cde/lib/DtSvc/DtUtil2/ChkpntListen.c

   1 /*
   2  * CDE - Common Desktop Environment
   3  *
   4  * Copyright (c) 1993-2012, The Open Group. All rights reserved.
   5  *
   6  * These libraries and programs are free software; you can
   7  * redistribute them and/or modify them under the terms of the GNU
   8  * Lesser General Public License as published by the Free Software
   9  * Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  * These libraries and programs are distributed in the hope that
  13  * they will be useful, but WITHOUT ANY WARRANTY; without even the
  14  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  15  * PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with these librararies and programs; if not, write
  20  * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
  21  * Floor, Boston, MA 02110-1301 USA
  22  */
  23 /*
  24  * (c) Copyright 1993, 1994 Hewlett-Packard Company                     *
  25  * (c) Copyright 1993, 1994 International Business Machines Corp.       *
  26  * (c) Copyright 1993, 1994 Sun Microsystems, Inc.                      *
  27  * (c) Copyright 1993, 1994 Novell, Inc.                                *
  28  */
  29 /* -*-C-*-
  30 *******************************************************************************
  31 *
  32 * File:         ChkpntListen.c
  33 * Description:  CDE listener-side checkpoint protocol functions. Internal API
  34 *               functions for use by the CDE checkpoint listener.
  35 * Created:      Mon Sep  6 09:00:00 1993
  36 * Language:     C
  37 *
  38 * $XConsortium: ChkpntListen.c /main/6 1996/08/28 15:14:40 drk $
  39 *
  40 * (C) Copyright 1993, Hewlett-Packard, all rights reserved.
  41 *
  42 *******************************************************************************
  43 */
  44
  45 #define INVALID_TIME    ((Time) -1)
  46
  47 #include <stdio.h>
  48 #include <string.h>
  49 #include "Dt/ChkpntP.h"
  50 #include "DtSvcLock.h"
  51
  52 static struct {
  53     Display     *display;               /* Display pointer              */
  54     Window      window;                 /* Window id for the program    */
  55     Atom        aSelection;             /* Atom  for root selection     */
  56     Boolean     bListen;                /* Should I do listening ?      */
  57 } dtsvc_info;
  58
  59 /* _DtPerfChkpntListenInit(): Start the Checkpoint listener */
  60 #ifdef _NOPROTO
  61 _DtPerfChkpntListenInit(display, parentwin)
  62 Display *display;       /* Current display */
  63 Window  parentwin;      /* Parent of window associated with listener */
  64 #else
  65 _DtPerfChkpntListenInit(Display *display, Window parentwin)
  66 #endif
  67 {
  68     Time   timestamp = INVALID_TIME;
  69     Window tmpwin;
  70     Bool   bsuccess = False;
  71
  72     _DtSvcProcessLock();
  73     dtsvc_info.display    = display;
  74     dtsvc_info.window     = XCreateSimpleWindow(display, parentwin,
  75                               1, 1, 100, 100, 1,
  76                               BlackPixel(display,DefaultScreen(display)),
  77                               WhitePixel(display,DefaultScreen(display)));
  78     dtsvc_info.bListen    = True;
  79     /*
  80      * Assert ownership over the appropriate root window selection
  81      */
  82     dtsvc_info.aSelection = XInternAtom(display, DT_PERF_CHKPNT_SEL, False);
  83     if (XGetSelectionOwner(dtsvc_info.display, dtsvc_info.aSelection) == None) {
  84         if (timestamp == INVALID_TIME) { /* Generate a valid timestamp */
  85             XEvent event;
  86             Atom aProperty;
  87             char   propname[80];        /* Temp buffer for property name */
  88
  89             sprintf(propname, "%s_%x", DT_PERF_CLIENT_CHKPNT_PROP, 0);
  90             aProperty  = XInternAtom(dtsvc_info.display, propname,False);
  91             XSelectInput(dtsvc_info.display,
  92                                     dtsvc_info.window, PropertyChangeMask);
  93
  94             XChangeProperty(dtsvc_info.display,  dtsvc_info.window,
  95                                     aProperty, XA_STRING, 8,
  96                                     PropModeAppend, (unsigned char *) NULL, 0);
  97             XFlush(dtsvc_info.display);
  98             loop:
  99             XWindowEvent(dtsvc_info.display, dtsvc_info.window,
 100                                     PropertyChangeMask,  &event);
 101             if (event.type == PropertyNotify) {
 102                 timestamp = event.xproperty.time;
 103             }
 104             else goto loop;
 105         }
 106         XSetSelectionOwner(dtsvc_info.display, dtsvc_info.aSelection,
