Actual source code: mprint.c

  1: /*
  2:       Utilities routines to add simple ASCII IO capability.
  3: */
  4: #include <../src/sys/fileio/mprint.h>
  5: #include <errno.h>
  6: /*
  7:    If petsc_history is on, then all Petsc*Printf() results are saved
  8:    if the appropriate (usually .petschistory) file.
  9: */
 10: PETSC_INTERN FILE *petsc_history;
 11: /*
 12:      Allows one to overwrite where standard out is sent. For example
 13:      PETSC_STDOUT = fopen("/dev/ttyXX","w") will cause all standard out
 14:      writes to go to terminal XX; assuming you have write permission there
 15: */
 16: FILE *PETSC_STDOUT = NULL;
 17: /*
 18:      Allows one to overwrite where standard error is sent. For example
 19:      PETSC_STDERR = fopen("/dev/ttyXX","w") will cause all standard error
 20:      writes to go to terminal XX; assuming you have write permission there
 21: */
 22: FILE *PETSC_STDERR = NULL;

 24: /*@C
 25:   PetscFormatConvertGetSize - Gets the length of a string needed to hold data converted with `PetscFormatConvert()` based on the format

 27:   No Fortran Support

 29:   Input Parameter:
 30: . format - the PETSc format string

 32:   Output Parameter:
 33: . size - the needed length of the new format

 35:   Level: developer

 37: .seealso: `PetscFormatConvert()`, `PetscVSNPrintf()`, `PetscVFPrintf()`
 38: @*/
 39: PetscErrorCode PetscFormatConvertGetSize(const char format[], size_t *size)
 40: {
 41:   size_t   sz = 0;
 42:   PetscInt i  = 0;

 44:   PetscFunctionBegin;
 45:   PetscAssertPointer(format, 1);
 46:   PetscAssertPointer(size, 2);
 47:   while (format[i]) {
 48:     if (format[i] == '%') {
 49:       if (format[i + 1] == '%') {
 50:         i += 2;
 51:         sz += 2;
 52:         continue;
 53:       }
 54:       /* Find the letter */
 55:       while (format[i] && (format[i] <= '9')) {
 56:         ++i;
 57:         ++sz;
 58:       }
 59:       switch (format[i]) {
 60: #if PetscDefined(USE_64BIT_INDICES)
 61:       case 'D':
 62:         sz += 2;
 63:         break;
 64: #endif
 65:       case 'g':
 66:         sz += 4;
 67:       default:
 68:         break;
 69:       }
 70:     }
 71:     ++i;
 72:     ++sz;
 73:   }
 74:   *size = sz + 1; /* space for NULL character */
 75:   PetscFunctionReturn(PETSC_SUCCESS);
 76: }

 78: /*@C
 79:   PetscFormatConvert - converts %g to [|%g|] so that `PetscVSNPrintf()` can ensure all %g formatted numbers have a decimal point when printed.

 81:   No Fortran Support

 83:   Input Parameter:
 84: . format - the PETSc format string

 86:   Output Parameter:
 87: . newformat - the formatted string, must be long enough to hold result

 89:   Level: developer

 91:   Note:
 92:   The decimal point is then used by the `petscdiff` script so that differences in floating
 93:   point number output is ignored in the test harness.

 95:   Deprecated usage also converts the `%D` to `%d` for 32-bit PETSc indices and to `%lld` for
 96:   64-bit PETSc indices. This feature is no longer used in PETSc code instead use %"
 97:   PetscInt_FMT " in the format string.

 99: .seealso: `PetscFormatConvertGetSize()`, `PetscVSNPrintf()`, `PetscVFPrintf()`
100: @*/
101: PetscErrorCode PetscFormatConvert(const char format[], char newformat[])
102: {
103:   PetscInt i = 0, j = 0;

