Merge pull request openjdk#33 from plummercj/fibers

Merge some commits I've accumulated in my personal fork.

Author: plummercj

src/jdk.jdwp.agent/share/native/libjdwp/ThreadReferenceImpl.c

@@ -49,24 +49,25 @@ name(PacketInputStream *in, PacketOutputStream *out)
         return JNI_TRUE;
     }
 
-    WITH_LOCAL_REFS(env, 3) {
-        /* Get the thread name */
+    WITH_LOCAL_REFS(env, 1) {
+
         jvmtiThreadInfo info;
         jvmtiError error;
 
         (void)memset(&info, 0, sizeof(info));
+
         error = JVMTI_FUNC_PTR(gdata->jvmti,GetThreadInfo)
-            (gdata->jvmti, thread, &info);
+                                (gdata->jvmti, thread, &info);
 
         if (error != JVMTI_ERROR_NONE) {
             outStream_setError(out, map2jdwpError(error));
         } else {
             (void)outStream_writeString(out, info.name);
         }
 
-        if ( info.name != NULL ) {
+        if ( info.name != NULL )
             jvmtiDeallocate(info.name);
-        }
+
     } END_WITH_LOCAL_REFS(env);
 
     return JNI_TRUE;
@@ -169,9 +170,11 @@ threadGroup(PacketInputStream *in, PacketOutputStream *out)
 
         jvmtiThreadInfo info;
         jvmtiError error;
+
         (void)memset(&info, 0, sizeof(info));
+
         error = JVMTI_FUNC_PTR(gdata->jvmti,GetThreadInfo)
-            (gdata->jvmti, thread, &info);
+                                (gdata->jvmti, thread, &info);
 
         if (error != JVMTI_ERROR_NONE) {
             outStream_setError(out, map2jdwpError(error));

src/jdk.jdwp.agent/share/native/libjdwp/debugLoop.c

@@ -83,7 +83,6 @@ debugLoop_run(void)
     jboolean shouldListen;
     jdwpPacket p;
     jvmtiStartFunction func;
-    JNIEnv *env = getEnv();
 
     /* Initialize all statics */
     /* We may be starting a new connection after an error */
@@ -158,15 +157,8 @@ debugLoop_run(void)
                  */
                 outStream_setError(&out, JDWP_ERROR(VM_DEAD));
             } else {
-              /* Provide 64 localrefs by default. */
-              /* vthread fixme: Now that this default set of localrefs is in place, we can remove a
-               * bunch of WITH_LOCAL_REFS/END_WITH_LOCAL_REFS blocks. The only ones needed are
-               * ones that could potentially go over 64, likes ones within loops. Note this only
-               * refers to command handlers called from here, not all uses of WITH_LOCAL_REFS. */
-                WITH_LOCAL_REFS(env, 64) {
-                    /* Call the command handler */
-                    replyToSender = func(&in, &out);
-                } END_WITH_LOCAL_REFS(env);
+                /* Call the command handler */
+                replyToSender = func(&in, &out);
             }
 
             /* Reply to the sender */

src/jdk.jdwp.agent/share/native/libjdwp/eventFilter.c

@@ -977,27 +977,6 @@ eventFilter_setStepFilter(HandlerNode *node, jint index,
     return JVMTI_ERROR_NONE;
 }
 
-/*
- * Finds the step filter in a node, and sets the thread for that filter.
- * vthread fixme: not used. delete once we know for sure we'll never need it.
- */
-void
-eventFilter_setStepFilterThread(HandlerNode *node, jthread thread)
-{
-    JNIEnv *env = getEnv();
-    Filter *filter = FILTERS_ARRAY(node);
-    int i;
-    for (i = 0; i < FILTER_COUNT(node); ++i, ++filter) {
-        switch (filter->modifier) {
-          case JDWP_REQUEST_MODIFIER(Step):
-            tossGlobalRef(env, &(filter->u.Step.thread));
-            saveGlobalRef(env, thread, &(filter->u.Step.thread));
-            return;
-        }
-    }
-    JDI_ASSERT(JNI_FALSE); /* We should have found a step filter, but didn't. */
-}
-
 jvmtiError
 eventFilter_setSourceNameMatchFilter(HandlerNode *node,
                                     jint index,

src/jdk.jdwp.agent/share/native/libjdwp/eventFilter.h

@@ -66,7 +66,6 @@ jvmtiError eventFilter_setStepFilter(HandlerNode *node,
                                jint index,
                                jthread thread,
                                jint size, jint depth);
-void eventFilter_setStepFilterThread(HandlerNode *node, jthread thread);
 jvmtiError eventFilter_setSourceNameMatchFilter(HandlerNode *node,
                                                 jint index,
                                                 char *sourceNamePattern);

