src/rt/rc3.c

#ifndef lint
static const char RCSid[] = "$Id: rc3.c,v 2.2 2012/06/09 16:47:27 greg Exp $";
#endif
/*
 * Accumulate ray contributions for a set of materials
 * Controlling process for multiple children
 */

#include "rcontrib.h"
#include "platform.h"
#include "rtprocess.h"
#include "selcall.h"

/* Modifier contribution queue (results waiting to be output) */
typedef struct s_binq {
        int             ndx;            /* index for this entry */
        int             n2add;          /* number left to add */
        struct s_binq   *next;          /* next in queue */
        MODCONT         *mca[1];        /* contrib. array (extends struct) */
} BINQ;

static BINQ     *out_bq = NULL;         /* output bin queue */
static BINQ     *free_bq = NULL;        /* free queue entries */

static SUBPROC  kida[MAXPROCESS];       /* child processes */
static FILE     *inq_fp[MAXPROCESS];    /* input streams */


/* Get new (empty) bin queue entry */
static BINQ *
new_binq()
{
        BINQ    *bp = free_bq;
        int     i;

        if (bp != NULL) {               /* something already available? */
                free_bq = bp->next;
                bp->next = NULL;
                bp->n2add = accumulate-1;
                return(bp);
        }
                                        /* else allocate fresh */
        bp = (BINQ *)malloc(sizeof(BINQ)+(nmods-1)*sizeof(MODCONT *));
        if (bp == NULL)
                goto memerr;
        for (i = nmods; i--; ) {
                MODCONT *mp = (MODCONT *)lu_find(&modconttab,modname[i])->data;
                bp->mca[i] = (MODCONT *)malloc(sizeof(MODCONT) +
                                                sizeof(DCOLOR)*(mp->nbins-1));
                if (bp->mca[i] == NULL)
                        goto memerr;
                memcpy(bp->mca[i], mp, sizeof(MODCONT)-sizeof(DCOLOR));
                /* memset(bp->mca[i]->cbin, 0, sizeof(DCOLOR)*mp->nbins); */
        }
        bp->ndx = 0;
        bp->n2add = accumulate-1;
        bp->next = NULL;
        return(bp);
memerr:
        error(SYSTEM, "out of memory in new_binq()");
        return(NULL);
}


/* Free a bin queue entry */
static void
free_binq(BINQ *bp)
{
        int     i;

        if (bp == NULL) {               /* signal to release our free list */
                while ((bp = free_bq) != NULL) {
                        free_bq = bp->next;
                        for (i = nmods; i--; )
                                free(bp->mca[i]);
                                /* Note: we don't own bp->mca[i]->binv */
                        free(bp);
                }
                return;
        }
                                        /* clear sums for next use */
/*      for (i = nmods; i--; )
                memset(bp->mca[i]->cbin, 0, sizeof(DCOLOR)*bp->mca[i]->nbins);
*/
        bp->ndx = 0;
        bp->next = free_bq;             /* push onto free list */
        free_bq = bp;
}


/* Add modifier values to accumulation record in queue and clear */
void
queue_modifiers()
{
        MODCONT *mpin, *mpout;
        int     i, j;

        if ((accumulate > 0) | (out_bq == NULL))
                error(CONSISTENCY, "bad call to queue_modifiers()");

        for (i = nmods; i--; ) {
                mpin = (MODCONT *)lu_find(&modconttab,modname[i])->data;
                mpout = out_bq->mca[i];
                for (j = mpout->nbins; j--; )
                        addcolor(mpout->cbin[j], mpin->cbin[j]);
                memset(mpin->cbin, 0, sizeof(DCOLOR)*mpin->nbins);
        }
}


/* Sum one modifier record into another (doesn't update n2add) */
static void
add_modbin(BINQ *dst, BINQ *src)
{
        int     i, j;
        
        for (i = nmods; i--; ) {
                MODCONT *mpin = src->mca[i];
                MODCONT *mpout = dst->mca[i];
                for (j = mpout->nbins; j--; )
                        addcolor(mpout->cbin[j], mpin->cbin[j]);
        }
}


