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root/radiance/ray/src/rt/raypcalls.c
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Comparing ray/src/rt/raypcalls.c (file contents):
Revision 2.6 by schorsch, Tue Mar 30 16:13:01 2004 UTC vs.
Revision 2.22 by greg, Sat Dec 12 05:20:10 2009 UTC

# Line 13 | Line 13 | static const char      RCSid[] = "$Id$";
13   *  These calls are designed similarly to the ones in raycalls.c,
14   *  but allow for multiple rendering processes on the same host
15   *  machine.  There is no sense in specifying more child processes
16 < *  than you have processors, but one child may help by allowing
16 > *  than you have processor cores, but one child may help by allowing
17   *  asynchronous ray computation in an interactive program, and
18   *  will protect the caller from fatal rendering errors.
19   *
20 < *  You should first read and undrstand the header in raycalls.c,
20 > *  You should first read and understand the header in raycalls.c,
21   *  as some things are explained there that are not repated here.
22   *
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
30 > *  between processes.  Rays are 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 > *  during evaluation.  Rays are not returned in the order
36 > *  they are sent when multiple processes are open.
37 > *
38 > *  Rays are queued and returned by a single
39   *  ray_pqueue() call.  A ray_pqueue() return
40   *  value of 0 indicates that no rays are ready
41   *  and the queue is not yet full.  A return value of 1
# Line 43 | Line 48 | static const char      RCSid[] = "$Id$";
48   *      myRay.rorg = ( ray origin point )
49   *      myRay.rdir = ( normalized ray direction )
50   *      myRay.rmax = ( maximum length, or zero for no limit )
51 < *      rayorigin(&myRay, NULL, PRIMARY, 1.0);
51 > *      rayorigin(&myRay, PRIMARY, NULL, NULL);
52   *      myRay.rno = ( my personal ray identifier )
53   *      if (ray_pqueue(&myRay) == 1)
54   *              { do something with results }
# Line 51 | Line 56 | static const char      RCSid[] = "$Id$";
56   *  Note the differences between this and the simpler ray_trace()
57   *  call.  In particular, the call may or may not return a value
58   *  in the passed ray structure.  Also, you need to call rayorigin()
59 < *  yourself, which is normally for you by ray_trace().  The
60 < *  great thing is that ray_pqueue() will trace rays faster in
59 > *  yourself, which is normally called for you by ray_trace().  The
60 > *  benefit is that ray_pqueue() will trace rays faster in
61   *  proportion to the number of CPUs you have available on your
62   *  system.  If the ray queue is full before the call, ray_pqueue()
63   *  will block until a result is ready so it can queue this one.
# Line 70 | Line 75 | static const char      RCSid[] = "$Id$";
75   *  until a value is available, returning 0 only if the
76   *  queue is completely empty.  A negative return value
77   *  indicates that a rendering process died.  If this
78 < *  happens, ray_close(0) is automatically called to close
78 > *  happens, ray_pclose(0) is automatically called to close
79   *  all child processes, and ray_pnprocs is set to zero.
80   *
81   *  If you just want to fill the ray queue without checking for
# Line 81 | Line 86 | static const char      RCSid[] = "$Id$";
86   *              ray_psend(&myRay);
87   *      }
88   *
89 < *  The ray_presult() and/or ray_pqueue() functions may then be
90 < *  called to read back the results.
89 > *  Note that it is a fatal error to call ra_psend() when
90 > *  ray_pnidle is zero.  The ray_presult() and/or ray_pqueue()
91 > *  functions may be called subsequently to read back the results.
92   *
93   *  When you are done, you may call ray_pdone(1) to close
94   *  all child processes and clean up memory used by Radiance.
95   *  Any queued ray calculations will be awaited and discarded.
96   *  As with ray_done(), ray_pdone(0) hangs onto data files
97   *  and fonts that are likely to be used in subsequent renderings.
98 < *  Whether you want to bother cleaning up memory or not, you
99 < *  should at least call ray_pclose(0) to clean the child processes.
