DrvChar.cpp@ 1959

Last change on this file since 1959 was 1884, checked in by vboxsync, 18 years ago
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1	/** @file
2	*
3	* VBox stream I/O devices:
4	* Generic char driver
5	*/
6
7	/*
8	* Copyright (C) 2006 InnoTek Systemberatung GmbH
9	*
10	* This file is part of VirtualBox Open Source Edition (OSE), as
11	* available from http://www.virtualbox.org. This file is free software;
12	* you can redistribute it and/or modify it under the terms of the GNU
13	* General Public License as published by the Free Software Foundation,
14	* in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
15	* distribution. VirtualBox OSE is distributed in the hope that it will
16	* be useful, but WITHOUT ANY WARRANTY of any kind.
17	*
18	* If you received this file as part of a commercial VirtualBox
19	* distribution, then only the terms of your commercial VirtualBox
20	* license agreement apply instead of the previous paragraph.
21	*/
22
23
24
25	/*******************************************************************************
26	* Header Files *
27	*******************************************************************************/
28	#define LOG_GROUP LOG_GROUP_DRV_CHAR
29	#include <VBox/pdm.h>
30	#include <VBox/err.h>
31
32	#include <VBox/log.h>
33	#include <iprt/asm.h>
34	#include <iprt/assert.h>
35	#include <iprt/stream.h>
36	#include <iprt/semaphore.h>
37
38	#include "Builtins.h"
39
40
41	/** Size of the send fifo queue (in bytes) */
42	#define CHAR_MAX_SEND_QUEUE 0x80
43	#define CHAR_MAX_SEND_QUEUE_MASK 0x7f
44
45	/*******************************************************************************
46	* Structures and Typedefs *
47	*******************************************************************************/
48
49	/**
50	* Char driver instance data.
51	*/
52	typedef struct DRVCHAR
53	{
54	/** Pointer to the driver instance structure. */
55	PPDMDRVINS pDrvIns;
56	/** Pointer to the char port interface of the driver/device above us. */
57	PPDMICHARPORT pDrvCharPort;
58	/** Pointer to the stream interface of the driver below us. */
59	PPDMISTREAM pDrvStream;
60	/** Our char interface. */
61	PDMICHAR IChar;
62	/** Flag to notify the receive thread it should terminate. */
63	volatile bool fShutdown;
64	/** Receive thread ID. */
65	RTTHREAD ReceiveThread;
66	/** Send thread ID. */
67	RTTHREAD SendThread;
68	/** Send event semephore */
69	RTSEMEVENT SendSem;
70
71	/** Internal send FIFO queue */
72	uint8_t aSendQueue[CHAR_MAX_SEND_QUEUE];
73	uint32_t iSendQueueHead;
74	uint32_t iSendQueueTail;
75
76	/** Read/write statistics */
77	STAMCOUNTER StatBytesRead;
78	STAMCOUNTER StatBytesWritten;
79	} DRVCHAR, *PDRVCHAR;
80
81
82	/** Converts a pointer to DRVCHAR::IChar to a PDRVCHAR. */
83	#define PDMICHAR_2_DRVCHAR(pInterface) ( (PDRVCHAR)((uintptr_t)pInterface - RT_OFFSETOF(DRVCHAR, IChar)) )
84
85
86	/* -=-=-=-=- IBase -=-=-=-=- */
87
88	/**
89	* Queries an interface to the driver.
90	*
91	* @returns Pointer to interface.
92	* @returns NULL if the interface was not supported by the driver.
93	* @param pInterface Pointer to this interface structure.
94	* @param enmInterface The requested interface identification.