/* Queue values for later output */
static void
queue_output(BINQ *bp)
{
        BINQ    *b_last, *b_cur;

        if (accumulate <= 0) {          /* just accumulating? */
                if (out_bq == NULL) {
                        bp->next = NULL;
                        out_bq = bp;
                } else {
                        add_modbin(out_bq, bp);
                        free_binq(bp);
                }
                return;
        }
        b_last = NULL;                  /* else insert in output queue */
        for (b_cur = out_bq; b_cur != NULL && b_cur->ndx < bp->ndx;
                                b_cur = b_cur->next)
                b_last = b_cur;
        if (b_last != NULL) {
                bp->next = b_cur;
                b_last->next = bp;
        } else {
                bp->next = out_bq;
                out_bq = bp;
        }
        if (accumulate == 1)            /* no accumulation? */
                return;
        b_cur = out_bq;                 /* else merge accumulation entries */
        while (b_cur->next != NULL) {
                if (b_cur->n2add <= 0 ||
                                (b_cur->ndx-1)/accumulate !=
                                (b_cur->next->ndx-1)/accumulate) {
                        b_cur = b_cur->next;
                        continue;
                }
                add_modbin(b_cur, b_cur->next);
                b_cur->n2add--;
                b_last = b_cur->next;
                b_cur->next = b_last->next;
                b_last->next = NULL;
                free_binq(b_last);
        }
}


/* Get current with output queue by producing ready results */
static int
output_catchup()
{
        int     nout = 0;
        BINQ    *bp;
        int     i;

        if (accumulate <= 0)            /* just accumulating? */
                return(0);
                                        /* else output ready results */
        while (out_bq != NULL && (out_bq->ndx == lastdone+1) & !out_bq->n2add) {
                bp = out_bq;                    /* pop off first entry */
                out_bq = bp->next;
                bp->next = NULL;
                for (i = 0; i < nmods; i++)     /* output record */
                        mod_output(bp->mca[i]);
                end_record();
                free_binq(bp);                  /* free this entry */
                lastdone += accumulate;
                ++nout;
        }
        return(nout);
}


/* Put a zero record in results queue & output */
void
put_zero_record(int ndx)
{
        BINQ    *bp = new_binq();
        int     i;

        for (i = nmods; i--; )
                memset(bp->mca[i]->cbin, 0, sizeof(DCOLOR)*bp->mca[i]->nbins);
        bp->ndx = ndx;
        queue_output(bp);
        output_catchup();
}


/* callback to set output spec to NULL (stdout) */
static int
set_stdout(const LUENT *le, void *p)
{
        (*(MODCONT *)le->data).outspec = NULL;
        return(0);
}


/* Start child processes if we can */
int
in_rchild()
{
#ifdef _WIN32
        error(WARNING, "multiprocessing unsupported -- running solo");
        nproc = 1;
        return(1);
#else
                                        /* try to fork ourselves */
        while (nchild < nproc) {
                int     p0[2], p1[2];
                int     pid;
                                        /* prepare i/o pipes */
                errno = 0;
                if (pipe(p0) < 0 || pipe(p1) < 0)
                        error(SYSTEM, "pipe() call failed!");
                pid = fork();           /* fork parent process */
                if (pid == 0) {         /* if in child, set up & return true */
                        close(p0[1]); close(p1[0]);
                        dup2(p0[0], 0); close(p0[0]);
                        dup2(p1[1], 1); close(p1[1]);
                        inpfmt = (sizeof(RREAL)==sizeof(double)) ? 'd' : 'f';
                        outfmt = 'd';
                        header = 0;
                        waitflush = xres = 1;
                        yres = 0;
                        raysleft = 0;
                        account = accumulate = 1;
                        lu_doall(&modconttab, set_stdout, NULL);
                        nchild = -1;
                        return(1);      /* child return value */
                }
                if (pid < 0)
                        error(SYSTEM, "fork() call failed!");
                                        /* connect parent's pipes */
                close(p0[0]); close(p1[1]);
                kida[nchild].r = p1[0];
                kida[nchild].w = p0[1];
                kida[nchild].pid = pid;
                kida[nchild].running = -1;
                inq_fp[nchild] = fdopen(p1[0], "rb");
                if (inq_fp[nchild] == NULL)
                        error(SYSTEM, "out of memory in in_rchild()");
#ifdef getc_unlocked
                flockfile(inq_fp[nchild]);      /* avoid mutex overhead */
#endif
                ++nchild;
        }
        return(0);                      /* parent return value */
#endif
}


