How to find out the running/start time of android

Question

Is there anyway to find out the start time of an application?ActivityManager provides pids etc for each application process but doesn't tell for how long process is running.

Answer 1

This will return process start time (since system boot):

private static long getStartTime(final int pid) throws IOException {
    final String path = "/proc/" + pid + "/stat";
    final BufferedReader reader = new BufferedReader(new FileReader(path));
    final String stat;
    try {
        stat = reader.readLine();
    } finally {
        reader.close();
    }
    final String field2End = ") ";
    final String fieldSep = " ";
    final int fieldStartTime = 20;
    final int msInSec = 1000;
    try {
        final String[] fields = stat.substring(stat.lastIndexOf(field2End)).split(fieldSep);
        final long t = Long.parseLong(fields[fieldStartTime]);
        final int tckName = Class.forName("libcore.io.OsConstants").getField("_SC_CLK_TCK").getInt(null);
        final Object os = Class.forName("libcore.io.Libcore").getField("os").get(null);
        final long tck = (Long)os.getClass().getMethod("sysconf", Integer.TYPE).invoke(os, tckName);
        return t * msInSec / tck;
    } catch (final NumberFormatException e) {
        throw new IOException(e);
    } catch (final IndexOutOfBoundsException e) {
        throw new IOException(e);
    } catch (ReflectiveOperationException e) {
        throw new IOException(e);
    }
}

To get process running time:

final long dt = SystemClock.elapsedRealtime() - getStartTime(Process.myPid());

Answer 2

I don't know wether there's an API for this. But one approach would be to use something like:

String pid = "yourpid";    
BufferedReader reader = new BufferedReader ( new InputStreamReader ( new FileInputStream ( "ls -ld /proc/"+pid)) , 1000 );

To get the start time of your application and the just subtract that with the currenttime.

Might not be the best way, but that's what came to mind. (And I haven't tried it..)

Gl !