Actual source code: adebug.c

  1: /*
  2:       Code to handle PETSc starting up in debuggers,etc.
  3: */
  4: #define PETSC_DESIRE_FEATURE_TEST_MACROS /* for fileno() */
  5: #include <petscsys.h>
  6: #include <signal.h>
  7: #if defined(PETSC_HAVE_UNISTD_H)
  8:   #include <unistd.h>
  9: #endif

 11: /*
 12:       These are the debugger and display used if the debugger is started up
 13: */
 14: static char      PetscDebugger[PETSC_MAX_PATH_LEN];
 15: static char      DebugTerminal[PETSC_MAX_PATH_LEN];
 16: static PetscBool UseDebugTerminal    = PETSC_TRUE;
 17: PetscBool        petscwaitonerrorflg = PETSC_FALSE;
 18: PetscBool        petscindebugger     = PETSC_FALSE;

 20: /*@
 21:   PetscSetDebugTerminal - Sets the terminal to use for debugging.

 23:   Not Collective; No Fortran Support

 25:   Input Parameter:
 26: . terminal - name of terminal and any flags required to execute a program.
 27:               For example "xterm", "urxvt -e", "gnome-terminal -x".
 28:               On Apple macOS you can use "Terminal" (note the capital T)

 30:   Options Database Key:
 31: . -debug_terminal terminal - use this terminal instead of the default

 33:   Level: developer

 35:   Notes:
 36:   You can start the debugger for all processes in the same GNU screen session.
 37: .vb
 38:   mpiexec -n 4 ./myapp -start_in_debugger -debug_terminal "screen -X -S debug screen"
 39: .ve

 41:   will open 4 windows in the session named "debug".

 43:   The default terminal on Apple is Terminal, on other systems the default is xterm

 45: .seealso: `PetscSetDebugger()`, `PetscAttachDebugger()`
 46: @*/
 47: PetscErrorCode PetscSetDebugTerminal(const char terminal[])
 48: {
 49:   PetscBool xterm;

 51:   PetscFunctionBegin;
 52:   PetscCall(PetscStrncpy(DebugTerminal, terminal, sizeof(DebugTerminal)));
 53:   PetscCall(PetscStrcmp(terminal, "xterm", &xterm));
 54:   if (xterm) PetscCall(PetscStrlcat(DebugTerminal, " -e", sizeof(DebugTerminal)));
 55:   PetscFunctionReturn(PETSC_SUCCESS);
 56: }

 58: /*@
 59:   PetscSetDebugger - Sets options associated with the debugger.

 61:   Not Collective; No Fortran Support

 63:   Input Parameters:
 64: + debugger         - name of debugger, which should be in your path,
 65:                      usually "lldb", "dbx", "gdb", "cuda-gdb", "idb", "xxgdb", "kdgb" or "ddd". Also, HP-UX
 66:                      supports "xdb", and IBM rs6000 supports "xldb".

 68: - usedebugterminal - flag to indicate debugger window, set to either `PETSC_TRUE` (to indicate
 69:                      debugger should be started in a new terminal window) or `PETSC_FALSE` (to start debugger
 70:                      in initial window (the option `PETSC_FALSE` makes no sense when using more
 71:                      than one MPI process.)

 73:   Level: developer

 75: .seealso: `PetscAttachDebugger()`, `PetscAttachDebuggerErrorHandler()`, `PetscSetDebugTerminal()`
 76: @*/
 77: PetscErrorCode PetscSetDebugger(const char debugger[], PetscBool usedebugterminal)
 78: {
 79:   PetscFunctionBegin;
 80:   if (debugger) PetscCall(PetscStrncpy(PetscDebugger, debugger, sizeof(PetscDebugger)));
 81:   if (UseDebugTerminal) UseDebugTerminal = usedebugterminal;
 82:   PetscFunctionReturn(PETSC_SUCCESS);
 83: }

 85: /*@
 86:   PetscSetDefaultDebugger - Causes PETSc to use its default debugger and output terminal

 88:   Not Collective, No Fortran Support

 90:   Level: developer

 92: .seealso: `PetscSetDebugger()`, `PetscSetDebuggerFromString()`, `PetscAttachDebugger()`
 93: @*/
 94: PetscErrorCode PetscSetDefaultDebugger(void)
 95: {
 96:   PetscFunctionBegin;
 97: #if defined(PETSC_USE_DEBUGGER)
 98:   PetscCall(PetscSetDebugger(PETSC_USE_DEBUGGER, PETSC_TRUE));
 99: #endif
100: #if defined(__APPLE__)
101:   PetscCall(PetscSetDebugTerminal("Terminal"));
102: #else
103:   PetscCall(PetscSetDebugTerminal("xterm"));
104: #endif
105:   PetscFunctionReturn(PETSC_SUCCESS);
106: }

