org.eclipse.tracecompass.lttng2.ust.core/src/org/eclipse/tracecompass/internal/lttng2/ust/core/trace/callstack/LttngUstCallStackProvider.java

   1 /*******************************************************************************
   2  * Copyright (c) 2013, 2015 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Alexandre Montplaisir - Initial API and implementation
  11  *   Patrick Tasse - Add support for thread id
  12  *******************************************************************************/
  13
  14 package org.eclipse.tracecompass.internal.lttng2.ust.core.trace.callstack;
  15
  16 import java.util.HashSet;
  17 import java.util.Set;
  18
  19 import org.eclipse.jdt.annotation.NonNull;
  20 import org.eclipse.tracecompass.tmf.core.callstack.CallStackStateProvider;
  21 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  22 import org.eclipse.tracecompass.tmf.core.event.ITmfEventField;
  23 import org.eclipse.tracecompass.tmf.core.trace.ITmfTrace;
  24 import org.eclipse.tracecompass.tmf.ctf.core.event.CtfTmfEvent;
  25
  26 /**
  27  * Callstack provider for LTTng-UST traces.
  28  *
  29  * If the traces contains 'func_entry' and 'func_exit' event (see the
  30  * lttng-ust-cyg-profile manpage), AND contains vtid and procname contexts, we
  31  * can use this information to populate the TMF Callstack View.
  32  *
  33  * Granted, most UST traces will not contain this information. In this case,
  34  * this will simply build an empty state system, and the view will remain
  35  * unavailable.
  36  *
  37  * @author Alexandre Montplaisir
  38  */
  39 public class LttngUstCallStackProvider extends CallStackStateProvider {
  40
  41     // ------------------------------------------------------------------------
  42     // Event strings
  43     // ------------------------------------------------------------------------
  44
  45     /** Name of the fake field for the vtid contexts */
  46     private static final String CONTEXT_VTID = "context._vtid"; //$NON-NLS-1$
  47
  48     /** Name of the fake field for the procname context */
  49     private static final String CONTEXT_PROCNAME = "context._procname"; //$NON-NLS-1$
  50
  51     /** Field name for the target function address */
  52     private static final String FIELD_ADDR = "addr"; //$NON-NLS-1$
  53
  54     /** Event names indicating function entry */
  55     private static final Set<String> FUNC_ENTRY_EVENTS = new HashSet<>();
  56
  57     /** Event names indicating function exit */
  58     private static final Set<String> FUNC_EXIT_EVENTS = new HashSet<>();
  59
  60     static {
  61         /* This seems overkill, but it will be checked every event. Gotta go FAST! */
  62         FUNC_ENTRY_EVENTS.add("lttng_ust_cyg_profile:func_entry"); //$NON-NLS-1$
  63         FUNC_ENTRY_EVENTS.add("lttng_ust_cyg_profile_fast:func_entry"); //$NON-NLS-1$
  64
  65         FUNC_EXIT_EVENTS.add("lttng_ust_cyg_profile:func_exit"); //$NON-NLS-1$
  66         FUNC_EXIT_EVENTS.add("lttng_ust_cyg_profile_fast:func_exit"); //$NON-NLS-1$
  67     }
  68
  69     /**
  70      * Version number of this state provider. Please bump this if you modify
  71      * the contents of the generated state history in some way.
  72      */
  73     private static final int VERSION = 2;
  74
  75     // ------------------------------------------------------------------------
  76     // Constructor
  77     // ------------------------------------------------------------------------
  78
  79     /**
  80      * Constructor
  81      *
  82      * @param trace
  83      *            The UST trace
  84      */
  85     public LttngUstCallStackProvider(@NonNull ITmfTrace trace) {
  86         super(trace);
  87     }
  88
  89     // ------------------------------------------------------------------------
  90     // Methods from AbstractTmfStateProvider
  91     // ------------------------------------------------------------------------
  92
  93     @Override
  94     public LttngUstCallStackProvider getNewInstance() {
  95         return new LttngUstCallStackProvider(getTrace());
  96     }
  97
  98     @Override
  99     public int getVersion() {
 100         return VERSION;
 101     }
 102
 103     // ------------------------------------------------------------------------
 104     // Methods from CallStackStateProvider
 105     // ------------------------------------------------------------------------
 106
 107     /**
 108      * Check that this event contains the required information we need to be
 109      * used in the call stack view. We need at least the "procname" and "vtid"
 110      * contexts.
 111      */
 112     @Override
 113     protected boolean considerEvent(ITmfEvent event) {
 114         if (!(event instanceof CtfTmfEvent)) {
 115             return false;
 116         }
 117         ITmfEventField content = ((CtfTmfEvent) event).getContent();
 118         if (content.getField(CONTEXT_VTID) == null ||
 119                 content.getField(CONTEXT_PROCNAME) == null) {
 120             return false;
 121         }
 122         return true;
 123     }
 124
 125     @Override
 126     public String functionEntry(ITmfEvent event) {
 127         String eventName = event.getType().getName();
 128         if (!FUNC_ENTRY_EVENTS.contains(eventName)) {
 129             return null;
 130         }
 131         Long address = (Long) event.getContent().getField(FIELD_ADDR).getValue();
 132         return Long.toHexString(address);
 133     }
 134
 135     @Override
 136     public String functionExit(ITmfEvent event) {
 137         String eventName = event.getType().getName();
 138         if (!FUNC_EXIT_EVENTS.contains(eventName)) {
 139             return null;
 140         }
 141         /*
 142          * The 'addr' field may or may not be present in func_exit events,
 143          * depending on if cyg-profile.so or cyg-profile-fast.so was used.
 144          */
 145         ITmfEventField field = event.getContent().getField(FIELD_ADDR);
 146         if (field == null) {
 147             return CallStackStateProvider.UNDEFINED;
 148         }
 149         Long address = (Long) field.getValue();
 150         return Long.toHexString(address);
 151     }
 152
 153     @Override
 154     public String getThreadName(ITmfEvent event) {
 155         /* Class type and content was already checked if we get called here */
 156         ITmfEventField content = ((CtfTmfEvent) event).getContent();
 157         String procName = (String) content.getField(CONTEXT_PROCNAME).getValue();
 158         Long vtid = (Long) content.getField(CONTEXT_VTID).getValue();
 159
 160         if (procName == null || vtid == null) {
 161             throw new IllegalStateException();
 162         }
 163
 164         return new String(procName + '-' + vtid.toString());
 165     }
 166
 167     @Override
 168     protected Long getThreadId(ITmfEvent event) {
 169         ITmfEventField content = ((CtfTmfEvent) event).getContent();
 170         return (Long) content.getField(CONTEXT_VTID).getValue();
 171     }
 172 }