1 /*----------------------------------------------------------------------------
2 *
3 * File:
4 * eas_hostmm.c
5 *
6 * Contents and purpose:
7 * This file contains the host wrapper functions for stdio, stdlib, etc.
8 * This is a sample version that reads from a filedescriptor.
9 * The file locator (EAS_FILE_LOCATOR) handle passed to
10 * HWOpenFile is the same one that is passed to EAS_OpenFile.
11 *
12 * Modify this file to suit the needs of your particular system.
13 *
14 * EAS_MAX_FILE_HANDLES sets the maximum number of MIDI streams within
15 * a MIDI type 1 file that can be played.
16 *
17 * EAS_HW_FILE is a structure to support the file I/O functions. It
18 * comprises the file descriptor, the file read pointer, and
19 * the dup flag, which when set, indicates that the file handle has
20 * been duplicated, and offset and length within the file.
21 *
22 * Copyright 2005 Sonic Network Inc.
23
24 * Licensed under the Apache License, Version 2.0 (the "License");
25 * you may not use this file except in compliance with the License.
26 * You may obtain a copy of the License at
27 *
28 * http://www.apache.org/licenses/LICENSE-2.0
29 *
30 * Unless required by applicable law or agreed to in writing, software
31 * distributed under the License is distributed on an "AS IS" BASIS,
32 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
33 * See the License for the specific language governing permissions and
34 * limitations under the License.
35 *
36 *----------------------------------------------------------------------------
37 * Revision Control:
38 * $Revision: 795 $
39 * $Date: 2007-08-01 00:14:45 -0700 (Wed, 01 Aug 2007) $
40 *----------------------------------------------------------------------------
41 */
42
43 #ifdef _lint
44 #include "lint_stdlib.h"
45 #else
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <sys/types.h>
51 #include <sys/stat.h>
52 #include <fcntl.h>
53 #include <limits.h>
54 #include <sys/mman.h>
55 #include <errno.h>
56 #include <signal.h>
57 #include <pthread.h>
58 #include <media/MediaPlayerInterface.h>
59 #endif
60
61 #include "eas_host.h"
62
63 /* Only for debugging LED, vibrate, and backlight functions */
64 #include "eas_report.h"
65
66 /* this module requires dynamic memory support */
67 #ifdef _STATIC_MEMORY
68 #error "eas_hostmm.c requires the dynamic memory model!\n"
69 #endif
70
71 #ifndef EAS_MAX_FILE_HANDLES
72 // 100 max file handles == 3 * (nb tracks(32) + 1 for the segment) + 1 for jet file
73 // 3 == 1(playing segment) + 1(prepared segment)
74 // + 1(after end of playing segment, before files closed)
75 #define EAS_MAX_FILE_HANDLES 100
76 #endif
77
78 /*
79 * this structure and the related function are here
80 * to support the ability to create duplicate handles
81 * and buffering it in memory. If your system uses
82 * in-memory resources, you can eliminate the calls
83 * to malloc and free, the dup flag, and simply track
84 * the file size and read position.