108: static PetscErrorCode PetscCheckDebugger_Private(const char defaultDbg[], const char string[], const char *debugger[])
109: {
110:   char *f = NULL;

112:   PetscFunctionBegin;
113:   PetscCall(PetscStrstr(string, defaultDbg, &f));
114:   if (f) {
115:     PetscBool exists;

117:     PetscCall(PetscTestFile(string, 'x', &exists));
118:     if (exists) *debugger = string;
119:     else *debugger = defaultDbg;
120:   }
121:   PetscFunctionReturn(PETSC_SUCCESS);
122: }

124: /*@
125:   PetscSetDebuggerFromString - Set the complete path for the
126:   debugger for PETSc to use.

128:   Not Collective

130:   Input Parameter:
131: . string - the name of the debugger, for example "gdb"

133:   Level: developer

135: .seealso: `PetscSetDebugger()`, `PetscSetDefaultDebugger()`, `PetscAttachDebugger()`
136: @*/
137: PetscErrorCode PetscSetDebuggerFromString(const char string[])
138: {
139:   const char *debugger    = NULL;
140:   PetscBool   useterminal = PETSC_TRUE;
141:   char       *f           = NULL;

143:   PetscFunctionBegin;
144:   PetscCall(PetscStrstr(string, "noxterm", &f));
145:   if (f) useterminal = PETSC_FALSE;
146:   PetscCall(PetscStrstr(string, "ddd", &f));
147:   if (f) useterminal = PETSC_FALSE;
148:   PetscCall(PetscStrstr(string, "noterminal", &f));
149:   if (f) useterminal = PETSC_FALSE;
150:   PetscCall(PetscCheckDebugger_Private("xdb", string, &debugger));
151:   PetscCall(PetscCheckDebugger_Private("dbx", string, &debugger));
152:   PetscCall(PetscCheckDebugger_Private("xldb", string, &debugger));
153:   PetscCall(PetscCheckDebugger_Private("gdb", string, &debugger));
154:   PetscCall(PetscCheckDebugger_Private("cuda-gdb", string, &debugger));
155:   PetscCall(PetscCheckDebugger_Private("idb", string, &debugger));
156:   PetscCall(PetscCheckDebugger_Private("xxgdb", string, &debugger));
157:   PetscCall(PetscCheckDebugger_Private("ddd", string, &debugger));
158:   PetscCall(PetscCheckDebugger_Private("kdbg", string, &debugger));
159:   PetscCall(PetscCheckDebugger_Private("ups", string, &debugger));
160:   PetscCall(PetscCheckDebugger_Private("workshop", string, &debugger));
161:   PetscCall(PetscCheckDebugger_Private("pgdbg", string, &debugger));
162:   PetscCall(PetscCheckDebugger_Private("pathdb", string, &debugger));
163:   PetscCall(PetscCheckDebugger_Private("lldb", string, &debugger));
164:   PetscCall(PetscSetDebugger(debugger, useterminal));
165:   PetscFunctionReturn(PETSC_SUCCESS);
166: }

168: /*@
169:   PetscWaitOnError - If an error is detected and the process would normally exit the main program with `MPI_Abort()` sleep instead
170:   of exiting.

172:   Not Collective

174:   Level: advanced

176:   Note:
177:   When `-start_in_debugger -debugger_ranks x,y,z` is used this prevents the processes NOT listed in x,y,z from calling `MPI_Abort()` and
178:   killing the user's debugging sessions.

180: .seealso: `PetscSetDebugger()`, `PetscAttachDebugger()`
181: @*/
182: PetscErrorCode PetscWaitOnError(void)
183: {
184:   petscwaitonerrorflg = PETSC_TRUE;
185:   return PETSC_SUCCESS;
186: }

188: /*@
189:   PetscAttachDebugger - Attaches the debugger to the running process.

