/**
* Test concurrent reader and writer (GH-458).
*
* <p><b>Test case:</b>
*
* <ol>
* <li/>start a long running reader;
* <li/>try to start a writer: it should time out;
* <li/>stop the reader;
* <li/>start the writer again: it should succeed.
* </ol>
*
* @throws Exception error during request execution
*/
@Test
@Ignore("There is no way to stop a query on the server!")
public void testReaderWriter() throws Exception {
final String readerQuery = "?query=(1%20to%20100000000000000)%5b.=1%5d";
final String writerQuery = "/test.xml";
final byte[] content = Token.token("<a/>");
final Get readerAction = new Get(readerQuery);
final Put writerAction = new Put(writerQuery, content);
final ExecutorService exec = Executors.newFixedThreadPool(2);
// start reader
exec.submit(readerAction);
Performance.sleep(TIMEOUT); // delay in order to be sure that the reader has started
// start writer
Future<HTTPResponse> writer = exec.submit(writerAction);
try {
final HTTPResponse result = writer.get(TIMEOUT, TimeUnit.MILLISECONDS);
if (result.status.isSuccess()) fail("Database modified while a reader is running");
throw new Exception(result.toString());
} catch (final TimeoutException e) {
// writer is blocked by the reader: stop it
writerAction.stop = true;
}
// stop reader
readerAction.stop = true;
// start the writer again
writer = exec.submit(writerAction);
assertEquals(HTTPCode.CREATED, writer.get().status);
}
/**
* Runs the command without permission, data and concurrency checks.
*
* @param ctx database context
* @param os output stream
* @return result of check
*/
public boolean run(final Context ctx, final OutputStream os) {
perf = new Performance();
context = ctx;
prop = ctx.prop;
mprop = ctx.mprop;
out = PrintOutput.get(os);
try {
return run();
} catch (final ProgressException ex) {
// process was interrupted by the user or server
abort();
return error(INTERRUPTED);
} catch (final Throwable ex) {
// unexpected error
Performance.gc(2);
abort();
if (ex instanceof OutOfMemoryError) {
Util.debug(ex);
return error(OUT_OF_MEM + (createWrite() ? H_OUT_OF_MEM : ""));
}
return error(Util.bug(ex) + NL + info.toString());
} finally {
// flushes the output
try {
if (out != null) out.flush();
} catch (final IOException ignored) {
}
}
}
/** Drops users. */
@Test
public void dropUsers() {
no(new DropUser(NAME), testSession);
no(new DropUser(NAME), adminSession);
ok(new Exit(), testSession);
// give the server some time to close the client session
Performance.sleep(50);
ok(new DropUser(NAME), adminSession);
}
/** Clean up method. */
@After
public void cleanUp() {
try {
testSession.close();
adminSession.execute(new DropDB(RENAMED));
adminSession.execute(new DropDB(NAME));
adminSession.close();
// give the server some time to clean up the sessions before next test
Performance.sleep(100);
} catch (final Exception ex) {
fail(Util.message(ex));
}
}
@Override
public void run() {
try {
for (int i = 0; i < runs; ++i) {
Performance.sleep((long) (50 * RND.nextDouble()));
// Return nth text of the database
final int n = RND.nextInt() % MAX + 1;
final String qu = Util.info(QUERY, n);
new XQuery(qu).execute(context);
}
} catch (final BaseXException ex) {
ex.printStackTrace();
}
}
@Override
public DiskData build() throws IOException {
meta.assign(parser);
meta.dirty = true;
// calculate optimized output buffer sizes to reduce disk fragmentation
final Runtime rt = Runtime.getRuntime();
final long max = Math.min(1 << 22, rt.maxMemory() - rt.freeMemory() >> 2);
int bs = (int) Math.min(meta.filesize, max);
bs = Math.max(IO.BLOCKSIZE, bs - bs % IO.BLOCKSIZE);
// drop old database (if available) and create new one
DropDB.drop(dbname, sopts);
sopts.dbpath(dbname).md();
elemNames = new Names(meta);
attrNames = new Names(meta);
try {
tout = new DataOutput(new TableOutput(meta, DATATBL));
xout = new DataOutput(meta.dbfile(DATATXT), bs);
vout = new DataOutput(meta.dbfile(DATAATV), bs);
sout = new DataOutput(meta.dbfile(DATATMP), bs);
final Performance perf = Prop.debug ? new Performance() : null;
Util.debug(tit() + DOTS);
parse();
if (Prop.debug) Util.errln(" " + perf + " (" + Performance.getMemory() + ')');
} catch (final IOException ex) {
try {
close();
} catch (final IOException ignored) {
}
throw ex;
}
close();
// copy temporary values into database table
try (final DataInput in = new DataInput(meta.dbfile(DATATMP))) {
final TableAccess ta = new TableDiskAccess(meta, true);
for (; spos < ssize; ++spos) ta.write4(in.readNum(), 8, in.readNum());
ta.close();
}
meta.dbfile(DATATMP).delete();
// return database instance
return new DiskData(meta, elemNames, attrNames, path, ns);
}
/**
* Test 2 concurrent readers (GH-458).
*
* <p><b>Test case:</b>
*
* <ol>
* <li/>start a long running reader;
* <li/>start a fast reader: it should succeed.
* </ol>
*
* @throws Exception error during request execution
*/
@Test
public void testMultipleReaders() throws Exception {
final String number = "63177";
final String slowQuery = "?query=(1%20to%20100000000000000)%5b.=1%5d";
final String fastQuery = "?query=" + number;
final Get slowAction = new Get(slowQuery);
final Get fastAction = new Get(fastQuery);
final ExecutorService exec = Executors.newFixedThreadPool(2);
exec.submit(slowAction);
Performance.sleep(TIMEOUT); // delay in order to be sure that the reader has started
final Future<HTTPResponse> fast = exec.submit(fastAction);
try {
final HTTPResponse result = fast.get(TIMEOUT, TimeUnit.MILLISECONDS);
assertEquals(HTTPCode.OK, result.status);
assertEquals(number, result.data);
} finally {
slowAction.stop = true;
}
}
/** Stop BaseX HTTP. */
private void stopBaseXHTTP() {
Util.start(BaseXHTTP.class, "stop");
Performance.sleep(TIMEOUT); // give the server some time to stop
}
/** Start BaseX HTTP. */
private void startBaseXHTTP() {
Util.start(BaseXHTTP.class, "-U" + UserText.ADMIN, "-P" + UserText.ADMIN);
Performance.sleep(TIMEOUT); // give the server some time to stop
}