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_CURRENT_H
18 #define _LIBBACKTRACE_BACKTRACE_CURRENT_H
19 
20 #include <stdint.h>
21 #include <sys/types.h>
22 
23 #include <backtrace/Backtrace.h>
24 
25 // The signal used to cause a thread to dump the stack.
26 #if defined(__GLIBC__)
27 // In order to run the backtrace_tests on the host, we can't use
28 // the internal real time signals used by GLIBC. To avoid this,
29 // use SIGRTMIN for the signal to dump the stack.
30 #define THREAD_SIGNAL SIGRTMIN
31 #else
32 #define THREAD_SIGNAL (__SIGRTMIN+1)
33 #endif
34 
35 class BacktraceMap;
36 
37 class BacktraceCurrent : public Backtrace {
38  public:
BacktraceCurrent(pid_t pid,pid_t tid,BacktraceMap * map)39   BacktraceCurrent(pid_t pid, pid_t tid, BacktraceMap* map) : Backtrace(pid, tid, map) {}
~BacktraceCurrent()40   virtual ~BacktraceCurrent() {}
41 
42   size_t Read(uint64_t addr, uint8_t* buffer, size_t bytes) override;
43 
44   bool ReadWord(uint64_t ptr, word_t* out_value) override;
45 
46   bool Unwind(size_t num_ignore_frames, void* ucontext) override;
47 
48  protected:
49   bool DiscardFrame(const backtrace_frame_data_t& frame);
50 
51  private:
52   bool UnwindThread(size_t num_ignore_frames);
53 
54   virtual bool UnwindFromContext(size_t num_ignore_frames, void* ucontext) = 0;
55 };
56 
57 #endif // _LIBBACKTRACE_BACKTRACE_CURRENT_H
58