85 */
86 typedef struct eas_hw_file_tag
87 {
88 EAS_I32 fileSize;
89 EAS_I32 filePos;
90 EAS_BOOL dup;
91 int fd;
92 EAS_I32 offset;
93 } EAS_HW_FILE;
94
95 typedef struct eas_hw_inst_data_tag
96 {
97 EAS_HW_FILE files[EAS_MAX_FILE_HANDLES];
98 } EAS_HW_INST_DATA;
99
100 pthread_key_t EAS_sigbuskey;
101
102 /*----------------------------------------------------------------------------
103 * EAS_HWInit
104 *
105 * Initialize host wrapper interface
106 *
107 *----------------------------------------------------------------------------
108 */
EAS_HWInit(EAS_HW_DATA_HANDLE * pHWInstData)109 EAS_RESULT EAS_HWInit (EAS_HW_DATA_HANDLE *pHWInstData)
110 {
111 EAS_HW_FILE *file;
112 int i;
113
114 /* need to track file opens for duplicate handles */
115 *pHWInstData = malloc(sizeof(EAS_HW_INST_DATA));
116 if (!(*pHWInstData))
117 return EAS_ERROR_MALLOC_FAILED;
118
119 EAS_HWMemSet(*pHWInstData, 0, sizeof(EAS_HW_INST_DATA));
120
121 file = (*pHWInstData)->files;
122 for (i = 0; i < EAS_MAX_FILE_HANDLES; i++)
123 {
124 file->fd = -1;
125 file++;
126 }
127
128
129 return EAS_SUCCESS;
130 }
131
132 /*----------------------------------------------------------------------------
133 * EAS_HWShutdown
134 *
135 * Shut down host wrapper interface
136 *
137 *----------------------------------------------------------------------------
138 */
EAS_HWShutdown(EAS_HW_DATA_HANDLE hwInstData)139 EAS_RESULT EAS_HWShutdown (EAS_HW_DATA_HANDLE hwInstData)
140 {
141
142 free(hwInstData);
143 return EAS_SUCCESS;
144 }
145
146 /*----------------------------------------------------------------------------
147 *
148 * EAS_HWMalloc
149 *
150 * Allocates dynamic memory
151 *
152 *----------------------------------------------------------------------------
153 */
154 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWMalloc(EAS_HW_DATA_HANDLE hwInstData,EAS_I32 size)155 void *EAS_HWMalloc (EAS_HW_DATA_HANDLE hwInstData, EAS_I32 size)
156 {
157 /* Since this whole library loves signed sizes, let's not let
158 * negative or 0 values through */
159 if (size <= 0)
160 return NULL;
161 return malloc((size_t) size);
162 }
163
164 /*----------------------------------------------------------------------------
165 *
166 * EAS_HWFree
167 *
168 * Frees dynamic memory
169 *
170 *----------------------------------------------------------------------------
171 */
172 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWFree(EAS_HW_DATA_HANDLE hwInstData,void * p)173 void EAS_HWFree (EAS_HW_DATA_HANDLE hwInstData, void *p)
174 {
175 free(p);
176 }
177
178 /*----------------------------------------------------------------------------
179 *
180 * EAS_HWMemCpy
181 *
182 * Copy memory wrapper
183 *
184 *----------------------------------------------------------------------------
185 */
EAS_HWMemCpy(void * dest,const void * src,EAS_I32 amount)186 void *EAS_HWMemCpy (void *dest, const void *src, EAS_I32 amount)
187 {
188 if (amount < 0) {
189 EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x1a54b6e8, 0x00000004 , amount);
190 exit(255);
191 }
192 return memcpy(dest, src, (size_t) amount);
193 }
194
195 /*----------------------------------------------------------------------------
196 *
197 * EAS_HWMemSet
198 *
199 * Set memory wrapper
200 *
201 *----------------------------------------------------------------------------
202 */
EAS_HWMemSet(void * dest,int val,EAS_I32 amount)203 void *EAS_HWMemSet (void *dest, int val, EAS_I32 amount)
204 {
205 if (amount < 0) {
206 EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x1a54b6e8, 0x00000005 , amount);
207 exit(255);
208 }
209 return memset(dest, val, (size_t) amount);
210 }
211
212 /*----------------------------------------------------------------------------
213 *
214 * EAS_HWMemCmp
215 *
216 * Compare memory wrapper
217 *