105:   PetscFunctionBegin;
106:   while (format[i]) {
107:     if (format[i] == '%' && format[i + 1] == '%') {
108:       newformat[j++] = format[i++];
109:       newformat[j++] = format[i++];
110:     } else if (format[i] == '%') {
111:       if (format[i + 1] == 'g') {
112:         newformat[j++] = '[';
113:         newformat[j++] = '|';
114:       }
115:       /* Find the letter */
116:       for (; format[i] && format[i] <= '9'; i++) newformat[j++] = format[i];
117:       switch (format[i]) {
118:       case 'D':
119: #if !defined(PETSC_USE_64BIT_INDICES)
120:         newformat[j++] = 'd';
121: #else
122:         newformat[j++] = 'l';
123:         newformat[j++] = 'l';
124:         newformat[j++] = 'd';
125: #endif
126:         break;
127:       case 'g':
128:         newformat[j++] = format[i];
129:         if (format[i - 1] == '%') {
130:           newformat[j++] = '|';
131:           newformat[j++] = ']';
132:         }
133:         break;
134:       case 'G':
135:         SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "%%G format is no longer supported, use %%g and cast the argument to double");
136:       case 'F':
137:         SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "%%F format is no longer supported, use %%f and cast the argument to double");
138:       default:
139:         newformat[j++] = format[i];
140:         break;
141:       }
142:       i++;
143:     } else newformat[j++] = format[i++];
144:   }
145:   newformat[j] = 0;
146:   PetscFunctionReturn(PETSC_SUCCESS);
147: }

149: #define PETSCDEFAULTBUFFERSIZE 8 * 1024

151: /*@C
152:   PetscVSNPrintf - The PETSc version of `vsnprintf()`. Ensures that all `%g` formatted arguments' output contains the decimal point (which is used by the test harness)

154:   No Fortran Support

156:   Input Parameters:
157: + str    - location to put result
158: . len    - the length of `str`
159: . format - the PETSc format string
160: - Argp   - the variable argument list to format

162:   Output Parameter:
163: . fullLength - the amount of space in `str` actually used.

165:   Level: developer

167:   Developer Notes:
168:   This function may be called from an error handler, if an error occurs when it is called by the error handler than likely
169:   a recursion will occur resulting in a crash of the program.

171:   If the length of the format string `format` is on the order of `PETSCDEFAULTBUFFERSIZE` (8 * 1024 bytes) or larger, this function will call `PetscMalloc()`

173: .seealso: `PetscFormatConvert()`, `PetscFormatConvertGetSize()`, `PetscErrorPrintf()`, `PetscVPrintf()`
174: @*/
175: PetscErrorCode PetscVSNPrintf(char str[], size_t len, const char format[], size_t *fullLength, va_list Argp)
176: {
177:   char  *newformat = NULL;
178:   char   formatbuf[PETSCDEFAULTBUFFERSIZE];
179:   size_t newLength;
180:   int    flen;

