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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "Win32SerialOverlappedIO.h"
// ntddser.h depends on windows.h and winioctl.h, so disable clang-format to
// keep the include order.
// clang-format off
#include <windows.h>
#include <winioctl.h>
#include <ntddser.h>
// clang-format on
namespace mozilla::dom {
bool Win32SerialOverlappedIO::Init() {
mEvent = UniqueFileHandle(CreateEvent(nullptr, TRUE, FALSE, nullptr));
if (!mEvent) {
return false;
}
mOverlapped = {};
// Setting the low-order bit of hEvent prevents the I/O completion from
// being queued to the IOCP. This is necessary because PlatformPipeReader
// may have registered a DuplicateHandle of this port with the IOCP, and
// completions from our local OVERLAPPED would corrupt the IOCP handler
// lookup. GetOverlappedResult still works via the event.
HANDLE rawEvent = mEvent.get();
mOverlapped.hEvent =
reinterpret_cast<HANDLE>(reinterpret_cast<uintptr_t>(rawEvent) | 1);
return true;
}
void Win32SerialOverlappedIO::Reset() { ResetEvent(mEvent.get()); }
bool Win32SerialOverlappedIO::Wait(HANDLE aHandle, DWORD* aBytesTransferred) {
return GetOverlappedResult(aHandle, &mOverlapped, aBytesTransferred,
/* bWait */ TRUE);
}
/* static */
bool Win32SerialOverlappedIO::SyncCheckParity(HANDLE aHandle) {
// This is what ClearCommError() does internally.
SERIAL_STATUS status = {};
return !(Win32SerialOverlappedIO::SyncDeviceIoControl(
aHandle, IOCTL_SERIAL_GET_COMMSTATUS, nullptr, 0, &status,
sizeof(status)) &&
(status.Errors & SERIAL_ERROR_PARITY));
}
/* static */
bool Win32SerialOverlappedIO::SyncPurge(HANDLE aHandle, ULONG aPurgeFlags) {
ULONG purgeFlags = aPurgeFlags;
return Win32SerialOverlappedIO::SyncDeviceIoControl(
aHandle, IOCTL_SERIAL_PURGE, &purgeFlags, sizeof(purgeFlags), nullptr, 0);
}
/* static */
bool Win32SerialOverlappedIO::SyncSetSignal(HANDLE aHandle,
DWORD aIoControlCode) {
return Win32SerialOverlappedIO::SyncDeviceIoControl(aHandle, aIoControlCode,
nullptr, 0, nullptr, 0);
}
/* static */
bool Win32SerialOverlappedIO::SyncGetSignals(HANDLE aHandle, ULONG& aSignals) {
return Win32SerialOverlappedIO::SyncDeviceIoControl(
aHandle, IOCTL_SERIAL_GET_MODEMSTATUS, nullptr, 0, &aSignals,
sizeof(aSignals));
}
/* static */
bool Win32SerialOverlappedIO::SyncDeviceIoControl(
HANDLE aHandle, DWORD aIoControlCode, const void* aInBuffer,
DWORD aInBufferSize, void* aOutBuffer, DWORD aOutBufferSize,
DWORD* aBytesReturned) {
Win32SerialOverlappedIO io;
if (!io.Init()) {
return false;
}
if (!DeviceIoControl(aHandle, aIoControlCode, const_cast<void*>(aInBuffer),
aInBufferSize, aOutBuffer, aOutBufferSize,
/* lpBytesReturned */ nullptr, io.Get()) &&
GetLastError() != ERROR_IO_PENDING) {
return false;
}
DWORD bytes = 0;
if (!io.Wait(aHandle, &bytes)) {
return false;
}
if (aBytesReturned) {
*aBytesReturned = bytes;
}
return true;
}
} // namespace mozilla::dom