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

   1 /*******************************************************************************
   2  * Copyright (c) 2013, 2014 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.linuxtools.internal.lttng2.ust.core.trace.callstack;
  15
  16 import java.util.HashSet;
  17 import java.util.Set;
  18
  19 import org.eclipse.linuxtools.tmf.core.callstack.CallStackStateProvider;
  20 import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
  21 import org.eclipse.linuxtools.tmf.core.event.ITmfEventField;
  22 import org.eclipse.linuxtools.tmf.core.trace.ITmfTrace;
  23 import org.eclipse.linuxtools.tmf.ctf.core.CtfTmfEvent;
  24
  25 /**
  26  * Callstack provider for LTTng-UST traces.
  27  *
  28  * If the traces contains 'func_entry' and 'func_exit' event (see the
  29  * lttng-ust-cyg-profile manpage), AND contains vtid and procname contexts, we
  30  * can use this information to populate the TMF Callstack View.
  31  *
  32  * Granted, most UST traces will not contain this information. In this case,
  33  * this will simply build an empty state system, and the view will remain
  34  * unavailable.
  35  *
  36  * @author Alexandre Montplaisir
  37  */
  38 public class LttngUstCallStackProvider extends CallStackStateProvider {
  39
  40     // ------------------------------------------------------------------------
  41     // Event strings
  42     // ------------------------------------------------------------------------
  43
  44     /** Name of the fake field for the vtid contexts */
  45     private static final String CONTEXT_VTID = "context._vtid"; //$NON-NLS-1$
  46
  47     /** Name of the fake field for the procname context */
  48     private static final String CONTEXT_PROCNAME = "context._procname"; //$NON-NLS-1$
  49
  50     /** Field name for the target function address */
  51     private static final String FIELD_ADDR = "addr"; //$NON-NLS-1$
  52
  53     /** Event names indicating function entry */
  54     private static final Set<String> FUNC_ENTRY_EVENTS = new HashSet<>();
  55
  56     /** Event names indicating function exit */
  57     private static final Set<String> FUNC_EXIT_EVENTS = new HashSet<>();
  58
  59     static {
  60         /* This seems overkill, but it will be checked every event. Gotta go FAST! */
  61         FUNC_ENTRY_EVENTS.add("lttng_ust_cyg_profile:func_entry"); //$NON-NLS-1$
  62         FUNC_ENTRY_EVENTS.add("lttng_ust_cyg_profile_fast:func_entry"); //$NON-NLS-1$
  63
  64         FUNC_EXIT_EVENTS.add("lttng_ust_cyg_profile:func_exit"); //$NON-NLS-1$
  65         FUNC_EXIT_EVENTS.add("lttng_ust_cyg_profile_fast:func_exit"); //$NON-NLS-1$
  66     }
  67
  68     /**
  69      * Version number of this state provider. Please bump this if you modify
  70      * the contents of the generated state history in some way.
  71      */
  72     private static final int VERSION = 2;
  73
  74     // ------------------------------------------------------------------------
  75     // Constructor
  76     // ------------------------------------------------------------------------
  77
  78     /**
  79      * Constructor
  80      *
  81      * @param trace
  82      *            The UST trace
  83      */
  84     public LttngUstCallStackProvider(ITmfTrace trace) {
  85         super(trace);
  86     }
  87
  88     // ------------------------------------------------------------------------
  89     // Methods from AbstractTmfStateProvider
  90     // ------------------------------------------------------------------------
  91
  92     @Override
  93     public LttngUstCallStackProvider getNewInstance() {
  94         return new LttngUstCallStackProvider(getTrace());
  95     }
  96
  97     @Override
  98     public int getVersion() {
  99         return VERSION;
 100     }
 101
 102     // ------------------------------------------------------------------------
 103     // Methods from CallStackStateProvider
 104     // ------------------------------------------------------------------------
 105
 106     /**
 107      * Check that this event contains the required information we need to be
 108      * used in the call stack view. We need at least the "procname" and "vtid"
 109      * contexts.
 110      */
 111     @Override
 112     protected boolean considerEvent(ITmfEvent event) {
 113         if (!(event instanceof CtfTmfEvent)) {
 114             return false;
 115         }
 116         ITmfEventField content = ((CtfTmfEvent) event).getContent();
 117         if (content.getField(CONTEXT_VTID) == null ||
 118                 content.getField(CONTEXT_PROCNAME) == null) {
 119             return false;
 120         }
 121         return true;
 122     }
 123
 124     @Override
 125     public String functionEntry(ITmfEvent event) {
 126         String eventName = event.getType().getName();
 127         if (!FUNC_ENTRY_EVENTS.contains(eventName)) {
 128             return null;
 129         }
 130         Long address = (Long) event.getContent().getField(FIELD_ADDR).getValue();
 131         return Long.toHexString(address);
 132     }
 133
 134     @Override
 135     public String functionExit(ITmfEvent event) {
 136         String eventName = event.getType().getName();
 137         if (!FUNC_EXIT_EVENTS.contains(eventName)) {
 138             return null;
 139         }
 140         /*
 141          * The 'addr' field may or may not be present in func_exit events,
 142          * depending on if cyg-profile.so or cyg-profile-fast.so was used.
 143          */
 144         ITmfEventField field = event.getContent().getField(FIELD_ADDR);
 145         if (field == null) {
 146             return CallStackStateProvider.UNDEFINED;
 147         }
 148         Long address = (Long) field.getValue();
 149         return Long.toHexString(address);
 150     }
 151
 152     @Override
 153     public String getThreadName(ITmfEvent event) {
 154         /* Class type and content was already checked if we get called here */
 155         ITmfEventField content = ((CtfTmfEvent) event).getContent();
 156         String procName = (String) content.getField(CONTEXT_PROCNAME).getValue();
 157         Long vtid = (Long) content.getField(CONTEXT_VTID).getValue();
 158
 159         if (procName == null || vtid == null) {
 160             throw new IllegalStateException();
 161         }
 162
 163         return new String(procName + '-' + vtid.toString());
 164     }
 165
 166     @Override
 167     protected Long getThreadId(ITmfEvent event) {
 168         ITmfEventField content = ((CtfTmfEvent) event).getContent();
 169         return (Long) content.getField(CONTEXT_VTID).getValue();
 170     }
 171 }