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5580185e | 1 | /* |
2 | * $Source$ | |
3 | * $Header$ | |
4 | */ | |
5 | ||
6 | #ifndef lint | |
7 | static char *rcsid_gdb_trans2_c = "$Header$"; | |
8 | #endif lint | |
9 | ||
10 | ||
11 | ||
12 | ||
13 | ||
14 | ||
15 | ||
16 | ||
17 | ||
18 | ||
19 | ||
20 | ||
21 | ||
22 | ||
23 | ||
24 | ||
25 | ||
26 | ||
27 | ||
28 | ||
29 | ||
30 | /************************************************************************/ | |
31 | /* | |
32 | /* gdb_trans2.c | |
33 | /* | |
34 | /* GDB - Data Transport Services Routines (Part 2) | |
35 | /* | |
36 | /* Author: Noah Mendelsohn | |
37 | /* Copyright: 1986 MIT Project Athena | |
0a5ff702 | 38 | /* For copying and distribution information, please see |
39 | /* the file <mit-copyright.h>. | |
40 | /* | |
5580185e | 41 | /* |
42 | /* These routines implement layer 6 of the Client Library | |
43 | /* Specification of the GDB system, as well as the facilities | |
44 | /* outlined in the GDB Protocol Specification. Part 2 of 2. | |
45 | /* | |
46 | /* Some of the routines specified are actually implemented as | |
47 | /* macros defined in gdb.h. | |
48 | /* | |
49 | /************************************************************************/ | |
50 | ||
0a5ff702 | 51 | #include <mit-copyright.h> |
5580185e | 52 | #include <sys/types.h> |
53 | #include <errno.h> | |
54 | #include <stdio.h> | |
55 | #include "gdb.h" | |
56 | #include <sys/uio.h> | |
57 | #include <sys/socket.h> | |
58 | extern int errno; /* Unix error slot */ | |
59 | ||
60 | /* | |
61 | * The following values are returned by g_con_progress | |
62 | */ | |
63 | #define NOPROGRESS 0 /* nothing happened on this */ | |
64 | /* connection--must be 0*/ | |
65 | #define PROGRESS 1 /* connection has progressed */ | |
66 | #define COMPLETE 2 /* an operation has */ | |
67 | /* completed on this con */ | |
68 | \f | |
69 | /************************************************************************/ | |
70 | /* | |
71 | /* queue_operation(queue_operation) | |
72 | /* | |
73 | /* Add an operation to the queue for a given connection, and | |
74 | /* then allows all connections to progress. Returns the last | |
75 | /* known status of the operation. | |
76 | /* | |
77 | /************************************************************************/ | |
78 | ||
79 | int | |
80 | queue_operation(con, direction, op) | |
81 | CONNECTION con; | |
82 | int direction; | |
83 | OPERATION op; | |
84 | { | |
85 | register HALF_CONNECTION hcon = (direction==CON_INPUT)?(&(con->in)): | |
86 | (&(con->out)); | |
87 | GDB_CHECK_CON(con, "queue_operation") | |
88 | /* | |
89 | * Write message to debugging log | |
90 | */ | |
91 | if (gdb_Debug & GDB_LOG) | |
92 | fprintf(gdb_log, "op queued: con=0x%x dir=%s op=0x%x Q was %s empty\n", | |
93 | con, (direction == CON_INPUT)?"INPUT":"OUTPUT", | |
94 | op, (hcon->op_q_first == (OPERATION)hcon)?"":"not"); | |
95 | /* | |
96 | * Make sure connection is up | |
97 | */ | |
98 | if (con->status != CON_UP) { | |
99 | op->status = OP_CANCELLED; | |
100 | if (gdb_Debug & GDB_LOG) | |
101 | fprintf(gdb_log, "\nop NOT queued\n"); | |
102 | return OP_CANCELLED; | |
103 | } | |
104 | ||
105 | /* | |
106 | * Put the new operation at the end of the queue | |
107 | */ | |
108 | op->prev = hcon->op_q_last; | |
109 | op->next = (OPERATION)hcon; | |
110 | hcon->op_q_last->next = op; | |
111 | hcon->op_q_last = op; | |
112 | /* | |
113 | * Mark it as queued | |
114 | */ | |
115 | op->status = OP_QUEUED; | |
116 | op->halfcon = hcon; | |
117 | ||
118 | /* | |
119 | * Force progress on this connection | |
120 | */ | |
121 | (void) g_con_progress(con - gdb_cons); | |
122 | /* | |
123 | * Con_select with notime is used here as a kind of fudge for | |
124 | * doing a fastprogress with a select built in before it. | |
125 | */ | |
126 | (void) con_select(0, (fd_set *)0, (fd_set *)0, (fd_set *)0, | |
127 | &gdb_notime);/* XXX */ | |
128 | /* | |
129 | * Return the last known status of the operation | |
130 | */ | |
131 | return op->status; | |
132 | } | |
133 | /************************************************************************/ | |
134 | /* | |
135 | /* requeue_operation | |
136 | /* | |
137 | /* This routine may be called from an init or continuation routine | |
138 | /* to cause the current operation to be requeued on a new connection. | |
139 | /* The init routine field ofthe operation should be properly set to | |
140 | /* indicate the routine to receive control when the operation actually | |
141 | /* runs on the new connection. The caller of this routine is | |
142 | /* responsible for returning the status OP_REQUEUED to its caller. | |
143 | /* | |
144 | /* This routine returns the status of the newly queued operation. | |
145 | /* Note, however, that even if this operation returns the status | |
146 | /* CANCELLED, the operation itself may not continue to execute | |
147 | /* on the old connection and it should return the status OP_REQUEUED, | |
148 | /* NOT OP_CANCELLED (at least in this implementation.) | |
149 | /* | |
150 | /************************************************************************/ | |
151 | ||
152 | int | |
153 | requeue_operation(con, direction, op) | |
154 | CONNECTION con; | |
155 | int direction; | |
156 | OPERATION op; | |
157 | { | |
158 | /* | |
159 | * Make sure the connection supplied is a legal one | |
160 | */ | |
161 | GDB_CHECK_CON(con, "requeue_operation") | |
162 | /* | |
163 | * Write message to debugging log | |
164 | */ | |
165 | if (gdb_Debug & GDB_LOG) | |
166 | fprintf(gdb_log, "op requeued: new con=0x%x dir=%s op=0x%x\n", | |
167 | con, (direction == CON_INPUT)?"INPUT":"OUTPUT", | |
168 | op); | |
169 | /* | |
170 | * Dequeue the operation from its old half connection | |
171 | */ | |
172 | (void) g_op_newhead(op->halfcon); | |
173 | ||
174 | /* | |
175 | * Now queue it on the new one | |
176 | */ | |
