Files
i2p.i2p/router/java/src/net/i2p/router/JobQueue.java

741 lines
30 KiB
Java

package net.i2p.router;
/*
* free (adj.): unencumbered; not under the control of others
* Written by jrandom in 2003 and released into the public domain
* with no warranty of any kind, either expressed or implied.
* It probably won't make your computer catch on fire, or eat
* your children, but it might. Use at your own risk.
*
*/
import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.SortedMap;
import java.util.TreeMap;
import net.i2p.data.DataHelper;
import net.i2p.router.networkdb.HandleDatabaseLookupMessageJob;
import net.i2p.util.Clock;
import net.i2p.util.I2PThread;
import net.i2p.util.Log;
/**
* Manage the pending jobs according to whatever algorithm is appropriate, giving
* preference to earlier scheduled jobs.
*
*/
public class JobQueue {
private Log _log;
private RouterContext _context;
/** Integer (runnerId) to JobQueueRunner for created runners */
private final HashMap _queueRunners;
/** a counter to identify a job runner */
private volatile static int _runnerId = 0;
/** list of jobs that are ready to run ASAP */
private ArrayList _readyJobs;
/** list of jobs that are scheduled for running in the future */
private ArrayList _timedJobs;
/** job name to JobStat for that job */
private final SortedMap _jobStats;
/** how many job queue runners can go concurrently */
private int _maxRunners = 1;
private QueuePumper _pumper;
/** will we allow the # job runners to grow beyond 1? */
private boolean _allowParallelOperation;
/** have we been killed or are we alive? */
private boolean _alive;
private final Object _jobLock;
/** default max # job queue runners operating */
private final static int DEFAULT_MAX_RUNNERS = 1;
/** router.config parameter to override the max runners */
private final static String PROP_MAX_RUNNERS = "router.maxJobRunners";
/** how frequently should we check and update the max runners */
private final static long MAX_LIMIT_UPDATE_DELAY = 60*1000;
/** if a job is this lagged, spit out a warning, but keep going */
private long _lagWarning = DEFAULT_LAG_WARNING;
private final static long DEFAULT_LAG_WARNING = 5*1000;
private final static String PROP_LAG_WARNING = "router.jobLagWarning";
/** if a job is this lagged, the router is hosed, so shut it down */
private long _lagFatal = DEFAULT_LAG_FATAL;
private final static long DEFAULT_LAG_FATAL = 30*1000;
private final static String PROP_LAG_FATAL = "router.jobLagFatal";
/** if a job takes this long to run, spit out a warning, but keep going */
private long _runWarning = DEFAULT_RUN_WARNING;
private final static long DEFAULT_RUN_WARNING = 5*1000;
private final static String PROP_RUN_WARNING = "router.jobRunWarning";
/** if a job takes this long to run, the router is hosed, so shut it down */
private long _runFatal = DEFAULT_RUN_FATAL;
private final static long DEFAULT_RUN_FATAL = 30*1000;
private final static String PROP_RUN_FATAL = "router.jobRunFatal";
/** don't enforce fatal limits until the router has been up for this long */
private long _warmupTime = DEFAULT_WARMUP_TIME;
private final static long DEFAULT_WARMUP_TIME = 10*60*1000;
private final static String PROP_WARMUM_TIME = "router.jobWarmupTime";
/** max ready and waiting jobs before we start dropping 'em */
private int _maxWaitingJobs = DEFAULT_MAX_WAITING_JOBS;
private final static int DEFAULT_MAX_WAITING_JOBS = 100;
private final static String PROP_MAX_WAITING_JOBS = "router.maxWaitingJobs";
/**
* queue runners wait on this whenever they're not doing anything, and
* this gets notified *once* whenever there are ready jobs
*/
private final Object _runnerLock = new Object();
public JobQueue(RouterContext context) {
_context = context;
_log = context.logManager().getLog(JobQueue.class);
_context.statManager().createRateStat("jobQueue.readyJobs",
"How many ready and waiting jobs there are?",
"JobQueue",
new long[] { 60*1000l, 60*60*1000l, 24*60*60*1000l });
_context.statManager().createRateStat("jobQueue.droppedJobs",
"How many jobs do we drop due to insane overload?",
"JobQueue",
new long[] { 60*1000l, 60*60*1000l, 24*60*60*1000l });
_alive = true;
_readyJobs = new ArrayList(16);
_timedJobs = new ArrayList(64);
_jobLock = new Object();
_queueRunners = new HashMap();
