ensure weak refs are collect during gc_collect

Author: qunaibit

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/GcModuleBuiltins.java

@@ -180,12 +180,7 @@ static long javaCollect(Node inliningTarget, GilNode gil) {
             Runtime runtime = Runtime.getRuntime();
             long freeMemory = runtime.freeMemory();
             try {
-                PythonUtils.forceFullGC();
-                try {
-                    Thread.sleep(15);
-                } catch (InterruptedException e) {
-                    // doesn't matter, just trying to give the GC more time
-                }
+                CApiTransitions.ensurePollRefQueueCleanup();
             } finally {
                 gil.acquire();
             }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/cext/capi/CApiContext.java

@@ -958,7 +958,7 @@ public void exitCApiContext() {
              * deallocating objects may run arbitrary guest code that can again call into the
              * interpreter.
              */
-            CApiTransitions.exitPollCleanup();
+            CApiTransitions.ensurePollRefQueueCleanup();
             PythonThreadState threadState = getContext().getThreadState(getContext().getLanguage());
             Object nativeThreadState = PThreadState.getNativeThreadState(threadState);
             if (nativeThreadState != null) {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/cext/capi/transitions/CApiTransitions.java

@@ -408,7 +408,7 @@ public static PyCapsuleReference registerPyCapsuleDestructor(PyCapsule capsule)
     }
 
     @TruffleBoundary
-    public static void exitPollCleanup() {
+    public static void ensurePollRefQueueCleanup() {
         PythonUtils.forceFullGC();
         PythonContext context = PythonContext.get(null);
         HandleContext handleContext = context.nativeContext;