Alc/helpers.c

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 2011 by authors.
   4  * This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  *  License along with this library; if not, write to the
  16  *  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  *  Boston, MA  02111-1307, USA.
  18  * Or go to http://www.gnu.org/copyleft/lgpl.html
  19  */
  20
  21 #include "config.h"
  22
  23 #include <stdlib.h>
  24 #include <time.h>
  25 #include <errno.h>
  26 #include <stdarg.h>
  27 #ifdef HAVE_DLFCN_H
  28 #include <dlfcn.h>
  29 #endif
  30 #ifdef HAVE_CPUID_H
  31 #include <cpuid.h>
  32 #endif
  33 #ifdef HAVE_FLOAT_H
  34 #include <float.h>
  35 #endif
  36 #ifdef HAVE_IEEEFP_H
  37 #include <ieeefp.h>
  38 #endif
  39
  40 #if defined(HAVE_GUIDDEF_H) || defined(HAVE_INITGUID_H)
  41 #define INITGUID
  42 #include <windows.h>
  43 #ifdef HAVE_GUIDDEF_H
  44 #include <guiddef.h>
  45 #else
  46 #include <initguid.h>
  47 #endif
  48
  49 DEFINE_GUID(KSDATAFORMAT_SUBTYPE_PCM,        0x00000001, 0x0000, 0x0010, 0x80,0x00, 0x00,0xaa,0x00,0x38,0x9b,0x71);
  50 DEFINE_GUID(KSDATAFORMAT_SUBTYPE_IEEE_FLOAT, 0x00000003, 0x0000, 0x0010, 0x80,0x00, 0x00,0xaa,0x00,0x38,0x9b,0x71);
  51
  52 DEFINE_GUID(IID_IDirectSoundNotify,   0xb0210783, 0x89cd, 0x11d0, 0xaf,0x08, 0x00,0xa0,0xc9,0x25,0xcd,0x16);
  53
  54 DEFINE_GUID(CLSID_MMDeviceEnumerator, 0xbcde0395, 0xe52f, 0x467c, 0x8e,0x3d, 0xc4,0x57,0x92,0x91,0x69,0x2e);
  55 DEFINE_GUID(IID_IMMDeviceEnumerator,  0xa95664d2, 0x9614, 0x4f35, 0xa7,0x46, 0xde,0x8d,0xb6,0x36,0x17,0xe6);
  56 DEFINE_GUID(IID_IAudioClient,         0x1cb9ad4c, 0xdbfa, 0x4c32, 0xb1,0x78, 0xc2,0xf5,0x68,0xa7,0x03,0xb2);
  57 DEFINE_GUID(IID_IAudioRenderClient,   0xf294acfc, 0x3146, 0x4483, 0xa7,0xbf, 0xad,0xdc,0xa7,0xc2,0x60,0xe2);
  58
  59 #ifdef HAVE_MMDEVAPI
  60 #include <devpropdef.h>
  61
  62 DEFINE_DEVPROPKEY(DEVPKEY_Device_FriendlyName, 0xa45c254e, 0xdf1c, 0x4efd, 0x80,0x20, 0x67,0xd1,0x46,0xa8,0x50,0xe0, 14);
  63 #endif
  64
  65 #endif
  66
  67 #include "alMain.h"
  68
  69 ALuint CPUCapFlags = 0;
  70
  71
  72 void FillCPUCaps(ALuint capfilter)
  73 {
  74     ALuint caps = 0;
  75
  76 #if defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_X64)
  77 /* FIXME: We really should get this for all available CPUs in case different
  78  * CPUs have different caps (is that possible on one machine?). */
  79 #ifdef HAVE_CPUID_H
  80     union {
  81         unsigned int regs[4];
  82         char str[sizeof(unsigned int[4])];
  83     } cpuinf[3];
  84
  85     if(!__get_cpuid(0, &cpuinf[0].regs[0], &cpuinf[0].regs[1], &cpuinf[0].regs[2], &cpuinf[0].regs[3]))
  86         ERR("Failed to get CPUID\n");
  87     else
  88     {
  89         unsigned int maxfunc = cpuinf[0].regs[0];
  90         unsigned int maxextfunc = 0;
  91
  92         if(__get_cpuid(0x80000000, &cpuinf[0].regs[0], &cpuinf[0].regs[1], &cpuinf[0].regs[2], &cpuinf[0].regs[3]))
  93             maxextfunc = cpuinf[0].regs[0];
  94         TRACE("Detected max CPUID function: 0x%x (ext. 0x%x)\n", maxfunc, maxextfunc);
  95
  96         TRACE("Vendor ID: \"%.4s%.4s%.4s\"\n", cpuinf[0].str+4, cpuinf[0].str+12, cpuinf[0].str+8);
  97         if(maxextfunc >= 0x80000004 &&
  98            __get_cpuid(0x80000002, &cpuinf[0].regs[0], &cpuinf[0].regs[1], &cpuinf[0].regs[2], &cpuinf[0].regs[3]) &&
