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
@@ -40,12 +40,14 @@ void usage ( void );
 void sig_handler ( int sig );
 void error_msg_and_die ( int perr, const char *msg );
 int onac ( void );
 
 static int opiealarm_was_running;
 
+static pid_t startpid = 0;
+
 
 void log_msg ( const char *msg )
 {
 	if ( log ) {
 		fprintf ( log, msg );
 		fflush ( log );
@@ -55,25 +57,35 @@ void log_msg ( const char *msg )
 void error_msg_and_die ( int perr, const char *msg )
 {
 	if ( perr )
 		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 );
 }
 
 
 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" );
 	fprintf ( stderr, "\t-s\tSuspend mode: set RTC alarm\n" );
 	fprintf ( stderr, "\t-f    \tFix RTC, if RTC and system have more than 5sec difference (suspend mode)\n" );
 	fprintf ( stderr, "\t-r\tResume mode: kill running opiealarm\n" );
@@ -85,14 +97,18 @@ int fork_with_pidfile ( void )
 {
 	FILE *fp;
 	pid_t pid;
 	
 	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;
 	}
 
 	signal ( SIGTERM, sig_handler );
@@ -177,24 +193,26 @@ int main ( int argc, char **argv )
 	}
 	
 	if ( !mode )
 		usage ( );
 
 	// kill running opiealarm
+	startpid = getpid ( );
 	opiealarm_was_running = kill_with_pidfile ( );
 	remove_pidfile ( );
 
 	switch ( mode ) {
 		case 'r': return resume ( ac_resusp );
 		case 's':
 		default : return suspend ( fix_rtc );
 	}
 	return 0;
 }		
 		
 
+
 int suspend ( int fix_rtc )
 {
 	FILE *fp;
 	char buf [64];
 	time_t alrt, syst, rtct;
 	struct tm alr, sys, rtc;
@@ -206,13 +224,12 @@ int suspend ( int fix_rtc )
 		return 3;
 		
 	log = fopen ( "/tmp/opiealarm.log", "w" ); 
 	log_msg ( "STARTING\n" );
 	
 
-
 	if (!( fp = fopen ( "/etc/resumeat", "r" ))) 
 		error_msg_and_die ( 1, "/etc/resumeat" );
 	
 	if ( !fgets ( buf, sizeof( buf ) - 1, fp ))
 		error_msg_and_die ( 1, "/etc/resumeat" );
 
@@ -220,14 +237,14 @@ int suspend ( int fix_rtc )
 	
 	alrt = atoi ( buf );
 	
 	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 );
 
 	tzset ( );
 	
@@ -271,13 +288,15 @@ int suspend ( int fix_rtc )
 	if ( ioctl ( fd, RTC_ALM_SET, &alr ) < 0 )
 		error_msg_and_die ( 1, "ioctl RTC_ALM_SET" );		
 	// enable alarm irq	
 	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 )
 		error_msg_and_die ( 1, "read rtc alarm" );
 	
 	log_msg ( "WAKEUP\n" );
@@ -323,12 +342,13 @@ int resume ( int resuspend )
 		if ( resuspend && onac ( )) {	
 			time_t start, now;
 			char *argv [4];
 						
 			if ( !fork_with_pidfile ( ))
 				return 4;
+			kill ( startpid, SIGUSR1 );
 
 			// sleep <resuspend> sec (not less!)
 			time ( &start );
 			do {
 				sleep ( 1 );
 				time ( &now );