/* Close child processes */
void
end_children()
{
        int     status;
        
        while (nchild-- > 0) {
                kida[nchild].r = -1;    /* close(-1) error is ignored */
                if ((status = close_process(&kida[nchild])) > 0) {
                        sprintf(errmsg,
                                "rendering process returned bad status (%d)",
                                        status);
                        error(WARNING, errmsg);
                }
                fclose(inq_fp[nchild]); /* performs actual close() */
        }
}


/* Wait for the next available child, managing output queue as well */
static int
next_child_nq(int force_wait)
{
        static struct timeval   polling;
        struct timeval          *pmode = force_wait | (accumulate <= 0) ?
                                        (struct timeval *)NULL : &polling;
        fd_set                  readset, errset;
        int                     i, j, n, nr;

        if (!force_wait)                /* see if there's one free */
                for (i = nchild; i--; )
                        if (kida[i].running < 0)
                                return(i);
                                        /* prepare select() call */
        FD_ZERO(&readset); FD_ZERO(&errset);
        n = nr = 0;
        for (i = nchild; i--; ) {
                if (kida[i].running > 0) {
                        FD_SET(kida[i].r, &readset);
                        ++nr;
                }
                FD_SET(kida[i].r, &errset);
                if (kida[i].r >= n)
                        n = kida[i].r + 1;
        }
tryagain:
        if (pmode == NULL)              /* catch up in case we block */
                output_catchup();
        if (!nr)                        /* nothing to wait for? */
                return(-1);
        if ((nr > 1) | (pmode == &polling)) {
                errno = 0;
                i = select(n, &readset, NULL, &errset, pmode);
                if (!i) {
                        pmode = NULL;   /* try again, blocking this time */
                        goto tryagain;
                }
                if (i < 0)
                        error(SYSTEM, "select() error in next_child_nq()");
        } else
                FD_ZERO(&errset);
        n = -1;                         /* read results from child(ren) */
        for (i = nchild; i--; ) {
                BINQ    *bq;
                if (FD_ISSET(kida[i].r, &errset))
                        error(USER, "rendering process died");
                if (!FD_ISSET(kida[i].r, &readset))
                        continue;
                bq = new_binq();        /* get results holder */
                bq->ndx = kida[i].running;
                                        /* read from child */
                for (j = 0; j < nmods; j++) {
                        nr = bq->mca[j]->nbins;
                        if (fread(bq->mca[j]->cbin, sizeof(DCOLOR), nr,
                                                        inq_fp[i]) != nr)
                                error(SYSTEM, "read error from render process");
                }
                queue_output(bq);       /* add results to output queue */
                kida[i].running = -1;   /* mark child as available */
                n = i;
        }
        return(n);                      /* first available child */
}