182:   PetscFunctionBegin;
183:   PetscCall(PetscFormatConvertGetSize(format, &newLength));
184:   if (newLength < sizeof(formatbuf)) {
185:     newformat = formatbuf;
186:     newLength = sizeof(formatbuf) - 1;
187:   } else {
188:     PetscCall(PetscMalloc1(newLength, &newformat));
189:   }
190:   PetscCall(PetscFormatConvert(format, newformat));
191: #if defined(PETSC_HAVE_VSNPRINTF)
192:   flen = vsnprintf(str, len, newformat, Argp);
193: #else
194:   #error "vsnprintf not found"
195: #endif
196:   if (newLength > sizeof(formatbuf) - 1) PetscCall(PetscFree(newformat));
197:   {
198:     PetscBool foundedot;
199:     size_t    cnt = 0, ncnt = 0, leng;
200:     PetscCall(PetscStrlen(str, &leng));
201:     if (leng > 4) {
202:       for (cnt = 0; cnt < leng - 4; cnt++) {
203:         if (str[cnt] == '[' && str[cnt + 1] == '|') {
204:           flen -= 4;
205:           cnt++;
206:           cnt++;
207:           foundedot = PETSC_FALSE;
208:           for (; cnt < leng - 1; cnt++) {
209:             if (str[cnt] == '|' && str[cnt + 1] == ']') {
210:               cnt++;
211:               if (!foundedot) str[ncnt++] = '.';
212:               ncnt--;
213:               break;
214:             } else {
215:               if (str[cnt] == 'e' || str[cnt] == '.') foundedot = PETSC_TRUE;
216:               str[ncnt++] = str[cnt];
217:             }
218:           }
219:         } else {
220:           str[ncnt] = str[cnt];
221:         }
222:         ncnt++;
223:       }
224:       while (cnt < leng) {
225:         str[ncnt] = str[cnt];
226:         ncnt++;
227:         cnt++;
228:       }
229:       str[ncnt] = 0;
230:     }
231:   }
232: #if defined(PETSC_HAVE_WINDOWS_H) && !defined(PETSC_HAVE__SET_OUTPUT_FORMAT)
233:   /* older Windows OS always produces e-+0np for floating point output; remove the extra 0 */
234:   {
235:     size_t cnt = 0, ncnt = 0, leng;
236:     PetscCall(PetscStrlen(str, &leng));
237:     if (leng > 5) {
238:       for (cnt = 0; cnt < leng - 4; cnt++) {
239:         if (str[cnt] == 'e' && (str[cnt + 1] == '-' || str[cnt + 1] == '+') && str[cnt + 2] == '0' && str[cnt + 3] >= '0' && str[cnt + 3] <= '9' && str[cnt + 4] >= '0' && str[cnt + 4] <= '9') {
240:           str[ncnt] = str[cnt];
241:           ncnt++;
242:           cnt++;
243:           str[ncnt] = str[cnt];
244:           ncnt++;
245:           cnt++;
246:           cnt++;
247:           str[ncnt] = str[cnt];
248:         } else {
249:           str[ncnt] = str[cnt];
250:         }
251:         ncnt++;
252:       }
253:       while (cnt < leng) {
254:         str[ncnt] = str[cnt];
255:         ncnt++;
256:         cnt++;
257:       }
258:       str[ncnt] = 0;
259:     }
260:   }
261: #endif
262:   if (fullLength) *fullLength = 1 + (size_t)flen;
263:   PetscFunctionReturn(PETSC_SUCCESS);
264: }

266: /*@C
267:   PetscFFlush - Flush a file stream

269:   Input Parameter:
270: . fd - The file stream handle

272:   Level: intermediate

274:   Notes:
275:   For output streams (and for update streams on which the last operation was output), writes
276:   any unwritten data from the stream's buffer to the associated output device.

278:   For input streams (and for update streams on which the last operation was input), the
279:   behavior is undefined.

281:   If `fd` is `NULL`, all open output streams are flushed, including ones not directly
282:   accessible to the program.

284:   Fortran Note:
285:   Use `PetscFlush()`

287: .seealso: `PetscPrintf()`, `PetscFPrintf()`, `PetscVFPrintf()`, `PetscVSNPrintf()`
288: @*/
289: PetscErrorCode PetscFFlush(FILE *fd)
290: {
291:   int err;

293:   PetscFunctionBegin;
294:   if (fd) PetscAssertPointer(fd, 1);
295:   err = fflush(fd);
296: #if !defined(PETSC_MISSING_SIGPIPE) && defined(EPIPE) && defined(ECONNRESET)
297:   if (fd && err && (errno == EPIPE || errno == ECONNRESET)) err = 0; /* ignore error, rely on SIGPIPE */
298: #endif
299:   // could also use PetscCallExternal() here, but since we can get additional error explanation
300:   // from strerror() we opted for a manual check
301:   PetscCheck(0 == err, PETSC_COMM_SELF, PETSC_ERR_FILE_WRITE, "Error in fflush() due to \"%s\"", strerror(errno));
302:   PetscFunctionReturn(PETSC_SUCCESS);
303: }

305: /*@C
306:   PetscVFPrintfDefault -  All PETSc standard out and error messages are sent through this function; so, in theory, this can
307:   can be replaced with something that does not simply write to a file.

