8318422: Allow poller threads be virtual threads

Reviewed-by: michaelm
DataDog · Nov 4, 2023 · c099cf5 · c099cf5
1 parent 29cf2c4
commit c099cf5
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Showing 13 changed files with 347 additions and 378 deletions.
diff --git a/src/java.base/aix/classes/sun/nio/ch/DefaultPollerProvider.java b/src/java.base/aix/classes/sun/nio/ch/DefaultPollerProvider.java
@@ -33,12 +33,12 @@ class DefaultPollerProvider extends PollerProvider {
     DefaultPollerProvider() { }
 
     @Override
-    Poller readPoller() throws IOException {
+    Poller readPoller(boolean subPoller) throws IOException {
         return new PollsetPoller(true);
     }
 
     @Override
-    Poller writePoller() throws IOException {
+    Poller writePoller(boolean subPoller) throws IOException {
         return new PollsetPoller(false);
     }
 }
diff --git a/src/java.base/aix/classes/sun/nio/ch/PollsetPoller.java b/src/java.base/aix/classes/sun/nio/ch/PollsetPoller.java
@@ -42,11 +42,12 @@ class PollsetPoller extends Poller {
         MAX_EVENTS_TO_POLL = 512;
     }
 
+    private final int event;
     private final int setid;
     private final long pollBuffer;
 
     PollsetPoller(boolean read) throws IOException {
-        super(read);
+        this.event = (read) ? Net.POLLIN : Net.POLLOUT;
         this.setid = Pollset.pollsetCreate();
         this.pollBuffer = Pollset.allocatePollArray(MAX_EVENTS_TO_POLL);
     }
@@ -58,8 +59,7 @@ int fdVal() {
 
     @Override
     void implRegister(int fd) throws IOException {
-        int ret = Pollset.pollsetCtl(setid, Pollset.PS_MOD, fd,
-                          Pollset.PS_POLLPRI | (this.reading() ? Net.POLLIN : Net.POLLOUT));
+        int ret = Pollset.pollsetCtl(setid, Pollset.PS_MOD, fd, Pollset.PS_POLLPRI | event);
         if (ret != 0) {
             throw new IOException("Unable to register fd " + fd);
         }

diff --git a/src/java.base/linux/classes/sun/nio/ch/DefaultPollerProvider.java b/src/java.base/linux/classes/sun/nio/ch/DefaultPollerProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2023, 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
@@ -25,6 +25,7 @@
 package sun.nio.ch;
 
 import java.io.IOException;
+import jdk.internal.vm.ContinuationSupport;
 
 /**
  * Default PollerProvider for Linux.
@@ -33,12 +34,31 @@ class DefaultPollerProvider extends PollerProvider {
     DefaultPollerProvider() { }
 
     @Override
-    Poller readPoller() throws IOException {
-        return new EPollPoller(true);
+    Poller.Mode defaultPollerMode() {
+        if (ContinuationSupport.isSupported()) {
+            return Poller.Mode.VTHREAD_POLLERS;
+        } else {
+            return Poller.Mode.SYSTEM_THREADS;
+        }
     }
 
     @Override
-    Poller writePoller() throws IOException {
-        return new EPollPoller(false);
+    int defaultReadPollers(Poller.Mode mode) {
+        int ncpus = Runtime.getRuntime().availableProcessors();
+        if (mode == Poller.Mode.VTHREAD_POLLERS) {
+            return Math.min(Integer.highestOneBit(ncpus), 32);
+        } else {
+            return Math.max(Integer.highestOneBit(ncpus / 4), 1);
+        }
+    }
+
+    @Override
+    Poller readPoller(boolean subPoller) throws IOException {
+        return new EPollPoller(subPoller, true);
+    }
+
+    @Override
+    Poller writePoller(boolean subPoller) throws IOException {
+        return new EPollPoller(subPoller, false);
     }
 }
diff --git a/src/java.base/linux/classes/sun/nio/ch/EPollPoller.java b/src/java.base/linux/classes/sun/nio/ch/EPollPoller.java
@@ -32,18 +32,18 @@
  */
 
 class EPollPoller extends Poller {
-    private static final int MAX_EVENTS_TO_POLL = 512;
     private static final int ENOENT = 2;
 
     private final int epfd;
     private final int event;
+    private final int maxEvents;
     private final long address;
 
-    EPollPoller(boolean read) throws IOException {
-        super(read);
+    EPollPoller(boolean subPoller, boolean read) throws IOException {
         this.epfd = EPoll.create();
         this.event = (read) ? EPOLLIN : EPOLLOUT;
-        this.address = EPoll.allocatePollArray(MAX_EVENTS_TO_POLL);
+        this.maxEvents = (subPoller) ? 64 : 512;
+        this.address = EPoll.allocatePollArray(maxEvents);
     }
 
     @Override
@@ -68,7 +68,7 @@ void implDeregister(int fdVal) {
 
     @Override
     int poll(int timeout) throws IOException {
-        int n = EPoll.wait(epfd, address, MAX_EVENTS_TO_POLL, timeout);
+        int n = EPoll.wait(epfd, address, maxEvents, timeout);
         int i = 0;
         while (i < n) {
             long eventAddress = EPoll.getEvent(address, i);

diff --git a/src/java.base/macosx/classes/sun/nio/ch/DefaultPollerProvider.java b/src/java.base/macosx/classes/sun/nio/ch/DefaultPollerProvider.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2023, 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
@@ -33,12 +33,12 @@ class DefaultPollerProvider extends PollerProvider {
     DefaultPollerProvider() { }
 
     @Override
-    Poller readPoller() throws IOException {
-        return new KQueuePoller(true);
+    Poller readPoller(boolean subPoller) throws IOException {
+        return new KQueuePoller(subPoller, true);
     }
 
     @Override
-    Poller writePoller() throws IOException {
-        return new KQueuePoller(false);
+    Poller writePoller(boolean subPoller) throws IOException {
+        return new KQueuePoller(subPoller, false);
     }
 }
diff --git a/src/java.base/macosx/classes/sun/nio/ch/KQueuePoller.java b/src/java.base/macosx/classes/sun/nio/ch/KQueuePoller.java
@@ -31,17 +31,16 @@
  * Poller implementation based on the kqueue facility.
  */
 class KQueuePoller extends Poller {
-    private static final int MAX_EVENTS_TO_POLL = 512;
-
     private final int kqfd;
     private final int filter;
+    private final int maxEvents;
     private final long address;
 
-    KQueuePoller(boolean read) throws IOException {
-        super(read);
+    KQueuePoller(boolean subPoller, boolean read) throws IOException {
         this.kqfd = KQueue.create();
         this.filter = (read) ? EVFILT_READ : EVFILT_WRITE;
-        this.address = KQueue.allocatePollArray(MAX_EVENTS_TO_POLL);
+        this.maxEvents = (subPoller) ? 64 : 512;
+        this.address = KQueue.allocatePollArray(maxEvents);
     }
 
     @Override
@@ -63,7 +62,7 @@ void implDeregister(int fdVal) {
 
     @Override
     int poll(int timeout) throws IOException {
-        int n = KQueue.poll(kqfd, address, MAX_EVENTS_TO_POLL, timeout);
+        int n = KQueue.poll(kqfd, address, maxEvents, timeout);
         int i = 0;
         while (i < n) {
             long keventAddress = KQueue.getEvent(address, i);