1 /*
   2  * Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package jdk.vm.ci.hotspot;
  24 
  25 import jdk.vm.ci.meta.JavaMethodProfile;
  26 import jdk.vm.ci.meta.JavaTypeProfile;
  27 import jdk.vm.ci.meta.ProfilingInfo;
  28 import jdk.vm.ci.meta.TriState;
  29 
  30 /**
  31  * Base class for accessing the different kinds of data in a HotSpot {@code MethodData}. This is
  32  * similar to {@link ProfilingInfo}, but most methods require a {@link HotSpotMethodData} and the
  33  * exact position within the method data.
  34  */
  35 abstract class HotSpotMethodDataAccessor {
  36 
  37     final int tag;
  38     final int staticSize;
  39     final HotSpotMethodData.VMState state;
  40     final HotSpotVMConfig config;
  41 
  42     protected HotSpotMethodDataAccessor(HotSpotMethodData.VMState state, int tag, int staticSize) {
  43         this.state = state;
  44         this.config = state.config;
  45         this.tag = tag;
  46         this.staticSize = staticSize;
  47     }
  48 
  49     /**
  50      * Returns the tag stored in the LayoutData header.
  51      *
  52      * @return tag stored in the LayoutData header
  53      */
  54     int getTag() {
  55         return tag;
  56     }
  57 
  58     static int readTag(HotSpotVMConfig config, HotSpotMethodData data, int position) {
  59         final int tag = data.readUnsignedByte(position, config.dataLayoutTagOffset);
  60         assert tag >= config.dataLayoutNoTag && tag <= config.dataLayoutSpeculativeTrapDataTag : "profile data tag out of bounds: " + tag;
  61         return tag;
  62     }
  63 
  64     /**
  65      * Returns the BCI stored in the LayoutData header.
  66      *
  67      * @return an integer between 0 and {@link Short#MAX_VALUE} inclusive, or -1 if not supported
  68      */
  69     int getBCI(HotSpotMethodData data, int position) {
  70         return data.readUnsignedShort(position, config.dataLayoutBCIOffset);
  71     }
  72 
  73     /**
  74      * Computes the size for the specific data at the given position.
  75      *
  76      * @return a value greater than 0
  77      */
  78     final int getSize(HotSpotMethodData data, int position) {
  79         int size = staticSize + getDynamicSize(data, position);
  80         // Sanity check against VM
  81         int vmSize = HotSpotJVMCIRuntime.runtime().compilerToVm.methodDataProfileDataSize(data.metaspaceMethodData, position);
  82         assert size == vmSize : size + " != " + vmSize;
  83         return size;
  84     }
  85 
  86     TriState getExceptionSeen(HotSpotMethodData data, int position) {
  87         final int exceptionsMask = 1 << config.bitDataExceptionSeenFlag;
  88         return TriState.get((getFlags(data, position) & exceptionsMask) != 0);
  89     }
  90 
  91     /**
  92      * @param data
  93      * @param position
  94      */
  95     JavaTypeProfile getTypeProfile(HotSpotMethodData data, int position) {
  96         return null;
  97     }
  98 
  99     /**
 100      * @param data
 101      * @param position
 102      */
 103     JavaMethodProfile getMethodProfile(HotSpotMethodData data, int position) {
 104         return null;
 105     }
 106 
 107     /**
 108      * @param data
 109      * @param position
 110      */
 111     double getBranchTakenProbability(HotSpotMethodData data, int position) {
 112         return -1;
 113     }
 114 
 115     /**
 116      * @param data
 117      * @param position
 118      */
 119     double[] getSwitchProbabilities(HotSpotMethodData data, int position) {
 120         return null;
 121     }
 122 
 123     /**
 124      * @param data
 125      * @param position
 126      */
 127     int getExecutionCount(HotSpotMethodData data, int position) {
 128         return -1;
 129     }
 130 
 131     /**
 132      * @param data
 133      * @param position
 134      */
 135     TriState getNullSeen(HotSpotMethodData data, int position) {
 136         return TriState.UNKNOWN;
 137     }
 138 
 139     protected int getFlags(HotSpotMethodData data, int position) {
 140         return data.readUnsignedByte(position, config.dataLayoutFlagsOffset);
 141     }
 142 
 143     /**
 144      * @param data
 145      * @param position
 146      */
 147     protected int getDynamicSize(HotSpotMethodData data, int position) {
 148         return 0;
 149     }
 150 
 151     abstract StringBuilder appendTo(StringBuilder sb, HotSpotMethodData data, int pos);
 152 
 153 }