pack_buffer.c@ 34356

Last change on this file since 34356 was 34356, checked in by vboxsync, 14 years ago
crOpenGL: mt deadlock fix
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1	/* Copyright (c) 2001, Stanford University
2	* All rights reserved
3	*
4	* See the file LICENSE.txt for information on redistributing this software.
5	*/
6
7	#include "cr_mem.h"
8	#include "cr_string.h"
9	#include "packer.h"
10	#include "cr_error.h"
11	#include "cr_protocol.h"
12	#include "cr_unpack.h"
13
14
15	void crWriteUnalignedDouble( void *buffer, double d )
16	{
17	unsigned int ui = (unsigned int ) buffer;
18	ui[0] = ((unsigned int *) &d)[0];
19	ui[1] = ((unsigned int *) &d)[1];
20	}
21
22	void crWriteSwappedDouble( void *buffer, double d )
23	{
24	unsigned int ui = (unsigned int ) buffer;
25	ui[0] = SWAP32(((unsigned int *) &d)[1]);
26	ui[1] = SWAP32(((unsigned int *) &d)[0]);
27	}
28
29	double crReadUnalignedDouble( const void *buffer )
30	{
31	const unsigned int ui = (unsigned int ) buffer;
32	double d;
33	((unsigned int *) &d)[0] = ui[0];
34	((unsigned int *) &d)[1] = ui[1];
35	return d;
36	}
37
38	/*
39	* We need the packer to run as efficiently as possible. To avoid one
40	* pointer dereference from the CRPackContext to the current CRPackBuffer,
41	* we keep a _copy_ of the current CRPackBuffer in the CRPackContext and
42	* operate on the fields in CRPackContext, rather than the CRPackBuffer.
43	*
44	* To keep things in sync, when we change a context's
45	* buffer, we have to use the crPackSet/GetBuffer() functions.
46	*/
47
48	void crPackSetBuffer( CRPackContext pc, CRPackBuffer buffer )
49	{
50	CRASSERT( pc );
51	CRASSERT( buffer );
52
53	if (pc->currentBuffer == buffer)
54	return; /* re-bind is no-op */
55
56	if (pc->currentBuffer) {
57	/* Another buffer currently bound to this packer (shouldn't normally occur)
58	* Release it. Fixes Ensight issue.
59	*/
60	crPackReleaseBuffer(pc);
61	}
62
63	CRASSERT( pc->currentBuffer == NULL); /* release if NULL? */
64	CRASSERT( buffer->context == NULL );
65
66	/* bind context to buffer */
67	pc->currentBuffer = buffer;
68	buffer->context = pc;
69
70	/* update the context's packing fields with those from the buffer */
71	pc->buffer = buffer; / struct copy */
72	}
73
74	/* This is useful for debugging packer problems */
75	void crPackSetBufferDEBUG( const char *file, int line,
76	CRPackContext pc, CRPackBuffer buffer)
77
78	{
79	crPackSetBuffer( pc, buffer );
80	/* record debugging info */
81	pc->file = crStrdup(file);
82	pc->line = line;
83	}
84
85
86	/*
87	* Release the buffer currently attached to the context.
88	* Update/resync data structures.
89	*/
90	void crPackReleaseBuffer( CRPackContext *pc )
91	{
92	CRPackBuffer *buf;
93	CRASSERT( pc );
94
95	if (!pc->currentBuffer) {
96	crWarning("crPackReleaseBuffer called with no current buffer");
97	return; /* nothing to do */
98	}
99
100	CRASSERT( pc->currentBuffer->context == pc );
101
102	/* buffer to release */
103	buf = pc->currentBuffer;
104
105	/* copy context's fields back into the buffer to update it */
106	buf = pc->buffer; / struct copy */
107
108	/* unbind buffer from context */
109	buf->context = NULL;
110	pc->currentBuffer = NULL;
111
112	/* zero-out context's packing fields just to be safe */
113	crMemZero(&(pc->buffer), sizeof(pc->buffer));
114
115	/* update the debugging fields */
116	if (pc->file)
117	crFree(pc->file);
118	pc->file = NULL;
119	pc->line = -1;
120	}
121
122	void crPackFlushFunc( CRPackContext *pc, CRPackFlushFunc ff )
123	{
124	pc->Flush = ff;
125	}
126
127	void crPackFlushArg( CRPackContext pc, void flush_arg )
128	{
129	pc->flush_arg = flush_arg;
130	}
131
132	void crPackSendHugeFunc( CRPackContext *pc, CRPackSendHugeFunc shf )
133	{
134	pc->SendHuge = shf;
135	}
136
137	/*
138	* This basically resets the buffer attached to <pc> to the default, empty
139	* state.