177 | return queue_operation(con, direction, op); | |
178 | } | |
179 | ||
180 | /************************************************************************/ | |
181 | /* | |
182 | /* g_preempt_me | |
183 | /* | |
184 | /* Sticks a new operation in ahead of the current one and runs it | |
185 | /* on the current connection. May be called only from an init or | |
186 | /* continuation routine. The old operation must have completely | |
187 | /* prepared the descriptor for the new operation, i.e. it should | |
188 | /* be in the same state as it would be for a call to queue_operation. | |
189 | /* g_preempt_me makes it possible for operations to be built by | |
190 | /* composition of other smaller operations, since newop runs, in | |
191 | /* a sense, as a subroutine of oldop. opdop must (1) reset its | |
192 | /* initialization routine to be a routine to be called when newop | |
193 | /* completes or cancels and (2) return the status OP_PREEMPTED to | |
194 | /* its caller. | |
195 | /* | |
196 | /************************************************************************/ | |
197 | ||
198 | int | |
199 | g_preempt_me(oldop, newop) | |
200 | OPERATION oldop; | |
201 | OPERATION newop; | |
202 | { | |
203 | register OPERATION old=oldop, new=newop; | |
204 | register HALF_CONNECTION hc = old->halfcon; | |
205 | ||
206 | /* | |
207 | * Write message to debugging log | |
208 | */ | |
209 | if (gdb_Debug & GDB_LOG) | |
210 | fprintf(gdb_log, "op preempted: halfcon=0x%x oldop=0x%x newop=0x%x\n", | |
211 | oldop,newop); | |
212 | /* | |
213 | * link in the new operation | |
214 | */ | |
215 | old->prev = new; | |
216 | hc->op_q_first = new; | |
217 | new->prev = (OPERATION)hc; | |
218 | new->next = old; | |
219 | /* | |
220 | * Set the status of the new operation | |
221 | */ | |
222 | new->status = OP_QUEUED; | |
223 | new->halfcon = hc; | |
224 | /* | |
225 | * Change the status of the old operation (one could argue that | |
226 | * this should be done in gdb_hcon_progress after the return code | |
227 | * is detected.) | |
228 | */ | |
229 | old->status = OP_QUEUED; | |
230 | return OP_QUEUED; | |
231 | } | |
232 | ||
233 | ||
234 | \f | |
235 | /************************************************************************/ | |
236 | /* | |
237 | /* gdb_progress | |
238 | /* | |
239 | /* This routine should be called whenever it is suspected that | |
240 | /* progress can be made on any connection. This routine will | |
241 | /* cause all connections to proceed as far as they can without | |
242 | /* blocking, and will make a best effort to avoid long blocks. | |
243 | /* This routine MAY retain control for long periods when sustained | |
244 | /* progress is possible, but it will not knowingly hang. | |
245 | /* | |
246 | /* Returns: number of connections on which OPERATIONS have | |
247 | /* COMPLETED (not just progressed). | |
248 | /* | |
249 | /************************************************************************/ | |
250 | ||
251 | int | |
252 | ||
253 | gdb_progress() | |
254 | { | |
255 | register int i; /* index to available */ | |
256 | /* connections */ | |
257 | register int return_value = 0; /* the value we return */ | |
258 | int rc; /* short term storage for */ | |
259 | /* a return code */ | |
260 | int progress_made; /* true when some con */ | |
261 | /* made progress during */ | |
262 | /* latest pass through list */ | |
263 | int complete_map[GDB_MAX_CONNECTIONS]; /* indicates whether a */ | |
264 | /* transmission operation */ | |
265 | /* is newly complete on */ | |
266 | /* corresponding connection */ | |
267 | /* 1 if yes else 0 */ | |
268 | int maxcon = gdb_mcons; /* gdb_mcons may change */ | |
269 | /* out from under us if */ | |
270 | /* connections break. This */ | |
271 | /* is the initial value. */ | |
272 | ||
273 | /* | |
274 | * Zero out the completion map for all connections. | |
275 | */ | |
276 | for (i=0; i<maxcon; i++) | |
277 | complete_map[i]=0; | |
278 | ||
279 | /* | |
280 | * Make repeated passes through all the fd's until a pass is made | |
281 | * in which none makes any progress. This logic is important, | |
282 | * because it catches the case where A is blocked, B makes progress, | |
283 | * and A unblocks during the period where B is progressing. | |
284 | */ | |
285 | ||
286 | do { | |
287 | progress_made = FALSE; | |
288 | for (i=0; i<gdb_mcons; i++) { | |
289 | if (rc = g_con_progress(i)) { /* note: NOPROGRESS==0 */ | |
290 | progress_made = TRUE; | |
291 | if (rc == COMPLETE) | |
292 | complete_map[i] = 1; | |
293 | } | |
294 | } | |
295 | } while (progress_made); | |
296 | ||
297 | /* | |
298 | * We've gone as far as we can, now find out how many connections | |
299 | * have had operations complete. | |
300 | */ | |
301 | for (i=0; i<maxcon; i++) | |
302 | return_value += complete_map[i]; | |
303 | ||
304 | return return_value; | |
305 | } | |
306 | ||
307 | \f | |
308 | /************************************************************************/ | |
309 | /* | |
310 | /* gdb_fastprogress | |
311 | /* | |
312 | /* Similar to gdb_progress, but this routine attempts progress | |
313 | /* only on those connections which have already shown themselves | |
314 | /* to be ready for activity by a prior select. This is safe to do | |
315 | /* when (1) the only activity we are interested in is that related | |
316 | /* to ongoing I/O and (2) a select was recently done to set the | |
317 | /* last_c.fds flags. Condition (1) is violated in the case where | |
318 | /* an operation may be newly at the head of a queue and its init | |
319 | /* routine may not have had a chance to run. Condition (2) is violated | |
320 | /* when we are entering after having done significant computation. | |
321 | /* | |
322 | /* This routine was introduced by Bill Sommerfeld after profiling | |
323 | /* revealed that unnecessary attempts to progress on quiescent | |
324 | /* sockets were causing excessive overhead in the system. I am | |
