1 //===-- LockFilePosix.cpp -------------------------------------------------===//
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 #include "lldb/Host/posix/LockFilePosix.h"
10
11 #include "llvm/Support/Errno.h"
12
13 #include <fcntl.h>
14 #include <unistd.h>
15
16 using namespace lldb;
17 using namespace lldb_private;
18
fileLock(int fd,int cmd,int lock_type,const uint64_t start,const uint64_t len)19 static Status fileLock(int fd, int cmd, int lock_type, const uint64_t start,
20 const uint64_t len) {
21 struct flock fl;
22
23 fl.l_type = lock_type;
24 fl.l_whence = SEEK_SET;
25 fl.l_start = start;
26 fl.l_len = len;
27 fl.l_pid = ::getpid();
28
29 Status error;
30 if (llvm::sys::RetryAfterSignal(-1, ::fcntl, fd, cmd, &fl) == -1)
31 error.SetErrorToErrno();
32
33 return error;
34 }
35
LockFilePosix(int fd)36 LockFilePosix::LockFilePosix(int fd) : LockFileBase(fd) {}
37
~LockFilePosix()38 LockFilePosix::~LockFilePosix() { Unlock(); }
39
DoWriteLock(const uint64_t start,const uint64_t len)40 Status LockFilePosix::DoWriteLock(const uint64_t start, const uint64_t len) {
41 return fileLock(m_fd, F_SETLKW, F_WRLCK, start, len);
42 }
43
DoTryWriteLock(const uint64_t start,const uint64_t len)44 Status LockFilePosix::DoTryWriteLock(const uint64_t start, const uint64_t len) {
45 return fileLock(m_fd, F_SETLK, F_WRLCK, start, len);
46 }
47
DoReadLock(const uint64_t start,const uint64_t len)48 Status LockFilePosix::DoReadLock(const uint64_t start, const uint64_t len) {
49 return fileLock(m_fd, F_SETLKW, F_RDLCK, start, len);
50 }
51
DoTryReadLock(const uint64_t start,const uint64_t len)52 Status LockFilePosix::DoTryReadLock(const uint64_t start, const uint64_t len) {
53 return fileLock(m_fd, F_SETLK, F_RDLCK, start, len);
54 }
55
DoUnlock()56 Status LockFilePosix::DoUnlock() {
57 return fileLock(m_fd, F_SETLK, F_UNLCK, m_start, m_len);
58 }
59