_jobStats = Collections.synchronizedSortedMap(new TreeMap());
_allowParallelOperation = false;
_pumper = new QueuePumper();
I2PThread pumperThread = new I2PThread(_pumper);
pumperThread.setDaemon(true);
pumperThread.setName("QueuePumper");
//pumperThread.setPriority(I2PThread.NORM_PRIORITY+1);
pumperThread.start();
}
/**
* Enqueue the specified job
*
*/
public void addJob(Job job) {
if (job == null) return;
if (job instanceof JobImpl)
((JobImpl)job).addedToQueue();
long numReady = 0;
boolean alreadyExists = false;
boolean dropped = false;
synchronized (_jobLock) {
if (_readyJobs.contains(job))
alreadyExists = true;
numReady = _readyJobs.size();
if (!alreadyExists) {
if (_timedJobs.contains(job))
alreadyExists = true;
}
if (shouldDrop(job, numReady)) {
job.dropped();
dropped = true;
} else {
if (!alreadyExists) {
if (job.getTiming().getStartAfter() <= _context.clock().now()) {
// don't skew us - its 'start after' its been queued, or later
job.getTiming().setStartAfter(_context.clock().now());
if (job instanceof JobImpl)
((JobImpl)job).madeReady();
_readyJobs.add(job);
} else {
_timedJobs.add(job);
}
}
}
_jobLock.notifyAll();
}
_context.statManager().addRateData("jobQueue.readyJobs", numReady, 0);
if (dropped) {
_context.statManager().addRateData("jobQueue.droppedJobs", 1, 1);
if (_log.shouldLog(Log.WARN))
_log.warn("Dropping job due to overload! # ready jobs: "
+ numReady + ": job = " + job);
}
return;
}
public void removeJob(Job job) {
synchronized (_jobLock) {
_readyJobs.remove(job);
_timedJobs.remove(job);
}
}
public void timingUpdated() {
synchronized (_jobLock) {
_jobLock.notifyAll();
}
}
public int getReadyCount() {
synchronized (_jobLock) {
return _readyJobs.size();
}
}
public long getMaxLag() {
synchronized (_jobLock) {
if (_readyJobs.size() <= 0) return 0;
// first job is the one that has been waiting the longest
long startAfter = ((Job)_readyJobs.get(0)).getTiming().getStartAfter();
return _context.clock().now() - startAfter;
}
}
/**
* are we so overloaded that we should drop the given job?
* This is driven both by the numReady and waiting jobs, the type of job
* in question, and what the router's router.maxWaitingJobs config parameter
* is set to.
*
*/
private boolean shouldDrop(Job job, long numReady) {
if (_maxWaitingJobs <= 0) return false; // dont ever drop jobs
if (!_allowParallelOperation) return false; // dont drop during startup [duh]
Class cls = job.getClass();
if (numReady > _maxWaitingJobs) {
// lets not try to drop too many tunnel messages...
//if (cls == HandleTunnelMessageJob.class)
// return true;
// we don't really *need* to answer DB lookup messages
if (cls == HandleDatabaseLookupMessageJob.class)
return true;
}
return false;
}
public void allowParallelOperation() {
_allowParallelOperation = true;
runQueue(4);
}
public void restart() {
synchronized (_jobLock) {
_timedJobs.clear();
_readyJobs.clear();
_jobLock.notifyAll();
}
}
void shutdown() {
_alive = false;
synchronized (_jobLock) {
_jobLock.notifyAll();
}
if (_log.shouldLog(Log.WARN)) {
StringBuffer buf = new StringBuffer(1024);
buf.append("current jobs: \n");
for (Iterator iter = _queueRunners.values().iterator(); iter.hasNext(); ) {
JobQueueRunner runner = (JobQueueRunner)iter.next();
Job j = runner.getCurrentJob();
buf.append("Runner ").append(runner.getRunnerId()).append(": ");
if (j == null) {
buf.append("no current job ");
} else {
buf.append(j.toString());
buf.append(" started ").append(_context.clock().now() - j.getTiming().getActualStart());
buf.append("ms ago");
}
j = runner.getLastJob();
if (j == null) {
buf.append("no last job");
} else {
buf.append(j.toString());
buf.append(" started ").append(_context.clock().now() - j.getTiming().getActualStart());
buf.append("ms ago and finished ");
buf.append(_context.clock().now() - j.getTiming().getActualEnd());
buf.append("ms ago");
}
}
buf.append("\nready jobs: ").append(_readyJobs.size()).append("\n\t");
for (int i = 0; i < _readyJobs.size(); i++)
buf.append(_readyJobs.get(i).toString()).append("\n\t");
buf.append("\n\ntimed jobs: ").append(_timedJobs.size()).append("\n\t");
for (int i = 0; i < _timedJobs.size(); i++)
buf.append(_timedJobs.get(i).toString()).append("\n\t");
_log.log(Log.WARN, buf.toString());
}
}
boolean isAlive() { return _alive; }
/**
* When did the most recently begin job start?
