1 cananian 1.1.2.1 // AllocationInformation.java, created Thu Mar 30 05:39:25 2000 by cananian
2 cananian 1.1.2.1 // Copyright (C) 1999 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1.2.1 package harpoon.Analysis.Maps;
5 cananian 1.1.2.1
6 kkz 1.1.2.5 import harpoon.ClassFile.HClass;
7 cananian 1.1.2.1 import harpoon.ClassFile.HCodeElement;
8 salcianu 1.7 import harpoon.Temp.Label;
9 cananian 1.1.2.1 import harpoon.Temp.Temp;
10 salcianu 1.7
11 cananian 1.1.2.1 /**
12 cananian 1.1.2.1 * An <code>AllocationInformation</code> maps allocation sites
13 cananian 1.1.2.1 * to information about the allocation done at that site.
14 cananian 1.1.2.1 *
15 cananian 1.1.2.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
16 salcianu 1.7 * @version $Id: AllocationInformation.java,v 1.7 2003/03/03 23:41:34 salcianu Exp $
17 cananian 1.1.2.1 */
18 cananian 1.4 public interface AllocationInformation<HCE extends HCodeElement> {
19 cananian 1.1.2.1
20 cananian 1.1.2.1 /** <code>AllocationProperties</code> contains tests for the various
21 cananian 1.1.2.1 * possibly properties of an allocation site. "Atomic" allocations
22 cananian 1.1.2.1 * (of objects not containing interior pointers) can be done, as well
23 cananian 1.1.2.1 * as stack allocation, thread-local allocation, and pre-thread-start
24 cananian 1.1.2.1 * thread-local allocation. If none of these properties are true,
25 cananian 1.1.2.1 * the object must be allocated in a global heap. */
26 cananian 1.1.2.1 public static interface AllocationProperties {
27 cananian 1.1.2.1 /** @return <code>true</code> if the object allocated at this
28 bdemsky 1.1.2.3 * site has interior pointers; that is, it is not a primitive
29 bdemsky 1.1.2.3 * array, and some field in the allocated object is not primitive.
30 cananian 1.1.2.1 */
31 cananian 1.1.2.2 public boolean hasInteriorPointers();
32 cananian 1.1.2.1 /** @return <code>true</code> if the object can be allocated on
33 cananian 1.1.2.1 * the stack; that is, the lifetime of the object does not
34 cananian 1.1.2.1 * exceed the execution of the method containing the allocation.
35 cananian 1.1.2.1 */
36 cananian 1.1.2.2 public boolean canBeStackAllocated();
37 cananian 1.1.2.1 /** @return <code>true</code> if the object can be allocated on
38 cananian 1.1.2.1 * a thread-local heap; that is, the lifetime of the object does
39 cananian 1.1.2.1 * not exceed the lifetime of the thread object specified
40 cananian 1.1.2.1 * by the <code>allocationHeap</code> method. */
41 cananian 1.1.2.2 public boolean canBeThreadAllocated();
42 cananian 1.1.2.4 /** @return <code>true</code> if a thread-local heap should be
43 cananian 1.1.2.4 * associated with this object --- typically this means that
44 cananian 1.1.2.2 * the allocation site is a thread creation. If this is
45 cananian 1.1.2.4 * <code>true</code> and <code>canBeThreadAllocated()</code>
46 cananian 1.1.2.4 * is also <code>true</code>, then the new object will be
47 cananian 1.1.2.4 * itself allocated on the created heap; otherwise the
48 cananian 1.1.2.4 * new object will be globally allocated.
49 cananian 1.1.2.2 */
50 cananian 1.1.2.4 public boolean makeHeap();
51 cananian 1.1.2.1 /** @return a <code>Temp</code> which at the allocation site
52 cananian 1.1.2.1 * contains a reference to either the thread object of a
53 cananian 1.1.2.1 * thread-local allocation, or to another object whose lifetime
54 cananian 1.1.2.1 * is correlated with that of the (not-yet-created) thread object.
55 cananian 1.1.2.1 * Returns <code>null</code> if the allocation should use the
56 cananian 1.1.2.2 * heap associated with the "current" thread.
57 cananian 1.1.2.2 * If this returns non-<code>null</code>, then
58 cananian 1.1.2.4 * <code>makeHeap()</code> should return <code>false</code> and
59 cananian 1.1.2.2 * <code>canBeThreadAllocated()</code> should return <code>true</code>.
60 cananian 1.1.2.2 */
61 cananian 1.1.2.2 public Temp allocationHeap();
62 kkz 1.1.2.5 /** @return the <code>HClass</code> representing the
63 kkz 1.1.2.5 * "actual" or instantiated class of the object for which
64 kkz 1.1.2.5 * memory is being allocated (as opposed to the declared
65 kkz 1.1.2.5 * class).
66 kkz 1.1.2.5 */
67 kkz 1.1.2.5 public HClass actualClass();
68 salcianu 1.1.2.6
69 salcianu 1.1.2.6 /* Each sync on this object consists of NOTHING. */
70 salcianu 1.1.2.6 public boolean noSync();
71 kkz 1.3 /** @return <code>true</code> if the dynamic write barrier
72 kkz 1.3 * flag needs to be set when the object is allocated--this
73 kkz 1.3 * typically means that one or more write barriers associated
74 kkz 1.3 * with stores into the object created at this allocation site
75 kkz 1.3 * have been optimistically removed. */
76 kkz 1.3 public boolean setDynamicWBFlag();
77 salcianu 1.5
78 salcianu 1.7 /** @return a <code>Label</code> for a pointer that points (at
79 salcianu 1.7 runtime) to a preallocated memory chunk to be used for
80 salcianu 1.7 this allocation site. Returns <code>null</code> if we
81 salcianu 1.7 cannot preallocate this allocation site. */
82 salcianu 1.7 public Label getLabelOfPtrToMemoryChunk();
83 salcianu 1.6
84 salcianu 1.6 /** @return an unique integer ID for the allocation site.
85 salcianu 1.6 Useful for instrumentation purposes. */
86 salcianu 1.6 public int getUniqueID();
87 cananian 1.1.2.1 }
88 cananian 1.1.2.1
89 cananian 1.1.2.1 /** Query the properties of the allocation at the specified site. */
90 cananian 1.4 public AllocationProperties query(HCE allocationSite);
91 cananian 1.2 }