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 #include <ucontext.h>
23 
24 #include <backtrace/Backtrace.h>
25 
26 // The signal used to cause a thread to dump the stack.
27 #if defined(__GLIBC__)
28 // In order to run the backtrace_tests on the host, we can't use
29 // the internal real time signals used by GLIBC. To avoid this,
30 // use SIGRTMIN for the signal to dump the stack.
31 #define THREAD_SIGNAL SIGRTMIN
32 #else
33 #define THREAD_SIGNAL (__SIGRTMIN+1)
34 #endif
35 
36 class BacktraceMap;
37 
38 class BacktraceCurrent : public Backtrace {
39 public:
BacktraceCurrent(pid_t pid,pid_t tid,BacktraceMap * map)40   BacktraceCurrent(pid_t pid, pid_t tid, BacktraceMap* map) : Backtrace(pid, tid, map) {}
~BacktraceCurrent()41   virtual ~BacktraceCurrent() {}
42 
43   size_t Read(uintptr_t addr, uint8_t* buffer, size_t bytes) override;
44 
45   bool ReadWord(uintptr_t ptr, word_t* out_value) override;
46 
47   bool Unwind(size_t num_ignore_frames, ucontext_t* ucontext) override;
48 
49 protected:
50   bool DiscardFrame(const backtrace_frame_data_t& frame);
51 
52 private:
53   bool UnwindThread(size_t num_ignore_frames);
54 
55   virtual bool UnwindFromContext(size_t num_ignore_frames, ucontext_t* ucontext) = 0;
56 };
57 
58 #endif // _LIBBACKTRACE_BACKTRACE_CURRENT_H
59