1 //===-- LockFileWindows.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/windows/LockFileWindows.h"
10
11 #include <io.h>
12
13 using namespace lldb;
14 using namespace lldb_private;
15
16 namespace {
17
fileLock(HANDLE file_handle,DWORD flags,const uint64_t start,const uint64_t len)18 Status fileLock(HANDLE file_handle, DWORD flags, const uint64_t start,
19 const uint64_t len) {
20 if (start != 0)
21 return Status("Non-zero start lock regions are not supported");
22
23 OVERLAPPED overlapped = {};
24
25 if (!::LockFileEx(file_handle, flags, 0, len, 0, &overlapped) &&
26 ::GetLastError() != ERROR_IO_PENDING)
27 return Status(::GetLastError(), eErrorTypeWin32);
28
29 DWORD bytes;
30 if (!::GetOverlappedResult(file_handle, &overlapped, &bytes, TRUE))
31 return Status(::GetLastError(), eErrorTypeWin32);
32
33 return Status();
34 }
35
36 } // namespace
37
LockFileWindows(int fd)38 LockFileWindows::LockFileWindows(int fd)
39 : LockFileBase(fd), m_file(reinterpret_cast<HANDLE>(_get_osfhandle(fd))) {}
40
~LockFileWindows()41 LockFileWindows::~LockFileWindows() { Unlock(); }
42
IsValidFile() const43 bool LockFileWindows::IsValidFile() const {
44 return LockFileBase::IsValidFile() && m_file != INVALID_HANDLE_VALUE;
45 }
46
DoWriteLock(const uint64_t start,const uint64_t len)47 Status LockFileWindows::DoWriteLock(const uint64_t start, const uint64_t len) {
48 return fileLock(m_file, LOCKFILE_EXCLUSIVE_LOCK, start, len);
49 }
50
DoTryWriteLock(const uint64_t start,const uint64_t len)51 Status LockFileWindows::DoTryWriteLock(const uint64_t start,
52 const uint64_t len) {
53 return fileLock(m_file, LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY,
54 start, len);
55 }
56
DoReadLock(const uint64_t start,const uint64_t len)57 Status LockFileWindows::DoReadLock(const uint64_t start, const uint64_t len) {
58 return fileLock(m_file, 0, start, len);
59 }
60
DoTryReadLock(const uint64_t start,const uint64_t len)61 Status LockFileWindows::DoTryReadLock(const uint64_t start,
62 const uint64_t len) {
63 return fileLock(m_file, LOCKFILE_FAIL_IMMEDIATELY, start, len);
64 }
65
DoUnlock()66 Status LockFileWindows::DoUnlock() {
67 OVERLAPPED overlapped = {};
68
69 if (!::UnlockFileEx(m_file, 0, m_len, 0, &overlapped) &&
70 ::GetLastError() != ERROR_IO_PENDING)
71 return Status(::GetLastError(), eErrorTypeWin32);
72
73 DWORD bytes;
74 if (!::GetOverlappedResult(m_file, &overlapped, &bytes, TRUE))
75 return Status(::GetLastError(), eErrorTypeWin32);
76
77 return Status();
78 }
79