95	*/
96	static DECLCALLBACK(void *) drvCharQueryInterface(PPDMIBASE pInterface, PDMINTERFACE enmInterface)
97	{
98	PPDMDRVINS pDrvIns = PDMIBASE_2_PDMDRV(pInterface);
99	PDRVCHAR pData = PDMINS2DATA(pDrvIns, PDRVCHAR);
100	switch (enmInterface)
101	{
102	case PDMINTERFACE_BASE:
103	return &pDrvIns->IBase;
104	case PDMINTERFACE_CHAR:
105	return &pData->IChar;
106	default:
107	return NULL;
108	}
109	}
110
111
112	/* -=-=-=-=- IChar -=-=-=-=- */
113
114	/** @copydoc PDMICHAR::pfnWrite */
115	static DECLCALLBACK(int) drvCharWrite(PPDMICHAR pInterface, const void *pvBuf, size_t cbWrite)
116	{
117	PDRVCHAR pData = PDMICHAR_2_DRVCHAR(pInterface);
118	const char pBuffer = (const char )pvBuf;
119
120	LogFlow(("%s: pvBuf=%#p cbWrite=%d\n", __FUNCTION__, pvBuf, cbWrite));
121
122	for (uint32_t i=0;i<cbWrite;i++)
123	{
124	uint32_t idx = pData->iSendQueueHead;
125
126	pData->aSendQueue[idx] = pBuffer[i];
127	idx = (idx + 1) & CHAR_MAX_SEND_QUEUE_MASK;
128
129	STAM_COUNTER_INC(&pData->StatBytesWritten);
130	ASMAtomicXchgU32(&pData->iSendQueueHead, idx);
131	}
132	RTSemEventSignal(pData->SendSem);
133	return VINF_SUCCESS;
134	}
135
136
137	/* -=-=-=-=- receive thread -=-=-=-=- */
138
139	/**
140	* Send thread loop.
141	*
142	* @returns 0 on success.
143	* @param ThreadSelf Thread handle to this thread.
144	* @param pvUser User argument.
145	*/
146	static DECLCALLBACK(int) drvCharSendLoop(RTTHREAD ThreadSelf, void *pvUser)
147	{
148	PDRVCHAR pData = (PDRVCHAR)pvUser;
149
150	for(;;)
151	{
152	int rc = RTSemEventWait(pData->SendSem, RT_INDEFINITE_WAIT);
153	if (VBOX_FAILURE(rc))
154	break;
155
156	/*
157	* Write the character to the attached stream (if present).
158	*/
159	if ( !pData->fShutdown
160	&& pData->pDrvStream)
161	{
162	while (pData->iSendQueueTail != pData->iSendQueueHead)
163	{
164	size_t cbProcessed = 1;
165
166	rc = pData->pDrvStream->pfnWrite(pData->pDrvStream, &pData->aSendQueue[pData->iSendQueueTail], &cbProcessed);
167	if (VBOX_SUCCESS(rc))
168	{
169	Assert(cbProcessed);
170	pData->iSendQueueTail++;
171	pData->iSendQueueTail &= CHAR_MAX_SEND_QUEUE_MASK;
172	}
173	else if (rc == VERR_TIMEOUT)
174	{
175	/* Normal case, just means that the stream didn't accept a new
176	* character before the timeout elapsed. Just retry. */
177	rc = VINF_SUCCESS;
178	}
179	else
180	{
181	LogFlow(("Write failed with %Vrc; skipping\n", rc));
182	break;
183	}
184	}
185	}
186	else
187	break;
188	}
189
190	pData->SendThread = NIL_RTTHREAD;
191
192	return VINF_SUCCESS;
193	}
194
195
196	/* -=-=-=-=- receive thread -=-=-=-=- */
197
198	/**
199	* Receive thread loop.
200	*
201	* @returns 0 on success.
202	* @param ThreadSelf Thread handle to this thread.
203	* @param pvUser User argument.
