Showing the changes to java/pkg/com/sun/tracing/ProviderFactory.java (1 of 18352 files). Show all
Unified · Split
| @@ -0,0 +1,114 @@ | ||
| 1 | + | |
| 2 | +package com.sun.tracing; | |
| 3 | + | |
| 4 | +import java.util.HashSet; | |
| 5 | +import java.io.PrintStream; | |
| 6 | +import java.lang.reflect.Field; | |
| 7 | +import java.security.AccessController; | |
| 8 | +import java.security.PrivilegedActionException; | |
| 9 | +import java.security.PrivilegedExceptionAction; | |
| 10 | +import sun.security.action.GetPropertyAction; | |
| 11 | + | |
| 12 | +import sun.tracing.NullProviderFactory; | |
| 13 | +import sun.tracing.PrintStreamProviderFactory; | |
| 14 | +import sun.tracing.MultiplexProviderFactory; | |
| 15 | +import sun.tracing.dtrace.DTraceProviderFactory; | |
| 16 | + | |
| 17 | +/** | |
| 18 | + * {@code ProviderFactory} is a factory class used to create instances of | |
| 19 | + * providers. | |
| 20 | + * | |
| 21 | + * To enable tracing in an application, this class must be used to create | |
| 22 | + * instances of the provider interfaces defined by users. | |
| 23 | + * The system-defined factory is obtained by using the | |
| 24 | + * {@code getDefaultFactory()} static method. The resulting instance can be | |
| 25 | + * used to create any number of providers. | |
| 26 | + * | |
| 27 | + * @since 1.7 | |
| 28 | + */ | |
| 29 | +public abstract class ProviderFactory { | |
| 30 | + | |
| 31 | + protected ProviderFactory() {} | |
| 32 | + | |
| 33 | + /** | |
| 34 | + * Creates an implementation of a Provider interface. | |
| 35 | + * | |
| 36 | + * @param cls the provider interface to be defined. | |
| 37 | + * @return an implementation of {@code cls}, whose methods, when called, | |
| 38 | + * will trigger tracepoints in the application. | |
| 39 | + * @throws NullPointerException if cls is null | |
| 40 | + * @throws IllegalArgumentException if the class definition contains | |
| 41 | + * non-void methods | |
| 42 | + */ | |
| 43 | + public abstract <T extends Provider> T createProvider(Class<T> cls); | |
| 44 | + | |
| 45 | + /** | |
| 46 | + * Returns an implementation of a {@code ProviderFactory} which | |
| 47 | + * creates instances of Providers. | |
| 48 | + * | |
| 49 | + * The created Provider instances will be linked to all appropriate | |
| 50 | + * and enabled system-defined tracing mechanisms in the JDK. | |
| 51 | + * | |
| 52 | + * @return a {@code ProviderFactory} that is used to create Providers. | |
| 53 | + */ | |
| 54 | + public static ProviderFactory getDefaultFactory() { | |
| 55 | + HashSet<ProviderFactory> factories = new HashSet<ProviderFactory>(); | |
| 56 | + | |
| 57 | + // Try to instantiate a DTraceProviderFactory | |
| 58 | + String prop = AccessController.doPrivileged( | |
| 59 | + new GetPropertyAction("com.sun.tracing.dtrace")); | |
| 60 | + | |
| 61 | + if ( (prop == null || !prop.equals("disable")) && | |
| 62 | + DTraceProviderFactory.isSupported() ) { | |
| 63 | + factories.add(new DTraceProviderFactory()); | |
| 64 | + } | |
| 65 | + | |
| 66 | + // Try to instantiate an output stream factory | |
| 67 | + prop = AccessController.doPrivileged( | |
| 68 | + new GetPropertyAction("sun.tracing.stream")); | |
| 69 | + if (prop != null) { | |
| 70 | + for (String spec : prop.split(",")) { | |
| 71 | + PrintStream ps = getPrintStreamFromSpec(spec); | |
| 72 | + if (ps != null) { | |
| 73 | + factories.add(new PrintStreamProviderFactory(ps)); | |
| 74 | + } | |
| 75 | + } | |
| 76 | + } | |
| 77 | + | |
| 78 | + // See how many factories we instantiated, and return an appropriate | |
| 79 | + // factory that encapsulates that. | |
| 80 | + if (factories.size() == 0) { | |
| 81 | + return new NullProviderFactory(); | |
| 82 | + } else if (factories.size() == 1) { | |
| 83 | + return factories.toArray(new ProviderFactory[1])[0]; | |
| 84 | + } else { | |
| 85 | + return new MultiplexProviderFactory(factories); | |
| 86 | + } | |
| 87 | + } | |
| 88 | + | |
| 89 | + private static PrintStream getPrintStreamFromSpec(final String spec) { | |
| 90 | + try { | |
| 91 | + // spec is in the form of <class>.<field>, where <class> is | |
| 92 | + // a fully specified class name, and <field> is a static member | |
| 93 | + // in that class. The <field> must be a 'PrintStream' or subtype | |
| 94 | + // in order to be used. | |
| 95 | + final int fieldpos = spec.lastIndexOf('.'); | |
| 96 | + final Class<?> cls = Class.forName(spec.substring(0, fieldpos)); | |
| 97 | + | |
| 98 | + Field f = AccessController.doPrivileged(new PrivilegedExceptionAction<Field>() { | |
| 99 | + public Field run() throws NoSuchFieldException { | |
| 100 | + return cls.getField(spec.substring(fieldpos + 1)); | |
| 101 | + } | |
| 102 | + }); | |
| 103 | + | |
| 104 | + return (PrintStream)f.get(null); | |
| 105 | + } catch (ClassNotFoundException e) { | |
| 106 | + throw new AssertionError(e); | |
| 107 | + } catch (IllegalAccessException e) { | |
| 108 | + throw new AssertionError(e); | |
| 109 | + } catch (PrivilegedActionException e) { | |
| 110 | + throw new AssertionError(e); | |
| 111 | + } | |
| 112 | + } | |
| 113 | +} | |
| 114 | + | |