src/hd/rholo4.c

/* Copyright (c) 1997 Silicon Graphics, Inc. */

#ifndef lint
static char SCCSid[] = "$SunId$ SGI";
#endif

/*
 * Holodeck display process communication
 */

#include "rholo.h"
#include "rhdisp.h"
#include <sys/uio.h>

#ifndef HDSUF
#define HDSUF   ".hdisp"
#endif

static int      inp_flags;
static int      dpd[3];
static FILE     *dpout;


disp_open(dname)                /* open the named display driver */
char    *dname;
{
        char    dpath[128], *com[3];
        int     i;

#ifdef DEVPATH
        sprintf(dpath, "%s/%s%s", DEVPATH, dname, HDSUF);
#else
        sprintf(dpath, "dev/%s%s", dname, HDSUF);
#endif
        com[0] = dpath; com[1] = froot; com[2] = NULL;
        i = open_process(dpd, com);
        if (i <= 0)
                error(USER, "cannot start display process");
        if ((dpout = fdopen(dup(dpd[1]), "w")) == NULL)
                error(SYSTEM, "cannot associate FILE with display pipe");
        inp_flags = 0;
                                /* write out hologram grids */
        for (i = 0; hdlist[i] != NULL; i++)
                disp_result(DS_ADDHOLO, sizeof(HDGRID), (char *)hdlist[i]);
        disp_flush();
}


disp_packet(p)                  /* display a packet */
register PACKHEAD       *p;
{
        disp_result(DS_BUNDLE, packsiz(p->nr), (char *)p);
}


disp_check(block)               /* check display process */
int     block;
{
        MSGHEAD msg;
        int     n;
        char    *buf = NULL;

        if (dpout == NULL)
                return(-1);
                                        /* flush display output */
        disp_flush();
                                        /* check read blocking */
        if (block != (inp_flags == 0)) {
                inp_flags = block ? 0 : FNONBLK;
                if (fcntl(dpd[0], F_SETFL, inp_flags) < 0)
                        goto fcntlerr;
        }
                                        /* read message header */
        n = read(dpd[0], (char *)&msg, sizeof(MSGHEAD));
        if (n != sizeof(MSGHEAD)) {
                if (n >= 0) {
                        dpout = NULL;
                        error(USER, "display process died");
                }
                if (errno != EAGAIN & errno != EINTR)
                        goto readerr;
                return(2);              /* acceptable failure */
        }
        if (msg.nbytes) {               /* get the message body */
                buf = (char *)malloc(msg.nbytes);
                if (buf == NULL)
                        error(SYSTEM, "out of memory in disp_check");
                if (fcntl(dpd[0], F_SETFL, inp_flags=0) < 0)
                        goto fcntlerr;
                if (readbuf(dpd[0], buf, msg.nbytes) != msg.nbytes)
                        goto readerr;
        }
        switch (msg.type) {             /* take appropriate action */
        case DR_BUNDLE:
                if (msg.nbytes != sizeof(PACKHEAD))
                        error(INTERNAL, "bad DR_BUNDLE from display process");
                bundle_set(BS_ADD, (PACKHEAD *)buf, 1);
                break;
        case DR_NEWSET:
                if (msg.nbytes % sizeof(PACKHEAD))
                        error(INTERNAL, "bad DR_NEWSET from display process");
                disp_result(DS_STARTIMM, 0, NULL);
                bundle_set(BS_NEW, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
                disp_result(DS_ENDIMM, 0, NULL);
                disp_flush();
                break;
        case DR_ADDSET:
                if (msg.nbytes % sizeof(PACKHEAD))
                        error(INTERNAL, "bad DR_ADDSET from display process");
                disp_result(DS_STARTIMM, 0, NULL);
                bundle_set(BS_ADD, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
                disp_result(DS_ENDIMM, 0, NULL);
                disp_check(0);          /* hack -- delete usu. follows add */
                break;
        case DR_ADJSET:
                if (msg.nbytes % sizeof(PACKHEAD))
                        error(INTERNAL, "bad DR_ADJSET from display process");
                disp_result(DS_STARTIMM, 0, NULL);
                bundle_set(BS_ADJ, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
                disp_result(DS_ENDIMM, 0, NULL);
                disp_flush();
                break;
        case DR_DELSET:
                if (msg.nbytes % sizeof(PACKHEAD))
                        error(INTERNAL, "bad DR_DELSET from display process");
                bundle_set(BS_DEL, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
                break;
        case DR_ATTEN:
                if (msg.nbytes)
                        error(INTERNAL, "bad DR_ATTEN from display process");
                                        /* send acknowledgement */
                disp_result(DS_ACKNOW, 0, NULL);
                return(disp_check(1));  /* block on following request */
        case DR_SHUTDOWN:
                if (msg.nbytes)
                        error(INTERNAL, "bad DR_SHUTDOWN from display process");
                return(0);              /* zero return signals shutdown */
        case DR_NOOP:
                break;
        default:
                error(INTERNAL, "unrecognized request from display process");
        }
        if (msg.nbytes)                 /* clean up */
                free(buf);
        return(1);                      /* normal return value */
fcntlerr:
        error(SYSTEM, "cannot change display blocking mode");
readerr:
        error(SYSTEM, "error reading from display process");
}