140	*/
141	void crPackResetPointers( CRPackContext *pc )
142	{
143	const GLboolean geom_only = pc->buffer.geometry_only; /* save this flag */
144	const GLboolean holds_BeginEnd = pc->buffer.holds_BeginEnd;
145	const GLboolean in_BeginEnd = pc->buffer.in_BeginEnd;
146	const GLboolean canBarf = pc->buffer.canBarf;
147	CRPackBuffer *buf = pc->currentBuffer;
148	CRASSERT(buf);
149	crPackInitBuffer( buf, buf->pack, buf->size, buf->mtu );
150	pc->buffer.geometry_only = geom_only; /* restore the flag */
151	pc->buffer.holds_BeginEnd = holds_BeginEnd;
152	pc->buffer.in_BeginEnd = in_BeginEnd;
153	pc->buffer.canBarf = canBarf;
154	}
155
156
157	/**
158	* Return max number of opcodes that'll fit in the given buffer size.
159	* Each opcode has at least a 1-word payload, so opcodes can occupy at most
160	* 20% of the space.
161	*/
162	int
163	crPackMaxOpcodes( int buffer_size )
164	{
165	int n = ( buffer_size - sizeof(CRMessageOpcodes) ) / 5;
166	/* Don't forget to add one here in case the buffer size is not
167	* divisible by 4. Thanks to Ken Moreland for finding this.
168	*/
169	n++;
170	/* round up to multiple of 4 */
171	n = (n + 0x3) & (~0x3);
172	return n;
173	}
174
175
176	/**
177	* Return max number of data bytes that'll fit in the given buffer size.
178	*/
179	int
180	crPackMaxData( int buffer_size )
181	{
182	int n = buffer_size - sizeof(CRMessageOpcodes);
183	n -= crPackMaxOpcodes(buffer_size);
184	return n;
185	}
186
187
188	/**
189	* Initialize the given CRPackBuffer object.
190	* The buffer may or may not be currently bound to a CRPackContext.
191	*
192	* Opcodes and operands are packed into a buffer in a special way.
193	* Opcodes start at opcode_start and go downward in memory while operands
194	* start at data_start and go upward in memory. The buffer is full when we
195	* either run out of opcode space or operand space.
196	*
197	* Diagram (memory addresses increase upward):
198	*
199	* data_end -> \| \| <- buf->pack + buf->size
200	* +---------+
201	* \| \|
202	* \| \|
203	* \| operands\|
204	* \| \|
205	* \| \|
206	* data_start -> +---------+
207	* opcode_start -> \| \|
208	* \| \|
209	* \| opcodes \|
210	* \| \|
211	* \| \|
212	* opcode_end -> +---------+ <- buf->pack
213	*
214	* \param buf the CRPackBuffer to initialize
215	* \param pack the address of the buffer for packing opcodes/operands.
216	* \param size size of the buffer, in bytes
217	* \param mtu max transmission unit size, in bytes. When the buffer
218	* has 'mtu' bytes in it, we have to send it. The MTU might
219	* be somewhat smaller than the buffer size.
220	*/
221	void crPackInitBuffer( CRPackBuffer buf, void pack, int size, int mtu )
222	{
223	unsigned int num_opcodes;
224
225	CRASSERT(mtu <= size);
226
227	buf->size = size;
228	buf->mtu = mtu;
229	buf->pack = pack;
230
231	num_opcodes = crPackMaxOpcodes( buf->size );
232
233	buf->data_start =
234	(unsigned char *) buf->pack + num_opcodes + sizeof(CRMessageOpcodes);
235	buf->data_current = buf->data_start;
236	buf->data_end = (unsigned char *) buf->pack + buf->size;
237
238	buf->opcode_start = buf->data_start - 1;
239	buf->opcode_current = buf->opcode_start;
240	buf->opcode_end = buf->opcode_start - num_opcodes;
241
242	buf->geometry_only = GL_FALSE;
243	buf->holds_BeginEnd = GL_FALSE;
244	buf->in_BeginEnd = GL_FALSE;
245	buf->canBarf = GL_FALSE;
246
247	if (buf->context) {
248	/* Also reset context's packing fields */
249	CRPackContext *pc = buf->context;
250	CRASSERT(pc->currentBuffer == buf);
251	/crMemcpy( &(pc->buffer), buf, sizeof(buf) );*/
252	pc->buffer = *buf;
253	}
254	}
255
256
