTRACE_THREAD_H
19
20#include <inttypes.h>
21#include <pthread.h>
22#include <signal.h>
23#include <string.h>
24#include <sys/types.h>
25#include <ucontext.h>
26
27#include "BacktraceImpl.h"
28
29// The signal used to cause a thread to dump the stack.
30#if defined(__GLIBC__)
31// GLIBC reserves __SIGRTMIN signals, so use SIGRTMIN to avoid errors.
32#define THREAD_SIGNAL SIGRTMIN
33#else
34#define THREAD_SIGNAL (__SIGRTMIN+1)
35#endif
36
37class ThreadEntry {
38public:
39  static ThreadEntry* Get(pid_t pid, pid_t tid, bool create = true);
40
41  static void Remove(ThreadEntry* entry);
42
43  void Wake();
44
45  void Wait(int);
46
47  void CopyUcontextFromSigcontext(void*);
48
49  inline void Lock() {
50    pthread_mutex_lock(&mutex_);
51
52    // Always reset the wait value since this could be the first or nth
53    // time this entry is locked.
54    wait_value_ = 0;
55  }
56
57  inline void Unlock() {
58    pthread_mutex_unlock(&mutex_);
59  }
60
61  inline ucontext_t* GetUcontext() { return &ucontext_; }
62
63private:
64  ThreadEntry(pid_t pid, pid_t tid);
65  ~ThreadEntry();
66
67  bool Match(pid_t chk_pid, pid_t chk_tid) { return (chk_pid == pid_ && chk_tid == tid_); }
68
69  pid_t pid_;
70  pid_t tid_;
71  int ref_count_;
72  pthread_mutex_t mutex_;
73  pthread_mutex_t wait_mutex_;
74  pthread_cond_t wait_cond_;
75  int wait_value_;
76  ThreadEntry* next_;
77  ThreadEntry* prev_;
78  ucontext_t ucontext_;
79
80  static ThreadEntry* list_;
81  static pthread_mutex_t list_mutex_;
82};
83
84class BacktraceThread : public BacktraceCurrent {
85public:
86  BacktraceThread(BacktraceImpl* impl, pid_t tid, BacktraceMap* map);
87  virtual ~BacktraceThread();
88
89  virtual bool Unwind(size_t num_ignore_frames, ucontext_t* ucontext);
90};
91
92#endif // _LIBBACKTRACE_BACKTRACE_THREAD_H
93