98 > *  Whether you need to clean up memory or not, you should
99 > *  at least call ray_pclose(0) to await the child processes.
100   *
101   *  Warning:  You cannot affect any of the rendering processes
102   *  by changing global parameter values onece ray_pinit() has
# Line 99 | Line 105 | static const char      RCSid[] = "$Id$";
105   *  If you just want to reap children so that you can alter the
106   *  rendering parameters without reloading the scene, use the
107   *  ray_pclose(0) and ray_popen(nproc) calls to close
108 < *  then restart the child processes.
108 > *  then restart the child processes after the changes are made.
109   *
110   *  Note:  These routines are written to coordinate with the
111   *  definitions in raycalls.c, and in fact depend on them.
112   *  If you want to trace a ray and get a result synchronously,
113   *  use the ray_trace() call to compute it in the parent process.
114 + *  This will not interfere with any subprocess calculations,
115 + *  but beware that a fatal error may end with a call to quit().
116   *
117   *  Note:  One of the advantages of using separate processes
118   *  is that it gives the calling program some immunity from
119   *  fatal rendering errors.  As discussed in raycalls.c,
120   *  Radiance tends to throw up its hands and exit at the
121   *  first sign of trouble, calling quit() to return control
122 < *  to the system.  Although you can avoid exit() with
122 > *  to the top level.  Although you can avoid exit() with
123   *  your own longjmp() in quit(), the cleanup afterwards
124   *  is always suspect.  Through the use of subprocesses,
125   *  we avoid this pitfall by closing the processes and
126   *  returning a negative value from ray_pqueue() or
127   *  ray_presult().  If you get a negative value from either
128   *  of these calls, you can assume that the processes have
129 < *  been cleaned up with a call to ray_close(), though you
129 > *  been cleaned up with a call to ray_pclose(), though you
130   *  will have to call ray_pdone() yourself if you want to
131 < *  free memory.  Obviously, you cannot continue rendering,
132 < *  but otherwise your process should not be compromised.
131 > *  free memory.  Obviously, you cannot continue rendering
132 > *  without risking further errors, but otherwise your
133 > *  process should not be compromised.
134   */
135  
127 #include <stdio.h>
128 #include <sys/types.h>
129 #include <sys/wait.h> /* XXX platform */
130
136   #include  "rtprocess.h"
137   #include  "ray.h"
138   #include  "ambient.h"
139 + #include  <sys/types.h>
140 + #include  <sys/wait.h>
141   #include  "selcall.h"
142  
143   #ifndef RAYQLEN
144 < #define RAYQLEN         16              /* # rays to send at once */
144 > #define RAYQLEN         12              /* # rays to send at once */
145   #endif
146  
147   #ifndef MAX_RPROCS
# Line 155 | Line 162 | static struct child_proc {
162          int     fd_send;                        /* write to child here */
163          int     fd_recv;                        /* read from child here */
164          int     npending;                       /* # rays in process */
165 <        unsigned long  rno[RAYQLEN];            /* working on these rays */
165 >        RNUMBER rno[RAYQLEN];                   /* working on these rays */
166   } r_proc[MAX_NPROCS];                   /* our child processes */
167  
168   static RAY      r_queue[2*RAYQLEN];     /* ray i/o buffer */
169   static int      r_send_next;            /* next send ray placement */
170   static int      r_recv_first;           /* position of first unreported ray */
171 < static int      r_recv_next;            /* next receive ray placement */
171 > static int      r_recv_next;            /* next received ray placement */
172  
173   #define sendq_full()    (r_send_next >= RAYQLEN)
174  
175   static int ray_pflush(void);
176 < static void ray_pchild(int      fd_in, int      fd_out);
176 > static void ray_pchild(int fd_in, int fd_out);
177  
178  
179 < extern void
179 > void
180   ray_pinit(              /* initialize ray-tracing processes */
181          char    *otnm,
182          int     nproc
# Line 180 | Line 187 | ray_pinit(             /* initialize ray-tracing processes */
187  
188          ray_init(otnm);                 /* load the shared scene */
189  
183        preload_objs();                 /* preload auxiliary data */
184
