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

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