Wait on the pcap file handle to reduce cpu consumption during sniffing

git-svn-id: file:///home/svn/framework3/trunk@6814 4d416f70-5f16-0410-b530-b9f4589650da

external/pcaprub/pcaprub.c

@@ -389,14 +389,20 @@ static VALUE
 rbpcap_capture(VALUE self)
 {
     rbpcap_t *rbp;
+	int fno = -1;
 	
     Data_Get_Struct(self, rbpcap_t, rbp);
 
 	if(! rbpcap_ready(rbp)) return self; 
 	
+	fno = pcap_fileno(rbp->pd);
+	
     for(;;) {
 
-    	VALUE packet = rbpcap_next(self);
+    	VALUE packet;
+		if(fno != -1) rb_thread_wait_fd(fno);
+		
+		packet = rbpcap_next(self);
 
     	if(packet == Qnil && rbp->type == OFFLINE)
     		break;

external/pcaprub/test_pcaprub.rb

@@ -81,14 +81,23 @@ class Pcap::UnitTest < Test::Unit::TestCase
 	end
 
 	def test_pcap_next
-=begin
 		d = Pcap.lookupdev
 		o = Pcap.open_live(d, 1344, true, 1)
+
 		@c = 0
-		t = Thread.new { while(true); @c += 1; end; }
-		x = o.next
+		t = Thread.new { while(true); @c += 1; select(nil, nil, nil, 0.10); end; }
+
+		require 'timeout'
+		begin
+		Timeout.timeout(10) do
+			o.each do |pkt|
+			end
+		end
+		rescue ::Timeout::Error
+		end
+		
 		t.kill
-=end
+		puts "Background thread ticked #{@c} times while capture was running"
 		true
 	end