/src/CMake/Source/cmFileLockUnix.cxx
Line | Count | Source |
1 | | /* Distributed under the OSI-approved BSD 3-Clause License. See accompanying |
2 | | file LICENSE.rst or https://cmake.org/licensing for details. */ |
3 | | #include <cerrno> // errno |
4 | | #include <cstdio> // SEEK_SET |
5 | | |
6 | | #include <fcntl.h> |
7 | | #include <unistd.h> |
8 | | |
9 | | #include "cmFileLock.h" |
10 | | #include "cmSystemTools.h" |
11 | | |
12 | 141 | cmFileLock::cmFileLock() = default; |
13 | | |
14 | | cmFileLockResult cmFileLock::Release() |
15 | 141 | { |
16 | 141 | if (this->Filename.empty()) { |
17 | 79 | return cmFileLockResult::MakeOk(); |
18 | 79 | } |
19 | 62 | int const lockResult = this->LockFile(F_SETLK, F_UNLCK); |
20 | | |
21 | 62 | this->Filename = ""; |
22 | | |
23 | 62 | ::close(this->File); |
24 | 62 | this->File = -1; |
25 | | |
26 | 62 | if (lockResult == 0) { |
27 | 62 | return cmFileLockResult::MakeOk(); |
28 | 62 | } |
29 | 0 | return cmFileLockResult::MakeSystem(); |
30 | 62 | } |
31 | | |
32 | | cmFileLockResult cmFileLock::OpenFile() |
33 | 141 | { |
34 | 141 | this->File = ::open(this->Filename.c_str(), O_RDWR); |
35 | 141 | if (this->File == -1) { |
36 | 79 | return cmFileLockResult::MakeSystem(); |
37 | 79 | } |
38 | 62 | return cmFileLockResult::MakeOk(); |
39 | 141 | } |
40 | | |
41 | | cmFileLockResult cmFileLock::LockWithoutTimeout() |
42 | 0 | { |
43 | 0 | if (this->LockFile(F_SETLKW, F_WRLCK) == -1) { |
44 | 0 | return cmFileLockResult::MakeSystem(); |
45 | 0 | } |
46 | 0 | return cmFileLockResult::MakeOk(); |
47 | 0 | } |
48 | | |
49 | | cmFileLockResult cmFileLock::LockWithTimeout(unsigned long seconds) |
50 | 62 | { |
51 | 62 | while (true) { |
52 | 62 | if (this->LockFile(F_SETLK, F_WRLCK) == -1) { |
53 | 0 | if (errno != EACCES && errno != EAGAIN) { |
54 | 0 | return cmFileLockResult::MakeSystem(); |
55 | 0 | } |
56 | 62 | } else { |
57 | 62 | return cmFileLockResult::MakeOk(); |
58 | 62 | } |
59 | 0 | if (seconds == 0) { |
60 | 0 | return cmFileLockResult::MakeTimeout(); |
61 | 0 | } |
62 | 0 | --seconds; |
63 | 0 | cmSystemTools::Delay(1000); |
64 | 0 | } |
65 | 62 | } |
66 | | |
67 | | int cmFileLock::LockFile(int cmd, int type) const |
68 | 124 | { |
69 | 124 | struct ::flock lock; |
70 | 124 | lock.l_start = 0; |
71 | 124 | lock.l_len = 0; // lock all bytes |
72 | 124 | lock.l_pid = 0; // unused (for F_GETLK only) |
73 | 124 | lock.l_type = static_cast<short>(type); // exclusive lock |
74 | | lock.l_whence = SEEK_SET; |
75 | 124 | return ::fcntl(this->File, cmd, &lock); |
76 | 124 | } |