Bug 558514 - [OSGi R8] Core changes for Condition Service RFC 242

Change-Id: I7d27c1fe21d0bfcb4a621f5f5838b1cb029a82c3
Signed-off-by: Thomas Watson <tjwatson@us.ibm.com>

6 files changed, 168 insertions, 8 deletions

diff --git a/bundles/org.eclipse.osgi.tests/src/org/eclipse/osgi/tests/bundles/ConnectTests.java b/bundles/org.eclipse.osgi.tests/src/org/eclipse/osgi/tests/bundles/ConnectTests.java
index 2fef34ec0..75254b1d6 100644
--- a/bundles/org.eclipse.osgi.tests/src/org/eclipse/osgi/tests/bundles/ConnectTests.java
+++ b/bundles/org.eclipse.osgi.tests/src/org/eclipse/osgi/tests/bundles/ConnectTests.java
@@ -74,6 +74,7 @@ import org.osgi.framework.wiring.BundleRevision;
 import org.osgi.framework.wiring.BundleWiring;
 import org.osgi.framework.wiring.FrameworkWiring;
 import org.osgi.resource.Namespace;
+import org.osgi.service.condition.Condition;
 
 public class ConnectTests extends AbstractBundleTests {
 
@@ -390,6 +391,54 @@ public class ConnectTests extends AbstractBundleTests {
 		assertEquals("Wrong number of stop called.", 2, bundleActvatorStopCalled.get());
 	}
 