  99            __get_cpuid(0x80000003, &cpuinf[1].regs[0], &cpuinf[1].regs[1], &cpuinf[1].regs[2], &cpuinf[1].regs[3]) &&
 100            __get_cpuid(0x80000004, &cpuinf[2].regs[0], &cpuinf[2].regs[1], &cpuinf[2].regs[2], &cpuinf[2].regs[3]))
 101             TRACE("Name: \"%.16s%.16s%.16s\"\n", cpuinf[0].str, cpuinf[1].str, cpuinf[2].str);
 102
 103         if(maxfunc >= 1 &&
 104            __get_cpuid(1, &cpuinf[0].regs[0], &cpuinf[0].regs[1], &cpuinf[0].regs[2], &cpuinf[0].regs[3]))
 105         {
 106 #ifdef bit_SSE
 107             if((cpuinf[0].regs[3]&bit_SSE))
 108                 caps |= CPU_CAP_SSE;
 109 #endif
 110         }
 111     }
 112 #endif
 113 #endif
 114 #ifdef HAVE_NEON
 115     /* Assume Neon support if compiled with it */
 116     caps |= CPU_CAP_NEON;
 117 #endif
 118
 119     TRACE("Got caps:%s%s%s\n", ((caps&CPU_CAP_SSE)?((capfilter&CPU_CAP_SSE)?" SSE":" (SSE)"):""),
 120                                ((caps&CPU_CAP_NEON)?((capfilter&CPU_CAP_NEON)?" Neon":" (Neon)"):""),
 121                                ((!caps)?" -none-":""));
 122     CPUCapFlags = caps & capfilter;
 123 }
 124
 125
 126 void *al_malloc(size_t alignment, size_t size)
 127 {
 128 #if defined(HAVE_ALIGNED_ALLOC)
 129     size = (size+(alignment-1))&~(alignment-1);
 130     return aligned_alloc(alignment, size);
 131 #elif defined(HAVE_POSIX_MEMALIGN)
 132     void *ret;
 133     if(posix_memalign(&ret, alignment, size) == 0)
 134         return ret;
 135     return NULL;
 136 #elif defined(HAVE__ALIGNED_MALLOC)
 137     return _aligned_malloc(size, alignment);
 138 #else
 139     char *ret = malloc(size+alignment);
 140     if(ret != NULL)
 141     {
 142         *(ret++) = 0x00;
 143         while(((ALintptrEXT)ret&(alignment-1)) != 0)
 144             *(ret++) = 0x55;
 145     }
 146     return ret;
 147 #endif
 148 }
 149
 150 void *al_calloc(size_t alignment, size_t size)
 151 {
 152     void *ret = al_malloc(alignment, size);
 153     if(ret) memset(ret, 0, size);
 154     return ret;
 155 }
 156
 157 void al_free(void *ptr)
 158 {
 159 #if defined(HAVE_ALIGNED_ALLOC) || defined(HAVE_POSIX_MEMALIGN)
 160     free(ptr);
 161 #elif defined(HAVE__ALIGNED_MALLOC)
 162     _aligned_free(ptr);
 163 #else
 164     if(ptr != NULL)
 165     {
 166         char *finder = ptr;
 167         do {
 168             --finder;
 169         } while(*finder == 0x55);
 170         free(finder);
 171     }
 172 #endif
 173 }
 174
 175
 176 void SetMixerFPUMode(FPUCtl *ctl)
 177 {
 178 #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
 179     unsigned short fpuState;
 180     __asm__ __volatile__("fnstcw %0" : "=m" (*&fpuState));
 181     ctl->state = fpuState;
 182     fpuState &= ~0x300; /* clear precision to single */
 183     fpuState |=  0xC00; /* set round-to-zero */
 184     __asm__ __volatile__("fldcw %0" : : "m" (*&fpuState));
 185 #ifdef HAVE_SSE
 186     if((CPUCapFlags&CPU_CAP_SSE))
 187     {
 188         int sseState;
 189         __asm__ __volatile__("stmxcsr %0" : "=m" (*&sseState));
 190         ctl->sse_state = sseState;
 191         sseState &= ~0x300;  /* clear precision to single */
 192         sseState |=  0xC00;  /* set round-to-zero */
 193         sseState |=  0x8000; /* set flush-to-zero */
