Clear references to threads and thread contexts on teardown.

headius · headius · commit 9f72b0c83ec0 · 2018-10-30T16:22:47.000-05:00
This change clears the following on JRuby runtime teardown: * The thread-local context reference in ThreadService (dereferenced entirely) * The mainContext reference in ThreadService * The mapping from native threads to RubyThread instances. This should clear all JRuby-specific runtime data attached to both Ruby and adopted Java threads. Fixes #3313. Supersedes #3316.
diff --git a/core/src/main/java/org/jruby/Ruby.java b/core/src/main/java/org/jruby/Ruby.java
@@ -3370,8 +3370,6 @@ public void tearDown(boolean systemExit) {
             }
         }
 
-        getThreadService().disposeCurrentThread();
-
         getBeanManager().unregisterCompiler();
         getBeanManager().unregisterConfig();
         getBeanManager().unregisterParserStats();
@@ -3388,6 +3386,8 @@ public void tearDown(boolean systemExit) {
             printProfileData(profileCollection);
         }
 
+        getThreadService().teardown();
+
         if (systemExit && status != 0) {
             throw newSystemExit(status);
         }
diff --git a/core/src/main/java/org/jruby/RubyThread.java b/core/src/main/java/org/jruby/RubyThread.java
@@ -41,6 +41,7 @@
 import java.nio.channels.Selector;
 import java.util.Collections;
 import java.util.Iterator;
+import java.util.Optional;
 import java.util.Queue;
 import java.util.Vector;
 import java.util.WeakHashMap;
@@ -382,6 +383,7 @@ public void setContext(ThreadContext context) {
     }
 
     public ThreadContext getContext() {
+        WeakReference<ThreadContext> contextRef = this.contextRef;
         return contextRef == null ? null : contextRef.get();
     }
 
diff --git a/core/src/main/java/org/jruby/internal/runtime/ThreadService.java b/core/src/main/java/org/jruby/internal/runtime/ThreadService.java
@@ -121,7 +121,7 @@ public class ThreadService {
      * through ThreadContext instances every time a Java thread enters and exits
      * Ruby space.
      */
-    private final ThreadLocal<SoftReference<ThreadContext>> localContext;
+    private ThreadLocal<SoftReference<ThreadContext>> localContext;
 
     /**
      * The Java thread group into which we register all Ruby threads. This is
@@ -160,6 +160,17 @@ public void disposeCurrentThread() {
         rubyThreadMap.remove(Thread.currentThread());
     }
 
+    public void teardown() {
+        // clear all thread-local context references
+        localContext = new ThreadLocal<SoftReference<ThreadContext>>();
+
+        // clear main context reference
+        mainContext = null;
+
+        // clear thread map
+        rubyThreadMap.clear();
+    }
+
     public void initMainThread() {
         this.mainContext = ThreadContext.newContext(runtime);
 

Original file line number	Diff line number	Diff line change
`@@ -3370,8 +3370,6 @@ public void tearDown(boolean systemExit) {`
`3370`	`3370`	`}`
`3371`	`3371`	`}`
`3372`	`3372`
`3373`		`- getThreadService().disposeCurrentThread();`
`3374`		`-`
`3375`	`3373`	`getBeanManager().unregisterCompiler();`
`3376`	`3374`	`getBeanManager().unregisterConfig();`
`3377`	`3375`	`getBeanManager().unregisterParserStats();`
`@@ -3388,6 +3386,8 @@ public void tearDown(boolean systemExit) {`
`3388`	`3386`	`printProfileData(profileCollection);`
`3389`	`3387`	`}`
`3390`	`3388`
	`3389`	`+ getThreadService().teardown();`
	`3390`	`+`
`3391`	`3391`	`if (systemExit && status != 0) {`
`3392`	`3392`	`throw newSystemExit(status);`
`3393`	`3393`	`}`
Original file line number	Diff line number	Diff line change
`@@ -41,6 +41,7 @@`
`41`	`41`	`import java.nio.channels.Selector;`
`42`	`42`	`import java.util.Collections;`
`43`	`43`	`import java.util.Iterator;`
	`44`	`+import java.util.Optional;`
`44`	`45`	`import java.util.Queue;`
`45`	`46`	`import java.util.Vector;`
`46`	`47`	`import java.util.WeakHashMap;`
`@@ -382,6 +383,7 @@ public void setContext(ThreadContext context) {`
`382`	`383`	`}`
`383`	`384`
`384`	`385`	`public ThreadContext getContext() {`
	`386`	`+ WeakReference<ThreadContext> contextRef = this.contextRef;`
`385`	`387`	`return contextRef == null ? null : contextRef.get();`
`386`	`388`	`}`
`387`	`389`