/* Run parental oversight loop */
void
parental_loop()
{
        static int      ignore_warning_given = 0;
        FVECT           orgdir[2];
        double          d;
        int             i;
                                        /* load rays from stdin & process */
#ifdef getc_unlocked
        flockfile(stdin);               /* avoid lock/unlock overhead */
#endif
        while (getvec(orgdir[0]) == 0 && getvec(orgdir[1]) == 0) {
                d = normalize(orgdir[1]);
                                                        /* asking for flush? */
                if ((d == 0.0) & (accumulate != 1)) {
                        if (!ignore_warning_given++)
                                error(WARNING,
                                "dummy ray(s) ignored during accumulation\n");
                        continue;
                }
                if ((d == 0.0) | (lastray+1 < lastray)) {
                        while (next_child_nq(1) >= 0)
                                ;                       /* clear the queue */
                        lastdone = lastray = 0;
                }
                if (d == 0.0) {
                        if ((yres <= 0) | (xres <= 0))
                                waitflush = 1;          /* flush right after */
                        put_zero_record(++lastray);
                } else {                                /* else assign ray */
                        i = next_child_nq(0);
                        if (writebuf(kida[i].w, (char *)orgdir,
                                        sizeof(orgdir)) != sizeof(orgdir))
                                error(SYSTEM, "pipe write error");
                        kida[i].running = ++lastray;
                }
                if (raysleft && !--raysleft)
                        break;                          /* preemptive EOI */
        }
        while (next_child_nq(1) >= 0)           /* empty results queue */
                ;
                                                /* output accumulated record */
        if (accumulate <= 0 || account < accumulate) {
                if (account < accumulate) {
                        error(WARNING, "partial accumulation in final record");
                        accumulate -= account;
                }
                for (i = 0; i < nmods; i++)
                        mod_output(out_bq->mca[i]);
                end_record();
                free_binq(out_bq);
                out_bq = NULL;
        }
        if (raysleft)
                error(USER, "unexpected EOF on input");
        free_binq(NULL);                        /* clean up */
        lu_done(&ofiletab);
}
Revision:	2.3
Committed:	Sun Jun 10 05:25:42 2012 UTC (13 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.2:	+33 -26 lines
Log Message:	Tweaks and bug fixes to new code
#	User	Rev	Content
1	greg	2.1	#ifndef lint
2	greg	2.3	static const char RCSid[] = "$Id: rc3.c,v 2.2 2012/06/09 16:47:27 greg Exp $";
3	greg	2.1	#endif
4			/*
5			* Accumulate ray contributions for a set of materials
6			* Controlling process for multiple children
7			*/
8
9			#include "rcontrib.h"
10			#include "platform.h"
11			#include "rtprocess.h"
12			#include "selcall.h"
13
14			/* Modifier contribution queue (results waiting to be output) */
15			typedef struct s_binq {
16			int ndx; /* index for this entry */
17			int n2add; /* number left to add */
18			struct s_binq next; / next in queue */
19			MODCONT mca[1]; / contrib. array (extends struct) */
20			} BINQ;
21
22			static BINQ out_bq = NULL; / output bin queue */
23			static BINQ free_bq = NULL; / free queue entries */
24
25			static SUBPROC kida[MAXPROCESS]; /* child processes */
26	greg	2.2	static FILE inq_fp[MAXPROCESS]; / input streams */
