[SERVER] Add timer infrastructure

To be used by "close unused fd" checks, and others...

2 files changed, 134 insertions, 10 deletions

diff --git a/src/server/server.c b/src/server/server.c
index 922740a..1cdd2ab 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -45,6 +45,25 @@
 #define LONGOPT_SIZE       1004
 #define LONGOPT_ERRORMSG   1005
 
+typedef struct _job job_t;
+
+struct _job {
+	job_t *next;
+	void *(*startRoutine)(void *);
+	void *arg;
+	ticks dueDate;
+	int intervalSecs;
+};
+
+static job_t *jobHead;
+static _Atomic(job_t *) newJob;
+static bool hasTimerThread = false;
+static pthread_t timerThread;
+
+static pthread_t mainThread;
+
+#define DEFAULT_TIMER_TIMEOUT (60)
+
 static poll_list_t *listeners = NULL;
 
 /**
@@ -71,6 +90,12 @@ static void dnbd3_handleSignal2(int signum, siginfo_t *info, void *data);
 
 static void* server_asyncImageListLoad(void *data);
 
+static void* timerMainloop(void*);
+
+static int handlePendingJobs(void);
+
+static void queueJobInternal(job_t *job);
+
 /**
  * Print help text for usage instructions
  */
@@ -105,14 +130,21 @@ void dnbd3_printVersion()
 /**
  * Clean up structs, connections, write out data, then exit
  */
-void dnbd3_cleanup()
+_Noreturn static void dnbd3_cleanup()
 {
 	int retries;
 
 	_shutdown = true;
 	logadd( LOG_INFO, "Cleanup..." );
 
-	if ( listeners != NULL ) sock_destroyPollList( listeners );
+	if ( hasTimerThread ) {
+		pthread_kill( timerThread, SIGHUP );
+		thread_join( timerThread, NULL );
+	}
+
+	if ( listeners != NULL ) {
+		sock_destroyPollList( listeners );
+	}
 	listeners = NULL;
 
 	// Kill connection to all clients
@@ -172,6 +204,7 @@ int main(int argc, char *argv[])
 			{ 0, 0, 0, 0 }
 	};
 
+	mainThread = pthread_self();
 	opt = getopt_long( argc, argv, optString, longOpts, &longIndex );
 
 	while ( opt != -1 ) {
@@ -195,8 +228,12 @@ int main(int argc, char *argv[])
 		case LONGOPT_CRC4:
 			return image_generateCrcFile( optarg ) ? 0 : EXIT_FAILURE;
 		case LONGOPT_ASSERT:
+			printf( "Now leaking memory:\n" );
+			char *bla = malloc( 10 );
+			bla[2] = 3;
+			bla = NULL;
 			printf( "Testing use after free:\n" );
-			volatile char * volatile test = malloc( 10 );
+			char *test = malloc( 10 );
 			test[0] = 1;
 			free( (void*)test );
 			test[1] = 2;
@@ -303,11 +340,10 @@ int main(int argc, char *argv[])
 	}
 
 	// setup signal handler
-	struct sigaction sa;
-	memset( &sa, 0, sizeof(sa) );
-	sa.sa_sigaction = dnbd3_handleSignal2;
-	sa.sa_flags = SA_SIGINFO;
-	//sa.sa_mask = ;
+	struct sigaction sa = {
+		.sa_sigaction = dnbd3_handleSignal2,
+		.sa_flags = SA_SIGINFO,
+	};
 	sigaction( SIGTERM, &sa, NULL );
 	sigaction( SIGINT, &sa, NULL );
 	sigaction( SIGUSR1, &sa, NULL );
@@ -342,6 +378,10 @@ int main(int argc, char *argv[])
 
 	logadd( LOG_INFO, "Server is ready. (%s)", VERSION_STRING );
 
