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
19namespace __sanitizer {
20
21enum 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.
29class 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.
35  virtual PtraceRegistersStatus GetRegistersAndSP(uptr index, uptr *buffer,
36                                                  uptr *sp) const {
37    UNIMPLEMENTED();
38  }
39
40  // The buffer in GetRegistersAndSP should be at least this big.
41  virtual uptr RegisterCount() const { UNIMPLEMENTED(); }
42  virtual uptr ThreadCount() const { UNIMPLEMENTED(); }
43  virtual tid_t GetThreadID(uptr index) const { UNIMPLEMENTED(); }
44
45 private:
46  // Prohibit copy and assign.
47  SuspendedThreadsList(const SuspendedThreadsList&);
48  void operator=(const SuspendedThreadsList&);
49};
50
51typedef void (*StopTheWorldCallback)(
52    const SuspendedThreadsList &suspended_threads_list,
53    void *argument);
54
55// Suspend all threads in the current process and run the callback on the list
56// of suspended threads. This function will resume the threads before returning.
57// The callback should not call any libc functions. The callback must not call
58// exit() nor _exit() and instead return to the caller.
59// This function should NOT be called from multiple threads simultaneously.
60void StopTheWorld(StopTheWorldCallback callback, void *argument);
61
62}  // namespace __sanitizer
63
64#endif  // SANITIZER_STOPTHEWORLD_H
65