309:   No Fortran Support

311:   Input Parameters:
312: + fd     - the file descriptor to write to
313: . format - the format string to write with
314: - Argp   - the variable argument list of items to format and write

316:   Level: developer

318:   Note:
319:   For error messages this may be called by any MPI process, for regular standard out it is
320:   called only by MPI rank 0 of a given communicator

322:   Example Usage:
323:   To use, write your own function for example,
324: .vb
325:    PetscErrorCode mypetscvfprintf(FILE *fd, const char format[], va_list Argp)
326:    {

328:      PetscFunctionBegin;
329:       if (fd != stdout && fd != stderr) {  handle regular files
330:          CHKERR(PetscVFPrintfDefault(fd,format,Argp));
331:      } else {
332:         char   buff[BIG];
333:         size_t length;
334:         PetscCall(PetscVSNPrintf(buff,BIG,format,&length,Argp));
335:         now send buff to whatever stream or whatever you want
336:     }
337:     PetscFunctionReturn(PETSC_SUCCESS);
338:    }
339: .ve
340:   then before the call to `PetscInitialize()` do the assignment `PetscVFPrintf = mypetscvfprintf`;

342:   Developer Notes:
343:   This could be called by an error handler, if that happens then a recursion of the error handler may occur
344:   and a resulting crash

346: .seealso: `PetscVSNPrintf()`, `PetscErrorPrintf()`, `PetscFFlush()`
347: @*/
348: PetscErrorCode PetscVFPrintfDefault(FILE *fd, const char format[], va_list Argp)
349: {
350:   char   str[PETSCDEFAULTBUFFERSIZE];
351:   char  *buff = str;
352:   size_t fullLength;
353: #if defined(PETSC_HAVE_VA_COPY)
354:   va_list Argpcopy;
355: #endif

357:   PetscFunctionBegin;
358: #if defined(PETSC_HAVE_VA_COPY)
359:   va_copy(Argpcopy, Argp);
360: #endif
361:   PetscCall(PetscVSNPrintf(str, sizeof(str), format, &fullLength, Argp));
362:   if (fullLength > sizeof(str)) {
363:     PetscCall(PetscMalloc1(fullLength, &buff));
364: #if defined(PETSC_HAVE_VA_COPY)
365:     PetscCall(PetscVSNPrintf(buff, fullLength, format, NULL, Argpcopy));
366: #else
367:     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_LIB, "C89 does not support va_copy() hence cannot print long strings with PETSc printing routines");
368: #endif
369:   }
370: #if defined(PETSC_HAVE_VA_COPY)
371:   va_end(Argpcopy);
372: #endif
373:   {
374:     int err;

376:     // POSIX C sets errno but otherwise it may not be set for *printf() system calls
377:     // https://pubs.opengroup.org/onlinepubs/9699919799/functions/fprintf.html
378:     errno = 0;
379:     err   = fprintf(fd, "%s", buff);
380:     // cannot use PetscCallExternal() for fprintf since the return value is "number of
381:     // characters transmitted to the output stream" on success
382:     PetscCheck(err >= 0, PETSC_COMM_SELF, PETSC_ERR_FILE_WRITE, "fprintf() returned error code %d: %s", err, errno > 0 ? strerror(errno) : "unknown (errno not set)");
383:   }
384:   PetscCall(PetscFFlush(fd));
385:   if (buff != str) PetscCall(PetscFree(buff));
386:   PetscFunctionReturn(PETSC_SUCCESS);
387: }

389: /*@C
390:   PetscSNPrintf - Prints to a string of given length

392:   Not Collective, No Fortran Support

394:   Input Parameters:
395: + len    - the length of `str`
396: - format - the usual `printf()` format string

398:   Output Parameter:
399: . str - the resulting string

401:   Level: intermediate

403: .seealso: `PetscSynchronizedFlush()`, `PetscSynchronizedFPrintf()`, `PetscFPrintf()`, `PetscVSNPrintf()`,
404:           `PetscPrintf()`, `PetscViewerASCIIPrintf()`, `PetscViewerASCIISynchronizedPrintf()`,
405:           `PetscVFPrintf()`, `PetscFFlush()`
406: @*/
407: PetscErrorCode PetscSNPrintf(char str[], size_t len, const char format[], ...)
408: {
409:   size_t  fullLength;
410:   va_list Argp;

412:   PetscFunctionBegin;
413:   va_start(Argp, format);
414:   PetscCall(PetscVSNPrintf(str, len, format, &fullLength, Argp));
415:   va_end(Argp);
416:   PetscFunctionReturn(PETSC_SUCCESS);
417: }

