mod_statusbar/statusd-launch.c

   1 /*
   2  * ion/mod_statusbar/statusd-launch.c
   3  *
   4  * Copyright (c) Tuomo Valkonen 1999-2009.
   5  *
   6  * See the included file LICENSE for details.
   7  */
   8
   9 #include <sys/time.h>
  10 #include <sys/types.h>
  11 #include <signal.h>
  12 #include <unistd.h>
  13 #include <time.h>
  14 #include <errno.h>
  15
  16 #include <libtu/minmax.h>
  17 #include <libextl/readconfig.h>
  18 #include <libmainloop/exec.h>
  19 #include <libmainloop/select.h>
  20 #include <libmainloop/signal.h>
  21 #include <ioncore/saveload.h>
  22 #include <ioncore/bindmaps.h>
  23 #include <ioncore/global.h>
  24 #include <ioncore/ioncore.h>
  25
  26 #include "statusbar.h"
  27
  28
  29 #define CF_STATUSD_TIMEOUT_SEC 3
  30
  31 #define BL 1024
  32
  33 #define USEC 1000000
  34
  35 static bool process_pipe(int fd, ExtlFn fn,
  36                          bool *doneseen, bool *eagain)
  37 {
  38     char buf[BL];
  39     int n;
  40
  41     *eagain=FALSE;
  42
  43     n=read(fd, buf, BL-1);
  44
  45     if(n<0){
  46         if(errno==EAGAIN || errno==EINTR){
  47             *eagain=(errno==EAGAIN);
  48             return TRUE;
  49         }
  50         warn_err_obj(TR("reading a pipe"));
  51         return FALSE;
  52     }else if(n>0){
  53         buf[n]='\0';
  54         *doneseen=FALSE;
  55         return extl_call(fn, "s", "b", &buf, doneseen);
  56     }
  57
  58     return FALSE;
  59 }
  60
  61
  62 static bool wait_statusd_init(int outfd, int errfd, ExtlFn dh, ExtlFn eh)
  63 {
  64     fd_set rfds;
  65     struct timeval tv, endtime, now;
  66     int nfds=maxof(outfd, errfd);
  67     int retval;
  68     bool dummy, doneseen, eagain=FALSE;
  69
  70     if(mainloop_gettime(&endtime)!=0){
  71         warn_err();
  72         return FALSE;
  73     }
  74
  75     now=endtime;
  76     endtime.tv_sec+=CF_STATUSD_TIMEOUT_SEC;
  77
  78     while(1){
  79         FD_ZERO(&rfds);
  80
  81         /* Calculate remaining time */
  82         if(now.tv_sec>endtime.tv_sec){
  83             goto timeout;
  84         }else if(now.tv_sec==endtime.tv_sec){
  85             if(now.tv_usec>=endtime.tv_usec)
  86                 goto timeout;
  87             tv.tv_sec=0;
  88             tv.tv_usec=endtime.tv_usec-now.tv_usec;
  89         }else{
  90             tv.tv_usec=USEC+endtime.tv_usec-now.tv_usec;
  91             tv.tv_sec=-1+endtime.tv_sec-now.tv_sec;
  92             /* Kernel lameness tuner: */
  93             tv.tv_sec+=tv.tv_usec/USEC;
  94             tv.tv_usec%=USEC;
  95         }
  96
  97         FD_SET(outfd, &rfds);
  98         FD_SET(errfd, &rfds);
  99
 100         retval=select(nfds+1, &rfds, NULL, NULL, &tv);
 101         if(retval>0){
 102             if(FD_ISSET(errfd, &rfds)){
 103                 if(!process_pipe(errfd, eh, &dummy, &eagain))
 104                     return FALSE;
 105             }
 106             if(FD_ISSET(outfd, &rfds)){
 107                 if(!process_pipe(outfd, dh, &doneseen, &eagain))
 108                     return FALSE;
 109                 if(doneseen){
 110                     /* Read rest of errors. */
 111                     bool ok;
 112                     do{
 113                         ok=process_pipe(errfd, eh, &dummy, &eagain);
 114                     }while(ok && !eagain);
 115                     return TRUE;
 116                 }
 117             }
 118         }else if(retval==0){
 119             goto timeout;
 120         }
 121
 122         if(mainloop_gettime(&now)!=0){
 123             warn_err();
 124             return FALSE;
 125         }
 126     }
 127
 128     return TRUE;
 129
 130 timeout:
 131     /* Just complain to stderr, not startup error log, and do not fail.
 132      * The system might just be a bit slow. We can continue, but without
 133      * initial values for the meters, geometry adjustments may be necessary
 134      * when we finally get that information.
 135      */
 136     ioncore_warn_nolog(TR("ion-statusd timed out."));
 137     return TRUE;
 138 }
 139
 140
 141 EXTL_EXPORT
 142 int mod_statusbar__launch_statusd(const char *cmd,
 143                                   ExtlFn initdatahandler,
 144                                   ExtlFn initerrhandler,
 145                                   ExtlFn datahandler,
 146                                   ExtlFn errhandler)
 147 {
 148     pid_t pid;
 149     int outfd=-1, errfd=-1;
 150
 151     if(cmd==NULL)
 152         return -1;
 153
 154     pid=mainloop_do_spawn(cmd, NULL, NULL,
 155                           NULL, &outfd, &errfd);
 156
 157     if(pid<0)
 158         return -1;
 159
 160     if(!wait_statusd_init(outfd, errfd, initdatahandler, initerrhandler))
 161         goto err;
 162
 163     if(!mainloop_register_input_fd_extlfn(outfd, datahandler))
 164         goto err;
 165
 166     if(!mainloop_register_input_fd_extlfn(errfd, errhandler))
 167         goto err2;
 168
 169     return pid;
 170
 171 err2:
 172     mainloop_unregister_input_fd(outfd);
 173 err:
 174     close(outfd);
 175     close(errfd);
 176     return -1;
 177 }
 178
 179 /* statusd automatically exits when notion dies. However, when notion is
 180  * restarted (i.e. notioncore.restart()), the new notion process is simply
 181  * execve'ed on top of the old one, therefore the ion-statusd process must
 182  * be explicitly terminated on deinit. This function should be called
 183  * from Lua on deinit with the ion-statusd process id generated above.
 184  */
 185 EXTL_EXPORT
 186 int mod_statusbar__terminate_statusd(int pid)
 187 {
 188     if(pid==0) {
 189         return -1;
 190     }
 191
 192     /* Send SIGHUP to the specified statusd process to indicate
 193      * that we're done. */
 194     kill( (pid_t)pid, SIGHUP);
 195
 196     return 0;
 197 }
 198