204	*/
205	static DECLCALLBACK(int) drvCharReceiveLoop(RTTHREAD ThreadSelf, void *pvUser)
206	{
207	PDRVCHAR pData = (PDRVCHAR)pvUser;
208	char aBuffer[256], *pBuffer;
209	size_t cbRemaining, cbProcessed;
210	int rc;
211
212	cbRemaining = 0;
213	pBuffer = aBuffer;
214	while (!pData->fShutdown)
215	{
216	if (!cbRemaining)
217	{
218	/* Get block of data from stream driver. */
219	if (pData->pDrvStream)
220	{
221	cbRemaining = sizeof(aBuffer);
222	rc = pData->pDrvStream->pfnRead(pData->pDrvStream, aBuffer, &cbRemaining);
223	if (VBOX_FAILURE(rc))
224	{
225	LogFlow(("Read failed with %Vrc\n", rc));
226	break;
227	}
228	}
229	else
230	{
231	cbRemaining = 0;
232	RTThreadSleep(100);
233	}
234	pBuffer = aBuffer;
235	}
236	else
237	{
238	/* Send data to guest. */
239	cbProcessed = cbRemaining;
240	rc = pData->pDrvCharPort->pfnNotifyRead(pData->pDrvCharPort, pBuffer, &cbProcessed);
241	if (VBOX_SUCCESS(rc))
242	{
243	Assert(cbProcessed);
244	pBuffer += cbProcessed;
245	cbRemaining -= cbProcessed;
246	STAM_COUNTER_ADD(&pData->StatBytesRead, cbProcessed);
247	}
248	else if (rc == VERR_TIMEOUT)
249	{
250	/* Normal case, just means that the guest didn't accept a new
251	* character before the timeout elapsed. Just retry. */
252	rc = VINF_SUCCESS;
253	}
254	else
255	{
256	LogFlow(("NotifyRead failed with %Vrc\n", rc));
257	break;
258	}
259	}
260	}
261
262	pData->ReceiveThread = NIL_RTTHREAD;
263
264	return VINF_SUCCESS;
265	}
266
267
268	/* -=-=-=-=- driver interface -=-=-=-=- */
269
270	/**
271	* Construct a char driver instance.
272	*
273	* @returns VBox status.
274	* @param pDrvIns The driver instance data.
275	* If the registration structure is needed,
276	* pDrvIns->pDrvReg points to it.
277	* @param pCfgHandle Configuration node handle for the driver. Use this to
278	* obtain the configuration of the driver instance. It's
279	* also found in pDrvIns->pCfgHandle as it's expected to
280	* be used frequently in this function.
281	*/
282	static DECLCALLBACK(int) drvCharConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfgHandle)
283	{
284	PDRVCHAR pData = PDMINS2DATA(pDrvIns, PDRVCHAR);
285	LogFlow(("%s: iInstance=%d\n", __FUNCTION__, pDrvIns->iInstance));
286
287	/*
288	* Init basic data members and interfaces.
289	*/
290	pData->ReceiveThread = NIL_RTTHREAD;
291	pData->fShutdown = false;
292	/* IBase. */
293	pDrvIns->IBase.pfnQueryInterface = drvCharQueryInterface;
294	/* IChar. */
295	pData->IChar.pfnWrite = drvCharWrite;
296
297
298	/*
299	* Get the ICharPort interface of the above driver/device.
300	*/
301	pData->pDrvCharPort = (PPDMICHARPORT)pDrvIns->pUpBase->pfnQueryInterface(pDrvIns->pUpBase, PDMINTERFACE_CHAR_PORT);
302	if (!pData->pDrvCharPort)
303	return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_ABOVE, RT_SRC_POS, N_("Char#%d has no char port interface above"), pDrvIns->iInstance);
304
305	/*
306	* Attach driver below and query its stream interface.