*/
public long getLastJobBegin() {
long when = -1;
// not synchronized, so might b0rk if the runners are changed
for (Iterator iter = _queueRunners.values().iterator(); iter.hasNext(); ) {
long cur = ((JobQueueRunner)iter.next()).getLastBegin();
if (cur > when)
cur = when;
}
return when;
}
/**
* When did the most recently begin job start?
*/
public long getLastJobEnd() {
long when = -1;
// not synchronized, so might b0rk if the runners are changed
for (Iterator iter = _queueRunners.values().iterator(); iter.hasNext(); ) {
long cur = ((JobQueueRunner)iter.next()).getLastEnd();
if (cur > when)
cur = when;
}
return when;
}
/**
* retrieve the most recently begin and still currently active job, or null if
* no jobs are running
*/
public Job getLastJob() {
Job j = null;
long when = -1;
// not synchronized, so might b0rk if the runners are changed
for (Iterator iter = _queueRunners.values().iterator(); iter.hasNext(); ) {
JobQueueRunner cur = (JobQueueRunner)iter.next();
if (cur.getLastBegin() > when) {
j = cur.getCurrentJob();
when = cur.getLastBegin();
}
}
return j;
}
/**
* Blocking call to retrieve the next ready job
*
*/
Job getNext() {
while (_alive) {
try {
synchronized (_jobLock) {
if (_readyJobs.size() > 0) {
return (Job)_readyJobs.remove(0);
} else {
_jobLock.wait();
}
}
} catch (InterruptedException ie) {}
}
if (_log.shouldLog(Log.WARN))
_log.warn("No longer alive, returning null");
return null;
}
/**
* Start up the queue with the specified number of concurrent processors.
* If this method has already been called, it will adjust the number of
* runners to meet the new number. This does not kill jobs running on
* excess threads, it merely instructs the threads to die after finishing
* the current job.
*
*/
public void runQueue(int numThreads) {
synchronized (_queueRunners) {
// we're still starting up [serially] and we've got at least one runner,
// so dont do anything
if ( (_queueRunners.size() > 0) && (!_allowParallelOperation) ) return;
// we've already enabled parallel operation, so grow to however many are
// specified
if (_queueRunners.size() < numThreads) {
if (_log.shouldLog(Log.INFO))
_log.info("Increasing the number of queue runners from "
+ _queueRunners.size() + " to " + numThreads);
for (int i = _queueRunners.size(); i < numThreads; i++) {
JobQueueRunner runner = new JobQueueRunner(_context, i);
_queueRunners.put(Integer.valueOf(i), runner);
Thread t = new I2PThread(runner);
t.setName("JobQueue"+(_runnerId++));
//t.setPriority(I2PThread.MAX_PRIORITY-1);
t.setDaemon(false);
t.start();
}
} else if (_queueRunners.size() == numThreads) {
for (Iterator iter = _queueRunners.values().iterator(); iter.hasNext(); ) {
JobQueueRunner runner = (JobQueueRunner)iter.next();
runner.startRunning();
}
} else { // numThreads < # runners, so shrink
//for (int i = _queueRunners.size(); i > numThreads; i++) {
// QueueRunner runner = (QueueRunner)_queueRunners.get(new Integer(i));
// runner.stopRunning();
//}
}
}
}
void removeRunner(int id) { _queueRunners.remove(Integer.valueOf(id)); }
/**
* Responsible for moving jobs from the timed queue to the ready queue,
* adjusting the number of queue runners, as well as periodically updating the
* max number of runners.