 107                            dtsvc_info.window,  timestamp);
 108         tmpwin = XGetSelectionOwner(dtsvc_info.display, dtsvc_info.aSelection);
 109         if ( tmpwin == dtsvc_info.window)
 110                 bsuccess = True;/* We are now the listener! */
 111     }
 112
 113     if (bsuccess == False) {
 114         fprintf(stderr,
 115           "\t** Chkpnt listener: Cannot gain ownership of root selection **\n");
 116         fprintf(stderr,
 117           "\t** Chkpnt listener: Selection is owned by window: %lx **\n",
 118           (long) tmpwin);
 119         dtsvc_info.bListen = False;
 120         _DtSvcProcessUnlock();
 121         return(0);
 122     }
 123
 124     /* Express interests in Events on this window */
 125     XSelectInput(dtsvc_info.display, dtsvc_info.window,
 126                  SelectionRequest | SelectionClear);
 127
 128     _DtSvcProcessUnlock();
 129     return(1);
 130 }
 131
 132 /* Helper Boolean function to pass to XCheckIfEvent() */
 133 static Bool myCheckSelectionEvent(Display *display, XEvent *event, char *args)
 134 {
 135     _DtSvcProcessLock();
 136
 137     if (event->xany.window != dtsvc_info.window) { /* Only listener window events*/
 138         _DtSvcProcessUnlock();
 139         return(False);
 140     }
 141     else switch(event->type) {                  /* Selection stuff ? */
 142         case SelectionClear:
 143         case SelectionRequest:
 144             _DtSvcProcessUnlock();
 145             return (True);
 146             break;
 147         default:
 148             _DtSvcProcessUnlock();
 149             return (False);
 150             break;
 151     }
 152 }
 153
 154 /*
 155  * _DtPerfChkpntMsgReceive() Non blocking fetch from message queue
 156  */
 157 Bool _DtPerfChkpntMsgReceive(DtChkpntMsg *dtcp_msg, Bool bBlock)
 158 {
 159     XEvent        event;
 160     Bool          bool=True;
 161     XTextProperty tp;
 162     int           i;
 163     static char   **Stringlist;
 164     static int    numfields = 0;
 165
 166     _DtSvcProcessLock();
 167     if (dtsvc_info.bListen == False) {
 168         _DtSvcProcessUnlock();
 169         return(False);
 170     }
 171
 172     if (numfields) {    /* Free the storage from last time around */
 173         XFreeStringList(Stringlist);
 174         numfields = 0;
 175     }
 176
 177     if (bBlock == True)
 178         XIfEvent(dtsvc_info.display, &event, myCheckSelectionEvent, NULL);
 179     else
 180         bool = XCheckIfEvent(dtsvc_info.display, &event,
 181                                 myCheckSelectionEvent, NULL);
 182
 183     if (bool == True) {
 184         switch (event.type) {
 185             case SelectionRequest:      /* Message received from a client */
 186                 /* Is this a Checkpoint request ?*/
 187                 if (event.xselectionrequest.selection == dtsvc_info.aSelection){
 188                     /* Correct selection, now fetch the property */
 189                     /*
 190                      * Note: Need to handle errors if the client is dead
 191                      * and the property no longer exists.
 192                      */
 193                     XGetTextProperty(dtsvc_info.display,
 194                                      event.xselectionrequest.requestor,
 195                                      &tp,
 196                                      event.xselectionrequest.property);
 197                     XDeleteProperty (dtsvc_info.display,
 198                                      event.xselectionrequest.requestor,
 199                                      event.xselectionrequest.property);
 200                     XTextPropertyToStringList(&tp, &Stringlist, &numfields);
 201                     XFree(tp.value);
 202                     for (i = 0; i < DT_PERF_CHKPNT_MSG_SIZE; i++)
 203                         dtcp_msg->array[i] = (Stringlist)[i];
 204
 205                     /* End? Destroy the, RetainPermanent client window */
 206                     if (!strcmp(dtcp_msg->record.type, DT_PERF_CHKPNT_MSG_END))
 207                         XDestroyWindow(dtsvc_info.display,
 208                                        event.xselectionrequest.requestor);
 209                 }
 210                 break;
 211             /* */
 212             case SelectionClear:        /* We no longer own the selection */
 213             default:
 214                 fprintf(stderr,"\t** Chkpnt listener: Warning - loss of Selection ownership **\n");
 215                 bool = False;
 216                 break;
 217         }
 218     }
 219     _DtSvcProcessUnlock();
 220     return(bool);
 221 }