1//===-- LockFileBase.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/LockFileBase.h" 10 11using namespace lldb; 12using namespace lldb_private; 13 14namespace { 15 16Status AlreadyLocked() { return Status("Already locked"); } 17 18Status NotLocked() { return Status("Not locked"); } 19} 20 21LockFileBase::LockFileBase(int fd) 22 : m_fd(fd), m_locked(false), m_start(0), m_len(0) {} 23 24bool LockFileBase::IsLocked() const { return m_locked; } 25 26Status LockFileBase::WriteLock(const uint64_t start, const uint64_t len) { 27 return DoLock([&](const uint64_t start, 28 const uint64_t len) { return DoWriteLock(start, len); }, 29 start, len); 30} 31 32Status LockFileBase::TryWriteLock(const uint64_t start, const uint64_t len) { 33 return DoLock([&](const uint64_t start, 34 const uint64_t len) { return DoTryWriteLock(start, len); }, 35 start, len); 36} 37 38Status LockFileBase::ReadLock(const uint64_t start, const uint64_t len) { 39 return DoLock([&](const uint64_t start, 40 const uint64_t len) { return DoReadLock(start, len); }, 41 start, len); 42} 43 44Status LockFileBase::TryReadLock(const uint64_t start, const uint64_t len) { 45 return DoLock([&](const uint64_t start, 46 const uint64_t len) { return DoTryReadLock(start, len); }, 47 start, len); 48} 49 50Status LockFileBase::Unlock() { 51 if (!IsLocked()) 52 return NotLocked(); 53 54 const auto error = DoUnlock(); 55 if (error.Success()) { 56 m_locked = false; 57 m_start = 0; 58 m_len = 0; 59 } 60 return error; 61} 62 63bool LockFileBase::IsValidFile() const { return m_fd != -1; } 64 65Status LockFileBase::DoLock(const Locker &locker, const uint64_t start, 66 const uint64_t len) { 67 if (!IsValidFile()) 68 return Status("File is invalid"); 69 70 if (IsLocked()) 71 return AlreadyLocked(); 72 73 const auto error = locker(start, len); 74 if (error.Success()) { 75 m_locked = true; 76 m_start = start; 77 m_len = len; 78 } 79 80 return error; 81} 82