io_uring availability check

Motivation:

availability io_uring check for each test case

Modification:

added ioUringExit method to munmap the shared memory and close ring file descriptor which is required for the availability check

Result:

it's able to integrate testsuite tests

transport-native-io_uring/src/main/c/netty_io_uring_native.c

@@ -64,6 +64,21 @@ static jclass ringBufferClass = NULL;
 static jclass ioUringCompletionQueueClass = NULL;
 static jclass ioUringSubmissionQueueClass = NULL;
 
+static void netty_io_uring_native_JNI_OnUnLoad(JNIEnv* env) {
+    netty_unix_limits_JNI_OnUnLoad(env);
+    netty_unix_errors_JNI_OnUnLoad(env);
+    netty_unix_filedescriptor_JNI_OnUnLoad(env);
+    netty_unix_socket_JNI_OnUnLoad(env);
+    netty_unix_buffer_JNI_OnUnLoad(env);
+
+    ringBufferMethodId = NULL;
+    ioUringSubmissionQueueMethodId = NULL;
+    ioUringCommpletionQueueMethodId = NULL;
+    ringBufferClass = NULL;
+    ioUringCompletionQueueClass = NULL;
+    ioUringSubmissionQueueClass = NULL;
+}
+
 void io_uring_unmap_rings(struct io_uring_sq *sq, struct io_uring_cq *cq) {
     munmap(sq->ring_ptr, sq->ring_sz);
     if (cq->ring_ptr && cq->ring_ptr != sq->ring_ptr) {
@@ -210,6 +225,43 @@ static void netty_epoll_native_eventFdWrite(JNIEnv* env, jclass clazz, jint fd,
     }
 }
 
+static void netty_io_uring_ring_buffer_exit(JNIEnv *env, jclass class, jobject ringBuffer) {
+     // Find the id of the Java method to be called
+
+    jmethodID submissionQueueMethodId = (*env)->GetMethodID(env, ringBufferClass, "getIoUringSubmissionQueue", "()Lio/netty/channel/uring/IOUringSubmissionQueue;");
+    jmethodID completionQueueMethodId = (*env)->GetMethodID(env, ringBufferClass, "getIoUringCompletionQueue", "()Lio/netty/channel/uring/IOUringCompletionQueue;");
+
+    jobject submissionQueue = (*env)->CallObjectMethod(env, ringBuffer, submissionQueueMethodId);
+    jobject completionQueue = (*env)->CallObjectMethod(env, ringBuffer, completionQueueMethodId);
+
+    jmethodID submissionQueueArrayAddressMethodId = (*env)->GetMethodID(env, ioUringSubmissionQueueClass, "getSubmissionQueueArrayAddress", "()J");
+    jmethodID submissionQueueKringEntriesAddressMethodId = (*env)->GetMethodID(env, ioUringSubmissionQueueClass, "getKRingEntriesAddress", "()J");
+    jmethodID submissionQueueRingFdMethodId = (*env)->GetMethodID(env, ioUringSubmissionQueueClass, "getRingFd", "()I");
+    jmethodID submissionQueueRingAddressMethodId = (*env)->GetMethodID(env, ioUringSubmissionQueueClass, "getRingAddress", "()J");
+    jmethodID submissionQueueRingSizeMethodId = (*env)->GetMethodID(env, ioUringSubmissionQueueClass, "getRingSize", "()I");
+
+    jmethodID completionQueueRingAddressMethodId = (*env)->GetMethodID(env, ioUringCompletionQueueClass, "getRingAddress", "()J");
+    jmethodID completionQueueRingSizeMethodId = (*env)->GetMethodID(env, ioUringCompletionQueueClass, "getRingSize", "()I");
+
+    jlong submissionQueueArrayAddress = (*env)->CallLongMethod(env, submissionQueue, submissionQueueArrayAddressMethodId);
+    jlong submissionQueueKringEntriesAddress = (*env)->CallLongMethod(env, submissionQueue, submissionQueueKringEntriesAddressMethodId);
+    jint submissionQueueRingFd = (*env)->CallIntMethod(env, submissionQueue, submissionQueueRingFdMethodId);
+    jlong submissionQueueRingAddress = (*env)->CallLongMethod(env, submissionQueue, submissionQueueRingAddressMethodId);
+    jint submissionQueueRingSize = (*env)->CallIntMethod(env, submissionQueue, submissionQueueRingSizeMethodId);
+
+    jlong completionQueueRingAddress = (*env)->CallLongMethod(env, completionQueue, completionQueueRingAddressMethodId);
+    jint completionQueueRingSize = (*env)->CallIntMethod(env, completionQueue, completionQueueRingSizeMethodId);
+
+    unsigned submissionQueueKringEntries = *((unsigned int *) submissionQueueKringEntriesAddress);
+
+    munmap((struct io_uring_sqe*) submissionQueueArrayAddress, submissionQueueKringEntries * sizeof(struct io_uring_sqe));
+    munmap((void*) submissionQueueRingAddress, submissionQueueRingSize);
+	if (((void *) completionQueueRingAddress) && ((void *) completionQueueRingAddress) != ((void *) submissionQueueRingAddress)) {
+		munmap((void *)completionQueueRingAddress, completionQueueRingSize);
+	}
+	close(submissionQueueRingFd);
+}
+
 static int nettyBlockingSocket(int domain, int type, int protocol) {
     return socket(domain, type, protocol);
 }
@@ -261,13 +313,10 @@ static jint netty_create_file(JNIEnv *env, jclass class) {
     return open("io-uring-test.txt", O_RDWR | O_TRUNC | O_CREAT, 0644);
 }
 