185                                        /* set shared memory boundary */
186        shm_boundary = (char *)malloc(16);
187        strcpy(shm_boundary, "SHM_BOUNDARY");
188
190          r_send_next = 0;                /* set up queue */
191          r_recv_first = r_recv_next = RAYQLEN;
192  
# Line 228 | Line 229 | ray_pflush(void)                       /* send queued rays to idle childre
229   }
230  
231  
232 < extern void
232 > void
233   ray_psend(                      /* add a ray to our send queue */
234          RAY     *r
235   )
# Line 239 | Line 240 | ray_psend(                     /* add a ray to our send queue */
240          if (sendq_full() && ray_pflush() <= 0)
241                  error(INTERNAL, "ray_pflush failed in ray_psend");
242  
243 <        r_queue[r_send_next] = *r;
243 <        r_send_next++;
243 >        r_queue[r_send_next++] = *r;
244   }
245  
246  
247 < extern int
247 > int
248   ray_pqueue(                     /* queue a ray for computation */
249          RAY     *r
250   )
# Line 253 | Line 253 | ray_pqueue(                    /* queue a ray for computation */
253                  return(0);
254                                          /* check for full send queue */
255          if (sendq_full()) {
256 <                RAY     mySend;
257 <                int     rval;
258 <                mySend = *r;
256 >                RAY     mySend = *r;
257                                          /* wait for a result */
258 <                rval = ray_presult(r, 0);
258 >                if (ray_presult(r, 0) <= 0)
259 >                        return(-1);
260                                          /* put new ray in queue */
261 <                r_queue[r_send_next] = mySend;
262 <                r_send_next++;
263 <                return(rval);           /* done */
261 >                r_queue[r_send_next++] = mySend;
262 >                                /* XXX r_send_next may now be > RAYQLEN */
263 >                return(1);
264          }
265 <                                        /* add ray to send queue */
266 <        r_queue[r_send_next] = *r;
268 <        r_send_next++;
265 >                                        /* else add ray to send queue */
266 >        r_queue[r_send_next++] = *r;
267                                          /* check for returned ray... */
268          if (r_recv_first >= r_recv_next)
269                  return(0);
270                                          /* ...one is sitting in queue */
271 <        *r = r_queue[r_recv_first];
274 <        r_recv_first++;
271 >        *r = r_queue[r_recv_first++];
272          return(1);
273   }
274  
275  
276 < extern int
276 > int
277   ray_presult(            /* check for a completed ray */
278          RAY     *r,
279          int     poll
# Line 291 | Line 288 | ray_presult(           /* check for a completed ray */
288                  return(0);
289                                          /* check queued results first */
290          if (r_recv_first < r_recv_next) {
291 <                *r = r_queue[r_recv_first];
295 <                r_recv_first++;
291 >                *r = r_queue[r_recv_first++];
292                  return(1);
293          }
294          n = ray_pnprocs - ray_pnidle;   /* pending before flush? */
# Line 306 | Line 302 | ray_presult(           /* check for a completed ray */
302                  n = ray_pnprocs - ray_pnidle;
303          if (n <= 0)                     /* return if nothing to await */
304                  return(0);
305 +        if (!poll && ray_pnprocs == 1)  /* one process -> skip select() */
306 +                FD_SET(r_proc[0].fd_recv, &readset);
307 +
308   getready:                               /* any children waiting for us? */
309          for (pn = ray_pnprocs; pn--; )
310                  if (FD_ISSET(r_proc[pn].fd_recv, &readset) ||
311                                  FD_ISSET(r_proc[pn].fd_recv, &errset))
312                          break;
313 <                                        /* call select if we must */
313 >                                        /* call select() if we must */
314          if (pn < 0) {
315                  FD_ZERO(&readset); FD_ZERO(&errset); n = 0;
316                  for (pn = ray_pnprocs; pn--; ) {
# Line 366 | Line 365 | getready:                              /* any children waiting for us? */
365                  rp->slights = NULL;
366          }
367                                          /* return first ray received */
