Poller object implemented in Java binding

bindings/java/Poller.cpp

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <assert.h>
+#include <errno.h>
+
+#include "../c/zmq.h"
+
+#include "org_zmq_Poller.h"
+
+static void *fetch_socket (JNIEnv *env, jobject socket);
+
+JNIEXPORT jlong JNICALL Java_org_zmq_Poller_run_1poll (JNIEnv *env,
+                                                       jobject obj,
+                                                       jint count,
+                                                       jobjectArray socket_0mq,
+                                                       jshortArray event_0mq,
+                                                       jshortArray revent_0mq,
+                                                       jlong timeout)
+{
+    int ls = (int) count;
+    if (ls <= 0)
+        return 0;
+    
+    int ls_0mq = 0;
+    int le_0mq = 0;
+    int lr_0mq = 0;
+
+    if (socket_0mq)
+        ls_0mq = env->GetArrayLength (socket_0mq);
+    if (event_0mq)
+        le_0mq = env->GetArrayLength (event_0mq);
+    if (revent_0mq)
+        lr_0mq = env->GetArrayLength (revent_0mq);
+
+    if (ls > ls_0mq || ls > le_0mq || ls > ls_0mq)
+        return 0;
+
+    zmq_pollitem_t *pitem = new zmq_pollitem_t [ls];
+    short pc = 0;
+    int rc = 0;
+
+    //  Add 0MQ sockets.
+    if (ls_0mq > 0) {
+        jshort *e_0mq = env->GetShortArrayElements (event_0mq, 0);
+        if (e_0mq != NULL) {
+            for (int i = 0; i < ls_0mq; ++i) {
+                jobject s_0mq = env->GetObjectArrayElement (socket_0mq, i);
+                if (!s_0mq)
+                    continue;
+                void *s = fetch_socket (env, s_0mq);
+                if (!s)
+                    continue;
+                pitem [pc].socket = s;
+                pitem [pc].fd = 0;
+                pitem [pc].events = e_0mq [i];
+                pitem [pc].revents = 0;
+                ++pc;
+            }
+            env->ReleaseShortArrayElements(event_0mq, e_0mq, 0);
+        }
+    }
+
+    if (pc == ls) {
+        pc = 0;
+        long tout = (long) timeout;
+        rc = zmq_poll (pitem, ls, tout);
+    }
+
+    //  Set 0MQ results.
+    if (ls_0mq > 0) {
+        jshort *r_0mq = env->GetShortArrayElements (revent_0mq, 0);
+        if (r_0mq) {
+            for (int i = 0; i < ls_0mq; ++i) {
+                r_0mq [i] = pitem [pc].revents;
+                ++pc;
+            }
+            env->ReleaseShortArrayElements(revent_0mq, r_0mq, 0);
+        }
+    }
+
+    delete [] pitem;
+    return rc;
+}
+  
+/**
+ * Get the value of socketHandle for the specified Java Socket.
+ * TODO: move this to a single util.h file.
+ */
+static void *fetch_socket (JNIEnv *env, jobject socket)
+{
+    static jmethodID get_socket_handle_mid = NULL;
+
+    if (get_socket_handle_mid == NULL) {
+        jclass cls = env->GetObjectClass (socket);
+        assert (cls);
+        get_socket_handle_mid = env->GetMethodID (cls,
+            "getSocketHandle", "()J");
+        env->DeleteLocalRef (cls);
+        assert (get_socket_handle_mid);
+    }
+  
+    void *s = (void*) env->CallLongMethod (socket, get_socket_handle_mid);
+    if (env->ExceptionCheck ()) {
+        s = NULL;
+    }
+  
+    assert (s);
+    return s;
+}

bindings/java/org/zmq/Poller.java

+/*
+    Copyright (c) 2007-2010 iMatix Corporation
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the Lesser GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ 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
+    Lesser GNU General Public License for more details.
+
+    You should have received a copy of the Lesser GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package org.zmq;
+
+public class Poller {
+    static {
+        System.loadLibrary("jzmq");
+    }
+
+    public static final int POLLIN = 1;
+    public static final int POLLOUT = 2;
+    public static final int POLLERR = 4;
+
+    /**
+     * Class constructor.
+     *
+     * @param context a 0MQ context previously created.
+     */
+    public Poller (Context context, int size) {
+        this.context = context;
+        this.size = size;
+        this.next = 0;
+
+        this.socket = new Socket[size];
+        this.event = new short[size];
+        this.revent = new short[size];
+
+        for (int i = 0; i < size; ++i) {
+            this.event[i] = (POLLIN | POLLOUT | POLLERR);
+        }
+    }
+
+    public int register (Socket socket) {
+        if (next >= size)
+            return -1;
+        this.socket[next] = socket;
+        return next++;
+    }
+    
+    public long getTimeout () {
+        return this.timeout;
+    }
+    
+    public void setTimeout (long timeout) {
+        this.timeout = timeout;
+    }
+
+    public int getSize () {
+        return this.size;
+    }
+
+    public int getNext () {
+        return this.next;
+    }
+
+    /**
+     * Issue a poll call.
+     * @return how many objects where signalled by poll().
+     */
+    public long poll () {
+        if (size <= 0 || next <= 0)
+            return 0;
+
+        for (int i = 0; i < next; ++i) {
+            revent[i] = 0;
+        }
+
+        return run_poll(next, socket, event, revent, timeout);
+    }
+
+    public boolean pollin(int index) {
+        return poll_mask(index, POLLIN);
+    }
+
+    public boolean pollout(int index) {
+        return poll_mask(index, POLLOUT);
+    }
+
+    public boolean pollerr(int index) {
+        return poll_mask(index, POLLERR);
+    }
+
+    /**
+     * Issue a poll call on the specified 0MQ sockets.
+     *
+     * @param socket an array of 0MQ Socket objects to poll.
+     * @param event an array of short values specifying what to poll for.
+     * @param revent an array of short values with the results.
+     * @param timeout the maximum timeout in microseconds.
+     * @return how many objects where signalled by poll().
+     */
+    private native long run_poll(int count,
+                                 Socket[] socket,
+                                 short[] event,
+                                 short[] revent,
+                                 long timeout);
+
+    /**
+     * Check whether a specific mask was signalled by latest poll call.
+     *
+     * @param index the index indicating the socket.
+     * @param mask a combination of POLLIN, POLLOUT and POLLERR.
+     * @return true if specific socket was signalled as specified.
+     */
+    private boolean poll_mask(int index, int mask) {
+        if (mask <= 0 || index < 0 || index >= next)
+            return false;
+        return (revent[index] & mask) > 0;
+    }
+
+    private Context context = null;
+    private long timeout = 0;
+    private int size = 0;
+    private int next = 0;
+    private Socket[] socket = null;
+    private short[] event = null;
+    private short[] revent = null;
+}