 194         __asm__ __volatile__("ldmxcsr %0" : : "m" (*&sseState));
 195     }
 196 #endif
 197 #elif defined(HAVE___CONTROL87_2)
 198     int mode;
 199     __control87_2(0, 0, &ctl->state, &ctl->sse_state);
 200     __control87_2(_RC_CHOP|_PC_24, _MCW_RC|_MCW_PC, &mode, NULL);
 201 #ifdef HAVE_SSE
 202     if((CPUCapFlags&CPU_CAP_SSE))
 203         __control87_2(_RC_CHOP|_PC_24|_DN_FLUSH, _MCW_RC|_MCW_PC|_MCW_DN, NULL, &mode);
 204 #endif
 205 #elif defined(HAVE__CONTROLFP)
 206     ctl->state = _controlfp(0, 0);
 207     (void)_controlfp(_RC_CHOP|_PC_24, _MCW_RC|_MCW_PC);
 208 #elif defined(HAVE_FESETROUND)
 209     ctl->state = fegetround();
 210 #ifdef FE_TOWARDZERO
 211     fesetround(FE_TOWARDZERO);
 212 #endif
 213 #endif
 214 }
 215
 216 void RestoreFPUMode(const FPUCtl *ctl)
 217 {
 218 #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
 219     unsigned short fpuState = ctl->state;
 220     __asm__ __volatile__("fldcw %0" : : "m" (*&fpuState));
 221 #ifdef HAVE_SSE
 222     if((CPUCapFlags&CPU_CAP_SSE))
 223         __asm__ __volatile__("ldmxcsr %0" : : "m" (*&ctl->sse_state));
 224 #endif
 225 #elif defined(HAVE___CONTROL87_2)
 226     int mode;
 227     __control87_2(ctl->state, _MCW_RC|_MCW_PC, &mode, NULL);
 228 #ifdef HAVE_SSE
 229     if((CPUCapFlags&CPU_CAP_SSE))
 230         __control87_2(ctl->sse_state, _MCW_RC|_MCW_PC|_MCW_DN, NULL, &mode);
 231 #endif
 232 #elif defined(HAVE__CONTROLFP)
 233     _controlfp(ctl->state, _MCW_RC|_MCW_PC);
 234 #elif defined(HAVE_FESETROUND)
 235     fesetround(ctl->state);
 236 #endif
 237 }
 238
 239
 240 #ifdef _WIN32
 241 void pthread_once(pthread_once_t *once, void (*callback)(void))
 242 {
 243     LONG ret;
 244     while((ret=InterlockedExchange(once, 1)) == 1)
 245         sched_yield();
 246     if(ret == 0)
 247         callback();
 248     InterlockedExchange(once, 2);
 249 }
 250
 251
 252 int pthread_key_create(pthread_key_t *key, void (*callback)(void*))
 253 {
 254     *key = TlsAlloc();
 255     if(callback)
 256         InsertUIntMapEntry(&TlsDestructor, *key, callback);
 257     return 0;
 258 }
 259
 260 int pthread_key_delete(pthread_key_t key)
 261 {
 262     InsertUIntMapEntry(&TlsDestructor, key, NULL);
 263     TlsFree(key);
 264     return 0;
 265 }
 266
 267 void *pthread_getspecific(pthread_key_t key)
 268 { return TlsGetValue(key); }
 269
 270 int pthread_setspecific(pthread_key_t key, void *val)
 271 {
 272     TlsSetValue(key, val);
 273     return 0;
 274 }
 275
 276
 277 void *LoadLib(const char *name)
 278 { return LoadLibraryA(name); }
 279 void CloseLib(void *handle)
 280 { FreeLibrary((HANDLE)handle); }
 281 void *GetSymbol(void *handle, const char *name)
 282 {
 283     void *ret;
 284
 285     ret = (void*)GetProcAddress((HANDLE)handle, name);
 286     if(ret == NULL)
 287         ERR("Failed to load %s\n", name);
 288     return ret;
 289 }
 290
 291 WCHAR *strdupW(const WCHAR *str)
 292 {
 293     const WCHAR *n;
 294     WCHAR *ret;
 295     size_t len;
 296
 297     n = str;
 298     while(*n) n++;
 299     len = n - str;
 300
 301     ret = calloc(sizeof(WCHAR), len+1);
 302     if(ret != NULL)
 303         memcpy(ret, str, sizeof(WCHAR)*len);
 304     return ret;
 305 }
 306
 307 #else
 308
 309 #include <pthread.h>
