Mercurial > hg > graal-compiler

comparison graal/com.oracle.truffle.api/src/com/oracle/truffle/api/Assumption.java @ 16868:db090a8d3705

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
clarify documentation about assumption and profile storage in final fields
author Michael Haupt <michael.haupt@oracle.com>
date Wed, 20 Aug 2014 15:16:11 +0200
parents 494b818b527c
children
comparison
equal deleted inserted replaced
16867:7af9301efe6b 16868:db090a8d3705
32 * invalidated, an assumption can never get valid again. Assumptions can be created using the 32 * invalidated, an assumption can never get valid again. Assumptions can be created using the
33 * {@link TruffleRuntime#createAssumption()} or the {@link TruffleRuntime#createAssumption(String)} 33 * {@link TruffleRuntime#createAssumption()} or the {@link TruffleRuntime#createAssumption(String)}
34 * method. The Truffle compiler has special knowledge of this class in order to produce efficient 34 * method. The Truffle compiler has special knowledge of this class in order to produce efficient
35 * machine code for checking an assumption in case the assumption object is a compile time constant. 35 * machine code for checking an assumption in case the assumption object is a compile time constant.
36 * Therefore, assumptions should be stored in final fields in Truffle nodes. 36 * Therefore, assumptions should be stored in final fields in Truffle nodes.
37 *
38 * All instances of classes implementing {@code Assumption} must be held in {@code final} fields for
39 * compiler optimizations to take effect.
37 */ 40 */
38 public interface Assumption { 41 public interface Assumption {
39 42
40 /** 43 /**
41 * Checks that this assumption is still valid. The method throws an exception, if this is no 44 * Checks that this assumption is still valid. The method throws an exception, if this is no
42 * longer the case. This method is preferred over the {@link #isValid()} method when writing 45 * longer the case. This method is preferred over the {@link #isValid()} method when writing
43 * guest language interpreter code. The catch block should perform a node rewrite (see 46 * guest language interpreter code. The catch block should perform a node rewrite (see
44 * {@link Node#replace(Node)}) with a node that no longer relies on the assumption. 47 * {@link Node#replace(Node)}) with a node that no longer relies on the assumption.
45 * 48 *
46 * @throws InvalidAssumptionException If the assumption is no longer valid. 49 * @throws InvalidAssumptionException If the assumption is no longer valid.
47 */ 50 */
48 void check() throws InvalidAssumptionException; 51 void check() throws InvalidAssumptionException;
49 52
50 /** 53 /**
51 * Checks whether the assumption is still valid. 54 * Checks whether the assumption is still valid.
52 * 55 *
53 * @return a boolean value indicating the validity of the assumption 56 * @return a boolean value indicating the validity of the assumption
54 */ 57 */
55 boolean isValid(); 58 boolean isValid();
56 59
57 /** 60 /**
59 */ 62 */
60 void invalidate(); 63 void invalidate();
61 64
62 /** 65 /**
63 * A name for the assumption that is used for debug output. 66 * A name for the assumption that is used for debug output.
64 * 67 *
65 * @return the name of the assumption 68 * @return the name of the assumption
66 */ 69 */
67 String getName(); 70 String getName();
68 } 71 }