Revamp the THREADS handling for aux run_host() and run_batch(). THREADS is

supposed to be the number of concurrent threads; however, what's been happening
is just the firing off of THREADS threads and then simply waiting for them all
to finish before doing another round.

Now it tries to keep new threads coming when possible.  It's not exactly smart,
but should usually beat the previous method (when using multiple threads) and
should never be any worse.

Here's the relevant code comment:

# Assume that the oldest thread will be one of the
# first to finish and wait for it.  After that's
# done, remove any finished threads from the list
# and continue on.  This will open up at least one
# spot for a new thread



git-svn-id: file:///home/svn/framework3/trunk@6809 4d416f70-5f16-0410-b530-b9f4589650da

lib/msf/core/auxiliary/scanner.rb

@@ -63,9 +63,9 @@ def run
 	if (self.respond_to?('run_host'))
 		ar = Rex::Socket::RangeWalker.new(datastore['RHOSTS'])
 		
-		while (true)
-			tl = []
+		tl = []
 
+		while (true)
 			# Spawn threads for each host
 			while (tl.length < threads_max)
 				ip = ar.next_ip
@@ -75,7 +75,7 @@ def run
 					targ = tip
 					nmod = self.replicant
 					nmod.datastore['RHOST'] = targ
-					
+
 					begin
 						nmod.run_host(targ)
 					rescue ::Interrupt
@@ -92,9 +92,14 @@ def run
 			if(tl.length == 0)
 				break
 			end
-			
-			# Wait for the threads
-			tl.each { |t| t.join }
+
+			# Assume that the oldest thread will be one of the
+			# first to finish and wait for it.  After that's
+			# done, remove any finished threads from the list
+			# and continue on.  This will open up at least one
+			# spot for a new thread
+			tl.first.join
+			tl.delete_if { |t| not t.alive? }
 		end
 		
 		return
@@ -111,10 +116,9 @@ def run
 
 		ar = Rex::Socket::RangeWalker.new(datastore['RHOSTS'])
 					
+		tl = []
+
 		while(true)
-			
-			tl = []
-			
 			nohosts = false	
 			while (tl.length < threads_max)
 				
@@ -130,7 +134,6 @@ def run
 					batch << ip
 				end
 				
-				
 				# Create a thread for each batch
 				if (batch.length > 0)
 					tl << Thread.new(batch) do |bat|
@@ -152,14 +155,19 @@ def run
 					break
 				end
 			end
-			
-			# Wait for the threads
-			tl.each { |t| t.join }
 
 			# Exit if there are no more pending threads
 			if (tl.length == 0)
 				break
 			end			
+
+			# Assume that the oldest thread will be one of the
+			# first to finish and wait for it.  After that's
+			# done, remove any finished threads from the list
+			# and continue on.  This will open up at least one
+			# spot for a new thread
+			tl.first.join
+			tl.delete_if { |t| not t.alive? }
 		end
 		
 		return