419: /*@C
420:   PetscSNPrintfCount - Prints to a string of given length, returns count of characters printed

422:   Not Collective, No Fortran Support

424:   Input Parameters:
425: + len    - the length of `str`
426: . format - the usual `printf()` format string
427: - ...    - args to format

429:   Output Parameters:
430: + str       - the resulting string
431: - countused - number of characters printed

433:   Level: intermediate

435: .seealso: `PetscSynchronizedFlush()`, `PetscSynchronizedFPrintf()`, `PetscFPrintf()`, `PetscVSNPrintf()`,
436:           `PetscPrintf()`, `PetscViewerASCIIPrintf()`, `PetscViewerASCIISynchronizedPrintf()`, `PetscSNPrintf()`, `PetscVFPrintf()`
437: @*/
438: PetscErrorCode PetscSNPrintfCount(char str[], size_t len, const char format[], size_t *countused, ...)
439: {
440:   va_list Argp;

442:   PetscFunctionBegin;
443:   va_start(Argp, countused);
444:   PetscCall(PetscVSNPrintf(str, len, format, countused, Argp));
445:   va_end(Argp);
446:   PetscFunctionReturn(PETSC_SUCCESS);
447: }

449: PrintfQueue petsc_printfqueue = NULL, petsc_printfqueuebase = NULL;
450: int         petsc_printfqueuelength = 0;

452: static inline PetscErrorCode PetscVFPrintf_Private(FILE *fd, const char format[], va_list Argp)
453: {
454:   const PetscBool tee = (PetscBool)(petsc_history && (fd != petsc_history));
455:   va_list         cpy;

457:   PetscFunctionBegin;
458:   // must do this before we possibly consume Argp
459:   if (tee) va_copy(cpy, Argp);
460:   PetscCall((*PetscVFPrintf)(fd, format, Argp));
461:   if (tee) {
462:     PetscCall((*PetscVFPrintf)(petsc_history, format, cpy));
463:     va_end(cpy);
464:   }
465:   PetscFunctionReturn(PETSC_SUCCESS);
466: }

468: PETSC_INTERN PetscErrorCode PetscVFPrintf_Internal(FILE *fd, const char format[], ...)
469: {
470:   va_list Argp;

472:   PetscFunctionBegin;
473:   va_start(Argp, format);
474:   PetscCall(PetscVFPrintf_Private(fd, format, Argp));
475:   va_end(Argp);
476:   PetscFunctionReturn(PETSC_SUCCESS);
477: }

479: static inline PetscErrorCode PetscSynchronizedFPrintf_Private(MPI_Comm comm, FILE *fp, const char format[], va_list Argp)
480: {
481:   PetscMPIInt rank;
482:   va_list     cpy;

484:   PetscFunctionBegin;
485:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
486:   /* First processor prints immediately to fp */
487:   if (rank == 0) {
488:     va_copy(cpy, Argp);
489:     PetscCall(PetscVFPrintf_Private(fp, format, cpy));
490:     va_end(cpy);
491:   } else { /* other processors add to local queue */
492:     PrintfQueue next;
493:     size_t      fullLength = PETSCDEFAULTBUFFERSIZE;

495:     PetscCall(PetscNew(&next));
496:     if (petsc_printfqueue) {
497:       petsc_printfqueue->next = next;
498:       petsc_printfqueue       = next;
499:       petsc_printfqueue->next = NULL;
500:     } else petsc_printfqueuebase = petsc_printfqueue = next;
501:     petsc_printfqueuelength++;
502:     next->size   = 0;
503:     next->string = NULL;
504:     while (fullLength >= next->size) {
505:       next->size = fullLength + 1;
506:       PetscCall(PetscFree(next->string));
507:       PetscCall(PetscMalloc1(next->size, &next->string));
508:       PetscCall(PetscArrayzero(next->string, next->size));
509:       va_copy(cpy, Argp);
510:       PetscCall(PetscVSNPrintf(next->string, next->size, format, &fullLength, cpy));
511:       va_end(cpy);
512:     }
513:   }
514:   PetscFunctionReturn(PETSC_SUCCESS);
515: }

517: /*@C
518:   PetscSynchronizedPrintf - Prints synchronized output from multiple MPI processes.
519:   Output of the first processor is followed by that of the second, etc.

