1 /* 2 * Copyright (C) 2008 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 ART_RUNTIME_SIGNAL_CATCHER_H_ 18 #define ART_RUNTIME_SIGNAL_CATCHER_H_ 19 20 #include "android-base/unique_fd.h" 21 #include "base/mutex.h" 22 23 namespace art { 24 25 class Runtime; 26 class SignalSet; 27 class Thread; 28 29 /* 30 * A daemon thread that catches signals and does something useful. For 31 * example, when a SIGQUIT (Ctrl-\) arrives, we suspend and dump the 32 * status of all threads. 33 */ 34 class SignalCatcher { 35 public: 36 // If |use_tombstoned_stack_trace_fd| is |true|, traces will be 37 // written to a file descriptor provided by tombstoned. The process 38 // will communicate with tombstoned via a unix domain socket. This 39 // mode of stack trace dumping is only supported in an Android 40 // environment. 41 // 42 // If false, all traces will be dumped to |stack_trace_file| if it's 43 // non-empty. If |stack_trace_file| is empty, all traces will be written 44 // to the log buffer. 45 SignalCatcher(const std::string& stack_trace_file, 46 const bool use_tombstoned_stack_trace_fd); 47 ~SignalCatcher(); 48 49 void HandleSigQuit() REQUIRES(!Locks::mutator_lock_, !Locks::thread_list_lock_, 50 !Locks::thread_suspend_count_lock_); 51 52 53 private: 54 // NO_THREAD_SAFETY_ANALYSIS for static function calling into member function with excludes lock. 55 static void* Run(void* arg) NO_THREAD_SAFETY_ANALYSIS; 56 57 // NOTE: We're using android::base::unique_fd here for easier 58 // interoperability with tombstoned client APIs. 59 bool OpenStackTraceFile(android::base::unique_fd* tombstone_fd, 60 android::base::unique_fd* output_fd); 61 void HandleSigUsr1(); 62 void Output(const std::string& s); 63 void SetHaltFlag(bool new_value) REQUIRES(!lock_); 64 bool ShouldHalt() REQUIRES(!lock_); 65 int WaitForSignal(Thread* self, SignalSet& signals) REQUIRES(!lock_); 66 67 std::string stack_trace_file_; 68 const bool use_tombstoned_stack_trace_fd_; 69 70 mutable Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER; 71 ConditionVariable cond_ GUARDED_BY(lock_); 72 bool halt_ GUARDED_BY(lock_); 73 pthread_t pthread_ GUARDED_BY(lock_); 74 Thread* thread_ GUARDED_BY(lock_); 75 }; 76 77 } // namespace art 78 79 #endif // ART_RUNTIME_SIGNAL_CATCHER_H_ 80
