mod_statusbar/statusd-launch.c

   1 /*
   2  * ion/mod_statusbar/statusd-launch.c
   3  *
   4  * Copyright (c) Tuomo Valkonen 1999-2008.
   5  *
   6  * See the included file LICENSE for details.
   7  */
   8
   9 #include <sys/time.h>
  10 #include <sys/types.h>
  11 #include <unistd.h>
  12 #include <time.h>
  13 #include <errno.h>
  14
  15 #include <libtu/minmax.h>
  16 #include <libextl/readconfig.h>
  17 #include <libmainloop/exec.h>
  18 #include <libmainloop/select.h>
  19 #include <libmainloop/signal.h>
  20 #include <ioncore/saveload.h>
  21 #include <ioncore/bindmaps.h>
  22 #include <ioncore/global.h>
  23 #include <ioncore/ioncore.h>
  24
  25 #include "statusbar.h"
  26
  27
  28 #define CF_STATUSD_TIMEOUT_SEC 3
  29
  30 #define BL 1024
  31
  32 #define USEC 1000000
  33
  34
  35 static bool process_pipe(int fd, ExtlFn fn,
  36                          bool *doneseen, bool *eagain)
  37 {
  38     char buf[BL];
  39     int n;
  40     bool fnret;
  41
  42     *eagain=FALSE;
  43
  44     n=read(fd, buf, BL-1);
  45
  46     if(n<0){
  47         if(errno==EAGAIN || errno==EINTR){
  48             *eagain=(errno==EAGAIN);
  49             return TRUE;
  50         }
  51         warn_err_obj(TR("reading a pipe"));
  52         return FALSE;
  53     }else if(n>0){
  54         buf[n]='\0';
  55         *doneseen=FALSE;
  56         return extl_call(fn, "s", "b", &buf, doneseen);
  57     }
  58
  59     return FALSE;
  60 }
  61
  62
  63 static bool wait_statusd_init(int outfd, int errfd, ExtlFn dh, ExtlFn eh)
  64 {
  65     fd_set rfds;
  66     struct timeval tv, endtime, now;
  67     int nfds=maxof(outfd, errfd);
  68     int retval;
  69     bool dummy, doneseen, eagain=FALSE;
  70
  71     if(mainloop_gettime(&endtime)!=0){
  72         warn_err();
  73         return FALSE;
  74     }
  75
  76     now=endtime;
  77     endtime.tv_sec+=CF_STATUSD_TIMEOUT_SEC;
  78
  79     while(1){
  80         FD_ZERO(&rfds);
  81
  82         /* Calculate remaining time */
  83         if(now.tv_sec>endtime.tv_sec){
  84             goto timeout;
  85         }else if(now.tv_sec==endtime.tv_sec){
  86             if(now.tv_usec>=endtime.tv_usec)
  87                 goto timeout;
  88             tv.tv_sec=0;
  89             tv.tv_usec=endtime.tv_usec-now.tv_usec;
  90         }else{
  91             tv.tv_usec=USEC+endtime.tv_usec-now.tv_usec;
  92             tv.tv_sec=-1+endtime.tv_sec-now.tv_sec;
  93             /* Kernel lameness tuner: */
  94             tv.tv_sec+=tv.tv_usec/USEC;
  95             tv.tv_usec%=USEC;
  96         }
  97
  98         FD_SET(outfd, &rfds);
  99         FD_SET(errfd, &rfds);
 100
 101         retval=select(nfds+1, &rfds, NULL, NULL, &tv);
 102         if(retval>0){
 103             if(FD_ISSET(errfd, &rfds)){
 104                 if(!process_pipe(errfd, eh, &dummy, &eagain))
 105                     return FALSE;
 106             }
 107             if(FD_ISSET(outfd, &rfds)){
 108                 if(!process_pipe(outfd, dh, &doneseen, &eagain))
 109                     return FALSE;
 110                 if(doneseen){
 111                     /* Read rest of errors. */
 112                     bool ok;
 113                     do{
 114                         ok=process_pipe(errfd, eh, &dummy, &eagain);
 115                     }while(ok && !eagain);
 116                     return TRUE;
 117                 }
 118             }
 119         }else if(retval==0){
 120             goto timeout;
 121         }
 122
 123         if(mainloop_gettime(&now)!=0){
 124             warn_err();
 125             return FALSE;
 126         }
 127     }
 128
 129     return TRUE;
 130
 131 timeout:
 132     /* Just complain to stderr, not startup error log, and do not fail.
 133      * The system might just be a bit slow. We can continue, but without
 134      * initial values for the meters, geometry adjustments may be necessary
 135      * when we finally get that information.
 136      */
 137     ioncore_warn_nolog(TR("ion-statusd timed out."));
 138     return TRUE;
 139 }
 140
 141
 142 EXTL_EXPORT
 143 int mod_statusbar__launch_statusd(const char *cmd,
 144                                   ExtlFn initdatahandler,
 145                                   ExtlFn initerrhandler,
 146                                   ExtlFn datahandler,
 147                                   ExtlFn errhandler)
 148 {
 149     pid_t pid;
 150     int outfd=-1, errfd=-1;
 151
 152     if(cmd==NULL)
 153         return -1;
 154
 155     pid=mainloop_do_spawn(cmd, NULL, NULL,
 156                           NULL, &outfd, &errfd);
 157
 158     if(pid<0)
 159         return -1;
 160
 161     if(!wait_statusd_init(outfd, errfd, initdatahandler, initerrhandler))
 162         goto err;
 163
 164     if(!mainloop_register_input_fd_extlfn(outfd, datahandler))
 165         goto err;
 166
 167     if(!mainloop_register_input_fd_extlfn(errfd, errhandler))
 168         goto err2;
 169
 170     return pid;
 171
 172 err2:
 173     mainloop_unregister_input_fd(outfd);
 174 err:
 175     close(outfd);
 176     close(errfd);
 177     return -1;
 178 }
 179