325 | /* still suspicious that this routine may be getting called in | |
326 | /* places where a full gdb_progress is needed. e.g. I'm not | |
327 | /* sure its use in op_select is entirely safe. | |
328 | /* | |
329 | /************************************************************************/ | |
330 | ||
331 | gdb_fastprogress() | |
332 | { | |
333 | int i; | |
334 | int retval=0, rc; | |
335 | ||
336 | for (i=0; i<gdb_mcons; i++) { | |
337 | register CONNECTION con = &gdb_cons[i]; | |
338 | register int infd = gdb_cons[i].in.fd; | |
339 | register int outfd = gdb_cons[i].out.fd; | |
340 | ||
341 | if(connection_status(con) != CON_UP) | |
342 | continue; | |
343 | ||
344 | gdb_conok = TRUE; | |
345 | if ((!(con->in.flags&HCON_UNUSED))&& | |
346 | ((con->in.stream_buffer_remaining > 0) | |
347 | || FD_ISSET(infd, &last_crfds))) { | |
348 | rc = gdb_hcon_progress(CON_INPUT, &con->in); | |
349 | if (!gdb_conok) { | |
350 | g_stop_with_errno(con); | |
351 | rc = COMPLETE; | |
352 | } | |
353 | if (rc == COMPLETE) | |
354 | retval++; | |
355 | } | |
356 | if ((!(con->out.flags&HCON_UNUSED))&& | |
357 | (FD_ISSET(outfd, &last_cwfds))) { | |
358 | rc = gdb_hcon_progress(CON_OUTPUT, &con->out); | |
359 | if (!gdb_conok) { | |
360 | g_stop_with_errno(con); | |
361 | rc = COMPLETE; | |
362 | } | |
363 | if (rc == COMPLETE) | |
364 | retval++; | |
365 | } | |
366 | } | |
367 | /* | |
368 | * We've gone as far as we can, now find out how many connections | |
369 | * have had operations complete. | |
370 | */ | |
371 | ||
372 | return retval; | |
373 | } | |
374 | \f | |
375 | /************************************************************************/ | |
376 | /* | |
377 | /* g_con_progress | |
378 | /* | |
379 | /* Make as much progress as possible on the specified connection. | |
380 | /* Returns NOPROGRESS if no bytes moved on either half connection, | |
381 | /* PROGRESS, if some moved and no operations completed, or COMPLETE if | |
382 | /* any of the operations completed. Note that each connection | |
383 | /* consists of two half connections, and we must make each of them | |
384 | /* progress as far as possible. | |
385 | /* | |
386 | /* The nest here starts getting so deep that it's hard to pass state | |
387 | /* around efficiently. We use a single global variable, gdb_conok, | |
388 | /* to indicate whether the connection we're working on now has died. | |
389 | /* The move data routines set this to FALSE whenever there is a | |
390 | /* fatal error on a connection. We check it, and do a proper | |
391 | /* sever on the connection if it seems to be in trouble. | |
392 | /* | |
393 | /************************************************************************/ | |
394 | ||
395 | ||
396 | int | |
397 | g_con_progress(con_id) | |
398 | int con_id; /* index of this connection */ | |
399 | /* in the connection desc. */ | |
400 | /* arrays*/ | |
401 | { | |
402 | register CONNECTION con= (&gdb_cons[con_id]); | |
403 | /* pointer to the connection */ | |
404 | /* data structure */ | |
405 | register int progress = NOPROGRESS; | |
406 | register int live = TRUE; /* true when we've seen */ | |
407 | /* enough to make sure we */ | |
408 | /* want to go around again*/ | |
409 | int rc; | |
410 | /* | |
411 | * Check status of connection-if it's not running, then just return. | |
412 | */ | |
413 | if (con->status != CON_UP) | |
414 | return NOPROGRESS; | |
415 | /* | |
416 | * Repeatedly make progress on each half connection until both | |
417 | * are idle. Important to keep trying as one may become active | |
418 | * while the other is progressing. | |
419 | */ | |
420 | ||
421 | gdb_conok = TRUE; /* this gets set to FALSE */ | |
422 | /* for fatal I/O errors */ | |
423 | /* there may be a timing */ | |
424 | /* window here in use of */ | |
425 | /* HCON_BUSY. Also: it is */ | |
426 | /* essential that errno */ | |
427 | /* remain valid after conok */ | |
428 | /* goes bad */ | |
429 | while (live) { | |
430 | live = FALSE; /* until proven otherwise */ | |
431 | /* | |
432 | * make progress on the input connection note that following | |
433 | * logic depends on NOPROGRESS being 0 | |
434 | */ | |
435 | if (rc = gdb_hcon_progress(CON_INPUT, &con->in)) { | |
436 | live = TRUE; | |
437 | progress = max(rc, progress); | |
438 | } | |
439 | /* | |
440 | * See if connection has died | |
441 | */ | |
442 | if (!gdb_conok) { | |
443 | g_stop_with_errno(con); | |
444 | return COMPLETE; /* dying connection always */ | |
445 | /* implies that the */ | |
446 | /* operation at the head */ | |
447 | /* of the queue completed */ | |
448 | } | |
449 | /* | |
450 | * make progress on the output connection | |
451 | */ | |
452 | if (rc = gdb_hcon_progress(CON_OUTPUT, &con->out)) { | |
453 | live = TRUE; | |
454 | progress = max(rc, progress); | |
455 | } | |
456 | /* | |
457 | * See if connection has died | |
458 | */ | |
459 | if (!gdb_conok) { | |
460 | g_stop_with_errno(con); | |
461 | return COMPLETE; | |
462 | } | |
463 | } | |
464 | ||
465 | return progress; | |
466 | } | |
467 | ||
468 | ||
469 | /************************************************************************/ | |
470 | /* | |
471 | /* gdb_hcon_progress | |
472 | /* | |
473 | /* Allows a specified half-connection to progress as much as possible, | |
474 | /* and returns true iff at least one operation is newly completed. | |
475 | /* | |
476 | /************************************************************************/ | |
477 | ||
478 | int | |
479 | gdb_hcon_progress(direction, hc) | |
480 | int direction; /* CON_INPUT or CON_OUTPUT */ | |
481 | struct half_con_data *hc; /* pointer to control struct */ | |
482 | /* for this half connection */ | |
483 | { | |
484 | HALF_CONNECTION half_con = hc; | |
485 | /* half connection pointer */ | |
486 | /* fast copy in register */ | |
487 | register OPERATION op; /* current operation on this */ | |
488 | /* half connection */ | |
