Ensure multiple shaded version of the same netty artifact can be load…

…ed as long as the shaded prefix is different (netty#8207)

Motivation:

We should support to load multiple shaded versions of the same netty artifact as netty is often used in multiple dependencies.

This is related to netty#7272.

Modifications:

- Use -fvisibility=hidden when compiling and use JNIEXPORT for things we really want to have exported
- Ensure fields are declared as static so these are not exported
- Adjust testsuite-shading to use install_name_tool on MacOS to change the id of the lib. Otherwise the wrong may be used.

Result:

Be able to use multiple shaded versions of the same netty artifact.

testsuite-shading/pom.xml

@@ -34,6 +34,8 @@
     <classesShadedDir>${project.build.directory}/classes-shaded</classesShadedDir>
     <classesShadedNativeDir>${classesShadedDir}/META-INF/native</classesShadedNativeDir>
     <shadingPrefix>shaded</shadingPrefix>
+    <shadingPrefix2>shaded2</shadingPrefix2>
+
     <jarName>${project.artifactId}-${project.version}.jar</jarName>
     <shadedPackagePrefix>io.netty.</shadedPackagePrefix>
   </properties>
@@ -104,6 +106,7 @@
             <artifactId>maven-shade-plugin</artifactId>
             <executions>
               <execution>
+                <id>shade</id>
                 <phase>package</phase>
                 <goals>
                   <goal>shade</goal>
@@ -122,6 +125,26 @@
                   </relocations>
                 </configuration>
               </execution>
+              <execution>
+                <id>shade-1</id>
+                <phase>package</phase>
+                <goals>
+                  <goal>shade</goal>
+                </goals>
+                <configuration>
+                  <artifactSet>
+                    <includes>
+                      <include>${project.groupId}</include>
+                    </includes>
+                  </artifactSet>
+                  <relocations>
+                    <relocation>
+                      <pattern>${shadedPackagePrefix}</pattern>
+                      <shadedPattern>${shadingPrefix2}.${shadedPackagePrefix}</shadedPattern>
+                    </relocation>
+                  </relocations>
+                </configuration>
+              </execution>
             </executions>
           </plugin>
           <plugin>
@@ -141,8 +164,36 @@
                         <include name="${jarName}" />
                       </fileset>
                     </unzip>
-                    <move file="${classesShadedNativeDir}/lib${nativeTransportLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTransportLib}" />
-                    <move file="${classesShadedNativeDir}/lib${nativeTcnativeLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTcnativeLib}" />
+                    <copy file="${classesShadedNativeDir}/lib${nativeTransportLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTransportLib}" />
+                    <copy file="${classesShadedNativeDir}/lib${nativeTransportLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix2}_${nativeTransportLib}" />
+                    <exec executable="install_name_tool" failonerror="true" dir="${project.build.directory}/" resolveexecutable="true">
+                      <arg value="-id" />
+                      <arg value="lib${shadingPrefix}_${nativeTransportLib}" />
+                      <arg value="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTransportLib}" />
+                    </exec>
+                    <!-- We need to adjust the ID used on MacOS so we are sure the correct lib is loaded later on -->
+                    <exec executable="install_name_tool" failonerror="true" dir="${project.build.directory}/" resolveexecutable="true">
+                      <arg value="-id" />
+                      <arg value="lib${shadingPrefix2}_${nativeTransportLib}" />
+                      <arg value="${classesShadedNativeDir}/lib${shadingPrefix2}_${nativeTransportLib}" />
+                    </exec>
+                    <delete file="${classesShadedNativeDir}/lib${nativeTransportLib}" />
+
+                    <copy file="${classesShadedNativeDir}/lib${nativeTcnativeLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTcnativeLib}" />
+                    <copy file="${classesShadedNativeDir}/lib${nativeTcnativeLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix2}_${nativeTcnativeLib}" />
