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. |
18 | namespace 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 | |
25 | class ProcessRunLock { |
26 | public: |
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 | |
74 | protected: |
75 | lldb::rwlock_t m_rwlock; |
76 | bool m_running = false; |
77 | |
78 | private: |
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 | |