489 | int progress = NOPROGRESS; /* can indicate any progress */ | |
490 | /* on the half con or */ | |
491 | /* whether any operations */ | |
492 | /* completed */ | |
493 | int done; /* true when no more progress*/ | |
494 | /* can be made */ | |
495 | int fcn_result; /* result of latest init or */ | |
496 | /* continue function */ | |
497 | ||
498 | /* | |
499 | * Write message to debugging log | |
500 | */ | |
501 | if (gdb_Debug & GDB_LOG) | |
502 | fprintf(gdb_log, "hcon_progress: halfcon=0x%x dir=%s ", | |
503 | half_con, (direction==CON_INPUT)?"INPUT":"OUTPUT"); | |
504 | ||
505 | /*----------------------------------------------------------*/ | |
506 | /* | |
507 | /* See if we are being re-entered and are already working | |
508 | /* on this half_con. If so, return right now. | |
509 | /* | |
510 | /*----------------------------------------------------------*/ | |
511 | ||
512 | if (half_con->flags & HCON_BUSY) { | |
513 | /* | |
514 | * Write message to debugging log | |
515 | */ | |
516 | if (gdb_Debug & GDB_LOG) | |
517 | fprintf(gdb_log, "BUSY, returning\n"); | |
518 | return NOPROGRESS; | |
519 | } | |
520 | ||
521 | /*----------------------------------------------------------*/ | |
522 | /* | |
523 | /* See if there is an operation on this half connection. | |
524 | /* If not, return. | |
525 | /* | |
526 | /*----------------------------------------------------------*/ | |
527 | ||
528 | ||
529 | op = half_con->op_q_first; /* pick up first operation */ | |
530 | /* in queue */ | |
531 | if (op == (OPERATION)half_con) { /* see if end of circular */ | |
532 | /* list */ | |
533 | /* | |
534 | * Write message to debugging log | |
535 | */ | |
536 | if (gdb_Debug & GDB_LOG) | |
537 | fprintf(gdb_log, "Q EMPTY, returning\n"); | |
538 | return NOPROGRESS; /* nothing to do on */ | |
539 | /* this half session */ | |
540 | } | |
541 | ||
542 | ||
543 | /*----------------------------------------------------------*/ | |
544 | /* | |
545 | /* Loop until all operations are complete, or until no further | |
546 | /* progress can be made on this one. | |
547 | /* | |
548 | /* Loop invariants: | |
549 | /* | |
550 | /* 1) Op contains the operation at the head of the q, or | |
551 | /* else is == half_con, indicating no more operationos | |
552 | /* to be processed. | |
553 | /* | |
554 | /* 2) The operation at the head of the queue is either running | |
555 | /* or continuing. As soon as one completes, it is dequeued. | |
556 | /* | |
557 | /* Progress is declared whenever an operation newly | |
558 | /* returns OP_COMPLETE, i.e. whenever there has been | |
559 | /* an operation which went from running to complete. | |
560 | /* | |
561 | /* Done is declared whenever an operation returns anything | |
562 | /* other than complete, indicating that it cannot progress | |
563 | /* further at this time. Loop ends. | |
564 | /* | |
565 | /* While we're here, mark us busy so we won't try the | |
566 | /* same half_con on reentry. | |
567 | /* | |
568 | /*----------------------------------------------------------*/ | |
569 | ||
570 | done = FALSE; /* this one may be able to */ | |
571 | /* progress */ | |
572 | ||
573 | half_con->flags |= HCON_BUSY; /* don't try this hcon */ | |
574 | /* while we already doing */ | |
575 | /* it. Could happen if */ | |
576 | /* we queue new ops */ | |
577 | half_con->flags &= ~HCON_PROGRESS; /* gdb_move_data will */ | |
578 | /* indicate progress here*/ | |
579 | if (gdb_Debug & GDB_LOG) | |
580 | fprintf(gdb_log, "LOOPING\n"); | |
581 | ||
582 | /*----------------------------------------------------------*/ | |
583 | /* | |
584 | /* Loop through the operations queued on this half con | |
585 | /* trying to make progress on them, in order. | |
586 | /* | |
587 | /*----------------------------------------------------------*/ | |
588 | ||
589 | while (!done && | |
590 | op != (OPERATION)half_con) { | |
591 | ||
592 | if (gdb_Debug & GDB_LOG) | |
593 | fprintf(gdb_log, "\top=0x%x status%d...", | |
594 | op, OP_STATUS(op)); | |
595 | ||
596 | switch (op->status) { | |
597 | /* | |
598 | * Operation is at head of queue for first time and has | |
599 | * never been started. Try to start it up. | |
600 | */ | |
601 | case OP_QUEUED: | |
602 | /* | |
603 | * Call the initialization routine for this operation | |
604 | */ | |
605 | fcn_result = (*op->fcn.init)(op,half_con,op->arg); | |
606 | if (gdb_Debug & GDB_LOG) | |
607 | fprintf(gdb_log, "init result=%d\n", | |
608 | fcn_result); | |
609 | ||
610 | switch (fcn_result) { | |
611 | case OP_COMPLETE: | |
612 | case OP_CANCELLED: | |
613 | op->status = fcn_result; | |
614 | op = g_op_newhead(half_con); | |
615 | progress = COMPLETE; | |
616 | break; | |
617 | case OP_PREEMPTED: | |
618 | op->status = OP_QUEUED; | |
619 | /* fall thru */ | |
620 | case OP_REQUEUED: | |
621 | /* important: don't set status on re-queued */ | |
622 | /* op as it may already have completed in */ | |
623 | /* its second life ! */ | |
624 | op = half_con->op_q_first; | |
625 | progress = max(progress, PROGRESS); | |
626 | break; | |
627 | default: | |
628 | op->status = fcn_result; | |
629 | done = TRUE; /* could not get done */ | |
630 | } | |
631 | break; | |
632 | /* | |
633 | * Operation is at head of queue and has already | |
634 | * started trying to run. The only reason we could be in this | |
635 | * state is that the last time we tried to do the requested input | |
636 | * or output, all the data could not be moved synchronously. | |
637 | * We therefore try to move some more, and if it all goes now, | |
638 | * we call the continuation routine. | |
639 | */ | |
640 | case OP_RUNNING: | |
641 | /* | |
642 | * Try to move some more data. If it won't all | |
643 | * go now, we're done with this half connection. | |
644 | * | |
645 | * If this is a special listening connection which | |
646 | * has an operation queued trying to do a listen, | |
