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root/radiance/ray/src/rt/raypcalls.c
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Comparing ray/src/rt/raypcalls.c (file contents):
Revision 2.2 by greg, Tue Feb 25 02:47:23 2003 UTC vs.
Revision 2.18 by greg, Fri Feb 8 18:27:31 2008 UTC

# Line 23 | Line 23 | static const char      RCSid[] = "$Id$";
23   *  The first step is opening one or more rendering processes
24   *  with a call to ray_pinit(oct, nproc).  Before calling fork(),
25   *  ray_pinit() loads the octree and data structures into the
26 < *  caller's memory.  This permits all sorts of queries that
27 < *  wouldn't be possible otherwise, without causing any real
26 > *  caller's memory, and ray_popen() synchronizes the ambient
27 > *  file, if any.  Shared memory permits all sorts of queries
28 > *  that wouldn't be possible otherwise, without causing any real
29   *  memory overhead, since all the static data are shared
30   *  between processes.  Rays are then traced using a simple
31   *  queuing mechanism, explained below.
32   *
33 < *  The ray queue holds as many rays as there are rendering
34 < *  processes.  Rays are queued and returned by a single
33 > *  The ray queue buffers RAYQLEN rays before sending to
34 > *  children, each of which may internally buffer RAYQLEN rays.
35 > *
36 > *  Rays are queued and returned by a single
37   *  ray_pqueue() call.  A ray_pqueue() return
38   *  value of 0 indicates that no rays are ready
39   *  and the queue is not yet full.  A return value of 1
# Line 43 | Line 46 | static const char      RCSid[] = "$Id$";
46   *      myRay.rorg = ( ray origin point )
47   *      myRay.rdir = ( normalized ray direction )
48   *      myRay.rmax = ( maximum length, or zero for no limit )
49 < *      rayorigin(&myRay, NULL, PRIMARY, 1.0);
49 > *      rayorigin(&myRay, PRIMARY, NULL, NULL);
50   *      myRay.rno = ( my personal ray identifier )
51   *      if (ray_pqueue(&myRay) == 1)
52   *              { do something with results }
# Line 51 | Line 54 | static const char      RCSid[] = "$Id$";
54   *  Note the differences between this and the simpler ray_trace()
55   *  call.  In particular, the call may or may not return a value
56   *  in the passed ray structure.  Also, you need to call rayorigin()
57 < *  yourself, which is normally for you by ray_trace().  The
58 < *  great thing is that ray_pqueue() will trace rays faster in
57 > *  yourself, which is normally called for you by ray_trace().  The
58 > *  benefit is that ray_pqueue() will trace rays faster in
59   *  proportion to the number of CPUs you have available on your
60   *  system.  If the ray queue is full before the call, ray_pqueue()
61   *  will block until a result is ready so it can queue this one.
62 < *  The global int ray_idle indicates the number of currently idle
62 > *  The global int ray_pnidle indicates the number of currently idle
63   *  children.  If you want to check for completed rays without blocking,
64   *  or get the results from rays that have been queued without
65   *  queuing any new ones, the ray_presult() call is for you:
# Line 71 | Line 74 | static const char      RCSid[] = "$Id$";
74   *  queue is completely empty.  A negative return value
75   *  indicates that a rendering process died.  If this
76   *  happens, ray_close(0) is automatically called to close
77 < *  all child processes, and ray_nprocs is set to zero.
77 > *  all child processes, and ray_pnprocs is set to zero.
78   *
79   *  If you just want to fill the ray queue without checking for
80 < *  results, check ray_idle and call ray_psend():
80 > *  results, check ray_pnidle and call ray_psend():
81   *
82 < *      while (ray_idle) {
82 > *      while (ray_pnidle) {
83   *              ( set up ray )
84   *              ray_psend(&myRay);
85   *      }
86   *
87 < *  The ray_presult() and/or ray_pqueue() functions may then be
88 < *  called to read back the results.
87 > *  Note that it is a fatal error to call ra_psend() when
88 > *  ray_pnidle is zero.  The ray_presult() and/or ray_pqueue()
89 > *  functions may be called subsequently to read back the results.
90   *
91   *  When you are done, you may call ray_pdone(1) to close
92   *  all child processes and clean up memory used by Radiance.