+                    <exec executable="install_name_tool" failonerror="true" dir="${project.build.directory}/" resolveexecutable="true">
+                      <arg value="-id" />
+                      <arg value="lib${shadingPrefix}_${nativeTcnativeLib}" />
+                      <arg value="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTcnativeLib}" />
+                    </exec>
+                    <!-- We need to adjust the ID used on MacOS so we are sure the correct lib is loaded later on -->
+                    <exec executable="install_name_tool" failonerror="true" dir="${project.build.directory}/" resolveexecutable="true">
+                      <arg value="-id" />
+                      <arg value="lib${shadingPrefix2}_${nativeTcnativeLib}" />
+                      <arg value="${classesShadedNativeDir}/lib${shadingPrefix2}_${nativeTcnativeLib}" />
+                    </exec>
+                    <delete file="${classesShadedNativeDir}/lib${nativeTcnativeLib}" />
+
                     <jar destfile="${project.build.directory}/${jarName}" basedir="${classesShadedDir}" />
                     <delete dir="${classesShadedDir}" />
                   </target>
@@ -156,6 +207,7 @@
             <configuration>
               <systemPropertyVariables>
                 <shadingPrefix>${shadingPrefix}</shadingPrefix>
+                <shadingPrefix2>${shadingPrefix2}</shadingPrefix2>
               </systemPropertyVariables>
             </configuration>
             <executions>
@@ -211,6 +263,7 @@
             <artifactId>maven-shade-plugin</artifactId>
             <executions>
               <execution>
+                <id>shade</id>
                 <phase>package</phase>
                 <goals>
                   <goal>shade</goal>
@@ -229,6 +282,26 @@
                   </relocations>
                 </configuration>
               </execution>
+              <execution>
+                <id>shade-1</id>
+                <phase>package</phase>
+                <goals>
+                  <goal>shade</goal>
+                </goals>
+                <configuration>
+                  <artifactSet>
+                    <includes>
+                      <include>${project.groupId}</include>
+                    </includes>
+                  </artifactSet>
+                  <relocations>
+                    <relocation>
+                      <pattern>${shadedPackagePrefix}</pattern>
+                      <shadedPattern>${shadingPrefix2}.${shadedPackagePrefix}</shadedPattern>
+                    </relocation>
+                  </relocations>
+                </configuration>
+              </execution>
             </executions>
           </plugin>
           <plugin>
@@ -248,8 +321,14 @@
                         <include name="${jarName}" />
                       </fileset>
                     </unzip>
-                    <move file="${classesShadedNativeDir}/lib${nativeTransportLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTransportLib}" />
-                    <move file="${classesShadedNativeDir}/lib${nativeTcnativeLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTcnativeLib}" />
+                    <copy file="${classesShadedNativeDir}/lib${nativeTransportLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTransportLib}" />
+                    <copy file="${classesShadedNativeDir}/lib${nativeTransportLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix2}_${nativeTransportLib}" />
+                    <delete file="${classesShadedNativeDir}/lib${nativeTransportLib}" />
+
+                    <copy file="${classesShadedNativeDir}/lib${nativeTcnativeLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix}_${nativeTcnativeLib}" />
+                    <copy file="${classesShadedNativeDir}/lib${nativeTcnativeLib}" tofile="${classesShadedNativeDir}/lib${shadingPrefix2}_${nativeTcnativeLib}" />
+                    <delete file="${classesShadedNativeDir}/lib${nativeTcnativeLib}" />
+
                     <jar destfile="${project.build.directory}/${jarName}" basedir="${classesShadedDir}" />
                     <delete dir="${classesShadedDir}" />
                   </target>
@@ -263,6 +342,7 @@
             <configuration>
               <systemPropertyVariables>
                 <shadingPrefix>${shadingPrefix}</shadingPrefix>
+                <shadingPrefix2>${shadingPrefix2}</shadingPrefix2>
               </systemPropertyVariables>
             </configuration>
             <executions>

testsuite-shading/src/test/java/io/netty/testsuite/shading/ShadingIT.java

@@ -23,19 +23,26 @@
 
 public class ShadingIT {
 
+    private static final String SHADING_PREFIX = System.getProperty("shadingPrefix2");
+    private static final String SHADING_PREFIX2 = System.getProperty("shadingPrefix");
+
     @Test
     public void testShadingNativeTransport() throws Exception {
-        testShading0(PlatformDependent.isOsx() ? "io.netty.channel.kqueue.KQueue" : "io.netty.channel.epoll.Epoll");
+        String className = PlatformDependent.isOsx() ?
+                "io.netty.channel.kqueue.KQueue" : "io.netty.channel.epoll.Epoll";
+        testShading0(SHADING_PREFIX, className);
+        testShading0(SHADING_PREFIX2, className);
     }
 
     @Ignore("Figure out why this sometimes fail on the CI")
     @Test
     public void testShadingTcnative() throws Exception {
-        testShading0("io.netty.handler.ssl.OpenSsl");
+        String className = "io.netty.handler.ssl.OpenSsl";
+        testShading0(SHADING_PREFIX, className);
+        testShading0(SHADING_PREFIX2, className);
     }
 
-    private static void testShading0(String classname) throws Exception {
-        String shadingPrefix = System.getProperty("shadingPrefix");
+    private static void testShading0(String shadingPrefix, String classname) throws Exception {
         final Class<?> clazz = Class.forName(shadingPrefix + '.' + classname);
         Method method = clazz.getMethod("ensureAvailability");
         method.invoke(null);

transport-native-epoll/pom.xml

@@ -265,7 +265,7 @@
                   <value>${linux.sendmmsg.support}${glibc.sendmmsg.support}</value>
                   <!-- If glibc and linux kernel are both not sufficient...then define the CFLAGS -->
                   <regex>.*IO_NETTY_SENDMSSG_NOT_FOUND.*</regex>
-                  <replacement>CFLAGS=-O3 -DIO_NETTY_SENDMMSG_NOT_FOUND -Werror -fno-omit-frame-pointer -Wunused-variable -I${unix.common.include.unpacked.dir}</replacement>
+                  <replacement>CFLAGS=-O3 -DIO_NETTY_SENDMMSG_NOT_FOUND -Werror -fno-omit-frame-pointer -Wunused-variable -fvisibility=hidden -I${unix.common.include.unpacked.dir}</replacement>
                   <failIfNoMatch>false</failIfNoMatch>
                 </configuration>
               </execution>
@@ -281,7 +281,7 @@
                   <value>${jni.compiler.args.cflags}</value>
                   <!-- If glibc and linux kernel are both not sufficient...then define the CFLAGS -->
                   <regex>^((?!CFLAGS=).)*$</regex>
-                  <replacement>CFLAGS=-O3 -Werror -fno-omit-frame-pointer -Wunused-variable -I${unix.common.include.unpacked.dir}</replacement>
+                  <replacement>CFLAGS=-O3 -Werror -fno-omit-frame-pointer -Wunused-variable -fvisibility=hidden -I${unix.common.include.unpacked.dir}</replacement>
                   <failIfNoMatch>false</failIfNoMatch>
                 </configuration>
               </execution>

transport-native-epoll/src/main/c/netty_epoll_native.c

@@ -65,11 +65,11 @@ struct mmsghdr {
 #endif
 
 // Those are initialized in the init(...) method and cached for performance reasons
-jfieldID packetAddrFieldId = NULL;
-jfieldID packetScopeIdFieldId = NULL;
-jfieldID packetPortFieldId = NULL;
-jfieldID packetMemoryAddressFieldId = NULL;
-jfieldID packetCountFieldId = NULL;
+static jfieldID packetAddrFieldId = NULL;
+static jfieldID packetScopeIdFieldId = NULL;
+static jfieldID packetPortFieldId = NULL;
+static jfieldID packetMemoryAddressFieldId = NULL;
+static jfieldID packetCountFieldId = NULL;
 
 // util methods
 static int getSysctlValue(const char * property, int* returnValue) {
@@ -505,7 +505,7 @@ static void netty_epoll_native_JNI_OnUnLoad(JNIEnv* env) {
 }
 