218 *----------------------------------------------------------------------------
219 */
EAS_HWMemCmp(const void * s1,const void * s2,EAS_I32 amount)220 EAS_I32 EAS_HWMemCmp (const void *s1, const void *s2, EAS_I32 amount)
221 {
222 if (amount < 0) {
223 EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x1a54b6e8, 0x00000006 , amount);
224 exit(255);
225 }
226 return (EAS_I32) memcmp(s1, s2, (size_t) amount);
227 }
228
229 /*----------------------------------------------------------------------------
230 *
231 * EAS_HWOpenFile
232 *
233 * Open a file for read or write
234 *
235 *----------------------------------------------------------------------------
236 */
EAS_HWOpenFile(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_LOCATOR locator,EAS_FILE_HANDLE * pFile,EAS_FILE_MODE mode)237 EAS_RESULT EAS_HWOpenFile (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_LOCATOR locator, EAS_FILE_HANDLE *pFile, EAS_FILE_MODE mode)
238 {
239 EAS_HW_FILE *file;
240 int fd;
241 int i, temp;
242
243 /* set return value to NULL */
244 *pFile = NULL;
245
246 /* only support read mode at this time */
247 if (mode != EAS_FILE_READ)
248 return EAS_ERROR_INVALID_FILE_MODE;
249
250 /* find an empty entry in the file table */
251 file = hwInstData->files;
252 for (i = 0; i < EAS_MAX_FILE_HANDLES; i++)
253 {
254 /* is this slot being used? */
255 if (file->fd < 0)
256 {
257 if (locator->path) {
258 /* open the file */
259 if ((fd = open(locator->path, O_RDONLY)) < 0) {
260 return EAS_ERROR_FILE_OPEN_FAILED;
261 }
262 } else {
263 /* else file is already open */
264 fd = dup(locator->fd);
265 }
266
267 /* determine the file size */
268 if (locator->length == 0) {
269 if (lseek(fd, 0, SEEK_END) < 0) {
270 close(fd);
271 return EAS_ERROR_FILE_LENGTH;
272 }
273 if ((file->fileSize = lseek(fd, 0, SEEK_CUR)) == -1L) {
274 close(fd);
275 return EAS_ERROR_FILE_LENGTH;
276 }
277 }
278
279 // file size was passed in
280 else {
281 file->fileSize = (EAS_I32) locator->length;
282 }
283
284 file->fd = fd;
285 file->offset = locator->offset;
286
287 /* initialize some values */
288 file->filePos = 0;
289 file->dup = EAS_FALSE;
290
291 *pFile = file;
292 return EAS_SUCCESS;
293 }
294 file++;
295 }
296
297 /* too many open files */
298 return EAS_ERROR_MAX_FILES_OPEN;
299 }
300
301
302 /*----------------------------------------------------------------------------
303 *
304 * EAS_HWReadFile
305 *
306 * Read data from a file
307 *
308 *----------------------------------------------------------------------------
309 */
310 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWReadFile(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,void * pBuffer,EAS_I32 n,EAS_I32 * pBytesRead)311 EAS_RESULT EAS_HWReadFile (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, void *pBuffer, EAS_I32 n, EAS_I32 *pBytesRead)
312 {
313 EAS_I32 count;
314
315 /* make sure we have a valid handle */
316 if (file->fd < 0)
317 return EAS_ERROR_INVALID_HANDLE;
318
319 if (n < 0)
320 return EAS_EOF;
321
322 /* calculate the bytes to read */
323 count = file->fileSize - file->filePos;
324 if (n < count)
325 count = n;
326 if (count < 0)
327 return EAS_EOF;
328
329 /* copy the data to the requested location, and advance the pointer */
330 if (count) {
331 lseek(file->fd, file->filePos + file->offset, SEEK_SET);
332 count = read(file->fd, pBuffer, count);
333 }
334 file->filePos += count;
335 *pBytesRead = count;
336
337 /* were n bytes read? */
338 if (count!= n)
339 return EAS_EOF;
340 return EAS_SUCCESS;
341 }
342
343 /*----------------------------------------------------------------------------
344 *
345 * EAS_HWGetByte
346 *
347 * Read a byte from a file
348 *
349 *----------------------------------------------------------------------------
350 */