# Line 99 | Line 103 | static const char      RCSid[] = "$Id$";
103   *  If you just want to reap children so that you can alter the
104   *  rendering parameters without reloading the scene, use the
105   *  ray_pclose(0) and ray_popen(nproc) calls to close
106 < *  then restart the child processes.
106 > *  then restart the child processes after the changes are made.
107   *
108   *  Note:  These routines are written to coordinate with the
109   *  definitions in raycalls.c, and in fact depend on them.
110   *  If you want to trace a ray and get a result synchronously,
111   *  use the ray_trace() call to compute it in the parent process.
112 + *  This will not interfere with any subprocess calculations,
113 + *  but beware that a fatal error may end with a call to quit().
114   *
115   *  Note:  One of the advantages of using separate processes
116   *  is that it gives the calling program some immunity from
117   *  fatal rendering errors.  As discussed in raycalls.c,
118   *  Radiance tends to throw up its hands and exit at the
119   *  first sign of trouble, calling quit() to return control
120 < *  to the system.  Although you can avoid exit() with
120 > *  to the top level.  Although you can avoid exit() with
121   *  your own longjmp() in quit(), the cleanup afterwards
122   *  is always suspect.  Through the use of subprocesses,
123   *  we avoid this pitfall by closing the processes and
# Line 120 | Line 126 | static const char      RCSid[] = "$Id$";
126   *  of these calls, you can assume that the processes have
127   *  been cleaned up with a call to ray_close(), though you
128   *  will have to call ray_pdone() yourself if you want to
129 < *  free memory.  Obviously, you cannot continue rendering,
130 < *  but otherwise your process should not be compromised.
129 > *  free memory.  Obviously, you cannot continue rendering
130 > *  without risking further errors, but otherwise your
131 > *  process should not be compromised.
132   */
133  
134 + #include  "rtprocess.h"
135   #include  "ray.h"
136 <
136 > #include  "ambient.h"
137 > #include  <sys/types.h>
138 > #include  <sys/wait.h>
139   #include  "selcall.h"
140  
141   #ifndef RAYQLEN
142 < #define RAYQLEN         16              /* # rays to send at once */
142 > #define RAYQLEN         12              /* # rays to send at once */
143   #endif
144  
145   #ifndef MAX_RPROCS
# Line 142 | Line 152 | static const char      RCSid[] = "$Id$";
152  
153   extern char     *shm_boundary;          /* boundary of shared memory */
154  
155 < int             ray_nprocs = 0;         /* number of child processes */
156 < int             ray_idle = 0;           /* number of idle children */
155 > int             ray_pnprocs = 0;        /* number of child processes */
156 > int             ray_pnidle = 0;         /* number of idle children */
157  
158   static struct child_proc {
159          int     pid;                            /* child process id */
# Line 160 | Line 170 | static int     r_recv_next;            /* next receive ray placement
170  
171   #define sendq_full()    (r_send_next >= RAYQLEN)
172  
173 + static int ray_pflush(void);
174 + static void ray_pchild(int fd_in, int fd_out);
175  
176 < void
177 < ray_pinit(otnm, nproc)          /* initialize ray-tracing processes */
178 < char    *otnm;
179 < int     nproc;
176 >
177 > extern void
178 > ray_pinit(              /* initialize ray-tracing processes */
179 >        char    *otnm,
180 >        int     nproc
181 > )
182   {
183          if (nobjects > 0)               /* close old calculation */
184                  ray_pdone(0);
# Line 185 | Line 199 | int    nproc;
199  
200  
201   static int
202 < ray_pflush()                    /* send queued rays to idle children */
202 > ray_pflush(void)                        /* send queued rays to idle children */
203   {
204          int     nc, n, nw, i, sfirst;
205  
206 <        if ((ray_idle <= 0 | r_send_next <= 0))
206 >        if ((ray_pnidle <= 0) | (r_send_next <= 0))
207                  return(0);              /* nothing we can send */
208          
209          sfirst = 0;                     /* divvy up labor */
210 <        nc = ray_idle;
211 <        for (i = ray_nprocs; nc && i--; ) {
210 >        nc = ray_pnidle;
211 >        for (i = ray_pnprocs; nc && i--; ) {
212                  if (r_proc[i].npending > 0)
213                          continue;       /* child looks busy */
214                  n = (r_send_next - sfirst)/nc--;
# Line 210 | Line 224 | ray_pflush()                   /* send queued rays to idle children */
224                  while (n--)             /* record ray IDs */
