Fixed a race. Kernel could send iPAQ sleeping while opiealarm had not yet

set the RTC alarm.

1 files changed, 27 insertions, 7 deletions

diff --git a/core/opiealarm/opiealarm.c b/core/opiealarm/opiealarm.c
index ce0103e..d96ffaf 100644
--- a/core/opiealarm/opiealarm.c
+++ b/core/opiealarm/opiealarm.c
@@ -43,6 +43,8 @@ int onac ( void );
 
 static int opiealarm_was_running;
 
+static pid_t startpid = 0;
+
 
 void log_msg ( const char *msg )
 {
@@ -58,6 +60,9 @@ void error_msg_and_die ( int perr, const char *msg )
                 log_msg ( strerror ( errno ));
         log_msg ( msg );
 
+        if ( getpid ( ) != startpid ) 
+                kill ( startpid, SIGUSR1 );
+
                 while ( 1 )     // pretend we are waiting on RTC, so opiealarm -r can kill us
                 sleep ( 1 );
 }
@@ -65,12 +70,19 @@ void error_msg_and_die ( int perr, const char *msg )
 
 void sig_handler ( int sig )
 {
-        log_msg ( "GOT SIGNAL -> EXITING\n" );
-        fclose ( log );
+        if ( log ) {
+                log_msg ( "GOT SIGNAL -> EXITING\n" );
+                fclose ( log );
+        }
         remove_pidfile ( );
         exit ( 0 );
 }
 
+void sig_handler_parent ( int sig )
+{
+        exit ( 0 );
+}
+
 void usage ( void )
 {
         fprintf ( stderr, "Usage: opiealarm -s [-f] | -r [-a]\n\n" );
@@ -88,8 +100,12 @@ int fork_with_pidfile ( void )
         
         pid = fork ( );
         
-        if ( pid > 0 )
+        if ( pid > 0 ) {
+                signal ( SIGUSR1, sig_handler_parent );
+                while ( 1 )
+                        sleep ( 1000 );
                 exit ( 0 );
+        }
         else if ( pid < 0 ) {
                 perror ( "forking failed" );
                 return 0;
@@ -180,6 +196,7 @@ int main ( int argc, char **argv )
                 usage ( );
 
         // kill running opiealarm
+        startpid = getpid ( );
         opiealarm_was_running = kill_with_pidfile ( );
         remove_pidfile ( );
 
@@ -192,6 +209,7 @@ int main ( int argc, char **argv )
         }       
                 
 
+
 int suspend ( int fix_rtc )
 {
         FILE *fp;
@@ -209,7 +227,6 @@ int suspend ( int fix_rtc )
         log_msg ( "STARTING\n" );
         
 
-
         if (!( fp = fopen ( "/etc/resumeat", "r" ))) 
                 error_msg_and_die ( 1, "/etc/resumeat" );
         
@@ -223,8 +240,8 @@ int suspend ( int fix_rtc )
         if ( alrt == 0 )
                 error_msg_and_die ( 0, "/etc/resumeat contains an invalid time description" );
         
-        /* subtract 5 sec from event time... */
-        alrt -= 5;
+                alrt -= 5; // wake up 5 sec before the specified time
+
 
                 if ( log )
                 fprintf ( log, "Setting RTC alarm to %d\n", alrt );
@@ -274,7 +291,9 @@ int suspend ( int fix_rtc )
         if ( ioctl ( fd, RTC_AIE_ON, 0 ) < 0 )
                 error_msg_and_die ( 1, "ioctl RTC_AIE_ON" );
         
-        log_msg ( "SLEEPING\n" );
+        if ( log )
+                fprintf( log, "SIGUSR: pid %d - SLEEPING: pid %d\n", startpid, getpid ( ));
+        kill ( startpid, SIGUSR1 );
                         
         // wait for alarm irq
         if ( read ( fd, buf, sizeof( unsigned long )) < 0 )
@@ -326,6 +345,7 @@ int resume ( int resuspend )
                                                 
                         if ( !fork_with_pidfile ( ))
                                 return 4;
+                        kill ( startpid, SIGUSR1 );
 
                         // sleep <resuspend> sec (not less!)
                         time ( &start );