351 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWGetByte(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,void * p)352 EAS_RESULT EAS_HWGetByte (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, void *p)
353 {
354 EAS_I32 numread;
355 return EAS_HWReadFile(hwInstData, file, p, 1, &numread);
356 }
357
358 /*----------------------------------------------------------------------------
359 *
360 * EAS_HWGetWord
361 *
362 * Read a 16 bit word from a file
363 *
364 *----------------------------------------------------------------------------
365 */
366 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWGetWord(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,void * p,EAS_BOOL msbFirst)367 EAS_RESULT EAS_HWGetWord (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, void *p, EAS_BOOL msbFirst)
368 {
369 EAS_RESULT result;
370 EAS_U8 c1, c2;
371
372 /* read 2 bytes from the file */
373 if ((result = EAS_HWGetByte(hwInstData, file, &c1)) != EAS_SUCCESS)
374 return result;
375 if ((result = EAS_HWGetByte(hwInstData, file, &c2)) != EAS_SUCCESS)
376 return result;
377
378 /* order them as requested */
379 if (msbFirst)
380 *((EAS_U16*) p) = ((EAS_U16) c1 << 8) | c2;
381 else
382 *((EAS_U16*) p) = ((EAS_U16) c2 << 8) | c1;
383
384 return EAS_SUCCESS;
385 }
386
387 /*----------------------------------------------------------------------------
388 *
389 * EAS_HWGetDWord
390 *
391 * Returns the current location in the file
392 *
393 *----------------------------------------------------------------------------
394 */
395 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWGetDWord(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,void * p,EAS_BOOL msbFirst)396 EAS_RESULT EAS_HWGetDWord (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, void *p, EAS_BOOL msbFirst)
397 {
398 EAS_RESULT result;
399 EAS_U8 c1, c2,c3,c4;
400
401 /* read 4 bytes from the file */
402 if ((result = EAS_HWGetByte(hwInstData, file, &c1)) != EAS_SUCCESS)
403 return result;
404 if ((result = EAS_HWGetByte(hwInstData, file, &c2)) != EAS_SUCCESS)
405 return result;
406 if ((result = EAS_HWGetByte(hwInstData, file, &c3)) != EAS_SUCCESS)
407 return result;
408 if ((result = EAS_HWGetByte(hwInstData, file, &c4)) != EAS_SUCCESS)
409 return result;
410
411 /* order them as requested */
412 if (msbFirst)
413 *((EAS_U32*) p) = ((EAS_U32) c1 << 24) | ((EAS_U32) c2 << 16) | ((EAS_U32) c3 << 8) | c4;
414 else
415 *((EAS_U32*) p)= ((EAS_U32) c4 << 24) | ((EAS_U32) c3 << 16) | ((EAS_U32) c2 << 8) | c1;
416
417 return EAS_SUCCESS;
418 }
419
420 /*----------------------------------------------------------------------------
421 *
422 * EAS_HWFilePos
423 *
424 * Returns the current location in the file
425 *
426 *----------------------------------------------------------------------------
427 */
428 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWFilePos(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,EAS_I32 * pPosition)429 EAS_RESULT EAS_HWFilePos (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, EAS_I32 *pPosition)
430 {
431
432 /* make sure we have a valid handle */
433 if (file->fd < 0)
434 return EAS_ERROR_INVALID_HANDLE;
435
436 *pPosition = file->filePos;
437 return EAS_SUCCESS;
438 } /* end EAS_HWFilePos */
439
440 /*----------------------------------------------------------------------------
441 *
442 * EAS_HWFileSeek
443 *
444 * Seek to a specific location in the file
445 *
446 *----------------------------------------------------------------------------
447 */
448 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWFileSeek(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,EAS_I32 position)449 EAS_RESULT EAS_HWFileSeek (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, EAS_I32 position)
450 {
451
452 /* make sure we have a valid handle */
