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.
      35    virtual PtraceRegistersStatus GetRegistersAndSP(
      36        uptr index, InternalMmapVector<uptr> *buffer, uptr *sp) const {
      37      UNIMPLEMENTED();
      38    }
      39  
      40    virtual uptr ThreadCount() const { UNIMPLEMENTED(); }
      41    virtual tid_t GetThreadID(uptr index) const { UNIMPLEMENTED(); }
      42  
      43   protected:
      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