191:   Not Collective

193:   Options Database Keys:
194: + -start_in_debugger [noxterm,lldb or gdb] [-display name] [-debugger_ranks m,n] - set debugger debug_terminal xterm or Terminal (for Apple)
195: . -on_error_attach_debugger [noxterm,dbx,xxgdb,xdb,xldb,gdb] [-display name]     - Activates debugger attachment
196: - -stop_for_debugger                                                             - print a message on how to attach the process with a debugger and then wait for the user to attach

198:   Level: advanced

200:   Note:
201:   If you get the message " stdin is not a tty, hence unable to attach debugger, see PetscAttachDebugger()", this means the application
202:   is likely running in a batch system and you do not have terminal access to the process. You can try
203:   running with `-start_in_debugger` without the `noxterm` argument or `-stop_for_debugger`

205:   Developer Note:
206:   Since this can be called by the error handler, should it be calling `SETERRQ()` and `PetscCall()`?

208: .seealso: `PetscSetDebugger()`, `PetscSetDefaultDebugger()`, `PetscSetDebugTerminal()`, `PetscAttachDebuggerErrorHandler()`, `PetscStopForDebugger()`
209: @*/
210: PetscErrorCode PetscAttachDebugger(void)
211: {
212:   PetscErrorCode PETSC_UNUSED ierr;
213: #if !defined(PETSC_CANNOT_START_DEBUGGER) && defined(PETSC_HAVE_FORK)
214:   int       child     = 0;
215:   PetscReal sleeptime = 0;
216:   char      program[PETSC_MAX_PATH_LEN], display[256], hostname[64];
217: #endif

219: #if defined(PETSC_CANNOT_START_DEBUGGER) || !defined(PETSC_HAVE_FORK)
220:   ierr = (*PetscErrorPrintf)("System cannot start debugger\n");
221:   ierr = (*PetscErrorPrintf)("On Cray run program in Totalview debugger\n");
222:   ierr = (*PetscErrorPrintf)("On Windows use Developer Studio(MSDEV)\n");
223:   PETSCABORT(PETSC_COMM_WORLD, PETSC_ERR_SUP_SYS);
224: #else
225:   if (PetscUnlikely(PetscGetDisplay(display, sizeof(display)))) {
226:     ierr = (*PetscErrorPrintf)("PetscAttachDebugger: Cannot determine display\n");
227:     return PETSC_ERR_SYS;
228:   }
229:   if (PetscUnlikely(PetscGetProgramName(program, sizeof(program)))) {
230:     ierr = (*PetscErrorPrintf)("PetscAttachDebugger: Cannot determine program name needed to attach debugger\n");
231:     return PETSC_ERR_SYS;
232:   }
233:   if (PetscUnlikely(!program[0])) {
234:     ierr = (*PetscErrorPrintf)("PetscAttachDebugger: Cannot determine program name needed to attach debugger\n");
235:     return PETSC_ERR_SYS;
236:   }
237:   if (PetscUnlikely(!isatty(fileno(stdin))) && !UseDebugTerminal) { printf("If the debugger exits immediately or hangs, this indicates you cannot use PetscAttachDebugger() in this situation\n\n"); }
238:   child = (int)fork();
239:   if (PetscUnlikely(child < 0)) {
240:     ierr = (*PetscErrorPrintf)("PetscAttachDebugger: Error in fork() prior to attaching debugger\n");
241:     return PETSC_ERR_SYS;
242:   }
243:   petscindebugger = PETSC_TRUE;

245:   /*
246:       Swap role the parent and child. This is (I think) so that control c typed
247:     in the debugger goes to the correct process.
248:   */
249:   #if !defined(PETSC_DO_NOT_SWAP_CHILD_FOR_DEBUGGER)
250:   child = child ? 0 : (int)getppid();
251:   #endif

253:   if (child) { /* I am the parent, will run the debugger */
254:     const char *args[10];
255:     char        pid[10];
256:     PetscInt    j, jj;
257:     PetscBool   isdbx, isidb, isxldb, isxxgdb, isups, isxdb, isworkshop, isddd, iskdbg, islldb;

259:     PetscCall(PetscGetHostName(hostname, sizeof(hostname)));
260:     /*
261:          We need to send a continue signal to the "child" process on the
262:        alpha, otherwise it just stays off forever
263:     */
264:   #if defined(PETSC_NEED_KILL_FOR_DEBUGGER)
265:     kill(child, SIGCONT);
266:   #endif
267:     PetscCall(PetscSNPrintf(pid, PETSC_STATIC_ARRAY_LENGTH(pid), "%d", child));

