llvm-project/lldb/source/Host/windows/LockFileWindows.cpp

94 lines
2.3 KiB
C++

//===-- LockFileWindows.cpp -------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Host/windows/LockFileWindows.h"
#include <io.h>
using namespace lldb;
using namespace lldb_private;
namespace
{
Error fileLock (HANDLE file_handle, DWORD flags, const uint64_t start, const uint64_t len)
{
if (start != 0)
return Error ("Non-zero start lock regions are not supported");
OVERLAPPED overlapped = {0};
if (!::LockFileEx (file_handle, flags, 0, len, 0, &overlapped) && ::GetLastError () != ERROR_IO_PENDING)
return Error (::GetLastError (), eErrorTypeWin32);
DWORD bytes;
if (!::GetOverlappedResult (file_handle, &overlapped, &bytes, TRUE))
return Error (::GetLastError (), eErrorTypeWin32);
return Error ();
}
} // namespace
LockFileWindows::LockFileWindows (int fd)
: LockFileBase (fd),
m_file (reinterpret_cast<HANDLE> (_get_osfhandle (fd)))
{
}
LockFileWindows::~LockFileWindows ()
{
Unlock ();
}
bool
LockFileWindows::IsValidFile () const
{
return LockFileBase::IsValidFile() && m_file != INVALID_HANDLE_VALUE;
}
Error
LockFileWindows::DoWriteLock (const uint64_t start, const uint64_t len)
{
return fileLock (m_file, LOCKFILE_EXCLUSIVE_LOCK, start, len);
}
Error
LockFileWindows::DoTryWriteLock (const uint64_t start, const uint64_t len)
{
return fileLock (m_file, LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY, start, len);
}
Error
LockFileWindows::DoReadLock (const uint64_t start, const uint64_t len)
{
return fileLock (m_file, 0, start, len);
}
Error
LockFileWindows::DoTryReadLock (const uint64_t start, const uint64_t len)
{
return fileLock (m_file, LOCKFILE_FAIL_IMMEDIATELY, start, len);
}
Error
LockFileWindows::DoUnlock ()
{
OVERLAPPED overlapped = {0};
if (!::UnlockFileEx (m_file, 0, m_len, 0, &overlapped) && ::GetLastError () != ERROR_IO_PENDING)
return Error (::GetLastError (), eErrorTypeWin32);
DWORD bytes;
if (!::GetOverlappedResult (m_file, &overlapped, &bytes, TRUE))
return Error (::GetLastError (), eErrorTypeWin32);
return Error ();
}