521:   Not Collective

523:   Input Parameters:
524: + comm   - the MPI communicator
525: - format - the usual `printf()` format string

527:   Level: intermediate

529:   Note:
530:   REQUIRES a call to `PetscSynchronizedFlush()` by all the processes after the completion of the calls to `PetscSynchronizedPrintf()` for the information
531:   from all the processors to be printed.

533:   Fortran Note:
534:   The call sequence is `PetscSynchronizedPrintf`(`MPI_Comm`, `character`(*), `PetscErrorCode` ierr).
535:   That is, you can only pass a single character string from Fortran.

537: .seealso: `PetscSynchronizedFlush()`, `PetscSynchronizedFPrintf()`, `PetscFPrintf()`,
538:           `PetscPrintf()`, `PetscViewerASCIIPrintf()`, `PetscViewerASCIISynchronizedPrintf()`,
539:           `PetscFFlush()`
540: @*/
541: PetscErrorCode PetscSynchronizedPrintf(MPI_Comm comm, const char format[], ...)
542: {
543:   va_list Argp;

545:   PetscFunctionBegin;
546:   va_start(Argp, format);
547:   PetscCall(PetscSynchronizedFPrintf_Private(comm, PETSC_STDOUT, format, Argp));
548:   va_end(Argp);
549:   PetscFunctionReturn(PETSC_SUCCESS);
550: }

552: /*@C
553:   PetscSynchronizedFPrintf - Prints synchronized output to the specified file from
554:   several MPI processes.  Output of the first process is followed by that of the
555:   second, etc.

557:   Not Collective

559:   Input Parameters:
560: + comm   - the MPI communicator
561: . fp     - the file pointer, `PETSC_STDOUT` or value obtained from `PetscFOpen()`
562: - format - the usual `printf()` format string

564:   Level: intermediate

566:   Note:
567:   REQUIRES a intervening call to `PetscSynchronizedFlush()` for the information
568:   from all the processors to be printed.

570:   Fortran Note:
571:   The call sequence is `PetscSynchronizedPrintf`(`MPI_Comm`, fp, `character`(*), `PetscErrorCode` ierr).
572:   That is, you can only pass a single character string from Fortran.

574: .seealso: `PetscSynchronizedPrintf()`, `PetscSynchronizedFlush()`, `PetscFPrintf()`,
575:           `PetscFOpen()`, `PetscViewerASCIISynchronizedPrintf()`, `PetscViewerASCIIPrintf()`,
576:           `PetscFFlush()`
577: @*/
578: PetscErrorCode PetscSynchronizedFPrintf(MPI_Comm comm, FILE *fp, const char format[], ...)
579: {
580:   va_list Argp;

582:   PetscFunctionBegin;
583:   va_start(Argp, format);
584:   PetscCall(PetscSynchronizedFPrintf_Private(comm, fp, format, Argp));
585:   va_end(Argp);
586:   PetscFunctionReturn(PETSC_SUCCESS);
587: }

589: /*@C
590:   PetscSynchronizedFlush - Flushes to the screen output from all processors
591:   involved in previous `PetscSynchronizedPrintf()`/`PetscSynchronizedFPrintf()` calls.

593:   Collective

595:   Input Parameters:
596: + comm - the MPI communicator
597: - fd   - the file pointer (valid on MPI rank 0 of the communicator), `PETSC_STDOUT` or value obtained from `PetscFOpen()`

599:   Level: intermediate

601:   Note:
602:   If `PetscSynchronizedPrintf()` and/or `PetscSynchronizedFPrintf()` are called with
603:   different MPI communicators there must be an intervening call to `PetscSynchronizedFlush()` between the calls with different MPI communicators.