269:     PetscCall(PetscStrcmp(PetscDebugger, "xxgdb", &isxxgdb));
270:     PetscCall(PetscStrcmp(PetscDebugger, "ddd", &isddd));
271:     PetscCall(PetscStrcmp(PetscDebugger, "kdbg", &iskdbg));
272:     PetscCall(PetscStrcmp(PetscDebugger, "ups", &isups));
273:     PetscCall(PetscStrcmp(PetscDebugger, "xldb", &isxldb));
274:     PetscCall(PetscStrcmp(PetscDebugger, "xdb", &isxdb));
275:     PetscCall(PetscStrcmp(PetscDebugger, "dbx", &isdbx));
276:     PetscCall(PetscStrcmp(PetscDebugger, "idb", &isidb));
277:     PetscCall(PetscStrcmp(PetscDebugger, "workshop", &isworkshop));
278:     PetscCall(PetscStrcmp(PetscDebugger, "lldb", &islldb));

280:     if (isxxgdb || isups || isddd) {
281:       args[1] = program;
282:       args[2] = pid;
283:       args[3] = "-display";
284:       args[0] = PetscDebugger;
285:       args[4] = display;
286:       args[5] = NULL;
287:       printf("PETSC: Attaching %s to %s %s on %s\n", args[0], args[1], pid, hostname);
288:       if (execvp(args[0], (char **)args) < 0) {
289:         perror("Unable to start debugger");
290:         exit(0);
291:       }
292:     } else if (iskdbg) {
293:       args[1] = "-p";
294:       args[2] = pid;
295:       args[3] = program;
296:       args[4] = "-display";
297:       args[0] = PetscDebugger;
298:       args[5] = display;
299:       args[6] = NULL;
300:       printf("PETSC: Attaching %s to %s %s on %s\n", args[0], args[3], pid, hostname);
301:       if (execvp(args[0], (char **)args) < 0) {
302:         perror("Unable to start debugger");
303:         exit(0);
304:       }
305:     } else if (isxldb) {
306:       args[1] = "-a";
307:       args[2] = pid;
308:       args[3] = program;
309:       args[4] = "-display";
310:       args[0] = PetscDebugger;
311:       args[5] = display;
312:       args[6] = NULL;
313:       printf("PETSC: Attaching %s to %s %s on %s\n", args[0], args[1], pid, hostname);
314:       if (execvp(args[0], (char **)args) < 0) {
315:         perror("Unable to start debugger");
316:         exit(0);
317:       }
318:     } else if (isworkshop) {
319:       args[1] = "-s";
320:       args[2] = pid;
321:       args[3] = "-D";
322:       args[4] = "-";
323:       args[0] = PetscDebugger;
324:       args[5] = pid;
325:       args[6] = "-display";
326:       args[7] = display;
327:       args[8] = NULL;
328:       printf("PETSC: Attaching %s to %s on %s\n", args[0], pid, hostname);
329:       if (execvp(args[0], (char **)args) < 0) {
330:         perror("Unable to start debugger");
331:         exit(0);
332:       }
333:     } else {
334:       j = 0;
335:       if (UseDebugTerminal) {
336:         PetscBool cmp;
337:         char     *tmp, *tmp1 = NULL;
338:         PetscCall(PetscStrncmp(DebugTerminal, "Terminal", 8, &cmp));
339:         if (cmp) {
340:           char command[1024];
341:           if (islldb) PetscCall(PetscSNPrintf(command, sizeof(command), "osascript -e 'tell app \"Terminal\" to do script \"lldb  -p %s \"'\n", pid));
342:           else {
343:             char fullprogram[PETSC_MAX_PATH_LEN];
344:             PetscCall(PetscGetFullPath(program, fullprogram, sizeof(fullprogram)));
345:             PetscCall(PetscSNPrintf(command, sizeof(command), "osascript -e 'tell app \"Terminal\" to do script \"%s  %s %s \"'\n", PetscDebugger, fullprogram, pid));
346:           }
347:   #if defined(PETSC_HAVE_POPEN)
348:           PetscCall(PetscPOpen(PETSC_COMM_SELF, NULL, command, "r", NULL));
349:   #else
350:           printf("-debug_terminal Terminal is not available on this system since PETSC_HAVE_POPEN is not defined in this configuration\n");
351:   #endif
352:           exit(0);
353:         }