+	public void testTrueCondition() {
+		final AtomicReference<ServiceReference<Condition>> trueConditionStart = new AtomicReference<>();
+		final AtomicReference<ServiceReference<Condition>> trueConditionStop = new AtomicReference<>();
+
+		ModuleConnector activatorModuleConnector = new TestCountingModuleConnector() {
+			@Override
+			public Optional<BundleActivator> createBundleActivator() {
+				super.createBundleActivator();
+				return Optional.of(new BundleActivator() {
+
+					@Override
+					public void start(BundleContext context) throws Exception {
+						trueConditionStart.set(context
+								.getServiceReferences(Condition.class,
+										'(' + Condition.CONDITION_ID + '=' + Condition.CONDITION_ID_TRUE + ')')
+								.iterator().next());
+					}
+
+					@Override
+					public void stop(BundleContext context) throws Exception {
+						trueConditionStop.set(context
+								.getServiceReferences(Condition.class,
+										'(' + Condition.CONDITION_ID + '=' + Condition.CONDITION_ID_TRUE + ')')
+								.iterator().next());
+					}
+				});
+			}
+		};
+
+		doTestConnect(activatorModuleConnector, new HashMap<>(), (f) -> {
+			try {
+				f.start();
+				ServiceReference<Condition> trueCondition = trueConditionStart.get();
+				assertNotNull("No true condition found.", trueCondition);
+				assertEquals("Wrong bundle.", f.getBundleContext().getBundle(), trueCondition.getBundle());
+				f.stop();
+				f.waitForStop(5000);
+
+				assertEquals("Different true condition found on start and stop.", trueCondition,
+						trueConditionStop.get());
+				assertNull("True condition should be unregistered on stop.", trueCondition.getBundle());
+
+			} catch (Exception e) {
+				sneakyThrow(e);
+			}
+		});
+	}
+
 	public void testConnectInit() {
 		final AtomicReference<File> initFile = new AtomicReference<>();
 		final AtomicReference<File> storeFile = new AtomicReference<>();
diff --git a/bundles/org.eclipse.osgi/.settings/.api_filters b/bundles/org.eclipse.osgi/.settings/.api_filters
index e76dc4211..f1f547e91 100644
--- a/bundles/org.eclipse.osgi/.settings/.api_filters
+++ b/bundles/org.eclipse.osgi/.settings/.api_filters
@@ -52,13 +52,6 @@
             </message_arguments>
         </filter>
     </resource>
-    <resource path="osgi/src/org/osgi/framework/connect/ConnectFramework.java" type="org.osgi.framework.connect.ConnectFramework">
-        <filter comment="Not for OSGi API" id="1110441988">
-            <message_arguments>
-                <message_argument value="org.osgi.framework.connect.ConnectFramework"/>
-            </message_arguments>
-        </filter>
-    </resource>
     <resource path="osgi/src/org/osgi/framework/connect/ConnectFrameworkFactory.java" type="org.osgi.framework.connect.ConnectFrameworkFactory">
         <filter comment="Not for OSGi API" id="1110441988">
             <message_arguments>
@@ -116,4 +109,11 @@
             </message_arguments>
         </filter>
     </resource>
+    <resource path="osgi/src/org/osgi/service/condition/Condition.java" type="org.osgi.service.condition.Condition">
+        <filter comment="Not for OSGi API" id="1110441988">
+            <message_arguments>
+                <message_argument value="org.osgi.service.condition.Condition"/>
+            </message_arguments>
+        </filter>
+    </resource>
 </component>
diff --git a/bundles/org.eclipse.osgi/META-INF/MANIFEST.MF b/bundles/org.eclipse.osgi/META-INF/MANIFEST.MF
index 30f45f660..5bac1a7ab 100644
--- a/bundles/org.eclipse.osgi/META-INF/MANIFEST.MF
+++ b/bundles/org.eclipse.osgi/META-INF/MANIFEST.MF
@@ -68,6 +68,7 @@ Export-Package: org.eclipse.core.runtime.adaptor;x-friends:="org.eclipse.core.ru
  org.osgi.framework.wiring.dto;version="1.3";uses:="org.osgi.dto,org.osgi.resource.dto",
  org.osgi.resource;version="1.0",
  org.osgi.resource.dto;version="1.0";uses:="org.osgi.dto",
+ org.osgi.service.condition;version="1.0",
  org.osgi.service.condpermadmin;version="1.1.1";uses:="org.osgi.framework",
  org.osgi.service.log;version="1.4";uses:="org.osgi.framework",
  org.osgi.service.log.admin;version="1.0";uses:="org.osgi.service.log",
diff --git a/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/framework/SystemBundleActivator.java b/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/framework/SystemBundleActivator.java
index b1917a102..44e488c18 100644
--- a/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/framework/SystemBundleActivator.java
+++ b/bundles/org.eclipse.osgi/container/src/org/eclipse/osgi/internal/framework/SystemBundleActivator.java
@@ -40,6 +40,7 @@ import org.osgi.framework.BundleContext;
 import org.osgi.framework.BundleException;
 import org.osgi.framework.Constants;
 import org.osgi.framework.ServiceRegistration;
+import org.osgi.service.condition.Condition;
 import org.osgi.service.condpermadmin.ConditionalPermissionAdmin;
 import org.osgi.service.packageadmin.PackageAdmin;
 import org.osgi.service.permissionadmin.PermissionAdmin;
@@ -72,6 +73,11 @@ public class SystemBundleActivator implements BundleActivator {
 
 		FrameworkDebugOptions dbgOptions = (FrameworkDebugOptions) configuration.getDebugOptions();
 		dbgOptions.start(bc);
+		Hashtable<String, Object> props = new Hashtable<>(7);
+		props.clear();
+
+		props.put(Condition.CONDITION_ID, Condition.CONDITION_ID_TRUE);
+		register(bc, Condition.class, Condition.INSTANCE, false, props);
 
 		SecurityAdmin sa = bundle.getEquinoxContainer().getStorage().getSecurityAdmin();
 		ClassLoader tccl = bundle.getEquinoxContainer().getContextFinder();
@@ -84,7 +90,7 @@ public class SystemBundleActivator implements BundleActivator {
 		register(bc, PermissionAdmin.class, sa, null);
 		register(bc, ConditionalPermissionAdmin.class, sa, null);
 