-static void netty_io_uring_native_JNI_OnUnLoad(JNIEnv *env) {
-    // Todo OnUnLoad
-}
-
 // JNI Method Registration Table Begin
 static const JNINativeMethod method_table[] = {
     {"ioUringSetup", "(I)Lio/netty/channel/uring/RingBuffer;", (void *) netty_io_uring_setup},
+    {"ioUringExit", "(Lio/netty/channel/uring/RingBuffer;)V", (void *) netty_io_uring_ring_buffer_exit},
     {"createFile", "()I", (void *) netty_create_file},
     {"ioUringEnter", "(IIII)I", (void *)netty_io_uring_enter},
     {"eventFd", "()I", (void *) netty_epoll_native_eventFd},
@@ -280,6 +329,12 @@ static const jint method_table_size =
 // JNI Method Registration Table End
 
 JNIEXPORT jint JNI_OnLoad(JavaVM *vm, void *reserved) {
+    int ret = JNI_ERR;
+    int limitsOnLoadCalled = 0;
+    int errorsOnLoadCalled = 0;
+    int filedescriptorOnLoadCalled = 0;
+    int socketOnLoadCalled = 0;
+    int bufferOnLoadCalled = 0;
     JNIEnv *env;
     char *nettyClassName = NULL;
 
@@ -316,22 +371,27 @@ JNIEXPORT jint JNI_OnLoad(JavaVM *vm, void *reserved) {
     if (netty_unix_limits_JNI_OnLoad(env, packagePrefix) == JNI_ERR) {
         goto done;
     }
+    limitsOnLoadCalled = 1;
 
     if (netty_unix_errors_JNI_OnLoad(env, packagePrefix) == JNI_ERR) {
         goto done;
     }
+    errorsOnLoadCalled = 1;
 
     if (netty_unix_filedescriptor_JNI_OnLoad(env, packagePrefix) == JNI_ERR) {
         goto done;
     }
+    filedescriptorOnLoadCalled = 1;
 
     if (netty_unix_socket_JNI_OnLoad(env, packagePrefix) == JNI_ERR) {
         goto done;
     }
+    socketOnLoadCalled = 1;
 
     if (netty_unix_buffer_JNI_OnLoad(env, packagePrefix) == JNI_ERR) {
         goto done;
     }
+    bufferOnLoadCalled = 1;
 
     NETTY_PREPEND(packagePrefix, "io/netty/channel/uring/RingBuffer",
                 nettyClassName, done);
@@ -354,9 +414,45 @@ JNIEXPORT jint JNI_OnLoad(JavaVM *vm, void *reserved) {
     NETTY_GET_METHOD(env, ioUringCompletionQueueClass,
                    ioUringCommpletionQueueMethodId, "<init>", "(JJJJJJIJI)V",
                    done);
-
+    ret = NETTY_JNI_VERSION;
 done:
     //unload
+    free(nettyClassName);
 
-    return NETTY_JNI_VERSION;
+    if (ret == JNI_ERR) {
+        if (limitsOnLoadCalled == 1) {
+            netty_unix_limits_JNI_OnUnLoad(env);
+        }
+        if (errorsOnLoadCalled == 1) {
+            netty_unix_errors_JNI_OnUnLoad(env);
+        }
+        if (filedescriptorOnLoadCalled == 1) {
+            netty_unix_filedescriptor_JNI_OnUnLoad(env);
+        }
+        if (socketOnLoadCalled == 1) {
+            netty_unix_socket_JNI_OnUnLoad(env);
+        }
+        if (bufferOnLoadCalled == 1) {
+            netty_unix_buffer_JNI_OnUnLoad(env);
+        }
+
+        ringBufferMethodId = NULL;
+        ioUringSubmissionQueueMethodId = NULL;
+        ioUringCommpletionQueueMethodId = NULL;
+        ringBufferClass = NULL;
+        ioUringCompletionQueueClass = NULL;
+        ioUringSubmissionQueueClass = NULL;
+
+    }
+    return ret;
+}
+
+JNIEXPORT void JNI_OnUnload(JavaVM* vm, void* reserved) {
+    // Todo OnUnLoad
+    JNIEnv* env;
+    if ((*vm)->GetEnv(vm, (void**) &env, NETTY_JNI_VERSION) != JNI_OK) {
+        // Something is wrong but nothing we can do about this :(
+        return;
+    }
+    netty_io_uring_native_JNI_OnUnLoad(env);
 }

