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root/radiance/ray/src/hd/rholo4.c
Revision: 3.12
Committed: Thu Dec 11 17:40:04 1997 UTC (26 years, 3 months ago) by gregl
Content type: text/plain
Branch: MAIN
Changes since 3.11: +8 -8 lines
Log Message:
added comments

File Contents

# Content
1 /* Copyright (c) 1997 Silicon Graphics, Inc. */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ SGI";
5 #endif
6
7 /*
8 * Holodeck display process communication
9 */
10
11 #include "rholo.h"
12 #include "rhdisp.h"
13 #include <sys/uio.h>
14
15 #ifndef HDSUF
16 #define HDSUF ".hdisp"
17 #endif
18
19 static int inp_flags;
20 static int dpd[3];
21 static FILE *dpout;
22
23
24 disp_open(dname) /* open the named display driver */
25 char *dname;
26 {
27 char dpath[128], fd0[8], fd1[8], *cmd[5];
28 int i;
29 /* get full display program name */
30 #ifdef DEVPATH
31 sprintf(dpath, "%s/%s%s", DEVPATH, dname, HDSUF);
32 #else
33 sprintf(dpath, "dev/%s%s", dname, HDSUF);
34 #endif
35 /* dup stdin and stdout */
36 if (readinp)
37 sprintf(fd0, "%d", dup(0));
38 else
39 strcpy(fd0, "-1");
40 sprintf(fd1, "%d", dup(1));
41 /* start the display process */
42 cmd[0] = dpath;
43 cmd[1] = froot; cmd[2] = fd1; cmd[3] = fd0;
44 cmd[4] = NULL;
45 i = open_process(dpd, cmd);
46 if (i <= 0)
47 error(USER, "cannot start display process");
48 if ((dpout = fdopen(dpd[1], "w")) == NULL)
49 error(SYSTEM, "cannot associate FILE with display pipe");
50 dpd[1] = -1; /* causes ignored error in close_process() */
51 inp_flags = 0;
52 /* close dup'ed stdin and stdout */
53 if (readinp)
54 close(atoi(fd0));
55 close(atoi(fd1));
56 /* write out hologram grids */
57 for (i = 0; hdlist[i] != NULL; i++)
58 disp_result(DS_ADDHOLO, sizeof(HDGRID), (char *)hdlist[i]);
59 disp_flush();
60 }
61
62
63 disp_packet(p) /* display a packet */
64 register PACKHEAD *p;
65 {
66 disp_result(DS_BUNDLE, packsiz(p->nr), (char *)p);
67 }
68
69
70 disp_check(block) /* check display process */
71 int block;
72 {
73 MSGHEAD msg;
74 int n;
75 char *buf = NULL;
76
77 if (dpout == NULL)
78 return(-1);
79 /* flush display output */
80 disp_flush();
81 /* check read blocking */
82 if (block != (inp_flags == 0)) {
83 inp_flags = block ? 0 : FNONBLK;
84 if (fcntl(dpd[0], F_SETFL, inp_flags) < 0)
85 goto fcntlerr;
86 }
87 /* read message header */
88 n = read(dpd[0], (char *)&msg, sizeof(MSGHEAD));
89 if (n != sizeof(MSGHEAD)) {
90 if (n >= 0) {
91 dpout = NULL;
92 error(USER, "display process died");
93 }
94 if (errno != EAGAIN & errno != EINTR)
95 goto readerr;
96 return(2); /* acceptable failure */
97 }
98 if (msg.nbytes) { /* get the message body */
99 buf = (char *)malloc(msg.nbytes);
100 if (buf == NULL)
101 error(SYSTEM, "out of memory in disp_check");
102 if (fcntl(dpd[0], F_SETFL, inp_flags=0) < 0)
103 goto fcntlerr;
104 if (readbuf(dpd[0], buf, msg.nbytes) != msg.nbytes)
105 goto readerr;
106 }
107 switch (msg.type) { /* take appropriate action */
108 case DR_BUNDLE: /* new bundle to calculate */
109 if (msg.nbytes != sizeof(PACKHEAD))
110 error(INTERNAL, "bad DR_BUNDLE from display process");
111 bundle_set(BS_ADD, (PACKHEAD *)buf, 1);
112 break;
113 case DR_NEWSET: /* new calculation set */
114 if (msg.nbytes % sizeof(PACKHEAD))
115 error(INTERNAL, "bad DR_NEWSET from display process");
116 disp_result(DS_STARTIMM, 0, NULL);
117 bundle_set(BS_NEW, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
118 disp_result(DS_ENDIMM, 0, NULL);
119 disp_flush();
120 break;
121 case DR_ADDSET: /* add to calculation set */
122 if (msg.nbytes % sizeof(PACKHEAD))
123 error(INTERNAL, "bad DR_ADDSET from display process");
124 disp_result(DS_STARTIMM, 0, NULL);
125 bundle_set(BS_ADD, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
126 disp_result(DS_ENDIMM, 0, NULL);
127 disp_check(0); /* hack -- delete usu. follows add */
128 break;
129 case DR_ADJSET: /* adjust calculation set members */
130 if (msg.nbytes % sizeof(PACKHEAD))
131 error(INTERNAL, "bad DR_ADJSET from display process");
132 disp_result(DS_STARTIMM, 0, NULL);
133 bundle_set(BS_ADJ, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
134 disp_result(DS_ENDIMM, 0, NULL);
135 disp_flush();
136 break;
137 case DR_DELSET: /* delete from calculation set */
138 if (msg.nbytes % sizeof(PACKHEAD))
139 error(INTERNAL, "bad DR_DELSET from display process");
140 bundle_set(BS_DEL, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
141 break;
142 case DR_ATTEN: /* block for priority request */
143 if (msg.nbytes)
144 error(INTERNAL, "bad DR_ATTEN from display process");
145 /* send acknowledgement */
146 disp_result(DS_ACKNOW, 0, NULL);
147 return(disp_check(1)); /* block on following request */
148 case DR_SHUTDOWN: /* shut down program */
149 if (msg.nbytes)
150 error(INTERNAL, "bad DR_SHUTDOWN from display process");
151 return(0); /* zero return signals shutdown */
152 case DR_NOOP: /* do nothing */
153 break;
154 default:
155 error(INTERNAL, "unrecognized request from display process");
156 }
157 if (msg.nbytes) /* clean up */
158 free(buf);
159 return(1); /* normal return value */
160 fcntlerr:
161 error(SYSTEM, "cannot change display blocking mode");
162 readerr:
163 error(SYSTEM, "error reading from display process");
164 }
165
166
167 int
168 disp_close() /* close our display process */
169 {
170 int rval;
171
172 if (dpout == NULL)
173 return(-1);
174 disp_result(DS_SHUTDOWN, 0, NULL);
175 fclose(dpout);
176 dpout = NULL;
177 return(close_process(dpd));
178 }
179
180
181 disp_result(type, nbytes, p) /* queue result message to display process */
182 int type, nbytes;
183 char *p;
184 {
185 MSGHEAD msg;
186
187 if (dpout == NULL)
188 return;
189 msg.type = type;
190 msg.nbytes = nbytes;
191 fwrite((char *)&msg, sizeof(MSGHEAD), 1, dpout);
192 if (nbytes > 0)
193 fwrite(p, 1, nbytes, dpout);
194 }
195
196
197 disp_flush() /* flush output to display */
198 {
199 if (fflush(dpout) < 0)
200 error(SYSTEM, "error writing to the display process");
201 }