27	greg	2.1
28
29			/* Get new (empty) bin queue entry */
30			static BINQ *
31			new_binq()
32			{
33			BINQ *bp = free_bq;
34			int i;
35
36			if (bp != NULL) { /* something already available? */
37			free_bq = bp->next;
38			bp->next = NULL;
39			bp->n2add = accumulate-1;
40			return(bp);
41			}
42			/* else allocate fresh */
43			bp = (BINQ )malloc(sizeof(BINQ)+(nmods-1)sizeof(MODCONT *));
44			if (bp == NULL)
45			goto memerr;
46			for (i = nmods; i--; ) {
47			MODCONT mp = (MODCONT )lu_find(&modconttab,modname[i])->data;
48			bp->mca[i] = (MODCONT *)malloc(sizeof(MODCONT) +
49			sizeof(DCOLOR)*(mp->nbins-1));
50			if (bp->mca[i] == NULL)
51			goto memerr;
52			memcpy(bp->mca[i], mp, sizeof(MODCONT)-sizeof(DCOLOR));
53			/* memset(bp->mca[i]->cbin, 0, sizeof(DCOLOR)mp->nbins); /
54			}
55			bp->ndx = 0;
56			bp->n2add = accumulate-1;
57			bp->next = NULL;
58			return(bp);
59			memerr:
60			error(SYSTEM, "out of memory in new_binq()");
61			return(NULL);
62			}
63
64
65			/* Free a bin queue entry */
66			static void
67			free_binq(BINQ *bp)
68			{
69			int i;
70
71			if (bp == NULL) { /* signal to release our free list */
72			while ((bp = free_bq) != NULL) {
73			free_bq = bp->next;
74			for (i = nmods; i--; )
75			free(bp->mca[i]);
76			/* Note: we don't own bp->mca[i]->binv */
77			free(bp);
78			}
79			return;
80			}
81			/* clear sums for next use */
82			/* for (i = nmods; i--; )
83			memset(bp->mca[i]->cbin, 0, sizeof(DCOLOR)*bp->mca[i]->nbins);
84			*/
85			bp->ndx = 0;
86			bp->next = free_bq; /* push onto free list */
87			free_bq = bp;
88			}
89
90
91			/* Add modifier values to accumulation record in queue and clear */
92			void
93			queue_modifiers()
94			{
95			MODCONT mpin, mpout;
96			int i, j;
97
98			if ((accumulate > 0) \| (out_bq == NULL))
99			error(CONSISTENCY, "bad call to queue_modifiers()");
100
101			for (i = nmods; i--; ) {
102			mpin = (MODCONT *)lu_find(&modconttab,modname[i])->data;
103			mpout = out_bq->mca[i];
104			for (j = mpout->nbins; j--; )
105			addcolor(mpout->cbin[j], mpin->cbin[j]);
106			memset(mpin->cbin, 0, sizeof(DCOLOR)*mpin->nbins);
107			}
108			}
109
110
111			/* Sum one modifier record into another (doesn't update n2add) */
112			static void
113			add_modbin(BINQ dst, BINQ src)
114			{
115			int i, j;
116
117			for (i = nmods; i--; ) {
118			MODCONT *mpin = src->mca[i];
119			MODCONT *mpout = dst->mca[i];
120			for (j = mpout->nbins; j--; )
121			addcolor(mpout->cbin[j], mpin->cbin[j]);
122			}
123			}
124
125
126	greg	2.2	/* Queue values for later output */
127			static void
128	greg	2.1	queue_output(BINQ *bp)
129			{
130			BINQ b_last, b_cur;
131
132			if (accumulate <= 0) { /* just accumulating? */
133			if (out_bq == NULL) {
134			bp->next = NULL;
135			out_bq = bp;
136			} else {
137			add_modbin(out_bq, bp);
138			free_binq(bp);
139			}
140	greg	2.2	return;
141	greg	2.1	}
142			b_last = NULL; /* else insert in output queue */
143			for (b_cur = out_bq; b_cur != NULL && b_cur->ndx < bp->ndx;
144			b_cur = b_cur->next)
145			b_last = b_cur;
146			if (b_last != NULL) {
147			bp->next = b_cur;
148			b_last->next = bp;
149			} else {
150			bp->next = out_bq;
151			out_bq = bp;
152			}
153	greg	2.3	if (accumulate == 1) /* no accumulation? */
154	greg	2.2	return;
155			b_cur = out_bq; /* else merge accumulation entries */
156			while (b_cur->next != NULL) {
157			if (b_cur->n2add <= 0 \|\|
158			(b_cur->ndx-1)/accumulate !=
159			(b_cur->next->ndx-1)/accumulate) {
160			b_cur = b_cur->next;
161			continue;
162	greg	2.1	}
163	greg	2.2	add_modbin(b_cur, b_cur->next);
164			b_cur->n2add--;
165			b_last = b_cur->next;
166			b_cur->next = b_last->next;
167			b_last->next = NULL;
168			free_binq(b_last);
169	greg	2.1	}
