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