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 namespace {
15
AlreadyLocked()16 Status AlreadyLocked() { return Status("Already locked"); }
17
NotLocked()18 Status NotLocked() { return Status("Not locked"); }
19 }
20
LockFileBase(int fd)21 LockFileBase::LockFileBase(int fd)
22 : m_fd(fd), m_locked(false), m_start(0), m_len(0) {}
23
IsLocked() const24 bool LockFileBase::IsLocked() const { return m_locked; }
25
WriteLock(const uint64_t start,const uint64_t len)26 Status 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
TryWriteLock(const uint64_t start,const uint64_t len)32 Status 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
ReadLock(const uint64_t start,const uint64_t len)38 Status 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
TryReadLock(const uint64_t start,const uint64_t len)44 Status 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
Unlock()50 Status 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
IsValidFile() const63 bool LockFileBase::IsValidFile() const { return m_fd != -1; }
64
DoLock(const Locker & locker,const uint64_t start,const uint64_t len)65 Status 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