summaryrefslogtreecommitdiff
path: root/indra/llplugin/llpluginsharedmemory.cpp
blob: 3204bbd7157d7521fb0dfa9dae52ee2580d1ed3e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
/** 
 * @file llpluginsharedmemory.cpp
 * LLPluginSharedMemory manages a shared memory segment for use by the LLPlugin API.
 *
 * @cond
 * $LicenseInfo:firstyear=2008&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 * @endcond
 */

#include "linden_common.h"

#include "llpluginsharedmemory.h"

// on Mac and Linux, we use the native shm_open/mmap interface by using
//	#define USE_SHM_OPEN_SHARED_MEMORY 1
// in the appropriate sections below.

// For Windows, use:
//	#define USE_WIN32_SHARED_MEMORY 1

// If we ever want to fall back to the apr implementation for a platform, use:
//	#define USE_APR_SHARED_MEMORY 1

#if LL_WINDOWS
//	#define USE_APR_SHARED_MEMORY 1
	#define USE_WIN32_SHARED_MEMORY 1
#elif LL_DARWIN
	#define USE_SHM_OPEN_SHARED_MEMORY 1
#elif _POSIX_SHARED_MEMORY_OBJECTS == -1
	#define USE_APR_SHARED_MEMORY 1
#elif LL_LINUX
	#define USE_SHM_OPEN_SHARED_MEMORY 1
#elif LL_FREEBSD
	#define USE_SHM_OPEN_SHARED_MEMORY 1
#endif


// FIXME: This path thing is evil and unacceptable.
#if LL_WINDOWS
	#define APR_SHARED_MEMORY_PREFIX_STRING "C:\\LLPlugin_"
	// Apparnently using the "Global\\" prefix here only works from administrative accounts under Vista.
	// Other options I've seen referenced are "Local\\" and "Session\\".
	#define WIN32_SHARED_MEMORY_PREFIX_STRING "Local\\LL_"
#else
	// mac and linux
	#define APR_SHARED_MEMORY_PREFIX_STRING "/tmp/LLPlugin_"
	#define SHM_OPEN_SHARED_MEMORY_PREFIX_STRING "/LL"
#endif

#if USE_APR_SHARED_MEMORY 
	#include "llapr.h"
	#include "apr_shm.h"
#elif USE_SHM_OPEN_SHARED_MEMORY
	#include <sys/fcntl.h>
	#include <sys/mman.h>
	#include <errno.h>
#elif USE_WIN32_SHARED_MEMORY
#include <windows.h>
#endif // USE_APR_SHARED_MEMORY


int LLPluginSharedMemory::sSegmentNumber = 0;

std::string LLPluginSharedMemory::createName(void)
{
	std::stringstream newname;

#if LL_WINDOWS
	newname << GetCurrentProcessId();
#else // LL_WINDOWS
	newname << getpid();
#endif // LL_WINDOWS
		
	newname << "_" << sSegmentNumber++;
	
	return newname.str();
}

/**
 * @brief LLPluginSharedMemoryImpl is the platform-dependent implementation of LLPluginSharedMemory. TODO:DOC is this necessary/sufficient? kinda obvious.
 *
 */
class LLPluginSharedMemoryPlatformImpl
{
public:
	LLPluginSharedMemoryPlatformImpl();
	~LLPluginSharedMemoryPlatformImpl();
	
#if USE_APR_SHARED_MEMORY
	apr_shm_t* mAprSharedMemory;	
#elif USE_SHM_OPEN_SHARED_MEMORY
	int mSharedMemoryFD;
#elif USE_WIN32_SHARED_MEMORY
	HANDLE mMapFile;
#endif

};

/**
 * Constructor. Creates a shared memory segment.
 */
LLPluginSharedMemory::LLPluginSharedMemory()
{
	mSize = 0;
	mMappedAddress = NULL;
	mNeedsDestroy = false;

	mImpl = new LLPluginSharedMemoryPlatformImpl;
}

/**
 * Destructor. Uses destroy() and detach() to ensure shared memory segment is cleaned up.
 */
LLPluginSharedMemory::~LLPluginSharedMemory()
{
	if(mNeedsDestroy)
		destroy();
	else
		detach();
		
	unlink();
	
	delete mImpl;
}

#if USE_APR_SHARED_MEMORY
// MARK: apr implementation

LLPluginSharedMemoryPlatformImpl::LLPluginSharedMemoryPlatformImpl()
{
	mAprSharedMemory = NULL;
}

