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 37 class ThreadEntry { 38 public: 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 Lock()49 inline void Lock() { 50 pthread_mutex_lock(&mutex_); 51 // Reset the futex value in case of multiple unwinds of the same thread. 52 futex_ = 0; 53 } 54 Unlock()55 inline void Unlock() { 56 pthread_mutex_unlock(&mutex_); 57 } 58 GetUcontext()59 inline ucontext_t* GetUcontext() { return &ucontext_; } 60 61 private: 62 ThreadEntry(pid_t pid, pid_t tid); 63 ~ThreadEntry(); 64 Match(pid_t chk_pid,pid_t chk_tid)65 bool Match(pid_t chk_pid, pid_t chk_tid) { return (chk_pid == pid_ && chk_tid == tid_); } 66 67 pid_t pid_; 68 pid_t tid_; 69 int futex_; 70 int ref_count_; 71 pthread_mutex_t mutex_; 72 ThreadEntry* next_; 73 ThreadEntry* prev_; 74 ucontext_t ucontext_; 75 76 static ThreadEntry* list_; 77 static pthread_mutex_t list_mutex_; 78 }; 79 80 class BacktraceThread : public BacktraceCurrent { 81 public: 82 BacktraceThread(BacktraceImpl* impl, pid_t tid, BacktraceMap* map); 83 virtual ~BacktraceThread(); 84 85 virtual bool Unwind(size_t num_ignore_frames, ucontext_t* ucontext); 86 }; 87 88 #endif // _LIBBACKTRACE_BACKTRACE_THREAD_H 89