355:         PetscCall(PetscStrncmp(DebugTerminal, "screen", 6, &cmp));
356:         if (!cmp) PetscCall(PetscStrncmp(DebugTerminal, "gnome-terminal", 6, &cmp));
357:         if (cmp) display[0] = 0; /* when using screen, we never pass -display */
358:         args[j++] = tmp = DebugTerminal;
359:         if (display[0]) {
360:           args[j++] = "-display";
361:           args[j++] = display;
362:         }
363:         while (*tmp) {
364:           PetscCall(PetscStrchr(tmp, ' ', &tmp1));
365:           if (!tmp1) break;
366:           *tmp1     = 0;
367:           tmp       = tmp1 + 1;
368:           args[j++] = tmp;
369:         }
370:       }
371:       args[j++] = PetscDebugger;
372:       jj        = j;
373:       /* this is for default gdb */
374:       args[j++] = program;
375:       args[j++] = pid;
376:       args[j++] = NULL;

378:       if (isidb) {
379:         j         = jj;
380:         args[j++] = "-pid";
381:         args[j++] = pid;
382:         args[j++] = "-gdb";
383:         args[j++] = program;
384:         args[j++] = NULL;
385:       }
386:       if (islldb) {
387:         j         = jj;
388:         args[j++] = "-p";
389:         args[j++] = pid;
390:         args[j++] = NULL;
391:       }
392:       if (isdbx) {
393:         j = jj;
394:   #if defined(PETSC_USE_P_FOR_DEBUGGER)
395:         args[j++] = "-p";
396:         args[j++] = pid;
397:         args[j++] = program;
398:   #elif defined(PETSC_USE_LARGEP_FOR_DEBUGGER)
399:         args[j++] = "-l";
400:         args[j++] = "ALL";
401:         args[j++] = "-P";
402:         args[j++] = pid;
403:         args[j++] = program;
404:   #elif defined(PETSC_USE_A_FOR_DEBUGGER)
405:         args[j++] = "-a";
406:         args[j++] = pid;
407:   #elif defined(PETSC_USE_PID_FOR_DEBUGGER)
408:         args[j++] = "-pid";
409:         args[j++] = pid;
410:         args[j++] = program;
411:   #else
412:         args[j++] = program;
413:         args[j++] = pid;
414:   #endif
415:         args[j++] = NULL;
416:       }
417:       if (UseDebugTerminal) {
418:         if (display[0]) printf("PETSC: Attaching %s to %s of pid %s on display %s on machine %s\n", PetscDebugger, program, pid, display, hostname);
419:         else printf("PETSC: Attaching %s to %s on pid %s on %s\n", PetscDebugger, program, pid, hostname);

421:         if (execvp(args[0], (char **)args) < 0) {
422:           perror("Unable to start debugger in xterm");
423:           exit(0);
424:         }
425:       } else {
426:         printf("PETSC: Attaching %s to %s of pid %s on %s\n", PetscDebugger, program, pid, hostname);
427:         if (execvp(args[0], (char **)args) < 0) {
428:           perror("Unable to start debugger");
429:           exit(0);
430:         }
431:       }
432:     }
433:   } else {          /* I am the child, continue with user code */
434:     sleeptime = 10; /* default to sleep waiting for debugger */
435:     PetscCall(PetscOptionsGetReal(NULL, NULL, "-debugger_pause", &sleeptime, NULL));
436:     if (sleeptime < 0) sleeptime = -sleeptime;
437:   #if defined(PETSC_NEED_DEBUGGER_NO_SLEEP)
438:     /*
439:         HP cannot attach process to sleeping debugger, hence count instead
440:     */
441:     {
442:       PetscReal x = 1.0;
443:       int       i = 10000000;
444:       while (i--) x++; /* cannot attach to sleeper */
445:     }
446:   #elif defined(PETSC_HAVE_SLEEP_RETURNS_EARLY)
447:     /*
448:         IBM sleep may return at anytime, hence must see if there is more time to sleep
449:     */
450:     {
451:       int left = sleeptime;
452:       while (left > 0) left = PetscSleep(left) - 1;
453:     }
454:   #else
455:     PetscCall(PetscSleep(sleeptime));
456:   #endif
457:   }
458: #endif
459:   return PETSC_SUCCESS;
460: }

462: /*@C
463:   PetscAttachDebuggerErrorHandler - Error handler that attaches
464:   a debugger to a running process when an error is detected.
465:   This routine is useful for examining variables, etc.

