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