1//===-- ProcessRunLock.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#ifndef LLDB_HOST_PROCESSRUNLOCK_H
10#define LLDB_HOST_PROCESSRUNLOCK_H
11
12#include <cstdint>
13#include <ctime>
14
15#include "lldb/lldb-defines.h"
16
17/// Enumerations for broadcasting.
18namespace lldb_private {
19
20/// \class ProcessRunLock ProcessRunLock.h "lldb/Host/ProcessRunLock.h"
21/// A class used to prevent the process from starting while other
22/// threads are accessing its data, and prevent access to its data while it is
23/// running.
24
25class ProcessRunLock {
26public:
27 ProcessRunLock();
28 ~ProcessRunLock();
29
30 bool ReadTryLock();
31 bool ReadUnlock();
32 bool SetRunning();
33 bool TrySetRunning();
34 bool SetStopped();
35
36 class ProcessRunLocker {
37 public:
38 ProcessRunLocker() = default;
39
40 ~ProcessRunLocker() { Unlock(); }
41
42 // Try to lock the read lock, but only do so if there are no writers.
43 bool TryLock(ProcessRunLock *lock) {
44 if (m_lock) {
45 if (m_lock == lock)
46 return true; // We already have this lock locked
47 else
48 Unlock();
49 }
50 if (lock) {
51 if (lock->ReadTryLock()) {
52 m_lock = lock;
53 return true;
54 }
55 }
56 return false;
57 }
58
59 protected:
60 void Unlock() {
61 if (m_lock) {
62 m_lock->ReadUnlock();
63 m_lock = nullptr;
64 }
65 }
66
67 ProcessRunLock *m_lock = nullptr;
68
69 private:
70 ProcessRunLocker(const ProcessRunLocker &) = delete;
71 const ProcessRunLocker &operator=(const ProcessRunLocker &) = delete;
72 };
73
74protected:
75 lldb::rwlock_t m_rwlock;
76 bool m_running = false;
77
78private:
79 ProcessRunLock(const ProcessRunLock &) = delete;
80 const ProcessRunLock &operator=(const ProcessRunLock &) = delete;
81};
82
83} // namespace lldb_private
84
85#endif // LLDB_HOST_PROCESSRUNLOCK_H
86

source code of lldb/include/lldb/Host/ProcessRunLock.h