src/jdk.jdwp.agent/share/native/libjdwp/eventHandler.c

@@ -675,7 +675,7 @@ filterAndAddVThread(JNIEnv *env, EventInfo *evinfo, EventIndex ei, jbyte eventSe
  * consumes the event.
  */
 static void
-event_callback_helper(JNIEnv *env, EventInfo *evinfo)
+event_callback(JNIEnv *env, EventInfo *evinfo)
 {
     struct bag *eventBag;
     jbyte eventSessionID = currentSessionID; /* session could change */
@@ -743,8 +743,7 @@ event_callback_helper(JNIEnv *env, EventInfo *evinfo)
          * resources can be allocated.  This must be done before
          * grabbing any locks.
          */
-        eventBag = threadControl_onEventHandlerEntry(
-            eventSessionID, evinfo, currentException);
+        eventBag = threadControl_onEventHandlerEntry(eventSessionID, evinfo, currentException);
         if ( eventBag == NULL ) {
             jboolean invoking;
             do {
@@ -829,16 +828,6 @@ event_callback_helper(JNIEnv *env, EventInfo *evinfo)
     }
 }
 
-static void
-event_callback(JNIEnv *env, EventInfo *evinfo)
-{
-    /* vthread fixme: There are a bunch of WITH_LOCAL_REFS that we can remove now that
-     * we are doing one here. */
-    WITH_LOCAL_REFS(env, 64) {
-        event_callback_helper(env, evinfo);
-    } END_WITH_LOCAL_REFS(env);
-}
-
 /* Returns a local ref to the declaring class for an object. */
 static jclass
 getObjectClass(jobject object)

src/jdk.jdwp.agent/share/native/libjdwp/stepControl.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -86,14 +86,6 @@ disableStepping(jthread thread)
     }
 }
 
-void stepControl_enableStepping(jthread thread) {
-  enableStepping(thread);
-}
-
-void stepControl_disableStepping(jthread thread) {
-  disableStepping(thread);
-}
-
 static jvmtiError
 getFrameLocation(jthread thread,
         jclass *pclazz, jmethodID *pmethod, jlocation *plocation)
@@ -358,13 +350,12 @@ handleFramePopEvent(JNIEnv *env, EventInfo *evinfo,
                  * Resume stepping in the original frame.
                  */
                 LOG_STEP(("handleFramePopEvent: starting singlestep, have methodEnter handler && depth==INTO && fromDepth >= afterPopDepth (%d>=%d)", fromDepth, afterPopDepth));
+                enableStepping(thread);
+                (void)eventHandler_free(step->methodEnterHandlerNode);
+                step->methodEnterHandlerNode = NULL;
             } else {
                 LOG_STEP(("handleFramePopEvent: starting singlestep, have methodEnter handler && depth==INTO && fromDepth < afterPopDepth (%d<%d)", fromDepth, afterPopDepth));
-                JDI_ASSERT(fromDepth >= afterPopDepth);
             }
-            enableStepping(thread);
-            (void)eventHandler_free(step->methodEnterHandlerNode);
-            step->methodEnterHandlerNode = NULL;
         }
         LOG_STEP(("handleFramePopEvent: finished"));
     }
@@ -613,7 +604,7 @@ stepControl_handleStep(JNIEnv *env, jthread thread,
                                 "installing event method enter handler");
                 }
             }
-            LOG_STEP(("stepControl_handleStep: NotifyFramePop, (fromDepth currentDepth)(%d %d) ",
+            LOG_STEP(("stepControl_handleStep: NotifyFramePop (fromDepth=%d currentDepth=%d)",
                       fromDepth, currentDepth));
 
             error = JVMTI_FUNC_PTR(gdata->jvmti,NotifyFramePop)

src/jdk.jdwp.agent/share/native/libjdwp/stepControl.h

@@ -65,9 +65,6 @@ jvmtiError stepControl_endStep(jthread thread);
 void stepControl_clearRequest(jthread thread, StepRequest *step);
 void stepControl_resetRequest(jthread thread);
 
-void stepControl_enableStepping(jthread thread);
-void stepControl_disableStepping(jthread thread);
-
 void stepControl_lock(void);
 void stepControl_unlock(void);
 

src/jdk.jdwp.agent/share/native/libjdwp/threadControl.c

@@ -235,12 +235,8 @@ nonTlsSearch(JNIEnv *env, ThreadList *list, jthread thread)
  * All assume that the threadLock is held before calling.
  */
 