225                          r_proc[i].rno[n] = r_queue[sfirst+n].rno;
226                  sfirst += r_proc[i].npending;
227 <                ray_idle--;             /* now she's busy */
227 >                ray_pnidle--;           /* now she's busy */
228          }
229          if (sfirst != r_send_next)
230                  error(CONSISTENCY, "code screwup in ray_pflush");
# Line 219 | Line 233 | ray_pflush()                   /* send queued rays to idle children */
233   }
234  
235  
236 < void
237 < ray_psend(r)                    /* add a ray to our send queue */
238 < RAY     *r;
236 > extern void
237 > ray_psend(                      /* add a ray to our send queue */
238 >        RAY     *r
239 > )
240   {
241          if (r == NULL)
242                  return;
# Line 229 | Line 244 | RAY    *r;
244          if (sendq_full() && ray_pflush() <= 0)
245                  error(INTERNAL, "ray_pflush failed in ray_psend");
246  
247 <        copystruct(&r_queue[r_send_next], r);
233 <        r_send_next++;
247 >        r_queue[r_send_next++] = *r;
248   }
249  
250  
251 < int
252 < ray_pqueue(r)                   /* queue a ray for computation */
253 < RAY     *r;
251 > extern int
252 > ray_pqueue(                     /* queue a ray for computation */
253 >        RAY     *r
254 > )
255   {
256          if (r == NULL)
257                  return(0);
# Line 244 | Line 259 | RAY    *r;
259          if (sendq_full()) {
260                  RAY     mySend;
261                  int     rval;
262 <                copystruct(&mySend, r);
262 >                mySend = *r;
263                                          /* wait for a result */
264                  rval = ray_presult(r, 0);
265                                          /* put new ray in queue */
266 <                copystruct(&r_queue[r_send_next], &mySend);
252 <                r_send_next++;
266 >                r_queue[r_send_next++] = mySend;
267                  return(rval);           /* done */
268          }
269 <                                        /* add ray to send queue */
270 <        copystruct(&r_queue[r_send_next], r);
257 <        r_send_next++;
269 >                                        /* else add ray to send queue */
270 >        r_queue[r_send_next++] = *r;
271                                          /* check for returned ray... */
272          if (r_recv_first >= r_recv_next)
273                  return(0);
274                                          /* ...one is sitting in queue */
275 <        copystruct(r, &r_queue[r_recv_first]);
263 <        r_recv_first++;
275 >        *r = r_queue[r_recv_first++];
276          return(1);
277   }
278  
279  
280 < int
281 < ray_presult(r, poll)            /* check for a completed ray */
282 < RAY     *r;
283 < int     poll;
280 > extern int
281 > ray_presult(            /* check for a completed ray */
282 >        RAY     *r,
283 >        int     poll
284 > )
285   {
286          static struct timeval   tpoll;  /* zero timeval struct */
287          static fd_set   readset, errset;
# Line 279 | Line 292 | int    poll;
292                  return(0);
293                                          /* check queued results first */
294          if (r_recv_first < r_recv_next) {
295 <                copystruct(r, &r_queue[r_recv_first]);
296 <                r_recv_first++;
295 >                *r = r_queue[r_recv_first++];
296 >                                        /* make sure send queue has room */
297 >                if (sendq_full() && ray_pflush() <= 0)
298 >                        return(-1);
299                  return(1);
300          }
301 <        n = ray_nprocs - ray_idle;      /* pending before flush? */
301 >        n = ray_pnprocs - ray_pnidle;   /* pending before flush? */
302  
303          if (ray_pflush() < 0)           /* send new rays to process */
304                  return(-1);
# Line 291 | Line 306 | int    poll;
306          r_recv_first = r_recv_next = RAYQLEN;
307  
308          if (!poll)                      /* count newly sent unless polling */
309 <                n = ray_nprocs - ray_idle;
309 >                n = ray_pnprocs - ray_pnidle;
310          if (n <= 0)                     /* return if nothing to await */
311                  return(0);
312 +        if (!poll && ray_pnprocs == 1)  /* one process -> skip select() */
313 +                FD_SET(r_proc[0].fd_recv, &readset);
314 +
315   getready:                               /* any children waiting for us? */
316 <        for (pn = ray_nprocs; pn--; )
