guide/components/processes-and-threads.jd

page.title=
page.tags= ,

@jd:body

<div id="qv-wrapper">
<div id="qv">

<h2> </h2>
<ol>
<li><a href="#Processes"></a>
  <ol>
    <li><a href="#Lifecycle">  </a></li>
  </ol>
</li>
<li><a href="#Threads"></a>
  <ol>
    <li><a href="#WorkerThreads"> </a></li>
    <li><a href="#ThreadSafe"> </a></li>
  </ol>
</li>
<li><a href="#IPC"> </a></li>
</ol>

</div>
</div>

<p>
,  Android    Linux
.
(  ).
   (      ),
         .

   .</p>

<p>          Android.</p>


<h2 id="Processes"></h2>

<p>         ,
    . ,   ,
,      .</p>

<p>       &mdash;<a href="{@docRoot}guide/topics/manifest/activity-element.html">{@code
&lt;activity&gt;}</a>, <a href="{@docRoot}guide/topics/manifest/service-element.html">{@code
&lt;service&gt;}</a>, <a href="{@docRoot}guide/topics/manifest/receiver-element.html">{@code
&lt;receiver&gt;}</a>  <a href="{@docRoot}guide/topics/manifest/provider-element.html">{@code
&lt;provider&gt;}</a> &mdash;  {@code android:process},
,      .     ,
  ,  ,        .
{@code android:process} ,
,          Linux
 .</p>

<p> <a href="{@docRoot}guide/topics/manifest/application-element.html">{@code
&lt;application&gt;}</a>    {@code android:process},
  ,     .</p>

<p>Android      ,
,      .
,    ,  .
,     .</p>

<p>    ,  Android
 .  ,    ,  ,
   ,    ,   . ,
      ,    .   ,
        . </p>


<h3 id="Lifecycle">  </h3>

<p> Android       ,
       ,         .
,   ,
  ,
,   ,    .
    ,        ..,
   .</p>

<p>     .
     (   <em> </em>
<em>   </em>):</p>

<ol>
  <li><b>  </b>
    <p>,     .
    ,      :</p>

      <ul>
        <li>   {@link android.app.Activity},     (  {@link
android.app.Activity}
{@link android.app.Activity#onResume onResume()}).</li>

        <li>   {@link android.app.Service},   ,
 .</li>

        <li>   {@link android.app.Service},   "  ",&mdash;,
  {@link android.app.Service#startForeground startForeground()}.

        <li>  {@link android.app.Service},
   ({@link android.app.Service#onCreate onCreate()}, {@link android.app.Service#onStart
onStart()}  {@link android.app.Service#onDestroy onDestroy()}).</li>

        <li>   {@link android.content.BroadcastReceiver},    {@link
android.content.BroadcastReceiver#onReceive onReceive()}.</li>
    </ul>

    <p>       .
  ,     ,       .
      ,   ,       ,
     .</p></li>

  <li><b> </b>
    <p>,      ,
    .   ,
     :</p>

      <ul>
        <li>   {@link android.app.Activity},      ,
  (  {@link android.app.Activity#onPause onPause()}).
,   ,        ,
   .</li>

        <li>   {@link android.app.Service},
    .</li>
      </ul>

      <p>    ,
  ,        . </p>
    </li>

  <li><b> </b>
    <p>,   ,     {@link
android.content.Context#startService startService()},
   .        ,   ,
       (,
   ),     ,
          . </p>
  </li>

  <li><b> </b>
    <p>,  ,        (
{@link android.app.Activity#onStop onStop()} ).
   ,        ,
  ,
   .     ,
LRU ( ),  ,
 ,   ,    .        ,
    ,
 ,        ,
    .       .   <a href="{@docRoot}guide/components/activities.html#SavingActivityState"></a>
.</p>
  </li>

  <li><b> </b>
    <p>,      .
   ,
   .
       .</p>
  </li>
</ol>


  <p> Android
,      .  ,       ,
  ,    .</p>

  <p> ,     ,    ,   .
, ,   ,
. ,      A     B
  A      B,  A
,   B.</p>

  <p>  ,  ,      ,
,   ,   <a href="{@docRoot}guide/components/services.html"></a>   ,
  ,   ,     .
, ,     -,
,              .
  ,         ,
  ,    .
 ,       ,     .</p>


<h2 id="Threads"></h2>

<p>        ,
  .    ,
    ,    .    ,
         Android (   {@link
android.widget}  {@link android.view}).  ,    ,
  .</p>

<p> <em></em>       .
,     ,      ,
     .  ,
  (   {@link android.view.View#onKeyDown onKeyDown()}
     ),       .</p>

<p>,      ,
   , ,   ,
  .          ,
 .</p>

<p>         ,
   ,    .  ,
     ,   ,
   ,     .   ,     ,
   .
  .  ,
(    5 ),      <a href="http://developer.android.com/guide/practices/responsiveness.html">
</a>.
  .</p>

<p> ,     Andoid <em></em>  . ,
     .
  .  ,       Android:</p>

<ol>
<li>
<li>       Android
</ol>

<h3 id="WorkerThreads"> </h3>

<p>
      .    ,
  ,       (
 ).</p>

<p>,     ,
      {@link android.widget.ImageView}:</p>

<pre>
public void onClick(View v) {
    new Thread(new Runnable() {
        public void run() {
            Bitmap b = loadImageFromNetwork("http://example.com/image.png");
            mImageView.setImageBitmap(b);
        }
    }).start();
}
</pre>

