BacktraceThread.h revision a2efd3ac7abe223aa7a8ba8b5ba448216c4953b4 
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  inline void CopyUcontext(ucontext_t* ucontext) {
44    memcpy(&ucontext_, ucontext, sizeof(ucontext_));
45  }
46
47  void Wake();
48
49  void Wait(int);
50
51  inline void Lock() {
52    pthread_mutex_lock(&mutex_);
53    // Reset the futex value in case of multiple unwinds of the same thread.
54    futex_ = 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 futex_;
72  int ref_count_;
73  pthread_mutex_t mutex_;
74  ThreadEntry* next_;
75  ThreadEntry* prev_;
76  ucontext_t ucontext_;
77
78  static ThreadEntry* list_;
79  static pthread_mutex_t list_mutex_;
80};
81
82class BacktraceThread : public BacktraceCurrent {
83public:
84  BacktraceThread(BacktraceImpl* impl, pid_t tid, BacktraceMap* map);
85  virtual ~BacktraceThread();
86
87  virtual bool Unwind(size_t num_ignore_frames, ucontext_t* ucontext);
88};
89
90#endif // _LIBBACKTRACE_BACKTRACE_THREAD_H
91