serial: first steps to get a thread per IRP as a proof of concept. A bit of synchronization is still required.

channels/serial/client/serial_main.c

@@ -55,6 +55,8 @@
 #include <freerdp/channels/rdpdr.h>
 #include <freerdp/utils/svc_plugin.h>
 
+#define MAX_IRP_THREADS	5
+
 typedef struct _SERIAL_DEVICE SERIAL_DEVICE;
 
 struct _SERIAL_DEVICE
@@ -67,10 +69,19 @@ struct _SERIAL_DEVICE
 	HANDLE MainThread;
 	wMessageQueue* MainIrpQueue;
 
-	HANDLE ReadThread;
+	/* one thread per pending IRP and indexed according their CompletionId */
-	wMessageQueue* ReadIrpQueue;
+	wListDictionary *IrpThreads;
 };
 
+typedef struct _IRP_THREAD_DATA IRP_THREAD_DATA;
+
+struct _IRP_THREAD_DATA
+{
+	SERIAL_DEVICE *serial;
+	IRP *irp;
+};
+
+
 static void serial_process_irp_create(SERIAL_DEVICE* serial, IRP* irp)
 {
 	DWORD DesiredAccess;
@@ -138,7 +149,8 @@ static void serial_process_irp_create(SERIAL_DEVICE* serial, IRP* irp)
 	/* _comm_set_permissive(serial->hComm, TRUE); */
 
 	/* FIXME: this stinks, see also IOCTL_SERIAL_PURGE */
-	_comm_set_ReadIrpQueue(serial->hComm, serial->ReadIrpQueue);
+	// TMP: to be removed
+	//_comm_set_ReadIrpQueue(serial->hComm, serial->ReadIrpQueue);
 
 	/* NOTE: binary mode/raw mode required for the redirection. On
 	 * Linux, CommCreateFileA forces this setting.
@@ -498,36 +510,126 @@ static void serial_process_irp(SERIAL_DEVICE* serial, IRP* irp)
 	}
 }
 
-static void* serial_read_thread_func(void* arg)
+static void* irp_thread_func(void* arg)
 {
-	IRP* irp;
+	IRP_THREAD_DATA *data = (IRP_THREAD_DATA*)arg;
-	wMessage message;
-	SERIAL_DEVICE* serial = (SERIAL_DEVICE*) arg;
 
-	while (1)
+	/* blocks until the end of the request */
-	{
+	serial_process_irp(data->serial, data->irp);
-		if (!MessageQueue_Wait(serial->ReadIrpQueue))
-			break;
 
-		if (!MessageQueue_Peek(serial->ReadIrpQueue, &message, TRUE))
+	free(data);
-			break;
-
-		if (message.id == WMQ_QUIT)
-			break;
-
-		irp = (IRP*) message.wParam;
-
-		if (irp)
-		{
-			assert(irp->MajorFunction == IRP_MJ_READ);
-			serial_process_irp(serial, irp);
-		}
-	}
 
 	ExitThread(0);
 	return NULL;
 }
 
+
+static void create_irp_thread(SERIAL_DEVICE *serial, IRP *irp)
+{
+	IRP_THREAD_DATA *data = NULL;
+	HANDLE irpThread = INVALID_HANDLE_VALUE;
+	HANDLE previousIrpThread;
+
+	/* Checks whether a previous IRP with the same CompletionId
+	 * was completed. NB: this can be the a recall of the same
+	 * request let as blocking. Behavior at least observed with
+	 * IOCTL_SERIAL_WAIT_ON_MASK. FIXME: to be confirmed.
+	 */
+
+	// TMP: there is a slight chance that the server sends a new request with the same CompletionId whereas the previous thread is not yet terminated.
+
+	previousIrpThread = ListDictionary_GetItemValue(serial->IrpThreads, (void*)irp->CompletionId);
+
+	if (previousIrpThread) 
+	{
+		DWORD waitResult;
+
+		/* FIXME: not quite sure a zero timeout is a good thing to check whether a thread is stil alived or not */
+		waitResult = WaitForSingleObject(previousIrpThread, 0);
+
+		if (waitResult == WAIT_TIMEOUT)
+		{
+			/* Thread still alived */
+			/* FIXME: how to send a kind of wake up signal to accelerate the pending request */
+
+			DEBUG_WARN("IRP with the CompletionId=%d not yet completed!", irp->CompletionId);
+
+			// TMP:
+			assert(FALSE); /* assert() to be removed if it does realy happen */
+			
+			/* FIXME: asserts that the previous thread's IRP is well the same request */
+			irp->Discard(irp);
+			return;
+		}
+		else if(waitResult == WAIT_OBJECT_0)
+		{
+			DEBUG_SVC("previous IRP thread with CompletionId=%d naturally died", irp->CompletionId);
+
+			/* the previous thread naturally died */
+			CloseHandle(previousIrpThread);
+			ListDictionary_Remove(serial->IrpThreads, (void*)irp->CompletionId);
+		}
+		else
+		{
+			/* FIXME: handle more error cases */
+			DEBUG_WARN("IRP CompletionId=%d : unexpected waitResult=%X");
+			irp->Discard(irp);
+
+			assert(FALSE); /* should not happen */
+
+			return;
+		}
+	}
+
+	if (ListDictionary_Count(serial->IrpThreads) >= MAX_IRP_THREADS)
+	{
+		DEBUG_WARN("Maximal number of IRP threads reached: %d", ListDictionary_Count(serial->IrpThreads));
+		
+		assert(FALSE);
+		/* TODO: FIXME: WaitForMultipleObjects() not yet implemented for threads */
+	}
+
+	/* error_handle to be used ... */
+
+	data = (IRP_THREAD_DATA*)calloc(1, sizeof(IRP_THREAD_DATA));
+	if (data == NULL)
+	{
+		DEBUG_WARN("Could not allocate a new IRP_THREAD_DATA.");
+		goto error_handle;
+	}
+
+	data->serial = serial;
+	data->irp = irp;
+
+	irpThread = CreateThread(NULL, 
+				 0, 
+				 (LPTHREAD_START_ROUTINE)irp_thread_func, 
+				 (void*)data, 
+				 0, 
+				 NULL);
+
+	if (irpThread == INVALID_HANDLE_VALUE)
+	{
+		DEBUG_WARN("Could not allocate a new IRP thread.");
+		goto error_handle;
+	}
+
+
+
+	ListDictionary_Add(serial->IrpThreads, (void*)irp->CompletionId, irpThread);
+
+	return; /* data freed by irp_thread_func */
+
+  error_handle:
+
+	irp->IoStatus = STATUS_NO_MEMORY;
+	irp->Complete(irp);
+
+	if (data)
+		free(data);
+}
+
+
 static void* serial_thread_func(void* arg)
 {
 	IRP* irp;
@@ -548,7 +650,7 @@ static void* serial_thread_func(void* arg)
 		irp = (IRP*) message.wParam;
 
