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/* Copyright (c) 1997 Silicon Graphics, Inc. */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ SGI"; |
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#endif |
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|
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/* |
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* Holodeck display process communication |
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*/ |
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|
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#include "rholo.h" |
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#include "rhdisp.h" |
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#include <sys/uio.h> |
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|
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#ifndef HDSUF |
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#define HDSUF ".hdisp" |
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#endif |
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|
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static int inp_flags; |
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static int dpd[3]; |
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static int pipesiz; |
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static FILE *dpout; |
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|
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|
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disp_open(dname) /* open the named display driver */ |
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char *dname; |
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{ |
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char dpath[128], *com[3]; |
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int i; |
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|
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#ifdef DEVPATH |
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sprintf(dpath, "%s/%s%s", DEVPATH, dname, HDSUF); |
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#else |
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sprintf(dpath, "dev/%s%s", dname, HDSUF); |
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#endif |
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com[0] = dpath; com[1] = froot; com[2] = NULL; |
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pipesiz = open_process(dpd, com); |
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if (pipesiz <= 0) |
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error(USER, "cannot start display process"); |
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if ((dpout = fdopen(dup(dpd[1]), "w")) == NULL) |
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error(SYSTEM, "cannot associate FILE with display pipe"); |
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inp_flags = 0; |
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/* write out hologram grids */ |
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for (i = 0; hdlist[i] != NULL; i++) |
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disp_result(DS_ADDHOLO, sizeof(HDGRID), (char *)hdlist[i]); |
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disp_flush(); |
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} |
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|
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|
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disp_packet(p) /* display a packet */ |
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register PACKHEAD *p; |
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{ |
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disp_result(DS_BUNDLE, packsiz(p->nr), (char *)p); |
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} |
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|
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|
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disp_check(block) /* check display process */ |
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int block; |
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{ |
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MSGHEAD msg; |
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int n; |
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char *buf = NULL; |
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|
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if (pipesiz <= 0) |
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return(-1); |
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/* flush display output */ |
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disp_flush(); |
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/* check read blocking */ |
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if (block != (inp_flags == 0)) { |
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inp_flags = block ? 0 : FNONBLK; |
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if (fcntl(dpd[0], F_SETFL, inp_flags) < 0) |
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goto fcntlerr; |
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} |
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/* read message header */ |
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n = read(dpd[0], (char *)&msg, sizeof(MSGHEAD)); |
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if (n != sizeof(MSGHEAD)) { |
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if (n >= 0) |
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error(USER, "display process died"); |
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if (errno != EAGAIN & errno != EINTR) |
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goto readerr; |
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return(2); /* acceptable failure */ |
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} |
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if (msg.nbytes) { /* get the message body */ |
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buf = (char *)malloc(msg.nbytes); |
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if (buf == NULL) |
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error(SYSTEM, "out of memory in disp_check"); |
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if (fcntl(dpd[0], F_SETFL, inp_flags=0) < 0) |
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goto fcntlerr; |
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if (readbuf(dpd[0], buf, msg.nbytes) != msg.nbytes) |
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goto readerr; |
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} |
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switch (msg.type) { /* take appropriate action */ |
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case DR_BUNDLE: |
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if (msg.nbytes != sizeof(PACKHEAD)) |
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error(INTERNAL, "bad DR_BUNDLE from display process"); |
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bundle_set(BS_ADD, (PACKHEAD *)buf, 1); |
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break; |
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case DR_NEWSET: |
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if (msg.nbytes % sizeof(PACKHEAD)) |
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error(INTERNAL, "bad DR_NEWSET from display process"); |
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disp_result(DS_STARTIMM, 0, NULL); |
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bundle_set(BS_NEW, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD)); |
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disp_result(DS_ENDIMM, 0, NULL); |
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disp_flush(); |
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break; |
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case DR_ADDSET: |
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if (msg.nbytes % sizeof(PACKHEAD)) |
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error(INTERNAL, "bad DR_ADDSET from display process"); |
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disp_result(DS_STARTIMM, 0, NULL); |
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bundle_set(BS_ADD, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD)); |
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disp_result(DS_ENDIMM, 0, NULL); |
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disp_flush(); |
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break; |
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case DR_DELSET: |
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if (msg.nbytes % sizeof(PACKHEAD)) |
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error(INTERNAL, "bad DR_DELSET from display process"); |
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bundle_set(BS_DEL, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD)); |
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break; |
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case DR_ATTEN: |
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if (msg.nbytes) |
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error(INTERNAL, "bad DR_ATTEN from display process"); |
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/* send acknowledgement */ |
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disp_result(DS_ACKNOW, 0, NULL); |
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return(disp_check(1)); /* block on following request */ |
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case DR_SHUTDOWN: |
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if (msg.nbytes) |
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error(INTERNAL, "bad DR_SHUTDOWN from display process"); |
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return(0); /* zero return signals shutdown */ |
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default: |
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error(INTERNAL, "unrecognized request from display process"); |
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} |
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if (msg.nbytes) /* clean up */ |
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free(buf); |
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return(1); /* normal return value */ |
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fcntlerr: |
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error(SYSTEM, "cannot change display blocking mode"); |
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readerr: |
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error(SYSTEM, "error reading from display process"); |
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} |
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|
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|
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int |
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disp_close() /* close our display process */ |
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{ |
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int rval; |
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|
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if (pipesiz <= 0) |
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return(-1); |
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disp_result(DS_SHUTDOWN, 0, NULL); |
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fclose(dpout); |
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dpout = NULL; |
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pipesiz = 0; |
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return(close_process(dpd)); |
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} |
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|
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|
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disp_result(type, nbytes, p) /* queue result message to display process */ |
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int type, nbytes; |
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char *p; |
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{ |
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MSGHEAD msg; |
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|
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msg.type = type; |
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msg.nbytes = nbytes; |
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fwrite((char *)&msg, sizeof(MSGHEAD), 1, dpout); |
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if (nbytes > 0) |
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fwrite(p, 1, nbytes, dpout); |
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} |
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|
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|
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disp_flush() /* flush output to display */ |
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{ |
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if (fflush(dpout) < 0) |
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error(SYSTEM, "error writing to the display process"); |
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} |