-
 /*
  * Search for a thread on the list. If list==NULL, search all lists.
- * TODO: TLS cache is temporary diabled for all threads, not added for virtual threads yet
- * It cause intermittent failures because ThreadNode data is broken.
- * Need to enable setThreadLocalStorage in 2 places.
  */
 static ThreadNode *
 findThread(ThreadList *list, jthread thread)
@@ -1285,10 +1281,14 @@ commonResumeList(JNIEnv *env)
     /* count number of threads to hard resume */
     (void) enumerateOverThreadList(env, &runningThreads, resumeCountHelper,
                                    &reqCnt);
+    (void) enumerateOverThreadList(env, &runningVThreads, resumeCountHelper,
+                                   &reqCnt);
     if (reqCnt == 0) {
         /* nothing to hard resume so do just the accounting part */
         (void) enumerateOverThreadList(env, &runningThreads, resumeCopyHelper,
                                        NULL);
+        (void) enumerateOverThreadList(env, &runningVThreads, resumeCopyHelper,
+                                       NULL);
         return JVMTI_ERROR_NONE;
     }
 
@@ -1307,13 +1307,15 @@ commonResumeList(JNIEnv *env)
     reqPtr = reqList;
     (void) enumerateOverThreadList(env, &runningThreads, resumeCopyHelper,
                                    &reqPtr);
+    (void) enumerateOverThreadList(env, &runningVThreads, resumeCopyHelper,
+                                   &reqPtr);
 
     error = JVMTI_FUNC_PTR(gdata->jvmti,ResumeThreadList)
                 (gdata->jvmti, reqCnt, reqList, results);
     for (i = 0; i < reqCnt; i++) {
         ThreadNode *node;
 
-        node = findThread(&runningThreads, reqList[i]);
+        node = findRunningThread(reqList[i]);
         if (node == NULL) {
             EXIT_ERROR(AGENT_ERROR_INVALID_THREAD,"missing entry in running thread table");
         }
@@ -1623,7 +1625,12 @@ threadControl_suspendAll(void)
                 }
             }
 
-            /* Increment suspend count of each virtual thread that we are tracking. */
+            /*
+             * Increment suspendCount of each virtual thread that we are tracking. Note the
+             * compliment to this that happens during the resumeAll() is handled by
+             * commonResumeList(), so it's a bit orthogonal to how we handle incrementing
+             * the suspendCount.
+             */
             error = enumerateOverThreadList(env, &runningVThreads, incrementSupendCountHelper, NULL);
             JDI_ASSERT(error == JVMTI_ERROR_NONE);
         }
@@ -1681,16 +1688,6 @@ threadControl_suspendAll(void)
     return error;
 }
 
-static jvmtiError
-decrementSupendCountHelper(JNIEnv *env, ThreadNode *node, void *arg)
-{
-    // Some vthreads might already have a suspendCount of 0. Just ignore them.
-    if (node->suspendCount > 0) {
-        node->suspendCount--;
-    }
-    return JVMTI_ERROR_NONE;
-}
-
 static jvmtiError
 resumeHelper(JNIEnv *env, ThreadNode *node, void *ignored)
 {
@@ -1727,10 +1724,6 @@ threadControl_resumeAll(void)
                 EXIT_ERROR(error, "cannot resume all virtual threads");
             }
         }
-
-        /* Decrement suspend count of each virtual thread that we are tracking. */
-        error = enumerateOverThreadList(env, &runningVThreads, decrementSupendCountHelper, NULL);
-        JDI_ASSERT(error == JVMTI_ERROR_NONE);
     }
 
     /*
@@ -2567,6 +2560,18 @@ threadControl_reset(void)
     env = getEnv();
     eventHandler_lock(); /* for proper lock order */
     debugMonitorEnter(threadLock);
+
+    if (gdata->vthreadsSupported) {
+        if (suspendAllCount > 0) {
+            /* Tell JVMTI to resume all virtual threads. */
+            jvmtiError error = JVMTI_FUNC_PTR(gdata->jvmti,ResumeAllVirtualThreads)
+                    (gdata->jvmti);
+            if (error != JVMTI_ERROR_NONE) {
+                EXIT_ERROR(error, "cannot resume all virtual threads");
+            }
+        }
+    }
+
     (void)enumerateOverThreadList(env, &runningThreads, resetHelper, NULL);
     (void)enumerateOverThreadList(env, &otherThreads, resetHelper, NULL);
     (void)enumerateOverThreadList(env, &runningVThreads, resetHelper, NULL);