001 /*
002 * This file is part of the Jikes RVM project (http://jikesrvm.org).
003 *
004 * This file is licensed to You under the Eclipse Public License (EPL);
005 * You may not use this file except in compliance with the License. You
006 * may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/eclipse-1.0.php
009 *
010 * See the COPYRIGHT.txt file distributed with this work for information
011 * regarding copyright ownership.
012 */
013 package org.mmtk.plan;
014
015 import org.mmtk.policy.SegregatedFreeListSpace;
016 import org.vmmagic.pragma.*;
017
018 /**
019 * This class and its subclasses communicate to the host VM/Runtime
020 * any features of the selected plan that it needs to know. This is
021 * separate from the main Plan/PlanLocal class in order to bypass any
022 * issues with ordering of static initialization.
023 */
024 @Uninterruptible public abstract class PlanConstraints {
025 /** @return {@code true} if this Plan requires read barriers on java.lang.reference types. */
026 public boolean needsJavaLangReferenceReadBarrier() { return false; }
027
028 /** @return {@code true} if this Plan requires write barriers on booleans. */
029 public boolean needsBooleanWriteBarrier() { return false; }
030
031 /** @return {@code true} if this Plan requires read barriers on booleans. */
032 public boolean needsBooleanReadBarrier() { return false; }
033
034 /** @return {@code true} if this Plan can perform bulk boolean arraycopy barriers. */
035 public boolean booleanBulkCopySupported() { return false; }
036
037 /** @return {@code true} if this Plan requires write barriers on bytes. */
038 public boolean needsByteWriteBarrier() { return false; }
039
040 /** @return {@code true} if this Plan requires read barriers on bytes. */
041 public boolean needsByteReadBarrier() { return false; }
042
043 /** @return {@code true} if this Plan can perform bulk byte arraycopy barriers. */
044 public boolean byteBulkCopySupported() { return false; }
045
046 /** @return {@code true} if this Plan requires write barriers on chars. */
047 public boolean needsCharWriteBarrier() { return false; }
048
049 /** @return {@code true} if this Plan requires read barriers on chars. */
050 public boolean needsCharReadBarrier() { return false; }
051
052 /** @return {@code true} if this Plan can perform bulk char arraycopy barriers. */
053 public boolean charBulkCopySupported() { return false; }
054
055 /** @return {@code true} if this Plan requires write barriers on shorts. */
056 public boolean needsShortWriteBarrier() { return false; }
057
058 /** @return {@code true} if this Plan requires read barriers on shorts. */
059 public boolean needsShortReadBarrier() { return false; }
060
061 /** @return {@code true} if this Plan can perform bulk short arraycopy barriers. */
062 public boolean shortBulkCopySupported() { return false; }
063
064 /** @return {@code true} if this Plan requires write barriers on ints. */
065 public boolean needsIntWriteBarrier() { return false; }
066
067 /** @return {@code true} if this Plan requires read barriers on ints. */
068 public boolean needsIntReadBarrier() { return false; }
069
070 /** @return {@code true} if this Plan can perform bulk int arraycopy barriers. */
071 public boolean intBulkCopySupported() { return false; }
072
073 /** @return {@code true} if this Plan requires write barriers on longs. */
074 public boolean needsLongWriteBarrier() { return false; }
075
076 /** @return {@code true} if this Plan requires read barriers on longs. */
077 public boolean needsLongReadBarrier() { return false; }
078
079 /** @return {@code true} if this Plan can perform bulk long arraycopy barriers. */
080 public boolean longBulkCopySupported() { return false; }
081
082 /** @return {@code true} if this Plan requires write barriers on floats. */
083 public boolean needsFloatWriteBarrier() { return false; }
084
085 /** @return {@code true} if this Plan requires read barriers on floats. */
086 public boolean needsFloatReadBarrier() { return false; }
087
088 /** @return {@code true} if this Plan can perform bulk float arraycopy barriers. */
089 public boolean floatBulkCopySupported() { return false; }
090
091 /** @return {@code true} if this Plan requires write barriers on doubles. */
092 public boolean needsDoubleWriteBarrier() { return false; }
093
094 /** @return {@code true} if this Plan requires read barriers on doubles. */
095 public boolean needsDoubleReadBarrier() { return false; }
096
097 /** @return {@code true} if this Plan can perform bulk double arraycopy barriers. */
098 public boolean doubleBulkCopySupported() { return false; }
099
100 /** @return {@code true} if this Plan requires write barriers on Words. */
