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