*
*/
private final class QueuePumper implements Runnable, Clock.ClockUpdateListener {
public QueuePumper() {
_context.clock().addUpdateListener(this);
}
public void run() {
try {
while (_alive) {
long now = _context.clock().now();
long timeToWait = -1;
ArrayList toAdd = null;
try {
synchronized (_jobLock) {
for (int i = 0; i < _timedJobs.size(); i++) {
Job j = (Job)_timedJobs.get(i);
// find jobs due to start before now
long timeLeft = j.getTiming().getStartAfter() - now;
if (timeLeft <= 0) {
if (j instanceof JobImpl)
((JobImpl)j).madeReady();
if (toAdd == null) toAdd = new ArrayList(4);
toAdd.add(j);
_timedJobs.remove(i);
i--; // so the index stays consistent
} else {
if ( (timeToWait <= 0) || (timeLeft < timeToWait) )
timeToWait = timeLeft;
}
}
if (toAdd != null) {
if (_log.shouldLog(Log.DEBUG))
_log.debug("Not waiting - we have " + toAdd.size() + " newly ready jobs");
// rather than addAll, which allocs a byte array rv before adding,
// we iterate, since toAdd is usually going to only be 1 or 2 entries
// and since readyJobs will often have the space, we can avoid the
// extra alloc. (no, i'm not just being insane - i'm updating this based
// on some profiling data ;)
for (int i = 0; i < toAdd.size(); i++)
_readyJobs.add(toAdd.get(i));
_jobLock.notifyAll();
} else {
if (timeToWait < 0)
timeToWait = 30*1000;
else if (timeToWait < 10)
timeToWait = 10;
else if (timeToWait > 10*1000)
timeToWait = 10*1000;
//if (_log.shouldLog(Log.DEBUG))
// _log.debug("Waiting " + timeToWait + " before rechecking the timed queue");
_jobLock.wait(timeToWait);
}
} // synchronize (_jobLock)
} catch (InterruptedException ie) {}
} // while (_alive)
} catch (Throwable t) {
_context.clock().removeUpdateListener(this);
if (_log.shouldLog(Log.ERROR))
_log.error("wtf, pumper killed", t);
}
}
public void offsetChanged(long delta) {
updateJobTimings(delta);
synchronized (_jobLock) {
_jobLock.notifyAll();
}
}
}
/**
* Update the clock data for all jobs in process or scheduled for
* completion.
*/
private void updateJobTimings(long delta) {
synchronized (_jobLock) {
for (int i = 0; i < _timedJobs.size(); i++) {
Job j = (Job)_timedJobs.get(i);
j.getTiming().offsetChanged(delta);
}
for (int i = 0; i < _readyJobs.size(); i++) {
Job j = (Job)_readyJobs.get(i);
j.getTiming().offsetChanged(delta);
}
}
synchronized (_runnerLock) {
for (Iterator iter = _queueRunners.values().iterator(); iter.hasNext(); ) {
JobQueueRunner runner = (JobQueueRunner)iter.next();
Job job = runner.getCurrentJob();
if (job != null)
job.getTiming().offsetChanged(delta);
}
}
}
/**
* calculate and update the job timings
* if it was lagged too much or took too long to run, spit out
* a warning (and if its really excessive, kill the router)
*/
void updateStats(Job job, long doStart, long origStartAfter, long duration) {
if (_context.router() == null) return;
String key = job.getName();
long lag = doStart - origStartAfter; // how long were we ready and waiting?
MessageHistory hist = _context.messageHistory();
long uptime = _context.router().getUptime();
if (lag < 0) lag = 0;
if (duration < 0) duration = 0;
JobStats stats = null;
if (!_jobStats.containsKey(key)) {
_jobStats.put(key, new JobStats(key));
// yes, if two runners finish the same job at the same time, this could
// create an extra object. but, who cares, its pushed out of the map
// immediately anyway.
