1 //===-- LockFilePosix.cpp ---------------------------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "lldb/Host/posix/LockFilePosix.h"
11
12 #include <fcntl.h>
13 #include <unistd.h>
14
15 using namespace lldb;
16 using namespace lldb_private;
17
18 namespace {
19
fileLock(int fd,int cmd,int lock_type,const uint64_t start,const uint64_t len)20 Status fileLock(int fd, int cmd, int lock_type, const uint64_t start,
21 const uint64_t len) {
22 struct flock fl;
23
24 fl.l_type = lock_type;
25 fl.l_whence = SEEK_SET;
26 fl.l_start = start;
27 fl.l_len = len;
28 fl.l_pid = ::getpid();
29
30 Status error;
31 if (::fcntl(fd, cmd, &fl) == -1)
32 error.SetErrorToErrno();
33
34 return error;
35 }
36
37 } // namespace
38
LockFilePosix(int fd)39 LockFilePosix::LockFilePosix(int fd) : LockFileBase(fd) {}
40
~LockFilePosix()41 LockFilePosix::~LockFilePosix() { Unlock(); }
42
DoWriteLock(const uint64_t start,const uint64_t len)43 Status LockFilePosix::DoWriteLock(const uint64_t start, const uint64_t len) {
44 return fileLock(m_fd, F_SETLKW, F_WRLCK, start, len);
45 }
46
DoTryWriteLock(const uint64_t start,const uint64_t len)47 Status LockFilePosix::DoTryWriteLock(const uint64_t start, const uint64_t len) {
48 return fileLock(m_fd, F_SETLK, F_WRLCK, start, len);
49 }
50
DoReadLock(const uint64_t start,const uint64_t len)51 Status LockFilePosix::DoReadLock(const uint64_t start, const uint64_t len) {
52 return fileLock(m_fd, F_SETLKW, F_RDLCK, start, len);
53 }
54
DoTryReadLock(const uint64_t start,const uint64_t len)55 Status LockFilePosix::DoTryReadLock(const uint64_t start, const uint64_t len) {
56 return fileLock(m_fd, F_SETLK, F_RDLCK, start, len);
57 }
58
DoUnlock()59 Status LockFilePosix::DoUnlock() {
60 return fileLock(m_fd, F_SETLK, F_UNLCK, m_start, m_len);
61 }
62