RFR: JDK-8055767: Sjavac is leaking servers

[Erik Joelsson]

Hello,

Please review this simple fix to a rather annoying problem. Since 
JDK-8044131, Sjavac is never shutting down the server, at least not on 
Unix platforms. I have just killed a big bunch of stale servers in JPRT.

Bug: https://bugs.openjdk.java.net/browse/JDK-8055767
Patch inline:

diff -r 4d1ea4477956 
src/jdk.compiler/share/classes/com/sun/tools/sjavac/server/SjavacServer.java
--- 
a/src/jdk.compiler/share/classes/com/sun/tools/sjavac/server/SjavacServer.java
+++ 
b/src/jdk.compiler/share/classes/com/sun/tools/sjavac/server/SjavacServer.java
@@ -310,7 +310,7 @@

      @Override
      public void shutdown(String quitMsg) {
-        if (!keepAcceptingRequests.compareAndSet(false, true)) {
+        if (!keepAcceptingRequests.compareAndSet(true, false)) {
              // Already stopped, no need to shut down again
              return;
          }

/Erik