307	*/
308	PPDMIBASE pBase;
309	int rc = pDrvIns->pDrvHlp->pfnAttach(pDrvIns, &pBase);
310	if (VBOX_FAILURE(rc))
311	return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d failed to attach driver below"), pDrvIns->iInstance);
312	pData->pDrvStream = (PPDMISTREAM)pBase->pfnQueryInterface(pBase, PDMINTERFACE_STREAM);
313	if (!pData->pDrvStream)
314	return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_BELOW, RT_SRC_POS, N_("Char#%d has no stream interface below"), pDrvIns->iInstance);
315
316	rc = RTThreadCreate(&pData->ReceiveThread, drvCharReceiveLoop, (void *)pData, 0, RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "Char Receive");
317	if (VBOX_FAILURE(rc))
318	return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create receive thread"), pDrvIns->iInstance);
319
320	rc = RTSemEventCreate(&pData->SendSem);
321	AssertRC(rc);
322
323	rc = RTThreadCreate(&pData->SendThread, drvCharSendLoop, (void *)pData, 0, RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "Char Send");
324	if (VBOX_FAILURE(rc))
325	return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create send thread"), pDrvIns->iInstance);
326
327
328	PDMDrvHlpSTAMRegisterF(pDrvIns, &pData->StatBytesWritten, STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES, "Nr of bytes written", "/Devices/Char%d/Written", pDrvIns->iInstance);
329	PDMDrvHlpSTAMRegisterF(pDrvIns, &pData->StatBytesRead, STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES, "Nr of bytes read", "/Devices/Char%d/Read", pDrvIns->iInstance);
330
331	return VINF_SUCCESS;
332	}
333
334
335	/**
336	* Destruct a char driver instance.
337	*
338	* Most VM resources are freed by the VM. This callback is provided so that
339	* any non-VM resources can be freed correctly.
340	*
341	* @param pDrvIns The driver instance data.
342	*/
343	static DECLCALLBACK(void) drvCharDestruct(PPDMDRVINS pDrvIns)
344	{
345	PDRVCHAR pData = PDMINS2DATA(pDrvIns, PDRVCHAR);
346
347	LogFlow(("%s: iInstance=%d\n", __FUNCTION__, pDrvIns->iInstance));
348
349	pData->fShutdown = true;
350	if (pData->ReceiveThread)
351	{
352	RTThreadWait(pData->ReceiveThread, 1000, NULL);
353	if (pData->ReceiveThread != NIL_RTTHREAD)
354	LogRel(("Char%d: receive thread did not terminate\n", pDrvIns->iInstance));
355	}
356
357	/* Empty the send queue */
358	pData->iSendQueueTail = pData->iSendQueueHead = 0;
359
360	RTSemEventSignal(pData->SendSem);
361	RTSemEventDestroy(pData->SendSem);
362	pData->SendSem = NIL_RTSEMEVENT;
363
364	if (pData->SendThread)
365	{
366	RTThreadWait(pData->SendThread, 1000, NULL);
367	if (pData->SendThread != NIL_RTTHREAD)
368	LogRel(("Char%d: send thread did not terminate\n", pDrvIns->iInstance));
369	}
370	}
371
372	/**
373	* Char driver registration record.
374	*/
375	const PDMDRVREG g_DrvChar =
376	{
377	/* u32Version */
378	PDM_DRVREG_VERSION,
379	/* szDriverName */
380	"Char",
381	/* pszDescription */
382	"Generic char driver.",
383	/* fFlags */
384	PDM_DRVREG_FLAGS_HOST_BITS_DEFAULT,
385	/* fClass. */
386	PDM_DRVREG_CLASS_CHAR,
387	/* cMaxInstances */
388	~0,
389	/* cbInstance */
390	sizeof(DRVCHAR),
391	/* pfnConstruct */
392	drvCharConstruct,
393	/* pfnDestruct */
394	drvCharDestruct,
395	/* pfnIOCtl */
396	NULL,
397	/* pfnPowerOn */
398	NULL,
399	/* pfnReset */
400	NULL,
401	/* pfnSuspend */
402	NULL,
403	/* pfnResume */
404	NULL,
405	/* pfnDetach */
406	NULL,
407	/** pfnPowerOff */
408	NULL
409	};
410

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source: vbox/trunk/src/VBox/Devices/Serial/DrvChar.cpp@ 1959

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