LLPluginSharedMemoryPlatformImpl::~LLPluginSharedMemoryPlatformImpl()
{
	
}

bool LLPluginSharedMemory::map(void)
{
	mMappedAddress = apr_shm_baseaddr_get(mImpl->mAprSharedMemory);
	if(mMappedAddress == NULL)
	{
		return false;
	}
	
	return true;
}

bool LLPluginSharedMemory::unmap(void)
{
	// This is a no-op under apr.
	return true;
}

bool LLPluginSharedMemory::close(void)
{
	// This is a no-op under apr.
	return true;
}

bool LLPluginSharedMemory::unlink(void)
{
	// This is a no-op under apr.
	return true;
}


bool LLPluginSharedMemory::create(size_t size)
{
	mName = APR_SHARED_MEMORY_PREFIX_STRING;
	mName += createName();
	mSize = size;
	
	apr_status_t status = apr_shm_create( &(mImpl->mAprSharedMemory), mSize, mName.c_str(), gAPRPoolp );
	
	if(ll_apr_warn_status(status))
	{
		return false;
	}

	mNeedsDestroy = true;
	
	return map();
}

bool LLPluginSharedMemory::destroy(void)
{
	if(mImpl->mAprSharedMemory)
	{
		apr_status_t status = apr_shm_destroy(mImpl->mAprSharedMemory);
		if(ll_apr_warn_status(status))
		{
			// TODO: Is this a fatal error?  I think not...
		}
		mImpl->mAprSharedMemory = NULL;
	}
	
	return true;
}

bool LLPluginSharedMemory::attach(const std::string &name, size_t size)
{
	mName = name;
	mSize = size;
	
	apr_status_t status = apr_shm_attach( &(mImpl->mAprSharedMemory), mName.c_str(), gAPRPoolp );
	
	if(ll_apr_warn_status(status))
	{
		return false;
	}

	return map();
}


bool LLPluginSharedMemory::detach(void)
{
	if(mImpl->mAprSharedMemory)
	{
		apr_status_t status = apr_shm_detach(mImpl->mAprSharedMemory);
		if(ll_apr_warn_status(status))
		{
			// TODO: Is this a fatal error?  I think not...
		}
		mImpl->mAprSharedMemory = NULL;
	}
	
	return true;
}


#elif USE_SHM_OPEN_SHARED_MEMORY
// MARK: shm_open/mmap implementation

LLPluginSharedMemoryPlatformImpl::LLPluginSharedMemoryPlatformImpl()
{
	mSharedMemoryFD = -1;
}

LLPluginSharedMemoryPlatformImpl::~LLPluginSharedMemoryPlatformImpl()
{
}

bool LLPluginSharedMemory::map(void)
{
	mMappedAddress = ::mmap(NULL, mSize, PROT_READ | PROT_WRITE, MAP_SHARED, mImpl->mSharedMemoryFD, 0);
	if(mMappedAddress == NULL)
	{
		return false;
	}
	
	LL_DEBUGS("Plugin") << "memory mapped at " << mMappedAddress << LL_ENDL;

	return true;
}

bool LLPluginSharedMemory::unmap(void)
{
	if(mMappedAddress != NULL)
	{
		LL_DEBUGS("Plugin") << "calling munmap(" << mMappedAddress << ", " << mSize << ")" << LL_ENDL;
		if(::munmap(mMappedAddress, mSize) == -1)	
		{
			// TODO: Is this a fatal error?  I think not...
		}
		
		mMappedAddress = NULL;
	}

	return true;
}

bool LLPluginSharedMemory::close(void)
{
	if(mImpl->mSharedMemoryFD != -1)
	{
		LL_DEBUGS("Plugin") << "calling close(" << mImpl->mSharedMemoryFD << ")" << LL_ENDL;
		if(::close(mImpl->mSharedMemoryFD) == -1)
		{
			// TODO: Is this a fatal error?  I think not...
		}
		
		mImpl->mSharedMemoryFD = -1;
	}
	return true;
}

bool LLPluginSharedMemory::unlink(void)
{
	if(!mName.empty())
	{
		if(::shm_unlink(mName.c_str()) == -1)
		{
			return false;
		}
	}
		
	return true;
}


bool LLPluginSharedMemory::create(size_t size)
{
	mName = SHM_OPEN_SHARED_MEMORY_PREFIX_STRING;
	mName += createName();
	mSize = size;
	