647 | * then do the listen. Otherwise do an ordinary | |
648 | * data move. | |
649 | */ | |
650 | if (half_con->flags & HCON_PENDING_LISTEN) { | |
651 | if (gdb_listen(half_con)==FALSE) { | |
652 | if (gdb_Debug & GDB_LOG) | |
653 | fprintf(gdb_log, "NO LISTEN\n"); | |
654 | done = TRUE; | |
655 | break; | |
656 | } | |
657 | } else | |
658 | if (gdb_move_data(direction, half_con)==FALSE) { | |
659 | done = TRUE; | |
660 | if (gdb_Debug & GDB_LOG) | |
661 | fprintf(gdb_log, "NO DATA\n"); | |
662 | break; | |
663 | } | |
664 | /* | |
665 | * The pending data transmission has now completed. | |
666 | * Call the continuation routine for this operation | |
667 | */ | |
668 | fcn_result = (*op->fcn.cont)(op,half_con,op->arg); | |
669 | if (gdb_Debug & GDB_LOG) | |
670 | fprintf(gdb_log, "cont result=%d\n", | |
671 | fcn_result); | |
672 | ||
673 | switch (fcn_result) { | |
674 | case OP_COMPLETE: | |
675 | case OP_CANCELLED: | |
676 | op->status = fcn_result; | |
677 | op = g_op_newhead(half_con); | |
678 | progress = COMPLETE; | |
679 | break; | |
680 | case OP_PREEMPTED: | |
681 | op->status = OP_QUEUED; | |
682 | /* fall thru */ | |
683 | case OP_REQUEUED: | |
684 | /* important: don't set status on re-queued */ | |
685 | /* op as it may already have completed in */ | |
686 | /* its second life ! */ | |
687 | op = half_con->op_q_first; | |
688 | progress = max(progress, PROGRESS); | |
689 | break; | |
690 | default: | |
691 | op->status = fcn_result; | |
692 | done = TRUE; /* could not get done */ | |
693 | } | |
694 | break; | |
695 | /* | |
696 | * Following cases are all unexpected, at least for the | |
697 | * moment. (See explanation of loop invariants for this while | |
698 | * loop. Give up if they turn up. | |
699 | */ | |
700 | case OP_COMPLETE: | |
701 | GDB_GIVEUP("gdb_hcon_progress: found OP_COMPLETE on q") | |
702 | case OP_CANCELLED: | |
703 | GDB_GIVEUP("gdb_hcon_progress: found OP_CANCELLED on q") | |
704 | case OP_CANCELLING: | |
705 | GDB_GIVEUP("gdb_hcon_progress: OP_CANCELLING") | |
706 | default: | |
707 | GDB_GIVEUP("gdb_hcon_progress: Operation is queued, but is not runnable") | |
708 | } | |
709 | } | |
710 | ||
711 | if (progress == NOPROGRESS && (half_con->flags & HCON_PROGRESS)) | |
712 | progress = PROGRESS; | |
713 | ||
714 | half_con->flags &= ~HCON_BUSY; | |
715 | ||
716 | if (gdb_Debug & GDB_LOG) | |
717 | fprintf(gdb_log, "hcon_progress: returns %d\n",progress); | |
718 | ||
719 | return progress; /* NOPROGRESS, PROGRESS */ | |
720 | /* or COMPLETE */ | |
721 | } | |
722 | \f | |
723 | /************************************************************************/ | |
724 | /* | |
725 | /* g_op_newhead | |
726 | /* | |
727 | /* Dequeues the operation at the head of the queue for the | |
728 | /* given half connection and returns the pointer to the | |
729 | /* new head of the queue. If the queue is null, then a pointer | |
730 | /* to the half_con itself is returned. (The lists are | |
731 | /* linked circularly.) | |
732 | /* | |
733 | /************************************************************************/ | |
734 | ||
735 | OPERATION | |
736 | g_op_newhead(hcp) | |
737 | HALF_CONNECTION hcp; | |
738 | { | |
739 | register OPERATION newhead, oldhead; | |
740 | ||
741 | /* | |
742 | * Get old and new heads of chain | |
743 | */ | |
744 | oldhead = hcp->op_q_first; | |
745 | newhead = oldhead->next; | |
746 | /* | |
747 | * Make sure nobody chained a bad one on us | |
748 | */ | |
749 | if (newhead == NULL) { | |
750 | if (gdb_Debug & GDB_LOG) { | |
751 | fprintf(gdb_log,"\t\tg_op_newhead: found null link, oldhead = 0x%x newhead=0x%x halfcon=0x%x\n\t\t\t hc->first=0x%x hc->last=0x%x\n", | |
752 | oldhead, newhead, hcp, hcp->op_q_first, | |
753 | hcp->op_q_last); | |
754 | } | |
755 | GDB_GIVEUP("g_op_newhead: found NULL chain link") | |
756 | } | |
757 | /* | |
758 | * Remove oldhead from chain, fixing up chain pointers | |
759 | */ | |
760 | newhead->prev = oldhead->prev; | |
761 | hcp->op_q_first = newhead; | |
762 | ||
763 | /* | |
764 | * Clean up pointers in the newly dequeued operation. This is | |
765 | * just for cleanliness and ease of debugging. | |
766 | */ | |
767 | oldhead->next = oldhead->prev = NULL; | |
768 | oldhead->halfcon = NULL; | |
769 | ||
770 | return newhead; | |
771 | } | |
772 | \f | |
773 | /************************************************************************/ | |
774 | /* | |
775 | /* gdb_move_data | |
776 | /* | |
777 | /* This routine attempts to make further progress on the pending | |
778 | /* level transmission operation pending on this half connection. | |
779 | /* (Presumes that such an operation is pending.) Returns TRUE | |
780 | /* if all the requested data has been moved, else FALSE. | |
781 | /* | |
782 | /* We assume here that all fd's are set to non-blocking I/O, so | |
783 | /* we can safely try reading and writing until they return 0 bytes. | |
784 | /* | |
785 | /************************************************************************/ | |
786 | ||
787 | #define FIX_BUFFER_POINTERS(hc, count) if (count>0) {hc->next_byte += count; \ | |
788 | hc->remaining -= count;} | |
789 | int | |
790 | gdb_move_data(direction, hc) | |
791 | int direction; /* CON_INPUT or CON_OUTPUT */ | |
792 | struct half_con_data *hc; /* pointer to control struct */ | |
793 | /* for this half connection */ | |
794 | { | |
795 | register HALF_CONNECTION half_con = hc; | |
796 | /* half connection pointer */ | |
797 | /* fast copy in register */ | |
798 | register fd_set *fdbits; /* the mask we should adjust */ | |
799 | /* for this direction */ | |
800 | ||
801 | /* | |
802 | * For safety, in case we're called when nothing is pending. | |
803 | */ | |
804 | if (half_con->remaining == 0) | |
805 | return TRUE; | |
806 | /* | |
807 | * Move the data into the user's buffer. In the case of input | |
808 | * data may come first from the stream buffer, then from the socket | |
