[SERVER] Get rid of epoll in alservers.c, make valgrind+gdb happy by handling signals even though we block them

5 files changed, 17 insertions, 39 deletions

diff --git a/src/server/altservers.c b/src/server/altservers.c
index 7ed1a57..457405f 100644
--- a/src/server/altservers.c
+++ b/src/server/altservers.c
@@ -9,7 +9,6 @@
 #include "signal.h"
 #include <stdlib.h>
 #include <unistd.h>
-#include <sys/epoll.h>
 #include <sys/errno.h>
 #include <math.h>
 #include <assert.h>
@@ -21,7 +20,7 @@
 static dnbd3_connection_t *pending[SERVER_MAX_PENDING_ALT_CHECKS];
 static pthread_spinlock_t pendingLockProduce; // Lock for adding something to pending. (NULL -> nonNULL)
 static pthread_mutex_t pendingLockConsume = PTHREAD_MUTEX_INITIALIZER; // Lock for removing something (nonNULL -> NULL)
-static int signalPipe = -1;
+static int signalFd = -1;
 
 static dnbd3_alt_server_t altServers[SERVER_MAX_ALTS];
 static int numAltServers = 0;
@@ -52,7 +51,7 @@ void altservers_init()
 void altservers_shutdown()
 {
 	if ( !initDone ) return;
-	signal_call( signalPipe ); // Wake altservers thread up
+	signal_call( signalFd ); // Wake altservers thread up
 	thread_join( altThread, NULL );
 }
 
@@ -148,7 +147,7 @@ void altservers_findUplink(dnbd3_connection_t *uplink)
 		pending[i] = uplink;
 		uplink->rttTestResult = RTT_INPROGRESS;
 		spin_unlock( &pendingLockProduce );
-		signal_call( signalPipe ); // Wake altservers thread up
+		signal_call( signalFd ); // Wake altservers thread up
 		return;
 	}
 	// End of loop - no free slot
@@ -339,11 +338,8 @@ void altservers_serverFailed(const dnbd3_host_t * const host)
  */
 static void *altservers_main(void *data)
 {
-	const int MAXEVENTS = 3;
 	const int ALTS = 4;
-	struct epoll_event ev, events[MAXEVENTS];
-	int fdEpoll = -1;
-	int numSocks, ret, itLink, itAlt, numAlts;
+	int ret, itLink, itAlt, numAlts;
 	bool found;
 	char buffer[DNBD3_BLOCK_SIZE ];
 	dnbd3_reply_t reply;
@@ -360,39 +356,20 @@ static void *altservers_main(void *data)
 	for (int i = 0; i < SERVER_MAX_PENDING_ALT_CHECKS; ++i)
 		pending[i] = NULL;
 	// Init signal-pipe
-	fdEpoll = epoll_create( 2 );
-	if ( fdEpoll == -1 ) {
-		memlogf( "[WARNING] epoll_create failed. Uplink unavailable." );
+	signalFd = signal_new();
+	if ( signalFd < 0 ) {
+		memlogf( "[WARNING] error creating signal object. Uplink feature unavailable." );
 		goto cleanup;
 	}
-	{
-		signalPipe = signal_new();
-		if ( signalPipe < 0 ) {
-			memlogf( "[WARNING] error creating signal object. Uplink feature unavailable." );
-			goto cleanup;
-		}
-		memset( &ev, 0, sizeof(ev) );
-		ev.events = EPOLLIN;
-		ev.data.fd = signalPipe;
-		if ( epoll_ctl( fdEpoll, EPOLL_CTL_ADD, signalPipe, &ev ) < 0 ) {
-			memlogf( "[WARNING] adding read-signal-pipe to epoll set failed" );
-			goto cleanup;
-		}
-	}
 	// LOOP
 	while ( !_shutdown ) {
 		// Wait 5 seconds max.
-		numSocks = epoll_wait( fdEpoll, events, MAXEVENTS, 5000 );
-		if ( numSocks < 0 ) {
-			const int err = errno;
-			memlogf( "[WARNING] epoll_wait() error %d in uplink_connector", err );
-			usleep( 100000 );
-		}
+		ret = signal_wait( signalFd, 5000 );
 		if ( _shutdown ) goto cleanup;
-		// Clear signal
-		ret = signal_clear( signalPipe );
 		if ( ret == SIGNAL_ERROR ) {
+			if ( errno == EAGAIN || errno == EINTR ) continue;
 			memlogf( "[WARNING] Error on signal_clear on alservers_main! Things will break!" );
+			usleep( 100000 );
 		}
 		// Work your way through the queue
 		for (itLink = 0; itLink < SERVER_MAX_PENDING_ALT_CHECKS; ++itLink) {
@@ -536,9 +513,8 @@ static void *altservers_main(void *data)
 		}
 	}
 	cleanup: ;
-	if ( fdEpoll != -1 ) close( fdEpoll );
-	if ( signalPipe != -1 ) signal_close( signalPipe );
-	signalPipe = -1;
+	if ( signalFd != -1 ) signal_close( signalFd );
+	signalFd = -1;
 	return NULL ;
 }
 
diff --git a/src/server/globals.c b/src/server/globals.c
index 1e35a8f..b441c8e 100644
--- a/src/server/globals.c
+++ b/src/server/globals.c
@@ -9,7 +9,7 @@
 char *_configDir = NULL;
 char *_basePath = NULL;
 bool _vmdkLegacyMode = false;
-bool _shutdown = false;
+volatile bool _shutdown = false;
 int _serverPenalty = 0;
 int _clientPenalty = 0;
 bool _isProxy = false;
diff --git a/src/server/globals.h b/src/server/globals.h
index 09a9a5b..4b99e38 100644
--- a/src/server/globals.h
+++ b/src/server/globals.h
@@ -152,7 +152,7 @@ extern int _clientPenalty;
 /**
  * Is server shutting down?
  */
-extern bool _shutdown;
+extern volatile bool _shutdown;
 
 /**
  * Is server allowed to provide images in proxy mode?
diff --git a/src/server/locks.c b/src/server/locks.c
index e464182..3c1956f 100644
--- a/src/server/locks.c
+++ b/src/server/locks.c
@@ -305,5 +305,6 @@ void debug_locks_stop_watchdog()
 	signal_call( watchdogSignal );
 	pthread_spin_unlock( &initdestory );
 	thread_join( watchdog, NULL );
+	signal_close( watchdogSignal );
 #endif
 }
diff --git a/src/server/net.c b/src/server/net.c
index 5a9a640..3dfa231 100644
--- a/src/server/net.c
+++ b/src/server/net.c
@@ -49,7 +49,7 @@ static inline bool recv_request_header(int sock, dnbd3_request_t *request)
 	int ret, fails = 0;
 	// Read request header from socket
 	while ( (ret = recv( sock, request, sizeof(*request), MSG_WAITALL )) != sizeof(*request) ) {
-		if ( errno == EINTR ) continue;
+		if ( errno == EINTR && ++fails < 10 ) continue;
 		if ( ret >= 0 || ++fails > SOCKET_TIMEOUT_SERVER_RETRIES ) return false;
 		if ( errno == EAGAIN ) continue;
 		printf( "[DEBUG] Error receiving request: Could not read message header (%d/%d, e=%d)\n", ret, (int)sizeof(*request), errno );
@@ -196,6 +196,7 @@ void *net_client_handler(void *dnbd3_client)
 		}
 		// client handling mainloop
 		while ( recv_request_header( client->sock, &request ) ) {
+			if ( _shutdown ) break;
 			switch ( request.cmd ) {
 
 			case CMD_GET_BLOCK: