7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package jdk.vm.ci.services; 24 25 import java.util.ArrayList; 26 import java.util.List; 27 28 /** 29 * Service-provider class for the runtime to locate providers of JVMCI services where the latter are 30 * not in packages exported by the JVMCI module. As part of instantiating 31 * {@link JVMCIServiceLocator}, all JVMCI packages will be {@linkplain Services#exportJVMCITo(Class) 32 * exported} to the module defining the class of the instantiated object. 33 * 34 * While the {@link #getProvider(Class)} method can be used directly, it's usually easier to use 35 * {@link #getProviders(Class)}. 36 */ 37 public abstract class JVMCIServiceLocator { 38 39 private static Void checkPermission() { 40 SecurityManager sm = System.getSecurityManager(); 41 if (sm != null) { 42 sm.checkPermission(new JVMCIPermission()); 43 } 44 return null; 45 } 46 47 @SuppressWarnings("unused") 48 private JVMCIServiceLocator(Void ignore) { 49 } 50 51 /** 52 * Creates a capability for accessing JVMCI. Once successfully instantiated, JVMCI exports all 53 * its packages to the module defining the type of this object. 54 * 55 * @throws SecurityException if a security manager has been installed and it denies 56 * {@link JVMCIPermission} 57 */ 58 protected JVMCIServiceLocator() { 59 this(checkPermission()); 60 Services.exportJVMCITo(getClass()); 61 } 62 63 /** 64 * Gets the provider of the service defined by {@code service} or {@code null} if this object 65 * does not have a provider for {@code service}. 66 */ 67 public abstract <S> S getProvider(Class<S> service); 68 69 /** 70 * Gets the providers of the service defined by {@code service} by querying the 71 * {@link JVMCIServiceLocator} providers obtained by {@link Services#load(Class)}. 72 */ 73 public static <S> List<S> getProviders(Class<S> service) { 74 List<S> providers = new ArrayList<>(); 75 for (JVMCIServiceLocator access : Services.load(JVMCIServiceLocator.class)) { 76 S provider = access.getProvider(service); 77 if (provider != null) { 78 providers.add(provider); 79 } 80 } 81 return providers; 82 } 83 } | 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package jdk.vm.ci.services; 24 25 import java.util.ArrayList; 26 import java.util.List; 27 import java.util.ServiceLoader; 28 29 import jdk.vm.ci.services.internal.ReflectionAccessJDK; 30 31 /** 32 * Service-provider class for the runtime to locate providers of JVMCI services where the latter are 33 * not in packages exported by the JVMCI module. As part of instantiating a 34 * {@link JVMCIServiceLocator}, all JVMCI packages will be opened to the module defining the class 35 * of the instantiated object. 36 * 37 * While the {@link #getProvider(Class)} method can be used directly, it's usually easier to use 38 * {@link #getProviders(Class)}. 39 */ 40 public abstract class JVMCIServiceLocator { 41 42 private static Void checkPermission() { 43 SecurityManager sm = System.getSecurityManager(); 44 if (sm != null) { 45 sm.checkPermission(new JVMCIPermission()); 46 } 47 return null; 48 } 49 50 @SuppressWarnings("unused") 51 private JVMCIServiceLocator(Void ignore) { 52 } 53 54 /** 55 * Creates a capability for accessing JVMCI. Once successfully instantiated, JVMCI opens all its 56 * packages to the module defining the type of this object. 57 * 58 * @throws SecurityException if a security manager has been installed and it denies 59 * {@link JVMCIPermission} 60 */ 61 protected JVMCIServiceLocator() { 62 this(checkPermission()); 63 ReflectionAccessJDK.openJVMCITo(getClass()); 64 } 65 66 /** 67 * Gets the provider of the service defined by {@code service} or {@code null} if this object 68 * does not have a provider for {@code service}. 69 */ 70 protected abstract <S> S getProvider(Class<S> service); 71 72 /** 73 * Gets the providers of the service defined by {@code service} by querying the available 74 * {@link JVMCIServiceLocator} providers. 75 * 76 * @throws SecurityException if a security manager is present and it denies 77 * {@link JVMCIPermission} 78 */ 79 public static <S> List<S> getProviders(Class<S> service) { 80 SecurityManager sm = System.getSecurityManager(); 81 if (sm != null) { 82 sm.checkPermission(new JVMCIPermission()); 83 } 84 List<S> providers = new ArrayList<>(); 85 for (JVMCIServiceLocator access : ServiceLoader.load(JVMCIServiceLocator.class, ClassLoader.getSystemClassLoader())) { 86 S provider = access.getProvider(service); 87 if (provider != null) { 88 providers.add(provider); 89 } 90 } 91 return providers; 92 } 93 } |