--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.net.http/share/classes/jdk/internal/net/http/PushGroup.java	Tue Apr 17 08:54:17 2018 -0700
@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2016, 2018, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.internal.net.http;
+
+import java.security.AccessControlContext;
+import java.util.Objects;
+import java.util.concurrent.CompletableFuture;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.net.http.HttpResponse.BodyHandler;
+import java.net.http.HttpResponse.PushPromiseHandler;
+import java.util.concurrent.Executor;
+
+import jdk.internal.net.http.common.MinimalFuture;
+import jdk.internal.net.http.common.Log;
+
+/**
+ * One PushGroup object is associated with the parent Stream of the pushed
+ * Streams. This keeps track of all common state associated with the pushes.
+ */
+class PushGroup<T> {
+    private final HttpRequest initiatingRequest;
+
+    final CompletableFuture<Void> noMorePushesCF;
+
+    volatile Throwable error; // any exception that occurred during pushes
+
+    // user's subscriber object
+    final PushPromiseHandler<T> pushPromiseHandler;
+
+    private final Executor executor;
+
+    int numberOfPushes;
+    int remainingPushes;
+    boolean noMorePushes = false;
+
+    PushGroup(PushPromiseHandler<T> pushPromiseHandler,
+              HttpRequestImpl initiatingRequest,
+              Executor executor) {
+        this(pushPromiseHandler, initiatingRequest, new MinimalFuture<>(), executor);
+    }
+
+    // Check mainBodyHandler before calling nested constructor.
+    private PushGroup(HttpResponse.PushPromiseHandler<T> pushPromiseHandler,
+                      HttpRequestImpl initiatingRequest,
+                      CompletableFuture<HttpResponse<T>> mainResponse,
+                      Executor executor) {
+        this.noMorePushesCF = new MinimalFuture<>();
+        this.pushPromiseHandler = pushPromiseHandler;
+        this.initiatingRequest = initiatingRequest;
+        this.executor = executor;
+    }
+
+    interface Acceptor<T> {
+        BodyHandler<T> bodyHandler();
+        CompletableFuture<HttpResponse<T>> cf();
+        boolean accepted();
+    }
+
+    private static class AcceptorImpl<T> implements Acceptor<T> {
+        private final Executor executor;
+        private volatile HttpResponse.BodyHandler<T> bodyHandler;
+        private volatile CompletableFuture<HttpResponse<T>> cf;
+
+        AcceptorImpl(Executor executor) {
+            this.executor = executor;
+        }
+
+        CompletableFuture<HttpResponse<T>> accept(BodyHandler<T> bodyHandler) {
+            Objects.requireNonNull(bodyHandler);
+            if (this.bodyHandler != null)
+                throw new IllegalStateException("non-null bodyHandler");
+            this.bodyHandler = bodyHandler;
+            cf = new MinimalFuture<>();
+            return cf.whenCompleteAsync((r,t) -> {}, executor);
+        }
+
+        @Override public BodyHandler<T> bodyHandler() { return bodyHandler; }
+
+        @Override public CompletableFuture<HttpResponse<T>> cf() { return cf; }
+
+        @Override public boolean accepted() { return cf != null; }
+    }
+
+    Acceptor<T> acceptPushRequest(HttpRequest pushRequest) {
+        AcceptorImpl<T> acceptor = new AcceptorImpl<>(executor);
+        try {
+            pushPromiseHandler.applyPushPromise(initiatingRequest, pushRequest, acceptor::accept);
+        } catch (Throwable t) {
+            if (acceptor.accepted()) {
+                CompletableFuture<?> cf = acceptor.cf();
+                cf.completeExceptionally(t);
+            }
+            throw t;
+        }
+
+        synchronized (this) {
+            if (acceptor.accepted()) {
+                numberOfPushes++;
+                remainingPushes++;
+            }
+            return acceptor;
+        }
+    }
+
+    // This is called when the main body response completes because it means
+    // no more PUSH_PROMISEs are possible
+
+    synchronized void noMorePushes(boolean noMore) {
+        noMorePushes = noMore;
+        checkIfCompleted();
+        noMorePushesCF.complete(null);
+    }
+
+    synchronized CompletableFuture<Void> pushesCF() {
+        return noMorePushesCF;
+    }
+
+    synchronized boolean noMorePushes() {
+        return noMorePushes;
+    }
+
+    synchronized void pushCompleted() {
+        remainingPushes--;
+        checkIfCompleted();
+    }
+
+    synchronized void checkIfCompleted() {
+        if (Log.trace()) {
+            Log.logTrace("PushGroup remainingPushes={0} error={1} noMorePushes={2}",
+                         remainingPushes,
+                         (error==null)?error:error.getClass().getSimpleName(),
+                         noMorePushes);
+        }
+        if (remainingPushes == 0 && error == null && noMorePushes) {
+            if (Log.trace()) {
+                Log.logTrace("push completed");
+            }
+        }
+    }
+
+    synchronized void pushError(Throwable t) {
+        if (t == null) {
+            return;
+        }
+        this.error = t;
+    }
+}