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<erlref>
  <header>
    <copyright>
      <year>2002</year><year>2021</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      Licensed under the Apache License, Version 2.0 (the "License");
      you may not use this file except in compliance with the License.
      You may obtain a copy of the License at
 
          http://www.apache.org/licenses/LICENSE-2.0

      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.

    </legalnotice>

    <title>et</title>
    <prepared>H&aring;kan Mattsson</prepared>
    <responsible>H&aring;kan Mattsson</responsible>
    <docno></docno>
    <approved>H&aring;kan Mattsson</approved>
    <checked></checked>
    <date></date>
    <rev>%VSN%</rev>
    <file>et</file>
  </header>
  <module since="">et</module>
  <modulesummary>Main API of the Event Trace (ET) application</modulesummary>
  <description>
    <p>Interface module for the Event Trace (ET) application</p>
  </description>
  <funcs>
    <func>
      <name since="OTP R13B04">trace_me(DetailLevel, From, To, Label, Contents) -> hopefully_traced</name>
      <fsummary>A function that is intended to be traced.</fsummary>
      <type>
        <v>DetailLevel = integer(X) when X =&lt; 0, X >= 100</v>
        <v>From        = actor()</v>
        <v>To          = actor()</v>
        <v>Label       = atom() | string() | term()</v>
        <v>Contents    = [{Key, Value}] | term()</v>
        <v>actor()     = term()</v>
      </type>
      <desc>
        <p>A function that is intended to be traced.</p>
        <p>This function is intended to be invoked at strategic places
        in user applications in order to enable simplified
        tracing. The functions are extremely light weight as they do
        nothing besides returning an atom. The functions are designed
        for being traced. The global tracing mechanism in
        <c>et_collector</c> defaults to set its trace pattern to these
        functions.</p>
        <p>The label is intended to provide a brief summary of the
        event. It is preferred to use an atom but a string would also
        do.</p>
        <p>The contents can be any term but in order to simplify
          post processing of the traced events, a plain list
          of {Key, Value} tuples is preferred.</p>
        <p>Some events, such as messages, are directed from some actor to another.
          Other events (termed actions) may be undirected and only have one actor.</p>
      </desc>
    </func>

    <func>
      <name since="OTP R13B04">trace_me(DetailLevel, FromTo, Label, Contents) -> hopefully_traced</name>
      <fsummary>A function that is intended to be traced.</fsummary>
      <desc>
       <p>Invokes <c>et:trace_me/5</c> with both <c>From</c> and <c>To</c>
       set to <c>FromTo</c>.</p>
     </desc>
    </func>

    <func>
      <name since="">phone_home(DetailLevel, FromTo, Label, Contents) -> hopefully_traced</name>
      <name since="">phone_home(DetailLevel, From, To, Label, Contents) -> hopefully_traced</name>
      <fsummary>Send a signal to the outer space</fsummary>
      <desc>
        <p>These functions sends a signal to the outer space and the
        caller hopes that someone is listening. In other words, they
        invoke <c>et:trace_me/4</c> and <c>et:trace_me/5</c>
        respectively.</p>
      </desc>
    </func>
    <func>
      <name since="">report_event(DetailLevel, FromTo, Label, Contents) -> hopefully_traced</name>
      <name since="">report_event(DetailLevel, From, To, Label, Contents) -> hopefully_traced</name>
      <fsummary>Deprecated functions</fsummary>
      <desc>
        <p>Deprecated functions which for the time being are kept for
        backwards compatibility. Invokes <c>et:trace_me/4</c> and
        <c>et:trace_me/5</c> respectively.</p>
      </desc>
    </func>
  </funcs>
  
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