809 | * itself. | |
810 | */ | |
811 | if (direction == CON_INPUT) { | |
812 | gdb_transfer_from_buffer(half_con); | |
813 | /* | |
814 | * If remaining is greater than 0, then we emptied | |
815 | * the stream buffer and still weren't done. Try | |
816 | * to read it from the pipe and re-fill the stream | |
817 | * buffer. | |
818 | */ | |
819 | if (half_con->remaining) { | |
820 | gdb_read_data_and_buffer(half_con); | |
821 | } | |
822 | } else { | |
823 | gdb_write_data(half_con); | |
824 | } | |
825 | /* | |
826 | * The file descriptor masks used for doing selects must be activated | |
827 | * when and only when there is a pending operation trying to use | |
828 | * the connection. Update the masks for this half connection. | |
829 | */ | |
830 | fdbits = (direction == CON_INPUT)? &gdb_crfds : &gdb_cwfds; | |
831 | if (half_con->remaining >0 && gdb_conok) | |
832 | FD_SET(half_con->fd, fdbits); | |
833 | else | |
834 | FD_CLR(half_con->fd, fdbits); | |
835 | ||
836 | return (half_con->remaining == 0); | |
837 | } | |
838 | \f | |
839 | /************************************************************************/ | |
840 | /* | |
841 | /* gdb_transfer_from_buffer | |
842 | /* | |
843 | /* Given an inbound half connection, satisfy as much as possible | |
844 | /* of desired data from the stream buffer. | |
845 | /* | |
846 | /************************************************************************/ | |
847 | ||
848 | int | |
849 | gdb_transfer_from_buffer(hc) | |
850 | register HALF_CONNECTION hc; | |
851 | { | |
852 | register int count; /* amount to move */ | |
853 | ||
854 | /* | |
855 | * Figure out how much, if any, we'll be able to do here | |
856 | */ | |
857 | count = min(hc->remaining, hc->stream_buffer_remaining); | |
858 | if (count <= 0) | |
859 | return; /* could not satisfy */ | |
860 | /* any from buffered data*/ | |
861 | ||
862 | /* | |
863 | * Copy the data, update both stream and data buffer pointers | |
864 | */ | |
865 | ||
866 | bcopy(hc->stream_buffer_next, hc->next_byte, count); | |
867 | ||
868 | hc->stream_buffer_next += count; | |
869 | hc->stream_buffer_remaining -= count; | |
870 | FIX_BUFFER_POINTERS(hc, count) | |
871 | ||
872 | } | |
873 | ||
874 | \f/************************************************************************/ | |
875 | /* | |
876 | /* gdb_write_data | |
877 | /* | |
878 | /* This routine implements gdb_move_data for an outbound half | |
879 | /* connection. | |
880 | /* | |
881 | /************************************************************************/ | |
882 | ||
883 | int | |
884 | gdb_write_data(hc) | |
885 | struct half_con_data *hc; /* pointer to control struct */ | |
886 | /* for this half connection */ | |
887 | { | |
888 | register HALF_CONNECTION half_con = hc; | |
889 | /* half connection pointer */ | |
890 | /* fast copy in register */ | |
891 | register int count; /* number of bytes read */ | |
892 | /* or written in latest */ | |
893 | /* attempt */ | |
894 | fd_set *fdbits; /* the mask we should adjust */ | |
895 | /* for this direction */ | |
896 | fd_set tst_bits; /* these are used for */ | |
897 | /* the select we do prior */ | |
898 | /* to reading which tells */ | |
899 | /* us whether 0 byte read */ | |
900 | /* means empty or closed */ | |
901 | int selected; /* TRUE iff select says */ | |
902 | /* we should be able to */ | |
903 | /* progress */ | |
904 | ||
905 | /* | |
906 | * Loop writing to the socket until it claims that no more | |
907 | * progress can be made. Note that some versions of Unix report | |
908 | * socket failure by select = 1, write count = 0. To avoid | |
909 | * extra selects, we try the write first, and only do the select/write | |
910 | * sequence if write seems not to be progressing. | |
911 | */ | |
912 | FD_ZERO(&tst_bits); | |
913 | while(half_con->remaining>0) { | |
914 | count = write(half_con->fd, half_con->next_byte, | |
915 | (int)min(half_con->remaining, | |
916 | GDB_MAX_SOCK_WRITE)); | |
917 | if (count == 0) { | |
918 | FD_SET(half_con->fd,&tst_bits); | |
919 | selected = select(gdb_mfd, | |
920 | (fd_set *)NULL, &tst_bits, | |
921 | (fd_set *)NULL, | |
922 | &gdb_notime); | |
923 | if (selected == (-1)) { | |
924 | gdb_conok = FALSE; | |
925 | break; | |
926 | } | |
927 | if (selected == 0) { | |
928 | count =0; | |
929 | break; | |
930 | } | |
931 | count = write(half_con->fd, half_con->next_byte, | |
932 | (int)min(half_con->remaining, | |
933 | GDB_MAX_SOCK_WRITE)); | |
934 | if (count==0) { | |
935 | if (selected == 1) | |
936 | gdb_conok = FALSE; | |
937 | break; /* no more data available now*/ | |
938 | } | |
939 | } | |
940 | /* | |
941 | * Count is != 0 | |
942 | */ | |
943 | if (count<0) { | |
944 | count = 0; | |
945 | if (errno != EWOULDBLOCK) { | |
946 | gdb_conok = FALSE; /* tell callers */ | |
947 | /* that con has */ | |
948 | /* died */ | |
949 | } | |
950 | break; | |
951 | } | |
952 | ||
953 | half_con->flags |= HCON_PROGRESS; | |
954 | FIX_BUFFER_POINTERS(half_con, count) | |
955 | } | |
956 | /* | |
957 | * The file descriptor masks used for doing selects must be activated | |
958 | * when and only when there is a pending operation trying to use | |
959 | * the connection. Update the masks for this half connection. | |
960 | */ | |
961 | fdbits = &gdb_cwfds; | |
962 | if (half_con->remaining >0 && gdb_conok) | |
963 | FD_SET(half_con->fd, fdbits); | |
964 | else | |
965 | FD_CLR(half_con->fd, fdbits); | |
966 | ||
967 | return; | |
968 | } | |
969 | \f | |
970 | /************************************************************************/ | |
971 | /* | |
972 | /* | |
973 | /* gdb_read_data_and_buffer | |
974 | /* | |
975 | /* This routine is called only when the half_connection stream | |
976 | /* buffer is known to be empty and the "next-byte" buffer | |
977 | /* has more to be filled in. We try in one read to finish | |
978 | /* off the user's request and at the same time fill the stream | |