<p>  ,    ,
. ,      : <em>
Android    </em>&mdash;    {@link
android.widget.ImageView}   ,      .
    ,    .</p>

<p>    Android
.     :</p>

<ul>
<li>{@link android.app.Activity#runOnUiThread(java.lang.Runnable)
Activity.runOnUiThread(Runnable)}</li>
<li>{@link android.view.View#post(java.lang.Runnable) View.post(Runnable)}</li>
<li>{@link android.view.View#postDelayed(java.lang.Runnable, long) View.postDelayed(Runnable,
long)}</li>
</ul>

<p>,         {@link
android.view.View#post(java.lang.Runnable) View.post(Runnable)}:</p>

<pre>
public void onClick(View v) {
    new Thread(new Runnable() {
        public void run() {
            final Bitmap bitmap = loadImageFromNetwork("http://example.com/image.png");
            mImageView.post(new Runnable() {
                public void run() {
                    mImageView.setImageBitmap(bitmap);
                }
            });
        }
    }).start();
}
</pre>

<p>   :      ,
  {@link android.widget.ImageView}     .</p>

<p>    ,
 .        ,
  {@link android.os.Handler}      ,
 . ,       {@link android.os.AsyncTask},
     ,      .</p>


<h4 id="AsyncTask"> AsyncTask</h4>

<p> {@link android.os.AsyncTask}
.
       / .</p>

<p>       {@link android.os.AsyncTask}      {@link
android.os.AsyncTask#doInBackground doInBackground()},
 .    ,    {@link
android.os.AsyncTask#onPostExecute onPostExecute()},     {@link
android.os.AsyncTask#doInBackground doInBackground()}      ,
  .      {@link android.os.AsyncTask#execute execute()}
   .</p>

<p>,        {@link android.os.AsyncTask}
:</p>

<pre>
public void onClick(View v) {
    new DownloadImageTask().execute("http://example.com/image.png");
}

private class DownloadImageTask extends AsyncTask&lt;String, Void, Bitmap&gt; {
    /** The system calls this to perform work in a worker thread and
      * delivers it the parameters given to AsyncTask.execute() */
    protected Bitmap doInBackground(String... urls) {
        return loadImageFromNetwork(urls[0]);
    }

    /** The system calls this to perform work in the UI thread and delivers
      * the result from doInBackground() */
    protected void onPostExecute(Bitmap result) {
        mImageView.setImageBitmap(result);
    }
}
</pre>

<p>       ,
,      ,  ,       .</p>

<p>  {@link android.os.AsyncTask},
  .      :</p>

<ul>
<li>   ,
     </li>
<li> {@link android.os.AsyncTask#doInBackground doInBackground()}
  </li>
<li> {@link android.os.AsyncTask#onPreExecute onPreExecute()}, {@link
android.os.AsyncTask#onPostExecute onPostExecute()}  {@link
android.os.AsyncTask#onProgressUpdate onProgressUpdate()}     </li>
<li>,   {@link android.os.AsyncTask#doInBackground doInBackground()},
{@link android.os.AsyncTask#onPostExecute onPostExecute()}</li>
<li>  {@link android.os.AsyncTask#publishProgress publishProgress()}     {@link
android.os.AsyncTask#doInBackground doInBackground()}   {@link
android.os.AsyncTask#onProgressUpdate onProgressUpdate()}    </li>
<li>        </li>
</ul>

<p class="caution"><strong>!</strong>  ,
,       <a href="{@docRoot}guide/topics/resources/runtime-changes.html">    </a>,
(,     ),     .
,
  ,      <a href="http://code.google.com/p/shelves/">Shelves</a>.</p>


<h3 id="ThreadSafe"> </h3>

<p>           , ,
     . </p>

<p>      ,    , ,    <a href="{@docRoot}guide/components/bound-services.html"> </a>.
    {@link android.os.IBinder},     ,
{@link android.os.IBinder IBinder},      .
,      ,    ,
,       ,   {@link android.os.IBinder
IBinder} (       ).  ,
{@link android.app.Service#onBind onBind()}
 , ,   ,   {@link android.app.Service#onBind
onBind()} (, ,    RPC),
 .       ,
     {@link android.os.IBinder IBinder}.   {@link android.os.IBinder
IBinder}      .</p>

<p>        ,     .
  {@link android.content.ContentResolver}  {@link android.content.ContentProvider}
    ,  {@link
android.content.ContentProvider},     ,&mdash; {@link
android.content.ContentProvider#query query()}, {@link android.content.ContentProvider#insert
insert()}, {@link android.content.ContentProvider#delete delete()}, {@link
android.content.ContentProvider#update update()}  {@link android.content.ContentProvider#getType
getType()}&mdash;       ,
  .           ,
       . </p>


<h2 id="IPC"> </h2>

<p> Android     (IPC)
(RPC),         ,
 (  )
 .          ,
 ,
 ,       .
   .   Android        IPC,
           RPC. </p>

<p>  IPC          {@link
android.content.Context#bindService bindService()}.      <a href="{@docRoot}guide/components/services.html"></a>   .</p>


<!--
<h2>Beginner's Path</h2>

<p>For information about how to perform work in the background for an indefinite period of time
(without a user interface), continue with the <b><a
href="{@docRoot}guide/components/services.html">Services</a></b> document.</p>
-->