 310 #ifdef HAVE_PTHREAD_NP_H
 311 #include <pthread_np.h>
 312 #endif
 313 #include <sched.h>
 314
 315 void InitializeCriticalSection(CRITICAL_SECTION *cs)
 316 {
 317     pthread_mutexattr_t attrib;
 318     int ret;
 319
 320     ret = pthread_mutexattr_init(&attrib);
 321     assert(ret == 0);
 322
 323     ret = pthread_mutexattr_settype(&attrib, PTHREAD_MUTEX_RECURSIVE);
 324 #ifdef HAVE_PTHREAD_NP_H
 325     if(ret != 0)
 326         ret = pthread_mutexattr_setkind_np(&attrib, PTHREAD_MUTEX_RECURSIVE);
 327 #endif
 328     assert(ret == 0);
 329     ret = pthread_mutex_init(cs, &attrib);
 330     assert(ret == 0);
 331
 332     pthread_mutexattr_destroy(&attrib);
 333 }
 334 void DeleteCriticalSection(CRITICAL_SECTION *cs)
 335 {
 336     int ret;
 337     ret = pthread_mutex_destroy(cs);
 338     assert(ret == 0);
 339 }
 340 void EnterCriticalSection(CRITICAL_SECTION *cs)
 341 {
 342     int ret;
 343     ret = pthread_mutex_lock(cs);
 344     assert(ret == 0);
 345 }
 346 void LeaveCriticalSection(CRITICAL_SECTION *cs)
 347 {
 348     int ret;
 349     ret = pthread_mutex_unlock(cs);
 350     assert(ret == 0);
 351 }
 352
 353 /* NOTE: This wrapper isn't quite accurate as it returns an ALuint, as opposed
 354  * to the expected DWORD. Both are defined as unsigned 32-bit types, however.
 355  * Additionally, Win32 is supposed to measure the time since Windows started,
 356  * as opposed to the actual time. */
 357 ALuint timeGetTime(void)
 358 {
 359 #if _POSIX_TIMERS > 0
 360     struct timespec ts;
 361     int ret = -1;
 362
 363 #if defined(_POSIX_MONOTONIC_CLOCK) && (_POSIX_MONOTONIC_CLOCK >= 0)
 364 #if _POSIX_MONOTONIC_CLOCK == 0
 365     static int hasmono = 0;
 366     if(hasmono > 0 || (hasmono == 0 &&
 367                        (hasmono=sysconf(_SC_MONOTONIC_CLOCK)) > 0))
 368 #endif
 369         ret = clock_gettime(CLOCK_MONOTONIC, &ts);
 370 #endif
 371     if(ret != 0)
 372         ret = clock_gettime(CLOCK_REALTIME, &ts);
 373     assert(ret == 0);
 374
 375     return ts.tv_nsec/1000000 + ts.tv_sec*1000;
 376 #else
 377     struct timeval tv;
 378     int ret;
 379
 380     ret = gettimeofday(&tv, NULL);
 381     assert(ret == 0);
 382
 383     return tv.tv_usec/1000 + tv.tv_sec*1000;
 384 #endif
 385 }
 386
 387 void Sleep(ALuint t)
 388 {
 389     struct timespec tv, rem;
 390     tv.tv_nsec = (t*1000000)%1000000000;
 391     tv.tv_sec = t/1000;
 392
 393     while(nanosleep(&tv, &rem) == -1 && errno == EINTR)
 394         tv = rem;
 395 }
 396
 397 #ifdef HAVE_DLFCN_H
 398
 399 void *LoadLib(const char *name)
 400 {
 401     const char *err;
 402     void *handle;
 403
 404     dlerror();
 405     handle = dlopen(name, RTLD_NOW);
 406     if((err=dlerror()) != NULL)
 407         handle = NULL;
 408     return handle;
 409 }
 410 void CloseLib(void *handle)
 411 { dlclose(handle); }
 412 void *GetSymbol(void *handle, const char *name)
 413 {
 414     const char *err;
 415     void *sym;
 416
 417     dlerror();
 418     sym = dlsym(handle, name);
 419     if((err=dlerror()) != NULL)
 420     {
 421         WARN("Failed to load %s: %s\n", name, err);
 422         sym = NULL;
 423     }
 424     return sym;
 425 }
 426
 427 #endif
 428 #endif
 429
 430
 431 void al_print(const char *func, const char *fmt, ...)