605: .seealso: `PetscSynchronizedPrintf()`, `PetscFPrintf()`, `PetscPrintf()`, `PetscViewerASCIIPrintf()`,
606:           `PetscViewerASCIISynchronizedPrintf()`
607: @*/
608: PetscErrorCode PetscSynchronizedFlush(MPI_Comm comm, FILE *fd)
609: {
610:   PetscMPIInt rank, size, tag, i, j, n = 0, dummy = 0;
611:   char       *message;
612:   MPI_Status  status;

614:   PetscFunctionBegin;
615:   PetscCall(PetscCommDuplicate(comm, &comm, &tag));
616:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
617:   PetscCallMPI(MPI_Comm_size(comm, &size));

619:   /* First processor waits for messages from all other processors */
620:   if (rank == 0) {
621:     if (!fd) fd = PETSC_STDOUT;
622:     for (i = 1; i < size; i++) {
623:       /* to prevent a flood of messages to process zero, request each message separately */
624:       PetscCallMPI(MPI_Send(&dummy, 1, MPI_INT, i, tag, comm));
625:       PetscCallMPI(MPI_Recv(&n, 1, MPI_INT, i, tag, comm, &status));
626:       for (j = 0; j < n; j++) {
627:         PetscMPIInt size = 0;

629:         PetscCallMPI(MPI_Recv(&size, 1, MPI_INT, i, tag, comm, &status));
630:         PetscCall(PetscMalloc1(size, &message));
631:         PetscCallMPI(MPI_Recv(message, size, MPI_CHAR, i, tag, comm, &status));
632:         PetscCall(PetscFPrintf(comm, fd, "%s", message));
633:         PetscCall(PetscFree(message));
634:       }
635:     }
636:   } else { /* other processors send queue to processor 0 */
637:     PrintfQueue next = petsc_printfqueuebase, previous;

639:     PetscCallMPI(MPI_Recv(&dummy, 1, MPI_INT, 0, tag, comm, &status));
640:     PetscCallMPI(MPI_Send(&petsc_printfqueuelength, 1, MPI_INT, 0, tag, comm));
641:     for (i = 0; i < petsc_printfqueuelength; i++) {
642:       PetscCallMPI(MPI_Send(&next->size, 1, MPI_INT, 0, tag, comm));
643:       PetscCallMPI(MPI_Send(next->string, (PetscMPIInt)next->size, MPI_CHAR, 0, tag, comm));
644:       previous = next;
645:       next     = next->next;
646:       PetscCall(PetscFree(previous->string));
647:       PetscCall(PetscFree(previous));
648:     }
649:     petsc_printfqueue       = NULL;
650:     petsc_printfqueuelength = 0;
651:   }
652:   PetscCall(PetscCommDestroy(&comm));
653:   PetscFunctionReturn(PETSC_SUCCESS);
654: }

656: /*@C
657:   PetscFPrintf - Prints to a file, only from the first
658:   MPI process in the communicator.

660:   Not Collective

662:   Input Parameters:
663: + comm   - the MPI communicator
664: . fd     - the file pointer, `PETSC_STDOUT` or value obtained from `PetscFOpen()`
665: - format - the usual `printf()` format string

667:   Level: intermediate

669:   Fortran Note:
670:   The call sequence is `PetscFPrintf`(`MPI_Comm`, fp, `character`(*), `PetscErrorCode` ierr).
671:   That is, you can only pass a single character string from Fortran.

673:   Developer Notes:
674:   This maybe, and is, called from PETSc error handlers and `PetscMallocValidate()` hence it does not use `PetscCallMPI()` which
675:   could recursively restart the malloc validation.

677: .seealso: `PetscPrintf()`, `PetscSynchronizedPrintf()`, `PetscViewerASCIIPrintf()`,
678:           `PetscViewerASCIISynchronizedPrintf()`, `PetscSynchronizedFlush()`, `PetscFFlush()`
679: @*/
680: PetscErrorCode PetscFPrintf(MPI_Comm comm, FILE *fd, const char format[], ...)
681: {
682:   PetscMPIInt rank;
683:   va_list     Argp;

685:   PetscFunctionBegin;
686:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
687:   if (PetscLikely(rank != 0)) PetscFunctionReturn(PETSC_SUCCESS);
688:   va_start(Argp, format);
689:   PetscCall(PetscVFPrintf_Private(fd, format, Argp));
690:   va_end(Argp);
691:   PetscFunctionReturn(PETSC_SUCCESS);
692: }

694: /*@C
695:   PetscPrintf - Prints to standard out, only from the first
696:   MPI process in the communicator. Calls from other processes are ignored.

