1 //===-- LockFileBase.cpp ----------------------------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "lldb/Host/LockFileBase.h"
11
12 using namespace lldb;
13 using namespace lldb_private;
14
15 namespace {
16
AlreadyLocked()17 Status AlreadyLocked() { return Status("Already locked"); }
18
NotLocked()19 Status NotLocked() { return Status("Not locked"); }
20 }
21
LockFileBase(int fd)22 LockFileBase::LockFileBase(int fd)
23 : m_fd(fd), m_locked(false), m_start(0), m_len(0) {}
24
IsLocked() const25 bool LockFileBase::IsLocked() const { return m_locked; }
26
WriteLock(const uint64_t start,const uint64_t len)27 Status LockFileBase::WriteLock(const uint64_t start, const uint64_t len) {
28 return DoLock([&](const uint64_t start,
29 const uint64_t len) { return DoWriteLock(start, len); },
30 start, len);
31 }
32
TryWriteLock(const uint64_t start,const uint64_t len)33 Status LockFileBase::TryWriteLock(const uint64_t start, const uint64_t len) {
34 return DoLock([&](const uint64_t start,
35 const uint64_t len) { return DoTryWriteLock(start, len); },
36 start, len);
37 }
38
ReadLock(const uint64_t start,const uint64_t len)39 Status LockFileBase::ReadLock(const uint64_t start, const uint64_t len) {
40 return DoLock([&](const uint64_t start,
41 const uint64_t len) { return DoReadLock(start, len); },
42 start, len);
43 }
44
TryReadLock(const uint64_t start,const uint64_t len)45 Status LockFileBase::TryReadLock(const uint64_t start, const uint64_t len) {
46 return DoLock([&](const uint64_t start,
47 const uint64_t len) { return DoTryReadLock(start, len); },
48 start, len);
49 }
50
Unlock()51 Status LockFileBase::Unlock() {
52 if (!IsLocked())
53 return NotLocked();
54
55 const auto error = DoUnlock();
56 if (error.Success()) {
57 m_locked = false;
58 m_start = 0;
59 m_len = 0;
60 }
61 return error;
62 }
63
IsValidFile() const64 bool LockFileBase::IsValidFile() const { return m_fd != -1; }
65
DoLock(const Locker & locker,const uint64_t start,const uint64_t len)66 Status LockFileBase::DoLock(const Locker &locker, const uint64_t start,
67 const uint64_t len) {
68 if (!IsValidFile())
69 return Status("File is invalid");
70
71 if (IsLocked())
72 return AlreadyLocked();
73
74 const auto error = locker(start, len);
75 if (error.Success()) {
76 m_locked = true;
77 m_start = start;
78 m_len = len;
79 }
80
81 return error;
82 }
83