	// Preemptive unlink, just in case something didn't get cleaned up.
	unlink();

	mImpl->mSharedMemoryFD = ::shm_open(mName.c_str(), O_CREAT | O_RDWR, S_IRUSR | S_IWUSR);
	if(mImpl->mSharedMemoryFD == -1)
	{
		return false;
	}
	
	mNeedsDestroy = true;
	
	if(::ftruncate(mImpl->mSharedMemoryFD, mSize) == -1)
	{
		return false;
	}
	
	
	return map();
}

bool LLPluginSharedMemory::destroy(void)
{
	unmap();
	close();	
	
	return true;
}


bool LLPluginSharedMemory::attach(const std::string &name, size_t size)
{
	mName = name;
	mSize = size;

	mImpl->mSharedMemoryFD = ::shm_open(mName.c_str(), O_RDWR, S_IRUSR | S_IWUSR);
	if(mImpl->mSharedMemoryFD == -1)
	{
		return false;
	}
	
	// unlink here so the segment will be cleaned up automatically after the last close.
	unlink();
	
	return map();
}

bool LLPluginSharedMemory::detach(void)
{
	unmap();
	close();	
	return true;
}

#elif USE_WIN32_SHARED_MEMORY
// MARK: Win32 CreateFileMapping-based implementation

// Reference: http://msdn.microsoft.com/en-us/library/aa366551(VS.85).aspx

LLPluginSharedMemoryPlatformImpl::LLPluginSharedMemoryPlatformImpl()
{
	mMapFile = NULL;
}

LLPluginSharedMemoryPlatformImpl::~LLPluginSharedMemoryPlatformImpl()
{
	
}

bool LLPluginSharedMemory::map(void)
{
	mMappedAddress = MapViewOfFile(
		mImpl->mMapFile,			// handle to map object
		FILE_MAP_ALL_ACCESS,		// read/write permission
		0,                   
		0,                   
		mSize);
		
	if(mMappedAddress == NULL)
	{
		LL_WARNS("Plugin") << "MapViewOfFile failed: " << GetLastError() << LL_ENDL;
		return false;
	}
	
	LL_DEBUGS("Plugin") << "memory mapped at " << mMappedAddress << LL_ENDL;

	return true;
}

bool LLPluginSharedMemory::unmap(void)
{
	if(mMappedAddress != NULL)
	{
		UnmapViewOfFile(mMappedAddress);	
		mMappedAddress = NULL;
	}

	return true;
}

bool LLPluginSharedMemory::close(void)
{
	if(mImpl->mMapFile != NULL)
	{
		CloseHandle(mImpl->mMapFile);
		mImpl->mMapFile = NULL;
	}
	
	return true;
}

bool LLPluginSharedMemory::unlink(void)
{
	// This is a no-op on Windows.
	return true;
}


bool LLPluginSharedMemory::create(size_t size)
{
	mName = WIN32_SHARED_MEMORY_PREFIX_STRING;
	mName += createName();
	mSize = size;

	mImpl->mMapFile = CreateFileMappingA(
                 INVALID_HANDLE_VALUE,		// use paging file
                 NULL,						// default security 
                 PAGE_READWRITE,			// read/write access
                 0,							// max. object size 
                 mSize,						// buffer size  
                 mName.c_str());			// name of mapping object

	if(mImpl->mMapFile == NULL)
	{
		LL_WARNS("Plugin") << "CreateFileMapping failed: " << GetLastError() << LL_ENDL;
		return false;
	}

	mNeedsDestroy = true;
		
	return map();
}

bool LLPluginSharedMemory::destroy(void)
{
	unmap();
	close();
	return true;
}

bool LLPluginSharedMemory::attach(const std::string &name, size_t size)
{
	mName = name;
	mSize = size;

	mImpl->mMapFile = OpenFileMappingA(
				FILE_MAP_ALL_ACCESS,		// read/write access
				FALSE,						// do not inherit the name
				mName.c_str());				// name of mapping object
	
	if(mImpl->mMapFile == NULL)
	{
		LL_WARNS("Plugin") << "OpenFileMapping failed: " << GetLastError() << LL_ENDL;
		return false;
	}
		
	return map();
}

bool LLPluginSharedMemory::detach(void)
{
	unmap();
	close();
	return true;
}



#endif