transport-native-io_uring/src/main/java/io/netty/channel/uring/IOUring.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2020 The Netty Project
+ *
+ * The Netty Project licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.channel.uring;
+
+import io.netty.channel.unix.FileDescriptor;
+import io.netty.util.internal.SystemPropertyUtil;
+
+final class IOUring {
+
+      private static final Throwable UNAVAILABILITY_CAUSE;
+
+    static {
+        Throwable cause = null;
+
+        if (SystemPropertyUtil.getBoolean("io.netty.transport.noNative", false)) {
+            cause = new UnsupportedOperationException(
+                    "Native transport was explicit disabled with -Dio.netty.transport.noNative=true");
+        } else {
+            RingBuffer ringBuffer = null;
+            try {
+                ringBuffer = Native.createRingBuffer();
+            } catch (Throwable t) {
+                cause = t;
+            } finally {
+                if (ringBuffer != null) {
+                    try {
+                        ringBuffer.close();
+                    } catch (Exception ignore) {
+                        // ignore
+                    }
+                }
+            }
+        }
+
+        UNAVAILABILITY_CAUSE = cause;
+    }
+
+    public static boolean isAvailable() {
+        return UNAVAILABILITY_CAUSE == null;
+    }
+
+    public static void ensureAvailability() {
+        if (UNAVAILABILITY_CAUSE != null) {
+            throw (Error) new UnsatisfiedLinkError(
+                    "failed to load the required native library").initCause(UNAVAILABILITY_CAUSE);
+        }
+    }
+
+    public static Throwable unavailabilityCause() {
+        return UNAVAILABILITY_CAUSE;
+    }
+
+    private IOUring() {
+    }
+}

transport-native-io_uring/src/main/java/io/netty/channel/uring/Native.java

@@ -15,19 +15,52 @@
  */
 package io.netty.channel.uring;
 
+import io.netty.channel.DefaultFileRegion;
 import io.netty.channel.unix.FileDescriptor;
+import io.netty.channel.unix.PeerCredentials;
 import io.netty.channel.unix.Socket;
 import io.netty.util.internal.NativeLibraryLoader;
 import io.netty.util.internal.PlatformDependent;
 import io.netty.util.internal.SystemPropertyUtil;
 import io.netty.util.internal.ThrowableUtil;
+
+import java.io.IOException;
+import java.nio.channels.Selector;
 import java.util.Locale;
 
-final class Native {
+import static io.netty.channel.unix.Socket.isIPv6Preferred;
 
+
+final class Native {
     private static final int DEFAULT_RING_SIZE = SystemPropertyUtil.getInt("io.netty.uring.ringSize", 32);
+
      static {
+        Selector selector = null;
+        try {
+            // We call Selector.open() as this will under the hood cause IOUtil to be loaded.
+            // This is a workaround for a possible classloader deadlock that could happen otherwise:
+            //
+            // See https://github.com/netty/netty/issues/10187
+            selector = Selector.open();
+        } catch (IOException ignore) {
+            // Just ignore
+        }
+        try {
+            // First, try calling a side-effect free JNI method to see if the library was already
+            // loaded by the application.
+            Native.createFile();
+        } catch (UnsatisfiedLinkError ignore) {
+            // The library was not previously loaded, load it now.
             loadNativeLibrary();
+        } finally {
+            try {
+                if (selector != null) {
+                    selector.close();
+                }
+            } catch (IOException ignore) {
+                // Just ignore
+            }
+        }
         Socket.initialize();
     }
 
@@ -55,11 +88,17 @@ final class Native {
         return new FileDescriptor(eventFd());
     }
 
+    public static native void ioUringExit(RingBuffer ringBuffer);
+
     private static native int eventFd();
 
     // for testing(it is only temporary)
     public static native int createFile();
 
+    public static Socket newSocketStream() {
+        return Socket.newSocketStream();
+    }
+
     private Native() {
         // utility
     }

transport-native-io_uring/src/main/java/io/netty/channel/uring/RingBuffer.java

@@ -33,4 +33,8 @@ final class RingBuffer {
     return this.ioUringCompletionQueue;
   }
 
+  public void close() {
+      Native.ioUringExit(this);
+  }
+
 }

transport-native-io_uring/src/test/java/io/netty/channel/uring/IOUringSocketTest.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2020 The Netty Project
+ *
+ * The Netty Project licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.channel.uring;
+
+import io.netty.channel.unix.Socket;
+import io.netty.channel.unix.tests.SocketTest;
+import org.junit.BeforeClass;
+
+import static org.junit.Assume.assumeTrue;
+
+public class IOUringSocketTest extends SocketTest<Socket> {
+
+    @BeforeClass
+    public static void loadJNI() {
+        assumeTrue(IOUring.isAvailable());
+    }
+
+    @Override
+    protected Socket newSocket() {
+        return Socket.newSocketStream();
+    }
+}