1 //===-- sanitizer_stoptheworld.h --------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Defines the StopTheWorld function which suspends the execution of the current
10 // process and runs the user-supplied callback in the same address space.
11 //
12 //===----------------------------------------------------------------------===//
13 #ifndef SANITIZER_STOPTHEWORLD_H
14 #define SANITIZER_STOPTHEWORLD_H
15 
16 #include "sanitizer_internal_defs.h"
17 #include "sanitizer_common.h"
18 
19 namespace __sanitizer {
20 
21 enum PtraceRegistersStatus {
22   REGISTERS_UNAVAILABLE_FATAL = -1,
23   REGISTERS_UNAVAILABLE = 0,
24   REGISTERS_AVAILABLE = 1
25 };
26 
27 // Holds the list of suspended threads and provides an interface to dump their
28 // register contexts.
29 class SuspendedThreadsList {
30  public:
31   SuspendedThreadsList() = default;
32 
33   // Can't declare pure virtual functions in sanitizer runtimes:
34   // __cxa_pure_virtual might be unavailable. Use UNIMPLEMENTED() instead.
GetRegistersAndSP(uptr index,InternalMmapVector<uptr> * buffer,uptr * sp)35   virtual PtraceRegistersStatus GetRegistersAndSP(
36       uptr index, InternalMmapVector<uptr> *buffer, uptr *sp) const {
37     UNIMPLEMENTED();
38   }
39 
ThreadCount()40   virtual uptr ThreadCount() const { UNIMPLEMENTED(); }
GetThreadID(uptr index)41   virtual tid_t GetThreadID(uptr index) const { UNIMPLEMENTED(); }
42 
43  protected:
~SuspendedThreadsList()44   ~SuspendedThreadsList() {}
45 
46  private:
47   // Prohibit copy and assign.
48   SuspendedThreadsList(const SuspendedThreadsList &) = delete;
49   void operator=(const SuspendedThreadsList &) = delete;
50 };
51 
52 typedef void (*StopTheWorldCallback)(
53     const SuspendedThreadsList &suspended_threads_list,
54     void *argument);
55 
56 // Suspend all threads in the current process and run the callback on the list
57 // of suspended threads. This function will resume the threads before returning.
58 // The callback should not call any libc functions. The callback must not call
59 // exit() nor _exit() and instead return to the caller.
60 // This function should NOT be called from multiple threads simultaneously.
61 void StopTheWorld(StopTheWorldCallback callback, void *argument);
62 
63 }  // namespace __sanitizer
64 
65 #endif  // SANITIZER_STOPTHEWORLD_H
66