int
disp_close()                    /* close our display process */
{
        int     rval;

        if (dpout == NULL)
                return(-1);
        disp_result(DS_SHUTDOWN, 0, NULL);
        fclose(dpout);
        dpout = NULL;
        return(close_process(dpd));
}


disp_result(type, nbytes, p)    /* queue result message to display process */
int     type, nbytes;
char    *p;
{
        MSGHEAD msg;

        if (dpout == NULL)
                return;
        msg.type = type;
        msg.nbytes = nbytes;
        fwrite((char *)&msg, sizeof(MSGHEAD), 1, dpout);
        if (nbytes > 0)
                fwrite(p, 1, nbytes, dpout);
}


disp_flush()                    /* flush output to display */
{
        if (fflush(dpout) < 0)
                error(SYSTEM, "error writing to the display process");
}
Revision:	3.10
Committed:	Mon Dec 1 16:35:35 1997 UTC (26 years, 4 months ago) by gregl
Content type:	text/plain
Branch:	MAIN
Changes since 3.9:	+3 -1 lines
Log Message:	improved error recovery when display process dies
#	User	Rev	Content
1	gregl	3.1	/* 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	gregl	3.2	#include <sys/uio.h>
14	gregl	3.1
15	gregl	3.2	#ifndef HDSUF
16			#define HDSUF ".hdisp"
17			#endif
18	gregl	3.1
19	gregl	3.2	static int inp_flags;
20			static int dpd[3];
21	gregl	3.5	static FILE *dpout;
22	gregl	3.2
23
24			disp_open(dname) /* open the named display driver */
25	gregl	3.1	char *dname;
26			{
27	gregl	3.5	char dpath[128], *com[3];
28	gregl	3.2	int i;
29
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	gregl	3.5	com[0] = dpath; com[1] = froot; com[2] = NULL;
36	gregl	3.6	i = open_process(dpd, com);
37			if (i <= 0)
38	gregl	3.2	error(USER, "cannot start display process");
39	gregl	3.5	if ((dpout = fdopen(dup(dpd[1]), "w")) == NULL)
40			error(SYSTEM, "cannot associate FILE with display pipe");
41	gregl	3.2	inp_flags = 0;
42			/* write out hologram grids */
43			for (i = 0; hdlist[i] != NULL; i++)
44			disp_result(DS_ADDHOLO, sizeof(HDGRID), (char *)hdlist[i]);
45	gregl	3.5	disp_flush();
46	gregl	3.1	}
47
48
49	gregl	3.2	disp_packet(p) /* display a packet */
50	gregl	3.4	register PACKHEAD *p;
51	gregl	3.2	{
52	gregl	3.4	disp_result(DS_BUNDLE, packsiz(p->nr), (char *)p);
53	gregl	3.2	}
54
55
56	gregl	3.1	disp_check(block) /* check display process */
57			int block;
58			{
59	gregl	3.2	MSGHEAD msg;
60			int n;
61			char *buf = NULL;
62
63	gregl	3.6	if (dpout == NULL)
64	gregl	3.2	return(-1);
65	gregl	3.5	/* flush display output */
66			disp_flush();
67	gregl	3.3	/* check read blocking */
68	gregl	3.2	if (block != (inp_flags == 0)) {
69			inp_flags = block ? 0 : FNONBLK;
70			if (fcntl(dpd[0], F_SETFL, inp_flags) < 0)
71			goto fcntlerr;
72			}
73			/* read message header */
74			n = read(dpd[0], (char *)&msg, sizeof(MSGHEAD));
75			if (n != sizeof(MSGHEAD)) {
76	gregl	3.10	if (n >= 0) {
77			dpout = NULL;
78	gregl	3.2	error(USER, "display process died");
79	gregl	3.10	}
80	gregl	3.2	if (errno != EAGAIN & errno != EINTR)
81			goto readerr;
82	gregl	3.3	return(2); /* acceptable failure */
83	gregl	3.2	}
84			if (msg.nbytes) { /* get the message body */
85			buf = (char *)malloc(msg.nbytes);
86			if (buf == NULL)
87			error(SYSTEM, "out of memory in disp_check");
88			if (fcntl(dpd[0], F_SETFL, inp_flags=0) < 0)
