Mercurial > hg > truffle

comparison graal/com.oracle.jvmci.service/src/com/oracle/jvmci/service/Services.java @ 21760:55058b8000ea

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
updated javadoc to document that JVMCI services are disjoint from the standard service loading mechanism and tightened generic type constraint such that Services and @ServiceProcessor can only be used with classes implementing Service
author Doug Simon <doug.simon@oracle.com>
date Sat, 06 Jun 2015 09:23:37 +0200
parents 2e8c01def9a5
children
comparison
equal deleted inserted replaced
21759:75daca0c6a0f 21760:55058b8000ea
25 import java.util.*; 25 import java.util.*;
26 26
27 import sun.reflect.*; 27 import sun.reflect.*;
28 28
29 /** 29 /**
30 * A mechanism on top of the standard {@link ServiceLoader} that enables JVMCI enabled runtime to 30 * An mechanism for loading {@linkplain Service JVMCI services}.
31 * efficiently load services marked by {@link Service}. This is important to avoid the performance
32 * overhead of the standard service loader mechanism for services loaded in the runtime
33 * initialization process.
34 */ 31 */
35 public class Services { 32 public class Services {
36 33
37 /** 34 /**
38 * Determines whether to suppress the {@link NoClassDefFoundError} raised if a service 35 * Determines whether to suppress the {@link NoClassDefFoundError} raised if a service
53 } 50 }
54 } 51 }
55 }; 52 };
56 53
57 /** 54 /**
58 * Gets an {@link Iterable} of the implementations available for a given service. 55 * Gets an {@link Iterable} of the implementations available for a given JVMCI service.
59 * 56 *
60 * @throws SecurityException if a security manager is present and it denies 57 * @throws SecurityException if a security manager is present and it denies
61 * <tt>{@link RuntimePermission}("jvmciServices")</tt> 58 * <tt>{@link RuntimePermission}("jvmciServices")</tt>
62 */ 59 */
63 @SuppressWarnings("unchecked") 60 @SuppressWarnings("unchecked")
64 @CallerSensitive 61 @CallerSensitive
65 public static <S> Iterable<S> load(Class<S> service) { 62 public static <S extends Service> Iterable<S> load(Class<S> service) {
66 SecurityManager sm = System.getSecurityManager(); 63 SecurityManager sm = System.getSecurityManager();
67 if (sm != null) { 64 if (sm != null) {
68 sm.checkPermission(new RuntimePermission("jvmciServices")); 65 sm.checkPermission(new RuntimePermission("jvmciServices"));
69 } 66 }
70 if (Service.class.isAssignableFrom(service)) { 67 try {
71 try { 68 return (Iterable<S>) cache.get(service);
72 return (Iterable<S>) cache.get(service); 69 } catch (UnsatisfiedLinkError e) {
73 } catch (UnsatisfiedLinkError e) { 70 return Collections.emptyList();
74 // Fall back to standard ServiceLoader
75 }
76 } 71 }
77
78 // Need to use the ClassLoader of the caller
79 ClassLoader cl = Reflection.getCallerClass().getClassLoader();
80 return ServiceLoader.load(service, cl);
81 } 72 }
82 73
83 /** 74 /**
84 * Gets the implementation for a given service for which at most one implementation must be 75 * Gets the implementation for a given service for which at most one implementation must be
85 * available. 76 * available.
90 * @throws SecurityException if a security manager is present and it denies 81 * @throws SecurityException if a security manager is present and it denies
91 * <tt>{@link RuntimePermission}("jvmciServices")</tt> 82 * <tt>{@link RuntimePermission}("jvmciServices")</tt>
92 */ 83 */
93 @SuppressWarnings("unchecked") 84 @SuppressWarnings("unchecked")
94 @CallerSensitive 85 @CallerSensitive
95 public static <S> S loadSingle(Class<S> service, boolean required) { 86 public static <S extends Service> S loadSingle(Class<S> service, boolean required) {
96 SecurityManager sm = System.getSecurityManager(); 87 SecurityManager sm = System.getSecurityManager();
97 if (sm != null) { 88 if (sm != null) {
98 sm.checkPermission(new RuntimePermission("jvmciServices")); 89 sm.checkPermission(new RuntimePermission("jvmciServices"));
99 } 90 }
100 Iterable<S> impls; 91 Iterable<S> impls;
101 if (Service.class.isAssignableFrom(service)) { 92 try {
102 try { 93 impls = (Iterable<S>) cache.get(service);
103 impls = (Iterable<S>) cache.get(service); 94 } catch (UnsatisfiedLinkError e) {
104 } catch (UnsatisfiedLinkError e) { 95 impls = Collections.emptyList();
105 // Fall back to standard ServiceLoader
106 impls = null;
107 }
108 } else {
109 impls = null;
110 } 96 }
111 97
112 if (impls == null) {
113 // Need to use the ClassLoader of the caller
114 ClassLoader cl = Reflection.getCallerClass().getClassLoader();
115 impls = ServiceLoader.load(service, cl);
116 }
117 S singleImpl = null; 98 S singleImpl = null;
118 for (S impl : impls) { 99 for (S impl : impls) {
119 if (singleImpl != null) { 100 if (singleImpl != null) {
120 throw new InternalError(String.format("Multiple %s implementations found: %s, %s", service.getName(), singleImpl.getClass().getName(), impl.getClass().getName())); 101 throw new InternalError(String.format("Multiple %s implementations found: %s, %s", service.getName(), singleImpl.getClass().getName(), impl.getClass().getName()));
121 } 102 }