979 | /* buffer for later. | |
980 | /* | |
981 | /* We assume here that all fd's are set to non-blocking I/O, so | |
982 | /* we can safely try reading and writing until they return 0 bytes. | |
983 | /* | |
984 | /************************************************************************/ | |
985 | ||
986 | int | |
987 | gdb_read_data_and_buffer(hc) | |
988 | struct half_con_data *hc; /* pointer to control struct */ | |
989 | /* for this half connection */ | |
990 | { | |
991 | register HALF_CONNECTION half_con = hc; | |
992 | /* half connection pointer */ | |
993 | /* fast copy in register */ | |
994 | register int count; /* number of bytes read */ | |
995 | /* or written in latest */ | |
996 | /* attempt */ | |
997 | fd_set *fdbits; /* the mask we should adjust */ | |
998 | /* for this direction */ | |
999 | struct iovec iov[2]; /* we use this to hold */ | |
1000 | /* pointers to (1) the */ | |
1001 | /* actual user data buffer */ | |
1002 | /* and (2) the pipe length */ | |
1003 | /* pre-read buffer */ | |
1004 | int fix_amount; /* amount to adjust */ | |
1005 | /* half_con->remaining*/ | |
1006 | ||
1007 | /*----------------------------------------------------------*/ | |
1008 | /* | |
1009 | /* Mark the stream buffer as empty, in case we don't | |
1010 | /* get around to filling it. | |
1011 | /* | |
1012 | /*----------------------------------------------------------*/ | |
1013 | ||
1014 | half_con -> stream_buffer_next = half_con -> stream_buffer; | |
1015 | half_con -> stream_buffer_remaining = 0; | |
1016 | ||
1017 | /*----------------------------------------------------------*/ | |
1018 | /* | |
1019 | /* Loop trying to read data from the socket. We scatter | |
1020 | /* first into the user's buffer directly, then into | |
1021 | /* the stream buffer (which helps us save system | |
1022 | /* calls next time around.) We stop either when: | |
1023 | /* socket reports error/no progress or user's buffer is | |
1024 | /* full. | |
1025 | /* | |
1026 | /*----------------------------------------------------------*/ | |
1027 | ||
1028 | /* | |
1029 | * Loop until either (1) the connection reported that it could | |
1030 | * not progress any further or (2) the full count has been | |
1031 | * satisfied. Some versions of Unix observe the rule that | |
1032 | * a closed connection, especially when reading, is indicated | |
1033 | * by returning a count of 0 on read when select claims that progress | |
1034 | * can be made. We used to handle this case. Bill Sommerfeld | |
1035 | * has introduced a performance change which leaves that checking | |
1036 | * out in the latest version. To add it back, then ONLY in | |
1037 | * the case where read returned 0, do a select followed by another | |
1038 | * read (the order is important). If we ever run on a system that | |
1039 | * works in this way, we may hang at close time. | |
1040 | */ | |
1041 | ||
1042 | while(half_con->remaining>0) { | |
1043 | /* | |
1044 | * First we try a read, and if it works, we believe it | |
1045 | */ | |
1046 | iov[0].iov_base = half_con -> next_byte; | |
1047 | iov[0].iov_len = half_con -> remaining; | |
1048 | iov[1].iov_base = half_con -> stream_buffer; | |
1049 | iov[1].iov_len = half_con -> stream_buffer_length; | |
1050 | count = readv(half_con->fd, iov, 2); | |
1051 | ||
1052 | if (count<0) { | |
1053 | count = 0; | |
1054 | if (errno != EWOULDBLOCK) | |
1055 | gdb_conok = FALSE; /* tell callers that */ | |
1056 | /* con has died */ | |
1057 | break; | |
1058 | ||
1059 | } | |
1060 | if (count == 0) {/* We hit EOF */ | |
1061 | gdb_conok = FALSE; | |
1062 | break; | |
1063 | } | |
1064 | ||
1065 | /* | |
1066 | * Count is >0, we moved some data. Note, setting of | |
1067 | * stream_buffer_remaining can only be non-zero on last | |
1068 | * time through the loop, because that will be when | |
1069 | * half_con->remaining goes to zero. | |
1070 | */ | |
1071 | half_con->flags |= HCON_PROGRESS; | |
1072 | half_con->stream_buffer_remaining=max(0, count-iov[0].iov_len); | |
1073 | fix_amount = min(count,half_con->remaining); | |
1074 | FIX_BUFFER_POINTERS(half_con, fix_amount); | |
1075 | } | |
1076 | ||
1077 | /* | |
1078 | * The file descriptor masks used for doing selects must be activated | |
1079 | * when and only when there is a pending operation trying to use | |
1080 | * the connection. Update the masks for this half connection. | |
1081 | */ | |
1082 | fdbits = &gdb_crfds; | |
1083 | if (half_con->remaining >0) | |
1084 | FD_SET(half_con->fd, fdbits); | |
1085 | else | |
1086 | FD_CLR(half_con->fd, fdbits); | |
1087 | ||
1088 | return ; | |
1089 | } | |
1090 | \f | |
1091 | /************************************************************************/ | |
1092 | /* | |
1093 | /* gdb_receive_data (gdb_receive_data) | |
1094 | /* | |
1095 | /* This routine is called by an init or continuation routine to | |
1096 | /* request that a specified amount of data be read, without | |
1097 | /* blocking, on the supplied connection. This routine returns | |
1098 | /* OP_COMPLETE if the entire read completed synchronously, | |
1099 | /* or OP_RUNNING if the read remains ongoing or is cancelling | |
1100 | /* due to error on the socket. | |
1101 | /* | |
1102 | /************************************************************************/ | |
1103 | ||
1104 | int | |
1105 | gdb_receive_data(half_con, ptr, len) | |
1106 | HALF_CONNECTION half_con; /* read on this connection*/ | |
1107 | char *ptr; /* put first byte here */ | |
1108 | int len; /* number of bytes to read */ | |
1109 | { | |
1110 | /* | |
1111 | * Fill in the initial state of the attempted receive | |
1112 | */ | |
1113 | half_con->remaining = len; | |
1114 | half_con->next_byte = ptr; | |
1115 | ||
1116 | /* | |
1117 | * Now see if we can make some progress on this read, possibly | |
1118 | * even completing it synchronously. Return appropriate | |