453 if (file->fd < 0)
454 return EAS_ERROR_INVALID_HANDLE;
455
456 /* validate new position */
457 if ((position < 0) || (position > file->fileSize))
458 return EAS_ERROR_FILE_SEEK;
459
460 /* save new position */
461 file->filePos = position;
462 return EAS_SUCCESS;
463 }
464
465 /*----------------------------------------------------------------------------
466 *
467 * EAS_HWFileSeekOfs
468 *
469 * Seek forward or back relative to the current position
470 *
471 *----------------------------------------------------------------------------
472 */
473 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWFileSeekOfs(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,EAS_I32 position)474 EAS_RESULT EAS_HWFileSeekOfs (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, EAS_I32 position)
475 {
476
477 /* make sure we have a valid handle */
478 if (file->fd < 0)
479 return EAS_ERROR_INVALID_HANDLE;
480
481 /* determine the file position */
482 position += file->filePos;
483 if ((position < 0) || (position > file->fileSize))
484 return EAS_ERROR_FILE_SEEK;
485
486 /* save new position */
487 file->filePos = position;
488 return EAS_SUCCESS;
489 }
490
491 /*----------------------------------------------------------------------------
492 *
493 * EAS_HWFileLength
494 *
495 * Return the file length
496 *
497 *----------------------------------------------------------------------------
498 */
499 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWFileLength(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,EAS_I32 * pLength)500 EAS_RESULT EAS_HWFileLength (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, EAS_I32 *pLength)
501 {
502
503 /* make sure we have a valid handle */
504 if (file->fd < 0)
505 return EAS_ERROR_INVALID_HANDLE;
506
507 *pLength = file->fileSize;
508 return EAS_SUCCESS;
509 }
510
511 /*----------------------------------------------------------------------------
512 *
513 * EAS_HWDupHandle
514 *
515 * Duplicate a file handle
516 *
517 *----------------------------------------------------------------------------
518 */
EAS_HWDupHandle(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file,EAS_FILE_HANDLE * pDupFile)519 EAS_RESULT EAS_HWDupHandle (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file, EAS_FILE_HANDLE *pDupFile)
520 {
521 EAS_HW_FILE *dupFile;
522 int i;
523
524 /* make sure we have a valid handle */
525 if (file->fd < 0)
526 return EAS_ERROR_INVALID_HANDLE;
527
528 /* find an empty entry in the file table */
529 dupFile = hwInstData->files;
530 for (i = 0; i < EAS_MAX_FILE_HANDLES; i++)
531 {
532 /* is this slot being used? */
533 if (dupFile->fd < 0)
534 {
535 /* copy info from the handle to be duplicated */
536 dupFile->filePos = file->filePos;
537 dupFile->fileSize = file->fileSize;
538 dupFile->fd = file->fd;
539 dupFile->offset = file->offset;
540
541 /* set the duplicate handle flag */
542 dupFile->dup = file->dup = EAS_TRUE;
543
544 *pDupFile = dupFile;
545 return EAS_SUCCESS;
546 }
547 dupFile++;
548 }
549
550 /* too many open files */
551 return EAS_ERROR_MAX_FILES_OPEN;
552 }
553
554 /*----------------------------------------------------------------------------
555 *
556 * EAS_HWClose
557 *
558 * Wrapper for fclose function
559 *
560 *----------------------------------------------------------------------------
561 */
EAS_HWCloseFile(EAS_HW_DATA_HANDLE hwInstData,EAS_FILE_HANDLE file1)562 EAS_RESULT EAS_HWCloseFile (EAS_HW_DATA_HANDLE hwInstData, EAS_FILE_HANDLE file1)
563 {
564 EAS_HW_FILE *file2,*dupFile;
565 int i;
566
567
568 /* make sure we have a valid handle */
569 if (file1->fd < 0)
570 return EAS_ERROR_INVALID_HANDLE;
571
572 /* check for duplicate handle */
573 if (file1->dup)
574 {
575 dupFile = NULL;
576 file2 = hwInstData->files;
577 for (i = 0; i < EAS_MAX_FILE_HANDLES; i++)