467:   Not Collective, No Fortran Support

469:   Input Parameters:
470: + comm - communicator over which error occurred
471: . line - the line number of the error (usually indicated by `__LINE__` in the calling routine)
472: . fun  - the function name of the calling routine
473: . file - the file in which the error was detected (usually indicated by `__FILE__` in the calling routine)
474: . mess - an error text string, usually just printed to the screen
475: . num  - the generic error number
476: . p    - `PETSC_ERROR_INITIAL` if error just detected, otherwise `PETSC_ERROR_REPEAT`
477: - ctx  - error handler context

479:   Level: developer

481:   Notes:
482:   By default the GNU debugger, gdb, is used except on macOS where lldb is used.  Alternatives are cuda-gdb, lldb, dbx and
483:   xxgdb,xldb (on IBM rs6000), xdb (on HP-UX).

485:   Most users need not directly employ this routine and the other error
486:   handlers, but can instead use the simplified interface SETERR, which has
487:   the calling sequence
488: .vb
489:   SETERRQ(PETSC_COMM_SELF, number, p, message)
490: .ve

492:   Use `PetscPushErrorHandler()` to set the desired error handler.  The
493:   currently available PETSc error handlers are
494: .vb
495:     PetscTraceBackErrorHandler()
496:     PetscAttachDebuggerErrorHandler()
497:     PetscAbortErrorHandler()
498: .ve
499:   or you may write your own.

501:   Developer Note:
502:   This routine calls abort instead of returning because if it returned then `MPI_Abort()` would get called which can generate an exception
503:   causing the debugger to be attached again in a cycle.

505: .seealso: `PetscSetDebuggerFromString()`, `PetscSetDebugger()`, `PetscSetDefaultDebugger()`, `PetscError()`, `PetscPushErrorHandler()`, `PetscPopErrorHandler()`, `PetscTraceBackErrorHandler()`,
506:           `PetscAbortErrorHandler()`, `PetscMPIAbortErrorHandler()`, `PetscEmacsClientErrorHandler()`, `PetscReturnErrorHandler()`, `PetscSetDebugTermainal()`
507: @*/
508: PetscErrorCode PetscAttachDebuggerErrorHandler(MPI_Comm comm, int line, const char *fun, const char *file, PetscErrorCode num, PetscErrorType p, const char *mess, void *ctx)
509: {
510:   (void)comm;
511:   (void)num;
512:   (void)p;
513:   (void)ctx;
514:   if (!mess) mess = " ";

516:   if (fun) (void)(*PetscErrorPrintf)("%s() at %s:%d %s\n", fun, file, line, mess);
517:   else (void)(*PetscErrorPrintf)("%s:%d %s\n", file, line, mess);

519:   (void)PetscAttachDebugger();
520:   abort(); /* call abort because don't want to kill other MPI ranks that may successfully attach to debugger */
521:   PetscFunctionReturn(PETSC_SUCCESS);
522: }

524: /*@
525:   PetscStopForDebugger - Prints a message to the screen indicating how to
526:   attach to the process with the debugger and then waits for the
527:   debugger to attach.

529:   Not Collective, No Fortran Support

531:   Options Database Key:
532: . -stop_for_debugger - will stop for you to attach the debugger when `PetscInitialize()` is called

534:   Level: developer

536:   Note:
537:   This is likely never needed since `PetscAttachDebugger()` is easier to use and seems to always work.

539:   Developer Note:
540:   Since this can be called by the error handler, should it be calling `SETERRQ()` and `PetscCall()`?

542: .seealso: `PetscSetDebugger()`, `PetscAttachDebugger()`
543: @*/
544: PetscErrorCode PetscStopForDebugger(void)
545: {
546:   PetscErrorCode ierr;
547:   PetscInt       sleeptime = 0;
548: #if !defined(PETSC_CANNOT_START_DEBUGGER)
549:   int         ppid;
550:   PetscMPIInt rank;
551:   char        program[PETSC_MAX_PATH_LEN], hostname[256];
552:   PetscBool   isdbx, isxldb, isxxgdb, isddd, iskdbg, isups, isxdb, islldb;
553: #endif

