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
fileLock(HANDLE file_handle,DWORD flags,const uint64_t start,const uint64_t len)16 static Status fileLock(HANDLE file_handle, DWORD flags, const uint64_t start,
17 const uint64_t len) {
18 if (start != 0)
19 return Status("Non-zero start lock regions are not supported");
20
21 OVERLAPPED overlapped = {};
22
23 if (!::LockFileEx(file_handle, flags, 0, len, 0, &overlapped) &&
24 ::GetLastError() != ERROR_IO_PENDING)
25 return Status(::GetLastError(), eErrorTypeWin32);
26
27 DWORD bytes;
28 if (!::GetOverlappedResult(file_handle, &overlapped, &bytes, TRUE))
29 return Status(::GetLastError(), eErrorTypeWin32);
30
31 return Status();
32 }
33
LockFileWindows(int fd)34 LockFileWindows::LockFileWindows(int fd)
35 : LockFileBase(fd), m_file(reinterpret_cast<HANDLE>(_get_osfhandle(fd))) {}
36
~LockFileWindows()37 LockFileWindows::~LockFileWindows() { Unlock(); }
38
IsValidFile() const39 bool LockFileWindows::IsValidFile() const {
40 return LockFileBase::IsValidFile() && m_file != INVALID_HANDLE_VALUE;
41 }
42
DoWriteLock(const uint64_t start,const uint64_t len)43 Status LockFileWindows::DoWriteLock(const uint64_t start, const uint64_t len) {
44 return fileLock(m_file, LOCKFILE_EXCLUSIVE_LOCK, start, len);
45 }
46
DoTryWriteLock(const uint64_t start,const uint64_t len)47 Status LockFileWindows::DoTryWriteLock(const uint64_t start,
48 const uint64_t len) {
49 return fileLock(m_file, LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY,
50 start, len);
51 }
52
DoReadLock(const uint64_t start,const uint64_t len)53 Status LockFileWindows::DoReadLock(const uint64_t start, const uint64_t len) {
54 return fileLock(m_file, 0, start, len);
55 }
56
DoTryReadLock(const uint64_t start,const uint64_t len)57 Status LockFileWindows::DoTryReadLock(const uint64_t start,
58 const uint64_t len) {
59 return fileLock(m_file, LOCKFILE_FAIL_IMMEDIATELY, start, len);
60 }
61
DoUnlock()62 Status LockFileWindows::DoUnlock() {
63 OVERLAPPED overlapped = {};
64
65 if (!::UnlockFileEx(m_file, 0, m_len, 0, &overlapped) &&
66 ::GetLastError() != ERROR_IO_PENDING)
67 return Status(::GetLastError(), eErrorTypeWin32);
68
69 DWORD bytes;
70 if (!::GetOverlappedResult(m_file, &overlapped, &bytes, TRUE))
71 return Status(::GetLastError(), eErrorTypeWin32);
72
73 return Status();
74 }
75