}
stats = (JobStats)_jobStats.get(key);
stats.jobRan(duration, lag);
String dieMsg = null;
if (lag > _lagWarning) {
dieMsg = "Lag too long for job " + job.getName() + " [" + lag + "ms and a run time of " + duration + "ms]";
} else if (duration > _runWarning) {
dieMsg = "Job run too long for job " + job.getName() + " [" + lag + "ms lag and run time of " + duration + "ms]";
}
if (dieMsg != null) {
if (_log.shouldLog(Log.WARN))
_log.warn(dieMsg);
if (hist != null)
hist.messageProcessingError(-1, JobQueue.class.getName(), dieMsg);
}
if ( (lag > _lagFatal) && (uptime > _warmupTime) ) {
// this is fscking bad - the network at this size shouldn't have this much real contention
// so we're going to DIE DIE DIE
if (_log.shouldLog(Log.WARN))
_log.log(Log.WARN, "The router is either incredibly overloaded or (more likely) there's an error.", new Exception("ttttooooo mmmuuuccccchhhh llllaaagggg"));
//try { Thread.sleep(5000); } catch (InterruptedException ie) {}
//Router.getInstance().shutdown();
return;
}
if ( (uptime > _warmupTime) && (duration > _runFatal) ) {
// slow CPUs can get hosed with ElGamal, but 10s is too much.
if (_log.shouldLog(Log.WARN))
_log.log(Log.WARN, "The router is incredibly overloaded - either you have a 386, or (more likely) there's an error. ", new Exception("ttttooooo sssllloooowww"));
//try { Thread.sleep(5000); } catch (InterruptedException ie) {}
//Router.getInstance().shutdown();
return;
}
}
////
// the remainder are utility methods for dumping status info
////
public void renderStatusHTML(Writer out) throws IOException {
ArrayList readyJobs = null;
ArrayList timedJobs = null;
ArrayList activeJobs = new ArrayList(1);
ArrayList justFinishedJobs = new ArrayList(4);
out.write("<!-- jobQueue rendering -->\n");
out.flush();
int states[] = null;
int numRunners = 0;
synchronized (_queueRunners) {
states = new int[_queueRunners.size()];
int i = 0;
for (Iterator iter = _queueRunners.values().iterator(); iter.hasNext(); i++) {
JobQueueRunner runner = (JobQueueRunner)iter.next();
states[i] = runner.getState();
Job job = runner.getCurrentJob();
if (job != null) {
activeJobs.add(job);
} else {
job = runner.getLastJob();
if (job != null)
justFinishedJobs.add(job);
}
}
numRunners = _queueRunners.size();
}
StringBuffer str = new StringBuffer(128);
str.append("<!-- after queueRunner sync: states: ");
for (int i = 0; states != null && i < states.length; i++)
str.append(states[i]).append(" ");
str.append(" -->\n");
str.append("<!-- jobs: ");
for (int i = 0; i < activeJobs.size(); i++)
str.append(activeJobs.get(i).toString()).append(" ");
str.append("-->\n");
out.write(str.toString());
out.flush();
synchronized (_jobLock) {
readyJobs = new ArrayList(_readyJobs);
timedJobs = new ArrayList(_timedJobs);
}
out.write("<!-- jobQueue rendering: after jobLock sync -->\n");
out.flush();
StringBuffer buf = new StringBuffer(32*1024);
buf.append("<h2>JobQueue</h2>");
buf.append("# runners: ").append(numRunners).append(" [states=");
if (states != null)
for (int i = 0; i < states.length; i++)
buf.append(states[i]).append(" ");
buf.append("]<br />\n");
long now = _context.clock().now();
buf.append("# active jobs: ").append(activeJobs.size()).append("<ol>\n");
for (int i = 0; i < activeJobs.size(); i++) {
Job j = (Job)activeJobs.get(i);
buf.append("<li> [started ").append(now-j.getTiming().getStartAfter()).append("ms ago]: ");
buf.append(j.toString()).append("</li>\n");
}
buf.append("</ol>\n");
buf.append("# just finished jobs: ").append(justFinishedJobs.size()).append("<ol>\n");
for (int i = 0; i < justFinishedJobs.size(); i++) {
Job j = (Job)justFinishedJobs.get(i);
buf.append("<li> [finished ").append(now-j.getTiming().getActualEnd()).append("ms ago]: ");
buf.append(j.toString()).append("</li>\n");
}
buf.append("</ol>\n");
buf.append("# ready/waiting jobs: ").append(readyJobs.size()).append(" <i>(lots of these mean there's likely a big problem)</i><ol>\n");