1119 | * result to our caller. Note: errors are reflected as OP_RUNNING | |
1120 | * with global variable gdb_cnok set to FALSE. | |
1121 | */ | |
1122 | if(gdb_move_data(CON_INPUT, half_con)) | |
1123 | return OP_COMPLETE; | |
1124 | else | |
1125 | return OP_RUNNING; | |
1126 | } | |
1127 | ||
1128 | /************************************************************************/ | |
1129 | /* | |
1130 | /* gdb_send_data (gdb_send_data) | |
1131 | /* | |
1132 | /* This routine is called by an init or continuation routine to | |
1133 | /* request that a specified amount of data be written, without | |
1134 | /* blocking, on the supplied connection. This routine returns | |
1135 | /* OP_COMPLETE if the entire write completed synchronously, | |
1136 | /* or OP_RUNNING if the output remains ongoing or there was an error. | |
1137 | /* | |
1138 | /************************************************************************/ | |
1139 | ||
1140 | int | |
1141 | gdb_send_data(half_con, ptr, len) | |
1142 | HALF_CONNECTION half_con; /* write on this connection*/ | |
1143 | char *ptr; /* put first byte here */ | |
1144 | int len; /* number of bytes to read */ | |
1145 | { | |
1146 | ||
1147 | /* | |
1148 | * Fill in the initial state of the attempted receive | |
1149 | */ | |
1150 | half_con->remaining = len; | |
1151 | half_con->next_byte = ptr; | |
1152 | ||
1153 | /* | |
1154 | * Now see if we can make some progress on this read, possibly | |
1155 | * even completing it synchronously. Return appropriate | |
1156 | * result to our caller. | |
1157 | */ | |
1158 | if(gdb_move_data(CON_OUTPUT, half_con)) | |
1159 | return OP_COMPLETE; | |
1160 | else | |
1161 | return OP_RUNNING; | |
1162 | } | |
1163 | ||
1164 | /************************************************************************/ | |
1165 | /* | |
1166 | /* gdb_start_a_listen | |
1167 | /* | |
1168 | /* This routine is called by an init or continuation routine to | |
1169 | /* request that a connection be done. This routine returns | |
1170 | /* OP_COMPLETE if the accept completed synchronously, | |
1171 | /* or OP_RUNNING if the output remains ongoing or there was an error. | |
1172 | /* | |
1173 | /************************************************************************/ | |
1174 | ||
1175 | int | |
1176 | gdb_start_a_listen(half_con, otherside, lenp, fdp) | |
1177 | HALF_CONNECTION half_con; /* write on this connection*/ | |
1178 | char *otherside; /* put first byte here */ | |
1179 | int *lenp; /* number of bytes to read */ | |
1180 | int *fdp; | |
1181 | { | |
1182 | ||
1183 | /* | |
1184 | * Fill in the initial state of the attempted accept | |
1185 | */ | |
1186 | half_con->accepted_len = lenp; | |
1187 | half_con->next_byte = otherside; | |
1188 | half_con->accepted_fdp = fdp; | |
1189 | ||
1190 | /* | |
1191 | * Now see if we can make some progress on this read, possibly | |
1192 | * even completing it synchronously. Return appropriate | |
1193 | * result to our caller. | |
1194 | */ | |
1195 | if(gdb_listen(half_con)) | |
1196 | return OP_COMPLETE; | |
1197 | else | |
1198 | return OP_RUNNING; | |
1199 | } | |
1200 | \f | |
1201 | /************************************************************************/ | |
1202 | /* | |
1203 | /* gdb_listen (gdb_listen) | |
1204 | /* | |
1205 | /* This routine is called from gdb_start_a_listen or hcon_progress to attempt | |
1206 | /* to continue making progress in accepting a connection on a | |
1207 | /* listening connection. | |
1208 | /* | |
1209 | /************************************************************************/ | |
1210 | ||
1211 | int | |
1212 | gdb_listen(hc) | |
1213 | struct half_con_data *hc; /* pointer to control struct */ | |
1214 | /* for this half connection */ | |
1215 | { | |
1216 | register HALF_CONNECTION half_con = hc; | |
1217 | /* half connection pointer */ | |
1218 | /* fast copy in register */ | |
1219 | ||
1220 | GDB_INIT_CHECK | |
1221 | ||
1222 | half_con->flags &= ~HCON_PENDING_LISTEN;/* in case we succeed */ | |
1223 | ||
1224 | /* | |
1225 | * The first implementatin of this used to do a select to make sure | |
1226 | * that the accept would not block. Bill Sommerfeld has changed this | |
1227 | * to non-blocking I/O, so the following code is commented out. | |
1228 | */ | |
1229 | #ifdef notdef | |
1230 | FD_ZERO(&tst_bits); | |
1231 | FD_SET(half_con->fd,&tst_bits); | |
1232 | selected = select(gdb_mfd,&tst_bits, (fd_set *)NULL, (fd_set *)NULL, | |
1233 | &gdb_notime); | |
1234 | /* | |
1235 | * If selected==(-1), then we know there's something | |
1236 | * wrong with the socket | |
1237 | */ | |
1238 | if (selected == (-1)) { | |
1239 | gdb_conok = FALSE; | |
1240 | return FALSE; | |
1241 | } | |
1242 | /* | |
1243 | * if selected==0, then we know accept won't do anything, so | |
1244 | * don't try. | |
1245 | */ | |
1246 | if (selected == 0) { | |
1247 | half_con->flags |= HCON_PENDING_LISTEN; | |
1248 | FD_SET(half_con->fd, &gdb_crfds); /* we'll be looking for */ | |
1249 | /* this whenever we select*/ | |
1250 | return FALSE; | |
1251 | } | |
1252 | /* | |
1253 | * Selected is >0. The accept SHOULD not hang. | |
1254 | */ | |
1255 | #endif notdef | |
1256 | ||
1257 | /* | |
1258 | * Here is Bill's non-blocking implementation | |
1259 | */ | |
1260 | *(half_con->accepted_fdp) = accept(half_con->fd, | |
1261 | (struct sockaddr *)half_con->next_byte, | |
1262 | half_con->accepted_len); | |
1263 | /* | |
1264 | * See whether the accept succeeded | |
1265 | */ | |
1266 | if (*(half_con->accepted_fdp) < 0) { | |
1267 | if (errno != EWOULDBLOCK) { | |
1268 | gdb_conok = FALSE; /* error will be returned */ | |
1269 | /* in shut-down listening con*/ | |
1270 | } | |
1271 | half_con->flags |= HCON_PENDING_LISTEN; | |
1272 | FD_SET(half_con->fd, &gdb_crfds); | |
1273 | return FALSE; | |
1274 | } | |
1275 | ||
1276 | FD_CLR(half_con->fd, &gdb_crfds); /* don't select on this */ | |
1277 | return TRUE; | |
1278 | } |