257	int crPackCanHoldBuffer( const CRPackBuffer *src )
258	{
259	const int num_data = crPackNumData(src);
260	const int num_opcode = crPackNumOpcodes(src);
261	int res;
262	CR_GET_PACKER_CONTEXT(pc);
263	CR_LOCK_PACKER_CONTEXT(pc);
264	res = crPackCanHoldOpcode( pc, num_opcode, num_data );
265	CR_UNLOCK_PACKER_CONTEXT(pc);
266	return res;
267	}
268
269
270	int crPackCanHoldBoundedBuffer( const CRPackBuffer *src )
271	{
272	const int len_aligned = (src->data_current - src->opcode_current - 1 + 3) & ~3;
273	CR_GET_PACKER_CONTEXT(pc);
274	/* 24 is the size of the bounds-info packet... */
275	return crPackCanHoldOpcode( pc, 1, len_aligned + 24 );
276	}
277
278	void crPackAppendBuffer( const CRPackBuffer *src )
279	{
280	CR_GET_PACKER_CONTEXT(pc);
281	const int num_data = crPackNumData(src);
282	const int num_opcode = crPackNumOpcodes(src);
283
284	CRASSERT(num_data >= 0);
285	CRASSERT(num_opcode >= 0);
286
287	CR_LOCK_PACKER_CONTEXT(pc);
288
289	/* don't append onto ourself! */
290	CRASSERT(pc->currentBuffer);
291	CRASSERT(pc->currentBuffer != src);
292
293	if (!crPackCanHoldBuffer(src))
294	{
295	if (src->holds_BeginEnd)
296	{
297	crWarning( "crPackAppendBuffer: overflowed the destination!" );
298	CR_UNLOCK_PACKER_CONTEXT(pc);
299	return;
300	}
301	else
302	{
303	crError( "crPackAppendBuffer: overflowed the destination!" );
304	CR_UNLOCK_PACKER_CONTEXT(pc);
305	}
306	}
307
308	/* Copy the buffer data/operands which are at the head of the buffer */
309	crMemcpy( pc->buffer.data_current, src->data_start, num_data );
310	pc->buffer.data_current += num_data;
311
312	/* Copy the buffer opcodes which are at the tail of the buffer */
313	CRASSERT( pc->buffer.opcode_current - num_opcode >= pc->buffer.opcode_end );
314	crMemcpy( pc->buffer.opcode_current + 1 - num_opcode, src->opcode_current + 1,
315	num_opcode );
316	pc->buffer.opcode_current -= num_opcode;
317	pc->buffer.holds_BeginEnd \|= src->holds_BeginEnd;
318	pc->buffer.in_BeginEnd = src->in_BeginEnd;
319	pc->buffer.holds_List \|= src->holds_List;
320	CR_UNLOCK_PACKER_CONTEXT(pc);
321	}
322
323
324	void
325	crPackAppendBoundedBuffer( const CRPackBuffer src, const CRrecti bounds )
326	{
327	CR_GET_PACKER_CONTEXT(pc);
328	const GLbyte payload = (const GLbyte ) src->opcode_current + 1;
329	const int num_opcodes = crPackNumOpcodes(src);
330	const int length = src->data_current - src->opcode_current - 1;
331
332	CRASSERT(pc);
333	CR_LOCK_PACKER_CONTEXT(pc);
334	CRASSERT(pc->currentBuffer);
335	CRASSERT(pc->currentBuffer != src);
336
337	/*
338	* payload points to the block of opcodes immediately followed by operands.
339	*/
340
341	if ( !crPackCanHoldBoundedBuffer( src ) )
342	{
343	if (src->holds_BeginEnd)
344	{
345	crWarning( "crPackAppendBoundedBuffer: overflowed the destination!" );
346	CR_UNLOCK_PACKER_CONTEXT(pc);
347	return;
348	}
349	else
350	{
351	crError( "crPackAppendBoundedBuffer: overflowed the destination!" );
352	CR_UNLOCK_PACKER_CONTEXT(pc);
353	}
354	}
355
356	if (pc->swapping)
357	crPackBoundsInfoCRSWAP( bounds, payload, length, num_opcodes );
358	else
359	crPackBoundsInfoCR( bounds, payload, length, num_opcodes );
360
361	pc->buffer.holds_BeginEnd \|= src->holds_BeginEnd;
362	pc->buffer.in_BeginEnd = src->in_BeginEnd;
363	pc->buffer.holds_List \|= src->holds_List;
364	CR_UNLOCK_PACKER_CONTEXT(pc);
365	}
366
367
368	#ifndef CHROMIUM_THREADSAFE
369	static unsigned char *sanityCheckPointer = NULL;
370	#endif
371
372
373	/*
374	* Allocate space for a command that might be very large, such as
375	* glTexImage2D or glBufferDataARB call.
376	* The command buffer _MUST_ then be transmitted by calling crHugePacket.