101 public boolean needsWordWriteBarrier() { return false; }
102
103 /** @return {@code true} if this Plan requires read barriers on Words. */
104 public boolean needsWordReadBarrier() { return false; }
105
106 /** @return {@code true} if this Plan can perform bulk Word arraycopy barriers. */
107 public boolean wordBulkCopySupported() { return false; }
108
109 /** @return {@code true} if this Plan requires write barriers on Address's. */
110 public boolean needsAddressWriteBarrier() { return false; }
111
112 /** @return {@code true} if this Plan requires read barriers on Address's. */
113 public boolean needsAddressReadBarrier() { return false; }
114
115 /** @return {@code true} if this Plan can perform bulk Address arraycopy barriers. */
116 public boolean addressBulkCopySupported() { return false; }
117
118 /** @return {@code true} if this Plan requires write barriers on Extents. */
119 public boolean needsExtentWriteBarrier() { return false; }
120
121 /** @return {@code true} if this Plan requires read barriers on Extents. */
122 public boolean needsExtentReadBarrier() { return false; }
123
124 /** @return {@code true} if this Plan can perform bulk Extent arraycopy barriers. */
125 public boolean extentBulkCopySupported() { return false; }
126
127 /** @return {@code true} if this Plan requires write barriers on Offsets. */
128 public boolean needsOffsetWriteBarrier() { return false; }
129
130 /** @return {@code true} if this Plan requires read barriers on Offsets. */
131 public boolean needsOffsetReadBarrier() { return false; }
132
133 /** @return {@code true} if this Plan can perform bulk Offset arraycopy barriers. */
134 public boolean offsetBulkCopySupported() { return false; }
135
136 /** @return {@code true} if this Plan requires write barriers on object references. */
137 public boolean needsObjectReferenceWriteBarrier() { return false; }
138
139 /** @return {@code true} if this Plan requires read barriers on object references. */
140 public boolean needsObjectReferenceReadBarrier() { return false; }
141
142 /** @return {@code true} if this Plan requires non-heap write barriers on object references. */
143 public boolean needsObjectReferenceNonHeapWriteBarrier() { return false;}
144
145 /** @return {@code true} if this Plan requires non-heap read barriers on object references. */
146 public boolean needsObjectReferenceNonHeapReadBarrier() { return false; }
147
148 /** @return {@code true} if this Plan can perform bulk object arraycopy barriers. */
149 public boolean objectReferenceBulkCopySupported() { return false; }
150
151 /** @return {@code true} if this Plan requires linear scanning. */
152 public boolean needsLinearScan() { return org.mmtk.utility.Constants.SUPPORT_CARD_SCANNING;}
153
154 /** @return {@code true} if this Plan moves objects. */
155 public boolean movesObjects() { return false;}
156
157 /** @return Size (in bytes) beyond which new regular objects must be allocated to the LOS */
158 public int maxNonLOSDefaultAllocBytes() { return org.mmtk.utility.Constants.MAX_INT;}
159
160 /** @return Size (in bytes) beyond which new non-moving objects must be allocated to the LOS */
161 public int maxNonLOSNonMovingAllocBytes() { return SegregatedFreeListSpace.MAX_FREELIST_OBJECT_BYTES;}
162
163 /** @return Size (in bytes) beyond which copied objects must be copied to the LOS */
164 public int maxNonLOSCopyBytes() { return org.mmtk.utility.Constants.MAX_INT;}
165
166 /** @return {@code true} if this object forwards objects <i>after</i>
167 * determining global object liveness (e.g. many compacting collectors). */
168 public boolean needsForwardAfterLiveness() { return false;}
169
170 /** @return Is this plan generational in nature. */
171 public boolean generational() { return false;}
172
173 /** @return The number of header bits that are required. */
174 public abstract int gcHeaderBits();
175
176 /** @return The number of header words that are required. */
177 public abstract int gcHeaderWords();
178
179 /** @return {@code true} if this plan contains GCspy. */
180 public boolean withGCspy() { return false; }
181
182 /** @return {@code true} if this plan contains GCTrace. */
183 public boolean generateGCTrace() { return false; }
184
185 /** @return The specialized scan methods required */
186 public int numSpecializedScans() { return 0; }
187
188 /** @return {@code true} if this plan requires concurrent worker threads */
189 public boolean needsConcurrentWorkers() { return false; }
190
191 /** @return {@code true} if this Plan requires a header bit for object logging */
192 public boolean needsLogBitInHeader() { return false; }
193 }