89			goto fcntlerr;
90			if (readbuf(dpd[0], buf, msg.nbytes) != msg.nbytes)
91			goto readerr;
92			}
93			switch (msg.type) { /* take appropriate action */
94			case DR_BUNDLE:
95			if (msg.nbytes != sizeof(PACKHEAD))
96			error(INTERNAL, "bad DR_BUNDLE from display process");
97			bundle_set(BS_ADD, (PACKHEAD *)buf, 1);
98			break;
99			case DR_NEWSET:
100			if (msg.nbytes % sizeof(PACKHEAD))
101			error(INTERNAL, "bad DR_NEWSET from display process");
102			disp_result(DS_STARTIMM, 0, NULL);
103			bundle_set(BS_NEW, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
104			disp_result(DS_ENDIMM, 0, NULL);
105	gregl	3.5	disp_flush();
106	gregl	3.2	break;
107			case DR_ADDSET:
108			if (msg.nbytes % sizeof(PACKHEAD))
109			error(INTERNAL, "bad DR_ADDSET from display process");
110			disp_result(DS_STARTIMM, 0, NULL);
111			bundle_set(BS_ADD, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
112			disp_result(DS_ENDIMM, 0, NULL);
113	gregl	3.8	disp_check(0); /* hack -- delete usu. follows add */
114	gregl	3.2	break;
115	gregl	3.9	case DR_ADJSET:
116			if (msg.nbytes % sizeof(PACKHEAD))
117			error(INTERNAL, "bad DR_ADJSET from display process");
118			disp_result(DS_STARTIMM, 0, NULL);
119			bundle_set(BS_ADJ, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
120			disp_result(DS_ENDIMM, 0, NULL);
121			disp_flush();
122			break;
123	gregl	3.2	case DR_DELSET:
124			if (msg.nbytes % sizeof(PACKHEAD))
125			error(INTERNAL, "bad DR_DELSET from display process");
126			bundle_set(BS_DEL, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
127			break;
128			case DR_ATTEN:
129			if (msg.nbytes)
130			error(INTERNAL, "bad DR_ATTEN from display process");
131			/* send acknowledgement */
132			disp_result(DS_ACKNOW, 0, NULL);
133	gregl	3.3	return(disp_check(1)); /* block on following request */
134	gregl	3.2	case DR_SHUTDOWN:
135			if (msg.nbytes)
136			error(INTERNAL, "bad DR_SHUTDOWN from display process");
137			return(0); /* zero return signals shutdown */
138	gregl	3.7	case DR_NOOP:
139			break;
140	gregl	3.2	default:
141			error(INTERNAL, "unrecognized request from display process");
142			}
143	gregl	3.3	if (msg.nbytes) /* clean up */
144	gregl	3.2	free(buf);
145			return(1); /* normal return value */
146			fcntlerr:
147			error(SYSTEM, "cannot change display blocking mode");
148			readerr:
149			error(SYSTEM, "error reading from display process");
150	gregl	3.1	}
151
152
153	gregl	3.2	int
154			disp_close() /* close our display process */
155	gregl	3.1	{
156	gregl	3.2	int rval;
157
158	gregl	3.6	if (dpout == NULL)
159	gregl	3.2	return(-1);
160			disp_result(DS_SHUTDOWN, 0, NULL);
161	gregl	3.5	fclose(dpout);
162			dpout = NULL;
163	gregl	3.2	return(close_process(dpd));
164			}
165
166
167	gregl	3.5	disp_result(type, nbytes, p) /* queue result message to display process */
168	gregl	3.2	int type, nbytes;
169			char *p;
170			{
171			MSGHEAD msg;
172
173	gregl	3.6	if (dpout == NULL)
174			return;
175	gregl	3.2	msg.type = type;
176			msg.nbytes = nbytes;
177	gregl	3.5	fwrite((char *)&msg, sizeof(MSGHEAD), 1, dpout);
178			if (nbytes > 0)
179			fwrite(p, 1, nbytes, dpout);
180			}
181
182
183			disp_flush() /* flush output to display */
184			{
185			if (fflush(dpout) < 0)
186			error(SYSTEM, "error writing to the display process");
187	gregl	3.1	}