 // Invoked by the JVM when statically linked
-jint JNI_OnLoad_netty_transport_native_epoll(JavaVM* vm, void* reserved) {
+static jint JNI_OnLoad_netty_transport_native_epoll0(JavaVM* vm, void* reserved) {
     JNIEnv* env;
     if ((*vm)->GetEnv(vm, (void**) &env, NETTY_JNI_VERSION) != JNI_OK) {
         return JNI_ERR;
@@ -536,14 +536,7 @@ jint JNI_OnLoad_netty_transport_native_epoll(JavaVM* vm, void* reserved) {
     return ret;
 }
 
-#ifndef NETTY_BUILD_STATIC
-JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
-    return JNI_OnLoad_netty_transport_native_epoll(vm, reserved);
-}
-#endif /* NETTY_BUILD_STATIC */
-
-// Invoked by the JVM when statically linked
-void JNI_OnUnload_netty_transport_native_epoll(JavaVM* vm, void* reserved) {
+static void JNI_OnUnload_netty_transport_native_epoll0(JavaVM* vm, void* reserved) {
     JNIEnv* env;
     if ((*vm)->GetEnv(vm, (void**) &env, NETTY_JNI_VERSION) != JNI_OK) {
         // Something is wrong but nothing we can do about this :(
@@ -552,8 +545,25 @@ void JNI_OnUnload_netty_transport_native_epoll(JavaVM* vm, void* reserved) {
     netty_epoll_native_JNI_OnUnLoad(env);
 }
 
+// We build with -fvisibility=hidden so ensure we mark everything that needs to be visible with JNIEXPORT
+// http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-February/014549.html
+
+// Invoked by the JVM when statically linked
+JNIEXPORT jint JNI_OnLoad_netty_transport_native_epoll(JavaVM* vm, void* reserved) {
+    return JNI_OnLoad_netty_transport_native_epoll0(vm, reserved);
+}
+
+// Invoked by the JVM when statically linked
+JNIEXPORT void JNI_OnUnload_netty_transport_native_epoll(JavaVM* vm, void* reserved) {
+    JNI_OnUnload_netty_transport_native_epoll0(vm, reserved);
+}
+
 #ifndef NETTY_BUILD_STATIC
+JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
+    return JNI_OnLoad_netty_transport_native_epoll0(vm, reserved);
+}
+
 JNIEXPORT void JNI_OnUnload(JavaVM* vm, void* reserved) {
-  JNI_OnUnload_netty_transport_native_epoll(vm, reserved);
+    JNI_OnUnload_netty_transport_native_epoll0(vm, reserved);
 }
 #endif /* NETTY_BUILD_STATIC */

transport-native-kqueue/pom.xml

@@ -361,7 +361,7 @@
     <unix.common.lib.dir>${project.build.directory}/unix-common-lib</unix.common.lib.dir>
     <unix.common.lib.unpacked.dir>${unix.common.lib.dir}/META-INF/native/lib</unix.common.lib.unpacked.dir>
     <unix.common.include.unpacked.dir>${unix.common.lib.dir}/META-INF/native/include</unix.common.include.unpacked.dir>
-    <jni.compiler.args.cflags>CFLAGS=-O3 -Werror -fno-omit-frame-pointer -Wunused-variable -I${unix.common.include.unpacked.dir}</jni.compiler.args.cflags>
+    <jni.compiler.args.cflags>CFLAGS=-O3 -Werror -fno-omit-frame-pointer -Wunused-variable -fvisibility=hidden -I${unix.common.include.unpacked.dir}</jni.compiler.args.cflags>
     <jni.compiler.args.ldflags>LDFLAGS=-z now -L${unix.common.lib.unpacked.dir} -Wl,--whole-archive -l${unix.common.lib.name} -Wl,--no-whole-archive</jni.compiler.args.ldflags>
     <skipTests>true</skipTests>
   </properties>

transport-native-kqueue/src/main/c/netty_kqueue_eventarray.c

@@ -24,7 +24,7 @@
 #include "netty_unix_jni.h"
 #include "netty_unix_util.h"
 