 432 {
 433     char str[256];
 434     int i;
 435
 436     i = snprintf(str, sizeof(str), "AL lib: %s: ", func);
 437     if(i < (int)sizeof(str) && i > 0)
 438     {
 439         va_list ap;
 440         va_start(ap, fmt);
 441         vsnprintf(str+i, sizeof(str)-i, fmt, ap);
 442         va_end(ap);
 443     }
 444     str[sizeof(str)-1] = 0;
 445
 446     fprintf(LogFile, "%s", str);
 447     fflush(LogFile);
 448 }
 449
 450
 451 void SetRTPriority(void)
 452 {
 453     ALboolean failed = AL_FALSE;
 454
 455 #ifdef _WIN32
 456     if(RTPrioLevel > 0)
 457         failed = !SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
 458 #elif defined(HAVE_PTHREAD_SETSCHEDPARAM) && !defined(__OpenBSD__)
 459     if(RTPrioLevel > 0)
 460     {
 461         struct sched_param param;
 462         /* Use the minimum real-time priority possible for now (on Linux this
 463          * should be 1 for SCHED_RR) */
 464         param.sched_priority = sched_get_priority_min(SCHED_RR);
 465         failed = !!pthread_setschedparam(pthread_self(), SCHED_RR, &param);
 466     }
 467 #else
 468     /* Real-time priority not available */
 469     failed = (RTPrioLevel>0);
 470 #endif
 471     if(failed)
 472         ERR("Failed to set priority level for thread\n");
 473 }
 474
 475
 476 static void Lock(volatile ALenum *l)
 477 {
 478     while(ExchangeInt(l, AL_TRUE) == AL_TRUE)
 479         sched_yield();
 480 }
 481
 482 static void Unlock(volatile ALenum *l)
 483 {
 484     ExchangeInt(l, AL_FALSE);
 485 }
 486
 487 void RWLockInit(RWLock *lock)
 488 {
 489     lock->read_count = 0;
 490     lock->write_count = 0;
 491     lock->read_lock = AL_FALSE;
 492     lock->read_entry_lock = AL_FALSE;
 493     lock->write_lock = AL_FALSE;
 494 }
 495
 496 void ReadLock(RWLock *lock)
 497 {
 498     Lock(&lock->read_entry_lock);
 499     Lock(&lock->read_lock);
 500     if(IncrementRef(&lock->read_count) == 1)
 501         Lock(&lock->write_lock);
 502     Unlock(&lock->read_lock);
 503     Unlock(&lock->read_entry_lock);
 504 }
 505
 506 void ReadUnlock(RWLock *lock)
 507 {
 508     if(DecrementRef(&lock->read_count) == 0)
 509         Unlock(&lock->write_lock);
 510 }
 511
 512 void WriteLock(RWLock *lock)
 513 {
 514     if(IncrementRef(&lock->write_count) == 1)
 515         Lock(&lock->read_lock);
 516     Lock(&lock->write_lock);
 517 }
 518
 519 void WriteUnlock(RWLock *lock)
 520 {
 521     Unlock(&lock->write_lock);
 522     if(DecrementRef(&lock->write_count) == 0)
 523         Unlock(&lock->read_lock);
 524 }
 525
 526
 527 void InitUIntMap(UIntMap *map, ALsizei limit)
 528 {
 529     map->array = NULL;
 530     map->size = 0;
 531     map->maxsize = 0;
 532     map->limit = limit;
 533     RWLockInit(&map->lock);
 534 }
 535
 536 void ResetUIntMap(UIntMap *map)
 537 {
 538     WriteLock(&map->lock);
 539     free(map->array);
 540     map->array = NULL;
 541     map->size = 0;
 542     map->maxsize = 0;
 543     WriteUnlock(&map->lock);
 544 }
 545
 546 ALenum InsertUIntMapEntry(UIntMap *map, ALuint key, ALvoid *value)
 547 {
 548     ALsizei pos = 0;
 549
 550     WriteLock(&map->lock);
 551     if(map->size > 0)
