Fixed Scanner hanging long on strg+c

2 files changed, 6 insertions, 3 deletions

diff --git a/src/main/java/com/it_jaros/jscanner/Scan.java b/src/main/java/com/it_jaros/jscanner/Scan.java
index d276fd2..d58e8d0 100644
--- a/src/main/java/com/it_jaros/jscanner/Scan.java
+++ b/src/main/java/com/it_jaros/jscanner/Scan.java
@@ -8,6 +8,7 @@ import java.nio.file.Path;
 import java.util.List;
 import java.util.stream.Stream;
 
+// todo object/data asymmetry
 /**
  * Object holder for stateful volatile data during scan
  */
diff --git a/src/main/java/com/it_jaros/jscanner/Scanner.java b/src/main/java/com/it_jaros/jscanner/Scanner.java
index 337f5ed..b35161f 100644
--- a/src/main/java/com/it_jaros/jscanner/Scanner.java
+++ b/src/main/java/com/it_jaros/jscanner/Scanner.java
@@ -316,6 +316,9 @@ public class Scanner implements AutoCloseable {
                 return;
             }
             synchronized (lock) {
+                if (cancelled) {
+                    return;
+                }
                 long now = System.nanoTime();
                 if (nextAllowedTime > now) {
                     Thread.sleep(Duration.ofNanos(nextAllowedTime - now));
@@ -343,9 +346,9 @@ public class Scanner implements AutoCloseable {
         public PortResult call() throws Exception {
             try {
                 scan.getThreadCounter().inc();
-                portScanRateLimiter.apply();  // per-host serial pacing
+                portScanRateLimiter.apply();
                 if (cancelled) {
-                    return null;
+                    return new PortResult();
                 }
                 return checkPort();
             } finally {
@@ -361,7 +364,6 @@ public class Scanner implements AutoCloseable {
             // don't allow more sockets then specified
             socketLimit.acquire();
             // count how many ports are concurrently checked
-            // todo object/data asymmetry
             scan.getSocketCounter().inc();
             try (Socket socket = new Socket()) {
                 socket.connect(new InetSocketAddress(host, port), timeoutInMillis);