316 >        for (pn = ray_pnprocs; pn--; )
317                  if (FD_ISSET(r_proc[pn].fd_recv, &readset) ||
318                                  FD_ISSET(r_proc[pn].fd_recv, &errset))
319                          break;
320                                          /* call select if we must */
321          if (pn < 0) {
322                  FD_ZERO(&readset); FD_ZERO(&errset); n = 0;
323 <                for (pn = ray_nprocs; pn--; ) {
323 >                for (pn = ray_pnprocs; pn--; ) {
324                          if (r_proc[pn].npending > 0)
325                                  FD_SET(r_proc[pn].fd_recv, &readset);
326                          FD_SET(r_proc[pn].fd_recv, &errset);
# Line 338 | Line 356 | getready:                              /* any children waiting for us? */
356          if (n <= 0)
357                  FD_CLR(r_proc[pn].fd_recv, &errset);
358          r_proc[pn].npending = 0;
359 <        ray_idle++;
359 >        ray_pnidle++;
360                                          /* check for rendering errors */
361          if (!ok) {
362                  ray_pclose(0);          /* process died -- clean up */
# Line 354 | Line 372 | getready:                              /* any children waiting for us? */
372                  rp->slights = NULL;
373          }
374                                          /* return first ray received */
375 <        copystruct(r, &r_queue[r_recv_first]);
358 <        r_recv_first++;
375 >        *r = r_queue[r_recv_first++];
376          return(1);
377   }
378  
379  
380 < void
381 < ray_pdone(freall)               /* reap children and free data */
382 < int     freall;
380 > extern void
381 > ray_pdone(              /* reap children and free data */
382 >        int     freall
383 > )
384   {
385          ray_pclose(0);                  /* close child processes */
386  
# Line 375 | Line 393 | int    freall;
393  
394  
395   static void
396 < ray_pchild(fd_in, fd_out)       /* process rays (never returns) */
397 < int     fd_in;
398 < int     fd_out;
396 > ray_pchild(     /* process rays (never returns) */
397 >        int     fd_in,
398 >        int     fd_out
399 > )
400   {
401          int     n;
402          register int    i;
403 +                                        /* flag child process for quit() */
404 +        ray_pnprocs = -1;
405                                          /* read each ray request set */
406          while ((n = read(fd_in, (char *)r_queue, sizeof(r_queue))) > 0) {
407                  int     n2;
408 <                if (n % sizeof(RAY))
408 >                if (n < sizeof(RAY))
409                          break;
389 –                n /= sizeof(RAY);
410                                          /* get smuggled set length */
411 <                n2 = r_queue[0].crtype - n;
411 >                n2 = sizeof(RAY)*r_queue[0].crtype - n;
412                  if (n2 < 0)
413                          error(INTERNAL, "buffer over-read in ray_pchild");
414                  if (n2 > 0) {           /* read the rest of the set */
415 <                        i = readbuf(fd_in, (char *)(r_queue+n),
416 <                                        sizeof(RAY)*n2);
397 <                        if (i != sizeof(RAY)*n2)
415 >                        i = readbuf(fd_in, (char *)r_queue + n, n2);
416 >                        if (i != n2)
417                                  break;
418                          n += n2;
419                  }
420 +                n /= sizeof(RAY);
421                                          /* evaluate rays */
422                  for (i = 0; i < n; i++) {
423                          r_queue[i].crtype = r_queue[i].rtype;
424                          r_queue[i].parent = NULL;
425                          r_queue[i].clipset = NULL;
426                          r_queue[i].slights = NULL;
407 –                        r_queue[i].revf = raytrace;
427                          samplendx++;
428                          rayclear(&r_queue[i]);
429                          rayvalue(&r_queue[i]);
# Line 421 | Line 440 | int    fd_out;
440   }
441  
442  
443 < void
444 < ray_popen(nadd)                 /* open the specified # processes */
445 < int     nadd;
443 > extern void
444 > ray_popen(                      /* open the specified # processes */
445 >        int     nadd
446 > )
447   {
448                                          /* check if our table has room */
449 <        if (ray_nprocs + nadd > MAX_NPROCS)
450 <                nadd = MAX_NPROCS - ray_nprocs;
449 >        if (ray_pnprocs + nadd > MAX_NPROCS)
450 >                nadd = MAX_NPROCS - ray_pnprocs;
