1 //===-- LockFilePosix.cpp ---------------------------------------*- 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 #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 19 namespace { 20 21 Status fileLock(int fd, int cmd, int lock_type, const uint64_t start, 22 const uint64_t len) { 23 struct flock fl; 24 25 fl.l_type = lock_type; 26 fl.l_whence = SEEK_SET; 27 fl.l_start = start; 28 fl.l_len = len; 29 fl.l_pid = ::getpid(); 30 31 Status error; 32 if (llvm::sys::RetryAfterSignal(-1, ::fcntl, fd, cmd, &fl) == -1) 33 error.SetErrorToErrno(); 34 35 return error; 36 } 37 38 } // namespace 39 40 LockFilePosix::LockFilePosix(int fd) : LockFileBase(fd) {} 41 42 LockFilePosix::~LockFilePosix() { Unlock(); } 43 44 Status LockFilePosix::DoWriteLock(const uint64_t start, const uint64_t len) { 45 return fileLock(m_fd, F_SETLKW, F_WRLCK, start, len); 46 } 47 48 Status LockFilePosix::DoTryWriteLock(const uint64_t start, const uint64_t len) { 49 return fileLock(m_fd, F_SETLK, F_WRLCK, start, len); 50 } 51 52 Status LockFilePosix::DoReadLock(const uint64_t start, const uint64_t len) { 53 return fileLock(m_fd, F_SETLKW, F_RDLCK, start, len); 54 } 55 56 Status LockFilePosix::DoTryReadLock(const uint64_t start, const uint64_t len) { 57 return fileLock(m_fd, F_SETLK, F_RDLCK, start, len); 58 } 59 60 Status LockFilePosix::DoUnlock() { 61 return fileLock(m_fd, F_SETLK, F_UNLCK, m_start, m_len); 62 } 63