698:   Not Collective

700:   Input Parameters:
701: + comm   - the communicator
702: - format - the usual `printf()` format string

704:   Level: intermediate

706:   Note:
707:   Deprecated information: `PetscPrintf()` supports some format specifiers that are unique to PETSc.
708:   See the manual page for `PetscFormatConvert()` for details.

710:   Fortran Notes:
711:   The call sequence is `PetscPrintf`(MPI_Comm, character(*), `PetscErrorCode` ierr) from Fortran.
712:   That is, you can only pass a single character string from Fortran.

714: .seealso: `PetscFPrintf()`, `PetscSynchronizedPrintf()`, `PetscFormatConvert()`, `PetscFFlush()`
715: @*/
716: PetscErrorCode PetscPrintf(MPI_Comm comm, const char format[], ...)
717: {
718:   PetscMPIInt rank;
719:   va_list     Argp;

721:   PetscFunctionBegin;
722:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
723:   if (PetscLikely(rank != 0)) PetscFunctionReturn(PETSC_SUCCESS);
724:   va_start(Argp, format);
725:   PetscCall(PetscVFPrintf_Private(PETSC_STDOUT, format, Argp));
726:   va_end(Argp);
727:   PetscFunctionReturn(PETSC_SUCCESS);
728: }

730: PetscErrorCode PetscHelpPrintfDefault(MPI_Comm comm, const char format[], ...)
731: {
732:   PetscMPIInt rank;
733:   va_list     Argp;

735:   PetscFunctionBegin;
736:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
737:   if (PetscLikely(rank != 0)) PetscFunctionReturn(PETSC_SUCCESS);
738:   va_start(Argp, format);
739:   PetscCall(PetscVFPrintf_Private(PETSC_STDOUT, format, Argp));
740:   va_end(Argp);
741:   PetscFunctionReturn(PETSC_SUCCESS);
742: }

744: /*@C
745:   PetscSynchronizedFGets - Multiple MPI processes all get the same line from a file.

747:   Collective

749:   Input Parameters:
750: + comm - the MPI communicator
751: . fp   - the file pointer
752: - len  - the length of `string`

754:   Output Parameter:
755: . string - the line read from the file, at end of file `string`[0] == 0

757:   Level: intermediate

759: .seealso: `PetscSynchronizedPrintf()`, `PetscSynchronizedFlush()`,
760:           `PetscFOpen()`, `PetscViewerASCIISynchronizedPrintf()`, `PetscViewerASCIIPrintf()`
761: @*/
762: PetscErrorCode PetscSynchronizedFGets(MPI_Comm comm, FILE *fp, size_t len, char string[])
763: {
764:   PetscMPIInt rank;

766:   PetscFunctionBegin;
767:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
768:   if (rank == 0) {
769:     if (!fgets(string, (int)len, fp)) {
770:       string[0] = 0;
771:       PetscCheck(feof(fp), PETSC_COMM_SELF, PETSC_ERR_FILE_READ, "Error reading from file due to \"%s\"", strerror(errno));
772:     }
773:   }
774:   PetscCallMPI(MPI_Bcast(string, (PetscMPIInt)len, MPI_BYTE, 0, comm));
775:   PetscFunctionReturn(PETSC_SUCCESS);
776: }

778: PetscErrorCode PetscFormatRealArray(char buf[], size_t len, const char *fmt, PetscInt n, const PetscReal x[])
779: {
780:   PetscInt i;
781:   size_t   left, count;
782:   char    *p;

784:   PetscFunctionBegin;
785:   for (i = 0, p = buf, left = len; i < n; i++) {
786:     PetscCall(PetscSNPrintfCount(p, left, fmt, &count, (double)x[i]));
787:     PetscCheck(count < left, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Insufficient space in buffer");
788:     left -= count;
789:     p += count - 1;
790:     *p++ = ' ';
791:   }
792:   p[i ? 0 : -1] = 0;
793:   PetscFunctionReturn(PETSC_SUCCESS);
794: }