-		Hashtable<String, Object> props = new Hashtable<>(7);
+
 		props.clear();
 		props.put(Constants.SERVICE_RANKING, Integer.MIN_VALUE);
 		register(bc, Resolver.class, new ResolverImpl(new Logger(0), null), false, props);
diff --git a/bundles/org.eclipse.osgi/osgi/src/org/osgi/service/condition/Condition.java b/bundles/org.eclipse.osgi/osgi/src/org/osgi/service/condition/Condition.java
new file mode 100644
index 000000000..34980301c
--- /dev/null
+++ b/bundles/org.eclipse.osgi/osgi/src/org/osgi/service/condition/Condition.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) OSGi Alliance (2020). All Rights Reserved.
+ * 
+ * Licensed 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 org.osgi.service.condition;
+
+import org.osgi.annotation.versioning.ConsumerType;
+
+/**
+ * OSGi due to its modular nature provides <code>Requirements</code> and
+ * <code>Capabilities</code> to declare what a Bundle needs in order to run
+ * properly. This is honored by the resolver and enforced by the Framework at
+ * runtime. The dynamic nature however can provide some impediments at runtime.
+ * That there is a Bundle that might provide a certain service or capability
+ * does not mean, that it will be available when and a component expects it be.
+ * <p>
+ * Conditions are to the Service Layer what Requirements and Capabilities are to
+ * the module Layer
+ * <p>
+ * The <code>Condition</code> interface is designed to address this issue. Its
+ * task is to provide a marker that can be tracked if a some Condition is meet
+ * and for example a Requirement is meet at Runtime.
+ * <p>
+ * A Condition must be registered with the {@link Condition#CONDITION_ID} as
+ * property.
+ * 
+ * @ThreadSafe
+ * @author $Id$
+ */
+@ConsumerType
+public interface Condition {
+	/**
+	 * Service property identifying a condition's unique identifier. The type of
+	 * this service property is {@code String+}
+	 */
+	public static final String		CONDITION_ID		= "osgi.condition.id";
+
+	/**
+	 * The unique identifier for the TRUE Condition. The TRUE condition is
+	 * registered by the framework and therefore can always be relied upon.
+	 * 
+	 * @see Condition#CONDITION_ID
+	 */
+	public static final String		CONDITION_ID_TRUE	= "true";
+
+	/**
+	 * A singleton condition instance that can be used to register condition
+	 * services.
+	 */
+	public static final Condition	INSTANCE			= new Condition() {
+															/* Nothing to do */};
+
+}
diff --git a/bundles/org.eclipse.osgi/osgi/src/org/osgi/service/condition/package-info.java b/bundles/org.eclipse.osgi/osgi/src/org/osgi/service/condition/package-info.java
new file mode 100644
index 000000000..5bcd82de3
--- /dev/null
+++ b/bundles/org.eclipse.osgi/osgi/src/org/osgi/service/condition/package-info.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) OSGi Alliance (2013, 2016). All Rights Reserved.
+ * 
+ * Licensed 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.
+ */
+
+/**
+ * Condition Service Package Version 1.0.
+ * <p>
+ * Bundles wishing to use this package must list the package in the
+ * Import-Package header of the bundle's manifest. This package has two types of
+ * users: the consumers that use the API in this package and the providers that
+ * implement the API in this package.
+ * <p>
+ * Example import for consumers using the API in this package:
+ * <p>
+ * {@code  Import-Package: org.osgi.service.condition; version="[1.0,2.0)"}
+ * <p>
+ * Example import for providers implementing the API in this package:
+ * <p>
+ * {@code  Import-Package: org.osgi.service.condition; version="[1.0,1.1)"}
+ * 
+ * @author $Id$
+ */
+
+@Version("1.0")
+package org.osgi.service.condition;
+
+import org.osgi.annotation.versioning.Version;