555:   PetscFunctionBegin;
556: #if defined(PETSC_CANNOT_START_DEBUGGER)
557:   PetscCall((*PetscErrorPrintf)("System cannot start debugger; just continuing program\n"));
558: #else
559:   if (MPI_Comm_rank(PETSC_COMM_WORLD, &rank)) rank = 0; /* ignore error since this may be already in error handler */
560:   ierr = PetscGetHostName(hostname, sizeof(hostname));
561:   if (ierr) {
562:     PetscCall((*PetscErrorPrintf)("Cannot determine hostname; just continuing program\n"));
563:     PetscFunctionReturn(PETSC_SUCCESS);
564:   }

566:   ierr = PetscGetProgramName(program, sizeof(program));
567:   if (ierr) {
568:     PetscCall((*PetscErrorPrintf)("Cannot determine program name; just continuing program\n"));
569:     PetscFunctionReturn(PETSC_SUCCESS);
570:   }
571:   if (!program[0]) {
572:     PetscCall((*PetscErrorPrintf)("Cannot determine program name; just continuing program\n"));
573:     PetscFunctionReturn(PETSC_SUCCESS);
574:   }

576:   ppid = getpid();

578:   PetscCall(PetscStrcmp(PetscDebugger, "xxgdb", &isxxgdb));
579:   PetscCall(PetscStrcmp(PetscDebugger, "ddd", &isddd));
580:   PetscCall(PetscStrcmp(PetscDebugger, "kdbg", &iskdbg));
581:   PetscCall(PetscStrcmp(PetscDebugger, "ups", &isups));
582:   PetscCall(PetscStrcmp(PetscDebugger, "xldb", &isxldb));
583:   PetscCall(PetscStrcmp(PetscDebugger, "xdb", &isxdb));
584:   PetscCall(PetscStrcmp(PetscDebugger, "dbx", &isdbx));
585:   PetscCall(PetscStrcmp(PetscDebugger, "lldb", &islldb));

587:   if (isxxgdb || isups || isddd || iskdbg) printf("[%d]%s>>%s %s %d\n", rank, hostname, PetscDebugger, program, ppid);
588:   else if (isxldb) printf("[%d]%s>>%s -a %d %s\n", rank, hostname, PetscDebugger, ppid, program);
589:   else if (islldb) printf("[%d]%s>>%s -p %d\n", rank, hostname, PetscDebugger, ppid);
590:   else if (isdbx) {
591:   #if defined(PETSC_USE_P_FOR_DEBUGGER)
592:     printf("[%d]%s>>%s -p %d %s\n", rank, hostname, PetscDebugger, ppid, program);
593:   #elif defined(PETSC_USE_LARGEP_FOR_DEBUGGER)
594:     printf("[%d]%s>>%s -l ALL -P %d %s\n", rank, hostname, PetscDebugger, ppid, program);
595:   #elif defined(PETSC_USE_A_FOR_DEBUGGER)
596:     printf("[%d]%s>>%s -a %d\n", rank, hostname, PetscDebugger, ppid);
597:   #elif defined(PETSC_USE_PID_FOR_DEBUGGER)
598:     printf("[%d]%s>>%s -pid %d %s\n", rank, hostname, PetscDebugger, ppid, program);
599:   #else
600:     printf("[%d]%s>>%s %s %d\n", rank, hostname, PetscDebugger, program, ppid);
601:   #endif
602:   }
603: #endif /* PETSC_CANNOT_START_DEBUGGER */

605:   fflush(stdout); /* ignore error because may already be in error handler */

607:   sleeptime = 25;                                                                         /* default to sleep waiting for debugger */
608:   PetscCallContinue(PetscOptionsGetInt(NULL, NULL, "-debugger_pause", &sleeptime, NULL)); /* ignore error because may already be in error handler */
609:   if (sleeptime < 0) sleeptime = -sleeptime;
610: #if defined(PETSC_NEED_DEBUGGER_NO_SLEEP)
611:   /*
612:       HP cannot attach process to sleeping debugger, hence count instead
613:   */
614:   {
615:     // this *will* get optimized away by any compiler known to man
616:     PetscReal x = 1.0;
617:     int       i = 10000000;
618:     while (i--) x++; /* cannot attach to sleeper */
619:   }
620: #elif defined(PETSC_HAVE_SLEEP_RETURNS_EARLY)
621:   /*
622:       IBM sleep may return at anytime, hence must see if there is more time to sleep
623:   */
624:   {
625:     int left = sleeptime;
626:     while (left > 0) left = sleep(left) - 1;
627:   }
628: #else
629:   PetscCall(PetscSleep(sleeptime));
630: #endif
631:   PetscFunctionReturn(PETSC_SUCCESS);
632: }