58 lines · cpp
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-exception6//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 16using namespace lldb;17using namespace lldb_private;18 19static 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 if (llvm::sys::RetryAfterSignal(-1, ::fcntl, fd, cmd, &fl) == -1)30 return Status::FromErrno();31 32 return Status();33}34 35LockFilePosix::LockFilePosix(int fd) : LockFileBase(fd) {}36 37LockFilePosix::~LockFilePosix() { Unlock(); }38 39Status LockFilePosix::DoWriteLock(const uint64_t start, const uint64_t len) {40 return fileLock(m_fd, F_SETLKW, F_WRLCK, start, len);41}42 43Status LockFilePosix::DoTryWriteLock(const uint64_t start, const uint64_t len) {44 return fileLock(m_fd, F_SETLK, F_WRLCK, start, len);45}46 47Status LockFilePosix::DoReadLock(const uint64_t start, const uint64_t len) {48 return fileLock(m_fd, F_SETLKW, F_RDLCK, start, len);49}50 51Status LockFilePosix::DoTryReadLock(const uint64_t start, const uint64_t len) {52 return fileLock(m_fd, F_SETLK, F_RDLCK, start, len);53}54 55Status LockFilePosix::DoUnlock() {56 return fileLock(m_fd, F_SETLK, F_UNLCK, m_start, m_len);57}58