170	greg	2.2	}
171
172
173	greg	2.3	/* Get current with output queue by producing ready results */
174	greg	2.2	static int
175			output_catchup()
176			{
177			int nout = 0;
178			BINQ *bp;
179			int i;
180
181			if (accumulate <= 0) /* just accumulating? */
182			return(0);
183			/* else output ready results */
184	greg	2.1	while (out_bq != NULL && (out_bq->ndx == lastdone+1) & !out_bq->n2add) {
185	greg	2.2	bp = out_bq; /* pop off first entry */
186			out_bq = bp->next;
187			bp->next = NULL;
188	greg	2.1	for (i = 0; i < nmods; i++) /* output record */
189	greg	2.2	mod_output(bp->mca[i]);
190	greg	2.1	end_record();
191	greg	2.2	free_binq(bp); /* free this entry */
192	greg	2.1	lastdone += accumulate;
193			++nout;
194			}
195			return(nout);
196			}
197
198
199	greg	2.3	/* Put a zero record in results queue & output */
200	greg	2.1	void
201	greg	2.3	put_zero_record(int ndx)
202	greg	2.1	{
203			BINQ *bp = new_binq();
204			int i;
205
206			for (i = nmods; i--; )
207			memset(bp->mca[i]->cbin, 0, sizeof(DCOLOR)*bp->mca[i]->nbins);
208			bp->ndx = ndx;
209			queue_output(bp);
210	greg	2.3	output_catchup();
211	greg	2.1	}
212
213
214			/* callback to set output spec to NULL (stdout) */
215			static int
216			set_stdout(const LUENT le, void p)
217			{
218			((MODCONT )le->data).outspec = NULL;
219			return(0);
220			}
221
222
223			/* Start child processes if we can */
224			int
225			in_rchild()
226			{
227			#ifdef _WIN32
228			error(WARNING, "multiprocessing unsupported -- running solo");
229			nproc = 1;
230			return(1);
231			#else
232			/* try to fork ourselves */
233			while (nchild < nproc) {
234			int p0[2], p1[2];
235			int pid;
236			/* prepare i/o pipes */
237	greg	2.3	errno = 0;
238	greg	2.1	if (pipe(p0) < 0 \|\| pipe(p1) < 0)
239			error(SYSTEM, "pipe() call failed!");
240			pid = fork(); /* fork parent process */
241			if (pid == 0) { /* if in child, set up & return true */
242			close(p0[1]); close(p1[0]);
243			dup2(p0[0], 0); close(p0[0]);
244			dup2(p1[1], 1); close(p1[1]);
245			inpfmt = (sizeof(RREAL)==sizeof(double)) ? 'd' : 'f';
246			outfmt = 'd';
247			header = 0;
248			waitflush = xres = 1;
249			yres = 0;
250			raysleft = 0;
251			account = accumulate = 1;
252			lu_doall(&modconttab, set_stdout, NULL);
253			nchild = -1;
254			return(1); /* child return value */
255			}
256			if (pid < 0)
257			error(SYSTEM, "fork() call failed!");
258	greg	2.3	/* connect parent's pipes */
259	greg	2.1	close(p0[0]); close(p1[1]);
260			kida[nchild].r = p1[0];
261			kida[nchild].w = p0[1];
262			kida[nchild].pid = pid;
263			kida[nchild].running = -1;
264	greg	2.2	inq_fp[nchild] = fdopen(p1[0], "rb");
265			if (inq_fp[nchild] == NULL)
266			error(SYSTEM, "out of memory in in_rchild()");
267	greg	2.3	#ifdef getc_unlocked
268			flockfile(inq_fp[nchild]); /* avoid mutex overhead */
269			#endif
270	greg	2.1	++nchild;
271			}
272			return(0); /* parent return value */
273			#endif
274			}
275
276
277			/* Close child processes */
278			void
279			end_children()
280			{
281			int status;
282
283	greg	2.2	while (nchild-- > 0) {
284			kida[nchild].r = -1; /* close(-1) error is ignored */
285	greg	2.1	if ((status = close_process(&kida[nchild])) > 0) {
286			sprintf(errmsg,
287			"rendering process returned bad status (%d)",
288			status);
289			error(WARNING, errmsg);
290			}
291	greg	2.2	fclose(inq_fp[nchild]); /* performs actual close() */
292			}
293	greg	2.1	}
294
295
296	greg	2.2	/* Wait for the next available child, managing output queue as well */
297	greg	2.1	static int
298			next_child_nq(int force_wait)
299			{
300	greg	2.2	static struct timeval polling;
301			struct timeval *pmode = force_wait \| (accumulate <= 0) ?
302			(struct timeval *)NULL : &polling;