+	if ( thread_create( &timerThread, NULL, &timerMainloop, NULL ) == 0 ) {
+		hasTimerThread = true;
+	}
+
 	// +++++++++++++++++++++++++++++++++++++++++++++++++++ main loop
 	struct sockaddr_storage client;
 	socklen_t len;
@@ -365,7 +405,7 @@ int main(int argc, char *argv[])
 		//
 		len = sizeof(client);
 		fd = sock_accept( listeners, &client, &len );
-		if ( fd < 0 ) {
+		if ( fd == -1 ) {
 			const int err = errno;
 			if ( err == EINTR || err == EAGAIN ) continue;
 			logadd( LOG_ERROR, "Client accept failure (err=%d)", err );
@@ -469,6 +509,8 @@ static void dnbd3_handleSignal(int signum)
 
 static void dnbd3_handleSignal2(int signum, siginfo_t *info, void *data UNUSED)
 {
+	if ( !pthread_equal( pthread_self(), mainThread ) )
+		return;
 	memcpy( &lastSignal, info, sizeof(siginfo_t) );
 	dnbd3_handleSignal( signum );
 }
@@ -488,3 +530,85 @@ static void* server_asyncImageListLoad(void *data UNUSED)
 	return NULL;
 }
 
+static void* timerMainloop(void* stuff UNUSED)
+{
+	setThreadName( "timer" );
+	while ( !_shutdown ) {
+		// Handle jobs/timer events; returns timeout until next event
+		int to = handlePendingJobs();
+		sleep( MIN( MAX( 1, to ), DEFAULT_TIMER_TIMEOUT ) );
+	}
+	logadd( LOG_DEBUG1, "Timer thread done" );
+	return NULL;
+}
+
+static int handlePendingJobs(void)
+{
+	declare_now;
+	job_t *todo, **temp, *old;
+	int diff;
+	todo = jobHead;
+	for ( temp = &todo; *temp != NULL; temp = &(*temp)->next ) {
+		diff = (int)timing_diff( &now, &(*temp)->dueDate );
+		if ( diff > 0 ) // Found one that's in the future
+			break;
+	}
+	jobHead = *temp; // Make it list head
+	*temp = NULL; // Split off part before that
+	while ( todo != NULL ) {
+		threadpool_run( todo->startRoutine, todo->arg );
+		old = todo;
+		todo = todo->next;
+		if ( old->intervalSecs == 0 ) {
+			free( old ); // oneshot
+		} else {
+			timing_set( &old->dueDate, &now, old->intervalSecs );
+			queueJobInternal( old ); // repeated
+		}
+	}
+	// See if any new jobs have been queued
+	while ( newJob != NULL ) {
+		todo = newJob;
+		// NULL should never happen since we're the only consumer
+		assert( todo != NULL );
+		if ( !atomic_compare_exchange_weak( &newJob, &todo, NULL ) )
+			continue;
+		do {
+			old = todo;
+			todo = todo->next;
+			queueJobInternal( old );
+		} while ( todo != NULL );
+	}
+	// Return new timeout
+	if ( jobHead == NULL )
+		return DEFAULT_TIMER_TIMEOUT;
+	return (int)timing_diff( &now, &jobHead->dueDate );
+}
+
+static void queueJobInternal(job_t *job)
+{
+	assert( job != NULL );
+	job_t **it;
+	for ( it = &jobHead; *it != NULL; it = &(*it)->next ) {
+		if ( timing_1le2( &job->dueDate, &(*it)->dueDate ) )
+			break;
+	}
+	job->next = *it;
+	*it = job;
+}
+
+void server_addJob(void *(*startRoutine)(void *), void *arg, int delaySecs, int intervalSecs)
+{
+	declare_now;
+	job_t *new = malloc( sizeof(*new) );
+	new->startRoutine = startRoutine;
+	new->arg = arg;
+	new->intervalSecs = intervalSecs;
+	timing_set( &new->dueDate, &now, delaySecs );
+	for ( ;; ) {
+		new->next = newJob;
+		if ( atomic_compare_exchange_weak( &newJob, &new->next, new ) )
+			break;
+	}
+}
+
diff --git a/src/server/server.h b/src/server/server.h
index bab8421..a026eb6 100644
--- a/src/server/server.h
+++ b/src/server/server.h
@@ -24,8 +24,8 @@
 #include "globals.h"
 #include "../types.h"
 
-void dnbd3_cleanup();
 uint32_t dnbd3_serverUptime();
+void server_addJob(void *(*startRoutine)(void *), void *arg, int delaySecs, int intervalSecs);
 
 #if !defined(_FILE_OFFSET_BITS) || _FILE_OFFSET_BITS != 64
 #error Please set _FILE_OFFSET_BITS to 64 in your makefile/configuration