578 {
579 /* check for duplicate */
580 if ((file1 != file2) && (file2->fd == file1->fd))
581 {
582 /* is there more than one duplicate? */
583 if (dupFile != NULL)
584 {
585 /* clear this entry and return */
586 file1->fd = -1;
587 return EAS_SUCCESS;
588 }
589
590 /* this is the first duplicate found */
591 else
592 dupFile = file2;
593 }
594 file2++;
595 }
596
597 /* there is only one duplicate, clear the dup flag */
598 if (dupFile)
599 dupFile->dup = EAS_FALSE;
600 else
601 /* if we get here, there's a serious problem */
602 return EAS_ERROR_HANDLE_INTEGRITY;
603
604 /* clear this entry and return */
605 file1->fd = -1;
606 return EAS_SUCCESS;
607 }
608
609 /* no duplicates - close the file */
610 close(file1->fd);
611 /* clear this entry and return */
612 file1->fd = -1;
613 return EAS_SUCCESS;
614 }
615
616 /*----------------------------------------------------------------------------
617 *
618 * EAS_HWVibrate
619 *
620 * Turn on/off vibrate function
621 *
622 *----------------------------------------------------------------------------
623 */
624 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWVibrate(EAS_HW_DATA_HANDLE hwInstData,EAS_BOOL state)625 EAS_RESULT EAS_HWVibrate (EAS_HW_DATA_HANDLE hwInstData, EAS_BOOL state)
626 {
627 EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x1a54b6e8, 0x00000001 , state);
628 return EAS_SUCCESS;
629 } /* end EAS_HWVibrate */
630
631 /*----------------------------------------------------------------------------
632 *
633 * EAS_HWLED
634 *
635 * Turn on/off LED
636 *
637 *----------------------------------------------------------------------------
638 */
639 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWLED(EAS_HW_DATA_HANDLE hwInstData,EAS_BOOL state)640 EAS_RESULT EAS_HWLED (EAS_HW_DATA_HANDLE hwInstData, EAS_BOOL state)
641 {
642 EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x1a54b6e8, 0x00000002 , state);
643 return EAS_SUCCESS;
644 }
645
646 /*----------------------------------------------------------------------------
647 *
648 * EAS_HWBackLight
649 *
650 * Turn on/off backlight
651 *
652 *----------------------------------------------------------------------------
653 */
654 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWBackLight(EAS_HW_DATA_HANDLE hwInstData,EAS_BOOL state)655 EAS_RESULT EAS_HWBackLight (EAS_HW_DATA_HANDLE hwInstData, EAS_BOOL state)
656 {
657 EAS_ReportEx(_EAS_SEVERITY_NOFILTER, 0x1a54b6e8, 0x00000003 , state);
658 return EAS_SUCCESS;
659 }
660
661 /*----------------------------------------------------------------------------
662 *
663 * EAS_HWYield
664 *
665 * This function is called periodically by the EAS library to give the
666 * host an opportunity to allow other tasks to run. There are two ways to
667 * use this call:
668 *
669 * If you have a multi-tasking OS, you can call the yield function in the
670 * OS to allow other tasks to run. In this case, return EAS_FALSE to tell
671 * the EAS library to continue processing when control returns from this
672 * function.
673 *
674 * If tasks run in a single thread by sequential function calls (sometimes
675 * call a "commutator loop"), return EAS_TRUE to cause the EAS Library to
676 * return to the caller. Be sure to check the number of bytes rendered
677 * before passing the audio buffer to the codec - it may not be filled.
678 * The next call to EAS_Render will continue processing until the buffer
679 * has been filled.
680 *
681 *----------------------------------------------------------------------------
682 */
683 /*lint -esym(715, hwInstData) hwInstData available for customer use */
EAS_HWYield(EAS_HW_DATA_HANDLE hwInstData)684 EAS_BOOL EAS_HWYield (EAS_HW_DATA_HANDLE hwInstData)
685 {
686 /* put your code here */
687 return EAS_FALSE;
688 }
689
690