303			fd_set readset, errset;
304			int i, j, n, nr;
305	greg	2.1
306			if (!force_wait) /* see if there's one free */
307			for (i = nchild; i--; )
308			if (kida[i].running < 0)
309			return(i);
310			/* prepare select() call */
311			FD_ZERO(&readset); FD_ZERO(&errset);
312			n = nr = 0;
313			for (i = nchild; i--; ) {
314			if (kida[i].running > 0) {
315			FD_SET(kida[i].r, &readset);
316			++nr;
317			}
318			FD_SET(kida[i].r, &errset);
319			if (kida[i].r >= n)
320			n = kida[i].r + 1;
321			}
322	greg	2.2	tryagain:
323	greg	2.3	if (pmode == NULL) /* catch up in case we block */
324	greg	2.2	output_catchup();
325	greg	2.3	if (!nr) /* nothing to wait for? */
326			return(-1);
327	greg	2.2	if ((nr > 1) \| (pmode == &polling)) {
328	greg	2.1	errno = 0;
329	greg	2.3	i = select(n, &readset, NULL, &errset, pmode);
330			if (!i) {
331	greg	2.2	pmode = NULL; /* try again, blocking this time */
332			goto tryagain;
333			}
334	greg	2.3	if (i < 0)
335			error(SYSTEM, "select() error in next_child_nq()");
336	greg	2.1	} else
337			FD_ZERO(&errset);
338			n = -1; /* read results from child(ren) */
339			for (i = nchild; i--; ) {
340			BINQ *bq;
341			if (FD_ISSET(kida[i].r, &errset))
342			error(USER, "rendering process died");
343			if (!FD_ISSET(kida[i].r, &readset))
344			continue;
345			bq = new_binq(); /* get results holder */
346			bq->ndx = kida[i].running;
347			/* read from child */
348			for (j = 0; j < nmods; j++) {
349	greg	2.3	nr = bq->mca[j]->nbins;
350			if (fread(bq->mca[j]->cbin, sizeof(DCOLOR), nr,
351			inq_fp[i]) != nr)
352	greg	2.1	error(SYSTEM, "read error from render process");
353			}
354	greg	2.3	queue_output(bq); /* add results to output queue */
355	greg	2.1	kida[i].running = -1; /* mark child as available */
356			n = i;
357			}
358	greg	2.3	return(n); /* first available child */
359	greg	2.1	}
360
361
362			/* Run parental oversight loop */
363			void
364			parental_loop()
365			{
366			static int ignore_warning_given = 0;
367			FVECT orgdir[2];
368			double d;
369	greg	2.3	int i;
370	greg	2.1	/* load rays from stdin & process */
371			#ifdef getc_unlocked
372			flockfile(stdin); /* avoid lock/unlock overhead */
373			#endif
374			while (getvec(orgdir[0]) == 0 && getvec(orgdir[1]) == 0) {
375			d = normalize(orgdir[1]);
376			/* asking for flush? */
377			if ((d == 0.0) & (accumulate != 1)) {
378			if (!ignore_warning_given++)
379			error(WARNING,
380			"dummy ray(s) ignored during accumulation\n");
381			continue;
382			}
383			if ((d == 0.0) \| (lastray+1 < lastray)) {
384			while (next_child_nq(1) >= 0)
385	greg	2.3	; /* clear the queue */
386	greg	2.1	lastdone = lastray = 0;
387			}
388			if (d == 0.0) {
389			if ((yres <= 0) \| (xres <= 0))
390			waitflush = 1; /* flush right after */
391	greg	2.3	put_zero_record(++lastray);
392			} else { /* else assign ray */
393			i = next_child_nq(0);
394			if (writebuf(kida[i].w, (char *)orgdir,
395			sizeof(orgdir)) != sizeof(orgdir))
396	greg	2.1	error(SYSTEM, "pipe write error");
397	greg	2.3	kida[i].running = ++lastray;
398	greg	2.1	}
399			if (raysleft && !--raysleft)
400			break; /* preemptive EOI */
401			}
402			while (next_child_nq(1) >= 0) /* empty results queue */
403			;
404			/* output accumulated record */
405			if (accumulate <= 0 \|\| account < accumulate) {
406			if (account < accumulate) {
407			error(WARNING, "partial accumulation in final record");
408			accumulate -= account;
409			}
410			for (i = 0; i < nmods; i++)
411			mod_output(out_bq->mca[i]);
412			end_record();
413	greg	2.3	free_binq(out_bq);
414			out_bq = NULL;
415	greg	2.1	}
416			if (raysleft)
417			error(USER, "unexpected EOF on input");
418			free_binq(NULL); /* clean up */
419			lu_done(&ofiletab);
420			}