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