/**
* Handle the case where the device unexpectedly fails.
* @param device The device the failed.
* @param ec The error code from GetLastError()
* @return The device error code.
*/
int handleDeviceFailure(struct FreespaceDeviceStruct* device, int ec) {
int rc = FREESPACE_ERROR_UNEXPECTED;
int formatRc = 0;
LPVOID lpMsgBuf;
// Retrieve the system error message for the last-error code
formatRc = FormatMessage(
FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
ec,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &lpMsgBuf,
0, NULL );
if (formatRc == 0) {
DEBUG_WPRINTF(L"handleDeviceFailure: %d\n", ec);
} else {
// Display the error message and exit the process
DEBUG_WPRINTF(L"handleDeviceFailure: %d => %s\n", ec, lpMsgBuf);
LocalFree(lpMsgBuf);
}
// Clean up this device.
freespace_private_removeDevice(device);
freespace_private_forceCloseDevice(device);
freespace_private_requestDeviceRescan();
if (ec == ERROR_DEVICE_NOT_CONNECTED) {
rc = FREESPACE_ERROR_NOT_FOUND;
}
return rc;
}
int checkDiscovery() {
if (freespace_private_discoveryStatusChanged()) {
int rc;
int totalChanges = 0;
// Wait for system to stabilize before scanning.
if (CMP_WaitNoPendingInstallEvents(0) == WAIT_TIMEOUT) {
DEBUG_PRINTF("Pending install events. Wait for resolution.\n");
freespace_private_requestDeviceRescan();
return FREESPACE_ERROR_BUSY;
}
DEBUG_WPRINTF(L"Scanning devices\n");
// Mark and sweep the device list.
freespace_private_filterDevices(NULL, 0, NULL, filterInitialize);
// Mark everything that still exists and add new devices
rc = freespace_private_scanAndAddDevices();
if (rc != FREESPACE_SUCCESS) {
// Unexpected error. Schedule a rescan.
DEBUG_WPRINTF(L"Error %d while scanning devices. Request a rescan.\n", rc);
freespace_private_requestDeviceRescan();
return rc;
}
// Handle all changes.
totalChanges += checkDiscoveryRemoveDevices();
totalChanges += checkDiscoveryPartiallyRemovedDevices();
totalChanges += checkDiscoveryAddedDevices();
/*
* Continue to schedule a rescan until no changes are detected.
* Although this should not be necessary, rescanning until a
* stable state is reached should increase robustness.
*/
if (totalChanges != 0) {
DEBUG_WPRINTF(L"Detected %d changes. Schedule rescan\n", totalChanges);
freespace_private_requestDeviceRescan();
}
}
return freespace_private_discoveryGetThreadStatus();
}
BOOL freespace_private_discoveryStatusChanged() {
if ( freespace_instance_->needToRescanDevicesFlag_ ||
WaitForSingleObject(freespace_instance_->discoveryEvent_, 0) == WAIT_OBJECT_0) {
// Race condition note: the flags need to be reset before the scan takes
// place. If device status changes again between when this thread is notified
// and the flags get reset, we're ok, since the scan happens afterwards. If the
// change occurs after the reset of the flags, the flags will be set again, and
// we'll scan next trip around the event loop.
freespace_instance_->needToRescanDevicesFlag_ = FALSE;
// Force the timer to unsignaled by restarting and then cancelling.
freespace_private_requestDeviceRescan();
CancelWaitableTimer(freespace_instance_->discoveryEvent_);
return TRUE;
} else {
return FALSE;
}
}
LRESULT CALLBACK discoveryCallback(HWND hwnd, UINT nMsg, WPARAM wParam, LPARAM lParam) {
if (nMsg == WM_CLOSE) {
DestroyWindow(hwnd);
return DefWindowProc(hwnd, nMsg, wParam, lParam);
}
if (nMsg == WM_DESTROY) {
DEBUG_WPRINTF(L"discoveryCallback on WM_DESTROY\n");
// Remove the device notification
if (freespace_instance_->windowEvent_) {
UnregisterDeviceNotification(freespace_instance_->windowEvent_);
freespace_instance_->windowEvent_ = NULL;
}
CancelWaitableTimer(freespace_instance_->discoveryEvent_);
CloseHandle(freespace_instance_->discoveryEvent_);
freespace_instance_->discoveryEvent_ = NULL;
PostQuitMessage(0);
return DefWindowProc(hwnd, nMsg, wParam, lParam);
}
if (nMsg == WM_DEVICECHANGE) {
// Should start with DEV_BROADCAST_HDR and validate.
DEV_BROADCAST_DEVICEINTERFACE* hdr;
hdr = (DEV_BROADCAST_DEVICEINTERFACE*) lParam;
// Schedule a device list rescan.
freespace_private_requestDeviceRescan();
// Only handle all devices arrived or all devices removed.
if ((LOWORD(wParam) != DBT_DEVICEARRIVAL) &&
(LOWORD(wParam) != DBT_DEVICEREMOVECOMPLETE)) {
DEBUG_WPRINTF(L"WM_DEVICECHANGE => %d\n", LOWORD(wParam));
return TRUE;
}
/*
* NOTE: Device scan is only performed once changes have stabilized.
* The scan routine must be able to handled a device being removed
* and reinserted without scan calls between events.
*/
if (hdr->dbcc_devicetype != DBT_DEVTYP_DEVICEINTERFACE) {
return TRUE;
}
if (LOWORD(wParam) == DBT_DEVICEARRIVAL) {
DEBUG_WPRINTF(L"DBT_DEVICEARRIVAL => %s\n", hdr->dbcc_name);
} else if (LOWORD(wParam) == DBT_DEVICEREMOVECOMPLETE) {
DEBUG_WPRINTF(L"DBT_DEVICEREMOVECOMPLETE => %s\n", hdr->dbcc_name);
} else {
DEBUG_WPRINTF(L"discoveryCallback on unexpected change (%d) => %s\n",
LOWORD(wParam), hdr->dbcc_name);
}
return TRUE;
}
return DefWindowProc(hwnd, nMsg, wParam, lParam);
}
