reworking the signal system

CMakeLists.txt

@@ -65,6 +65,7 @@ set( MANTLE_CODE
 	${PROJECT_SOURCE_DIR}/mantle/syncmaster.lua
 	${PROJECT_SOURCE_DIR}/mantle/monitor.lua
 	${PROJECT_SOURCE_DIR}/mantle/fwriter.lua
+	${PROJECT_SOURCE_DIR}/mantle/signal.lua
 	${PROJECT_SOURCE_DIR}/mantle/statusfile.lua
 	${PROJECT_SOURCE_DIR}/mantle/useralarm.lua
 	${PROJECT_SOURCE_DIR}/mantle/mci.lua

mantle/mci.lua

@@ -386,14 +386,6 @@ function mci.initialize
 	firstTime  --  true when Lsyncd startups the first time,
 	--         --  false on resets, due to HUP signal or monitor queue overflow.
 )
-	print( 'HELLO' )
-	do
-		for num, name in pairs( signames )
-		do
-			print( 'SIG', num, name )
-		end
-	end
-
 	-- Checks if user overwrote the settings function.
 	-- ( was Lsyncd <2.1 style )
 	if userENV.settings ~= settings
@@ -407,6 +399,8 @@ function mci.initialize
 		os.exit( -1 )
 	end
 
+	initSignalHandlers( firstTime )
+
 	lastReportedWaiting = false
 
 	--

mantle/signal.lua

@@ -0,0 +1,105 @@
+--
+-- signal.lua from Lsyncd -- the Live (Mirror) Syncing Demon
+--
+--
+-- Handles signal handlers.
+--
+--
+-- License: GPLv2 (see COPYING) or any later version
+-- Authors: Axel Kittenberger <axkibe@gmail.com>
+--
+if mantle
+then
+	print( 'Error, Lsyncd mantle already loaded' )
+	os.exit( -1 )
+end
+
+-- "signames" is a a (mantle-)global table from signames.lua created by the
+-- build script following code creates a (hash)table for the other direction.
+local signums = { }
+
+for num, name in pairs( signames )
+do
+	signums[ name ] = num
+end
+
+
+-- a table of all registered signal handlers
+local sigHandlers = { }
+
+-- counter of signal handlers
+-- used to tell the core to enlarge the signal queue if needed
+-- (the queue must be as large as the number of different signals listened for)
+local sigHandlerCount = 0
+
+--
+-- onsignal function exported to userEnv
+--
+function onsignal
+(
+	signal, -- signal number or name
+	handler -- function to call
+	--      -- or nil to unload the handle
+	--      -- or false to disable default signal handlers
+)
+	local signum
+
+	if type( signal ) == 'number'
+	then
+		if signal < 0
+		or signal ~= signal
+		or signal - floor( signal ) ~= 0
+		then
+			error( 'signal ' .. signal .. ' is an invalid number.' , 2 )
+		end
+
+		signum = signal
+	elseif type( signal ) == 'string'
+	then
+		signum = signums[ signal ]
+
+		if signum == nil
+		then
+			error( 'signal "' .. signal .. '" unknown.' , 2 )
+		end
+	else
+		error( 'signal of type ' .. type( signal ) .. ' invalid.', 2 )
+	end
+
+	-- FIXME store the handler in a table
+	-- FIXME tell core of max queue size
+
+	core.onsignal( signum, handler );
+end
+
+
+--
+-- Sets up the default HUP/INT/TERM signal handlers.
+--
+-- Called after user scripts finished
+--
+function initSignalHandlers
+(
+	firstTime --- TODO check if needed
+)
+	onsignal(
+		'HUP',
+		function( )
+			console.log( 'GOT A HUP SIGNAL' );
+		end
+	)
+
+	onsignal(
+		'INT',
+		function( )
+			console.log( 'GOT A INT SIGNAL' );
+		end
+	)
+
+	onsignal(
+		'TERM',
+		function( )
+			console.log( 'GOT A TERM SIGNAL' );
+		end
+	)
+end

signames.sh

@@ -11,6 +11,9 @@
 #
 KILL=/bin/kill
 
+# Don't know a better way, checks only until this signal number
+# To quote, this ought to be enough for anybody.
+nmax=256
 
 if [ "$#" -ne 1 ];
 then
@@ -28,13 +31,14 @@ echo "signames =" >> $1
 echo "{" >> $1
 
 n=1
-while name=`kill -l $n 2>/dev/null`;
+while name=`$KILL --list=$n 2>/dev/null`;
 do
 	if ! [ -z $name ]
 	then
 		echo $echoe "\t[ $n ] = '$name'," >> $1
 	fi
 	n=$(( n + 1 ))
+	if [ $n -gt $nmax ]; then break; fi
 done
 
 echo "}" >> $1