-jfieldID kqueueJniPtrFieldId = NULL;
+static jfieldID kqueueJniPtrFieldId = NULL;
 
 static void netty_kqueue_eventarray_evSet(JNIEnv* env, jclass clzz, jlong keventAddress, jobject channel, jint ident, jshort filter, jshort flags, jint fflags) {
     // Create a global pointer, cast it as a long, and retain it in java to re-use and free later.

transport-native-kqueue/src/main/c/netty_kqueue_native.c

@@ -65,7 +65,7 @@
 #endif /* NOTE_DISCONNECTED */
 #endif /* __APPLE__ */
 
-clockid_t waitClockId = 0; // initialized by netty_unix_util_initialize_wait_clock
+static clockid_t waitClockId = 0; // initialized by netty_unix_util_initialize_wait_clock
 
 static jint netty_kqueue_native_kqueueCreate(JNIEnv* env, jclass clazz) {
     jint kq = kqueue();
@@ -318,8 +318,7 @@ static void netty_kqueue_native_JNI_OnUnLoad(JNIEnv* env) {
     netty_kqueue_eventarray_JNI_OnUnLoad(env);
 }
 
-// Invoked by the JVM when statically linked
-jint JNI_OnLoad_netty_transport_native_kqueue(JavaVM* vm, void* reserved) {
+static jint JNI_OnLoad_netty_transport_native_kqueue0(JavaVM* vm, void* reserved) {
     JNIEnv* env;
     if ((*vm)->GetEnv(vm, (void**) &env, NETTY_JNI_VERSION) != JNI_OK) {
         return JNI_ERR;
@@ -351,14 +350,7 @@ jint JNI_OnLoad_netty_transport_native_kqueue(JavaVM* vm, void* reserved) {
     return ret;
 }
 
-#ifndef NETTY_BUILD_STATIC
-JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
-    return JNI_OnLoad_netty_transport_native_kqueue(vm, reserved);
-}
-#endif /* NETTY_BUILD_STATIC */
-
-// Invoked by the JVM when statically linked
-void JNI_OnUnload_netty_transport_native_kqueue(JavaVM* vm, void* reserved) {
+static void JNI_OnUnload_netty_transport_native_kqueue0(JavaVM* vm, void* reserved) {
     JNIEnv* env;
     if ((*vm)->GetEnv(vm, (void**) &env, NETTY_JNI_VERSION) != JNI_OK) {
         // Something is wrong but nothing we can do about this :(
@@ -367,8 +359,25 @@ void JNI_OnUnload_netty_transport_native_kqueue(JavaVM* vm, void* reserved) {
     netty_kqueue_native_JNI_OnUnLoad(env);
 }
 
+// We build with -fvisibility=hidden so ensure we mark everything that needs to be visible with JNIEXPORT
+// http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-February/014549.html
+
+// Invoked by the JVM when statically linked
+JNIEXPORT jint JNI_OnLoad_netty_transport_native_kqueue(JavaVM* vm, void* reserved) {
+    return JNI_OnLoad_netty_transport_native_kqueue0(vm, reserved);
+}
+
+// Invoked by the JVM when statically linked
+JNIEXPORT void JNI_OnUnload_netty_transport_native_kqueue(JavaVM* vm, void* reserved) {
+    JNI_OnUnload_netty_transport_native_kqueue0(vm, reserved);
+}
+
 #ifndef NETTY_BUILD_STATIC
+JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* reserved) {
+    return JNI_OnLoad_netty_transport_native_kqueue0(vm, reserved);
+}
+
 JNIEXPORT void JNI_OnUnload(JavaVM* vm, void* reserved) {
-    return JNI_OnUnload_netty_transport_native_kqueue(vm, reserved);
+    return JNI_OnUnload_netty_transport_native_kqueue0(vm, reserved);
 }
 #endif /* NETTY_BUILD_STATIC */