377	*/
378	void *crPackAlloc( unsigned int size )
379	{
380	CR_GET_PACKER_CONTEXT(pc);
381	unsigned char *data_ptr;
382
383	/* include space for the length and make the payload word-aligned */
384	size = ( size + sizeof(unsigned int) + 0x3 ) & ~0x3;
385
386	CR_LOCK_PACKER_CONTEXT(pc);
387
388	if ( crPackCanHoldOpcode( pc, 1, size ) )
389	{
390	/* we can just put it in the current buffer */
391	CR_GET_BUFFERED_POINTER_NOLOCK(pc, size ); /* NOTE: this sets data_ptr */
392	}
393	else
394	{
395	/* Okay, it didn't fit. Maybe it will after we flush. */
396	CR_UNLOCK_PACKER_CONTEXT(pc)
397	pc->Flush( pc->flush_arg );
398	CR_LOCK_PACKER_CONTEXT(pc);
399	if ( crPackCanHoldOpcode( pc, 1, size ) )
400	{
401	CR_GET_BUFFERED_POINTER_NOLOCK(pc, size ); /* NOTE: this sets data_ptr */
402	}
403	else
404	{
405	/* It's really way too big, so allocate a temporary packet
406	* with space for the single opcode plus the payload &
407	* header.
408	*/
409	data_ptr = (unsigned char *)
410	crAlloc( sizeof(CRMessageOpcodes) + 4 + size );
411
412	/* skip the header & opcode space */
413	data_ptr += sizeof(CRMessageOpcodes) + 4;
414	}
415	}
416
417	/* At the top of the function, we added four to the request size and
418	* rounded it up to the next multiple of four.
419	*
420	* At this point, we have:
421	*
422	* HIGH MEM \| byte size - 1 \| \
423	* ... \|
424	* ... \| - original 'size' bytes for data
425	* \| operand data \| \|
426	* return value -> \| operand data \| /
427	* \| byte 3 \| \
428	* \| byte 2 \| \|- These bytes will store 'size'
429	* \| byte 1 \| \|
430	* data_ptr -> \| byte 0 \| /
431	* \| CR opcode \| <- Set in packspuHuge()
432	* \| unused \|
433	* \| unused \|
434	* \| unused \|
435	* \| CRMessageOpcodes \|
436	* \| CRMessageOpcodes \|
437	* ...
438	* \| CRMessageOpcodes \|
439	* \| CRMessageOpcodes \|
440	* LOW MEM +------------------+
441	*/
442
443	if (pc->swapping)
444	{
445	((unsigned int ) data_ptr) = SWAP32(size);
446	crDebug( "Just swapped the length, putting %d on the wire!", ((unsigned int ) data_ptr));
447	}
448	else
449	{
450	((unsigned int ) data_ptr) = size;
451	}
452	#ifndef CHROMIUM_THREADSAFE
453	sanityCheckPointer = data_ptr + 4;
454	#endif
455	return data_ptr + 4;
456	}
457
458	#define IS_BUFFERED( packet ) \
459	((unsigned char *) (packet) >= pc->buffer.data_start && \
460	(unsigned char *) (packet) < pc->buffer.data_end)
461
462
463	/*
464	* Transmit a packet which was allocated with crPackAlloc.
465	*/
466	void crHugePacket( CROpcode opcode, void *packet )
467	{
468	CR_GET_PACKER_CONTEXT(pc);
469	#ifndef CHROMIUM_THREADSAFE
470	CRASSERT(sanityCheckPointer == packet);
471	sanityCheckPointer = NULL;
472	#endif
473
474	if ( IS_BUFFERED( packet ) )
475	WRITE_OPCODE( pc, opcode );
476	else
477	pc->SendHuge( opcode, packet );
478	}
479
480	void crPackFree( void *packet )
481	{
482	CR_GET_PACKER_CONTEXT(pc);
483
484	if ( IS_BUFFERED( packet ) )
485	{
486	CR_UNLOCK_PACKER_CONTEXT(pc);
487	return;
488	}
489
490	CR_UNLOCK_PACKER_CONTEXT(pc);
491
492	/* the pointer passed in doesn't include the space for the single
493	* opcode (4 bytes because of the alignment requirement) or the
494	* length field or the header */
495	crFree( (unsigned char *) packet - 8 - sizeof(CRMessageOpcodes) );
496	}
497
498	void crNetworkPointerWrite( CRNetworkPointer dst, void src )
499	{
500	/* init CRNetworkPointer with invalid values */
501	dst->ptrAlign[0] = 0xDeadBeef;
502	dst->ptrAlign[1] = 0xCafeBabe;
503	/* copy the pointer's value into the CRNetworkPointer */
504	crMemcpy( dst, &src, sizeof(src) );
505
506	/* if either assertion fails, it probably means that a packer function
507	* (which returns a value) was called without setting up the writeback
508	* pointer, or something like that.
509	*/
510	CRASSERT(dst->ptrAlign[0] != 0xffffffff);
511	CRASSERT(dst->ptrAlign[0] != 0xDeadBeef);
512	}

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source: vbox/trunk/src/VBox/GuestHost/OpenGL/packer/pack_buffer.c@ 34356

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