451          if (nadd <= 0)
452                  return;
453 <        fflush(stderr);                 /* clear pending output */
454 <        fflush(stdout);
453 >        ambsync();                      /* load any new ambient values */
454 >        fflush(NULL);                   /* clear pending output */
455          while (nadd--) {                /* fork each new process */
456                  int     p0[2], p1[2];
457                  if (pipe(p0) < 0 || pipe(p1) < 0)
458                          error(SYSTEM, "cannot create pipe");
459 <                if ((r_proc[ray_nprocs].pid = fork()) == 0) {
459 >                if ((r_proc[ray_pnprocs].pid = fork()) == 0) {
460                          int     pn;     /* close others' descriptors */
461 <                        for (pn = ray_nprocs; pn--; ) {
461 >                        for (pn = ray_pnprocs; pn--; ) {
462                                  close(r_proc[pn].fd_send);
463                                  close(r_proc[pn].fd_recv);
464                          }
# Line 446 | Line 466 | int    nadd;
466                                          /* following call never returns */
467                          ray_pchild(p1[0], p0[1]);
468                  }
469 <                if (r_proc[ray_nprocs].pid < 0)
469 >                if (r_proc[ray_pnprocs].pid < 0)
470                          error(SYSTEM, "cannot fork child process");
471                  close(p1[0]); close(p0[1]);
472 <                r_proc[ray_nprocs].fd_send = p1[1];
473 <                r_proc[ray_nprocs].fd_recv = p0[0];
474 <                r_proc[ray_nprocs].npending = 0;
475 <                ray_nprocs++;
476 <                ray_idle++;
472 >                /*
473 >                 * Close write stream on exec to avoid multiprocessing deadlock.
474 >                 * No use in read stream without it, so set flag there as well.
475 >                 */
476 >                fcntl(p1[1], F_SETFD, FD_CLOEXEC);
477 >                fcntl(p0[0], F_SETFD, FD_CLOEXEC);
478 >                r_proc[ray_pnprocs].fd_send = p1[1];
479 >                r_proc[ray_pnprocs].fd_recv = p0[0];
480 >                r_proc[ray_pnprocs].npending = 0;
481 >                ray_pnprocs++;
482 >                ray_pnidle++;
483          }
484   }
485  
486  
487 < void
488 < ray_pclose(nsub)                /* close one or more child processes */
489 < int     nsub;
487 > extern void
488 > ray_pclose(             /* close one or more child processes */
489 >        int     nsub
490 > )
491   {
492          static int      inclose = 0;
493          RAY     res;
# Line 469 | Line 496 | int    nsub;
496                  return;
497          inclose++;
498                                          /* check argument */
499 <        if ((nsub <= 0 | nsub > ray_nprocs))
500 <                nsub = ray_nprocs;
499 >        if ((nsub <= 0) | (nsub > ray_pnprocs))
500 >                nsub = ray_pnprocs;
501                                          /* clear our ray queue */
502          while (ray_presult(&res,0) > 0)
503                  ;
504                                          /* clean up children */
505          while (nsub--) {
506                  int     status;
507 <                ray_nprocs--;
508 <                close(r_proc[ray_nprocs].fd_recv);
509 <                close(r_proc[ray_nprocs].fd_send);
510 <                while (wait(&status) != r_proc[ray_nprocs].pid)
511 <                        ;
507 >                ray_pnprocs--;
508 >                close(r_proc[ray_pnprocs].fd_recv);
509 >                close(r_proc[ray_pnprocs].fd_send);
510 >                if (waitpid(r_proc[ray_pnprocs].pid, &status, 0) < 0)
511 >                        status = 127<<8;
512                  if (status) {
513                          sprintf(errmsg,
514                                  "rendering process %d exited with code %d",
515 <                                        r_proc[ray_nprocs].pid, status>>8);
515 >                                        r_proc[ray_pnprocs].pid, status>>8);
516                          error(WARNING, errmsg);
517                  }
518 <                ray_idle--;
518 >                ray_pnidle--;
519          }
520          inclose--;
521   }
# Line 498 | Line 525 | void
525   quit(ec)                        /* make sure exit is called */
526   int     ec;
527   {
528 +        if (ray_pnprocs > 0)    /* close children if any */
529 +                ray_pclose(0);          
530          exit(ec);
531   }

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