368 <        *r = r_queue[r_recv_first];
370 <        r_recv_first++;
368 >        *r = r_queue[r_recv_first++];
369          return(1);
370   }
371  
372  
373 < extern void
373 > void
374   ray_pdone(              /* reap children and free data */
375          int     freall
376   )
# Line 395 | Line 393 | ray_pchild(    /* process rays (never returns) */
393   {
394          int     n;
395          register int    i;
396 +                                        /* flag child process for quit() */
397 +        ray_pnprocs = -1;
398                                          /* read each ray request set */
399          while ((n = read(fd_in, (char *)r_queue, sizeof(r_queue))) > 0) {
400                  int     n2;
401 <                if (n % sizeof(RAY))
401 >                if (n < sizeof(RAY))
402                          break;
403                n /= sizeof(RAY);
403                                          /* get smuggled set length */
404 <                n2 = r_queue[0].crtype - n;
404 >                n2 = sizeof(RAY)*r_queue[0].crtype - n;
405                  if (n2 < 0)
406                          error(INTERNAL, "buffer over-read in ray_pchild");
407                  if (n2 > 0) {           /* read the rest of the set */
408 <                        i = readbuf(fd_in, (char *)(r_queue+n),
409 <                                        sizeof(RAY)*n2);
411 <                        if (i != sizeof(RAY)*n2)
408 >                        i = readbuf(fd_in, (char *)r_queue + n, n2);
409 >                        if (i != n2)
410                                  break;
411                          n += n2;
412                  }
413 +                n /= sizeof(RAY);
414                                          /* evaluate rays */
415                  for (i = 0; i < n; i++) {
416                          r_queue[i].crtype = r_queue[i].rtype;
417                          r_queue[i].parent = NULL;
418                          r_queue[i].clipset = NULL;
419                          r_queue[i].slights = NULL;
420 <                        r_queue[i].revf = raytrace;
420 >                        r_queue[i].rlvl = 0;
421                          samplendx++;
422                          rayclear(&r_queue[i]);
423                          rayvalue(&r_queue[i]);
# Line 435 | Line 434 | ray_pchild(    /* process rays (never returns) */
434   }
435  
436  
437 < extern void
437 > void
438   ray_popen(                      /* open the specified # processes */
439          int     nadd
440   )
# Line 445 | Line 444 | ray_popen(                     /* open the specified # processes */
444                  nadd = MAX_NPROCS - ray_pnprocs;
445          if (nadd <= 0)
446                  return;
447 <        fflush(stderr);                 /* clear pending output */
448 <        fflush(stdout);
447 >        ambsync();                      /* load any new ambient values */
448 >        if (shm_boundary == NULL) {     /* first child process? */
449 >                preload_objs();         /* preload auxiliary data */
450 >                                        /* set shared memory boundary */
451 >                shm_boundary = (char *)malloc(16);
452 >                strcpy(shm_boundary, "SHM_BOUNDARY");
453 >        }
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)
# Line 464 | Line 469 | ray_popen(                     /* open the specified # processes */
469                  if (r_proc[ray_pnprocs].pid < 0)
470                          error(SYSTEM, "cannot fork child process");
471                  close(p1[0]); close(p0[1]);
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;
# Line 473 | Line 484 | ray_popen(                     /* open the specified # processes */
484   }
485  
486  
487 < extern void
487 > void
488   ray_pclose(             /* close one or more child processes */
489          int     nsub
490   )
# Line 496 | Line 507 | ray_pclose(            /* close one or more child processes */
507                  ray_pnprocs--;
508                  close(r_proc[ray_pnprocs].fd_recv);
509                  close(r_proc[ray_pnprocs].fd_send);
510 <                while (wait(&status) != r_proc[ray_pnprocs].pid)
511 <                        ;
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",
# Line 514 | 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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