 		if (irp)
-			serial_process_irp(serial, irp);
+			create_irp_thread(serial, irp);
 	}
 
 	ExitThread(0);
@@ -570,16 +672,8 @@ static void serial_irp_request(DEVICE* device, IRP* irp)
 	 * write requests.
 	 */
 
-	switch(irp->MajorFunction)
-	{
-		case IRP_MJ_READ:
-			MessageQueue_Post(serial->ReadIrpQueue, NULL, 0, (void*) irp, NULL);
-			break;
-
-		default:
 	MessageQueue_Post(serial->MainIrpQueue, NULL, 0, (void*) irp, NULL);
 }
-}
 
 static void serial_free(DEVICE* device)
 {
@@ -587,10 +681,6 @@ static void serial_free(DEVICE* device)
 	
 	WLog_Print(serial->log, WLOG_DEBUG, "freeing");
 
-	MessageQueue_PostQuit(serial->ReadIrpQueue, 0);
-	WaitForSingleObject(serial->ReadThread, 100 /* ms */); /* INFINITE can block the process on a Read, FIXME: is a better signal possible? */ 
-	CloseHandle(serial->ReadThread);
-
 	MessageQueue_PostQuit(serial->MainIrpQueue, 0);
 	WaitForSingleObject(serial->MainThread, INFINITE); /* FIXME: might likely block on a pending Write or ioctl */
 	CloseHandle(serial->MainThread);
@@ -600,8 +690,8 @@ static void serial_free(DEVICE* device)
 
 	/* Clean up resources */
 	Stream_Free(serial->device.data, TRUE);
-	MessageQueue_Free(serial->ReadIrpQueue);
 	MessageQueue_Free(serial->MainIrpQueue);
+	ListDictionary_Free(serial->IrpThreads);
 
 	free(serial);
 }
@@ -653,22 +743,16 @@ int DeviceServiceEntry(PDEVICE_SERVICE_ENTRY_POINTS pEntryPoints)
 		for (i = 0; i <= len; i++)
 			Stream_Write_UINT8(serial->device.data, name[i] < 0 ? '_' : name[i]);
 
-		serial->ReadIrpQueue = MessageQueue_New(NULL);
 		serial->MainIrpQueue = MessageQueue_New(NULL);
 
+		serial->IrpThreads = ListDictionary_New(FALSE); /* only handled in create_irp_thread() */
+
 		WLog_Init();
 		serial->log = WLog_Get("com.freerdp.channel.serial.client");
 		WLog_Print(serial->log, WLOG_DEBUG, "initializing");
 
 		pEntryPoints->RegisterDevice(pEntryPoints->devman, (DEVICE*) serial);
 
-		serial->ReadThread = CreateThread(NULL, 
-						  0, 
-						  (LPTHREAD_START_ROUTINE) serial_read_thread_func, 
-						  (void*) serial, 
-						  0, 
-						  NULL);
-
 		serial->MainThread = CreateThread(NULL, 
 						  0, 
 						  (LPTHREAD_START_ROUTINE) serial_thread_func, 

winpr/libwinpr/comm/comm.h

@@ -57,6 +57,7 @@ struct winpr_comm
 	BOOL permissive;
 
 
+	// TMP: to be renamed serverSerialDriverId
 	REMOTE_SERIAL_DRIVER_ID remoteSerialDriverId;
 
 	wMessageQueue* ReadIrpQueue; /* considered as optional since it is