 552     {
 553         ALsizei low = 0;
 554         ALsizei high = map->size - 1;
 555         while(low < high)
 556         {
 557             ALsizei mid = low + (high-low)/2;
 558             if(map->array[mid].key < key)
 559                 low = mid + 1;
 560             else
 561                 high = mid;
 562         }
 563         if(map->array[low].key < key)
 564             low++;
 565         pos = low;
 566     }
 567
 568     if(pos == map->size || map->array[pos].key != key)
 569     {
 570         if(map->size == map->limit)
 571         {
 572             WriteUnlock(&map->lock);
 573             return AL_OUT_OF_MEMORY;
 574         }
 575
 576         if(map->size == map->maxsize)
 577         {
 578             ALvoid *temp = NULL;
 579             ALsizei newsize;
 580
 581             newsize = (map->maxsize ? (map->maxsize<<1) : 4);
 582             if(newsize >= map->maxsize)
 583                 temp = realloc(map->array, newsize*sizeof(map->array[0]));
 584             if(!temp)
 585             {
 586                 WriteUnlock(&map->lock);
 587                 return AL_OUT_OF_MEMORY;
 588             }
 589             map->array = temp;
 590             map->maxsize = newsize;
 591         }
 592
 593         if(pos < map->size)
 594             memmove(&map->array[pos+1], &map->array[pos],
 595                     (map->size-pos)*sizeof(map->array[0]));
 596         map->size++;
 597     }
 598     map->array[pos].key = key;
 599     map->array[pos].value = value;
 600     WriteUnlock(&map->lock);
 601
 602     return AL_NO_ERROR;
 603 }
 604
 605 ALvoid *RemoveUIntMapKey(UIntMap *map, ALuint key)
 606 {
 607     ALvoid *ptr = NULL;
 608     WriteLock(&map->lock);
 609     if(map->size > 0)
 610     {
 611         ALsizei low = 0;
 612         ALsizei high = map->size - 1;
 613         while(low < high)
 614         {
 615             ALsizei mid = low + (high-low)/2;
 616             if(map->array[mid].key < key)
 617                 low = mid + 1;
 618             else
 619                 high = mid;
 620         }
 621         if(map->array[low].key == key)
 622         {
 623             ptr = map->array[low].value;
 624             if(low < map->size-1)
 625                 memmove(&map->array[low], &map->array[low+1],
 626                         (map->size-1-low)*sizeof(map->array[0]));
 627             map->size--;
 628         }
 629     }
 630     WriteUnlock(&map->lock);
 631     return ptr;
 632 }
 633
 634 ALvoid *LookupUIntMapKey(UIntMap *map, ALuint key)
 635 {
 636     ALvoid *ptr = NULL;
 637     ReadLock(&map->lock);
 638     if(map->size > 0)
 639     {
 640         ALsizei low = 0;
 641         ALsizei high = map->size - 1;
 642         while(low < high)
 643         {
 644             ALsizei mid = low + (high-low)/2;
 645             if(map->array[mid].key < key)
 646                 low = mid + 1;
 647             else
 648                 high = mid;
 649         }
 650         if(map->array[low].key == key)
 651             ptr = map->array[low].value;
 652     }
 653     ReadUnlock(&map->lock);
 654     return ptr;
 655 }