for (int i = 0; i < readyJobs.size(); i++) {
Job j = (Job)readyJobs.get(i);
buf.append("<li> [waiting ");
buf.append(DataHelper.formatDuration(now-j.getTiming().getStartAfter()));
buf.append("]: ");
buf.append(j.toString()).append("</li>\n");
}
buf.append("</ol>\n");
out.flush();
buf.append("# timed jobs: ").append(timedJobs.size()).append("<ol>\n");
TreeMap ordered = new TreeMap();
for (int i = 0; i < timedJobs.size(); i++) {
Job j = (Job)timedJobs.get(i);
ordered.put(new Long(j.getTiming().getStartAfter()), j);
}
for (Iterator iter = ordered.values().iterator(); iter.hasNext(); ) {
Job j = (Job)iter.next();
long time = j.getTiming().getStartAfter() - now;
buf.append("<li>").append(j.getName()).append(" in ");
buf.append(DataHelper.formatDuration(time)).append("</li>\n");
}
buf.append("</ol>\n");
out.write("<!-- jobQueue rendering: after main buffer, before stats -->\n");
out.flush();
getJobStats(buf);
out.write("<!-- jobQueue rendering: after stats -->\n");
out.flush();
out.write(buf.toString());
}
/** render the HTML for the job stats */
private void getJobStats(StringBuffer buf) {
buf.append("<table border=\"1\">\n");
buf.append("<tr><th>Job</th><th>Runs</th>");
buf.append("<th>Time</th><th><i>Avg</i></th><th><i>Max</i></th><th><i>Min</i></th>");
buf.append("<th>Pending</th><th><i>Avg</i></th><th><i>Max</i></th><th><i>Min</i></th></tr>\n");
long totRuns = 0;
long totExecTime = 0;
long avgExecTime = 0;
long maxExecTime = -1;
long minExecTime = -1;
long totPendingTime = 0;
long avgPendingTime = 0;
long maxPendingTime = -1;
long minPendingTime = -1;
TreeMap tstats = null;
synchronized (_jobStats) {
tstats = new TreeMap(_jobStats);
}
for (Iterator iter = tstats.values().iterator(); iter.hasNext(); ) {
JobStats stats = (JobStats)iter.next();
buf.append("<tr>");
buf.append("<td><b>").append(stats.getName()).append("</b></td>");
buf.append("<td>").append(stats.getRuns()).append("</td>");
buf.append("<td>").append(stats.getTotalTime()).append("</td>");
buf.append("<td>").append(stats.getAvgTime()).append("</td>");
buf.append("<td>").append(stats.getMaxTime()).append("</td>");
buf.append("<td>").append(stats.getMinTime()).append("</td>");
buf.append("<td>").append(stats.getTotalPendingTime()).append("</td>");
buf.append("<td>").append(stats.getAvgPendingTime()).append("</td>");
buf.append("<td>").append(stats.getMaxPendingTime()).append("</td>");
buf.append("<td>").append(stats.getMinPendingTime()).append("</td>");
buf.append("</tr>\n");
totRuns += stats.getRuns();
totExecTime += stats.getTotalTime();
if (stats.getMaxTime() > maxExecTime)
maxExecTime = stats.getMaxTime();
if ( (minExecTime < 0) || (minExecTime > stats.getMinTime()) )
minExecTime = stats.getMinTime();
totPendingTime += stats.getTotalPendingTime();
if (stats.getMaxPendingTime() > maxPendingTime)
maxPendingTime = stats.getMaxPendingTime();
if ( (minPendingTime < 0) || (minPendingTime > stats.getMinPendingTime()) )
minPendingTime = stats.getMinPendingTime();
}
if (totRuns != 0) {
if (totExecTime != 0)
avgExecTime = totExecTime / totRuns;
if (totPendingTime != 0)
avgPendingTime = totPendingTime / totRuns;
}
buf.append("<tr><td colspan=\"10\"><hr /></td><tr>");
buf.append("<tr>");
buf.append("<td><i><b>").append("SUMMARY").append("</b></i></td>");
buf.append("<td><i>").append(totRuns).append("</i></td>");
buf.append("<td><i>").append(totExecTime).append("</i></td>");
buf.append("<td><i>").append(avgExecTime).append("</i></td>");
buf.append("<td><i>").append(maxExecTime).append("</i></td>");
buf.append("<td><i>").append(minExecTime).append("</i></td>");
buf.append("<td><i>").append(totPendingTime).append("</i></td>");
buf.append("<td><i>").append(avgPendingTime).append("</i></td>");
buf.append("<td><i>").append(maxPendingTime).append("</i></td>");
buf.append("<td><i>").append(minPendingTime).append("</i></td>");
buf.append("</tr>\n");
buf.append("</table>\n");
}
}