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HBASE-14449 Rewrite deadlock prevention for concurrent connection close
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@tedyu
tedyu committed Sep 18, 2015
1 parent 8cdf4a8 commit b0f5233
Showing 1 changed file with 45 additions and 78 deletions.
123 changes: 45 additions & 78 deletions hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RpcClientImpl.java
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Expand Up @@ -88,10 +88,12 @@
import java.nio.ByteBuffer;
import java.security.PrivilegedExceptionAction;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Random;
import java.util.Set;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ConcurrentSkipListMap;
Expand Down Expand Up @@ -152,18 +154,6 @@ private static class CallFuture {
}
}

/*
* This is the return value from {@link #waitForWork()} indicating whether run() method should:
* read response
* close the connection
* take no action - connection would be closed by others
*/
private enum WaitForWorkResult {
READ_RESPONSE,
CALLER_SHOULD_CLOSE,
CLOSED
}

/** Thread that reads responses and notifies callers. Each connection owns a
* socket connected to a remote address. Calls are multiplexed through this
* socket: responses may be delivered out of order. */
Expand Down Expand Up @@ -255,13 +245,12 @@ public void remove(CallFuture cts){
*/
@Override
public void run() {
boolean closeBySelf = false;
while (!shouldCloseConnection.get()) {
CallFuture cts = null;
try {
cts = callsToWrite.take();
} catch (InterruptedException e) {
closeBySelf = markClosed(new InterruptedIOException());
markClosed(new InterruptedIOException());
}

if (cts == null || cts == CallFuture.DEATH_PILL) {
Expand All @@ -285,14 +274,11 @@ public void run() {
+ ", message =" + e.getMessage());
}
cts.call.setException(e);
closeBySelf = markClosed(e);
markClosed(e);
}
}

cleanup();
if (closeBySelf) {
close();
}
}

/**
Expand Down Expand Up @@ -526,40 +512,37 @@ private void checkIsOpen() throws IOException {
* it is idle too long, it is marked as to be closed,
* or the client is marked as not running.
*
* @return WaitForWorkResult indicating whether it is time to read response;
* if the caller should close; or otherwise
* @return true if it is time to read a response; false otherwise.
*/
protected synchronized WaitForWorkResult waitForWork() throws InterruptedException {
protected synchronized boolean waitForWork() throws InterruptedException {
// beware of the concurrent access to the calls list: we can add calls, but as well
// remove them.
long waitUntil = EnvironmentEdgeManager.currentTime() + minIdleTimeBeforeClose;

while (true) {
if (shouldCloseConnection.get()) {
return WaitForWorkResult.CLOSED;
return false;
}

if (!running.get()) {
if (markClosed(new IOException("stopped with " + calls.size() + " pending request(s)"))) {
return WaitForWorkResult.CALLER_SHOULD_CLOSE;
}
return WaitForWorkResult.CLOSED;
markClosed(new IOException("stopped with " + calls.size() + " pending request(s)"));
return false;
}

if (!calls.isEmpty()) {
return WaitForWorkResult.READ_RESPONSE;
// shouldCloseConnection can be set to true by a parallel thread here. The caller
// will need to check anyway.
return true;
}

if (EnvironmentEdgeManager.currentTime() >= waitUntil) {
// Connection is idle.
// We expect the number of calls to be zero here, but actually someone can
// adds a call at the any moment, as there is no synchronization between this task
// and adding new calls. It's not a big issue, but it will get an exception.
if (markClosed(new IOException(
"idle connection closed with " + calls.size() + " pending request(s)"))) {
return WaitForWorkResult.CALLER_SHOULD_CLOSE;
}
return WaitForWorkResult.CLOSED;
markClosed(new IOException(
"idle connection closed with " + calls.size() + " pending request(s)"));
return false;
}

wait(Math.min(minIdleTimeBeforeClose, 1000));
Expand All @@ -576,38 +559,24 @@ public void run() {
LOG.trace(getName() + ": starting, connections " + connections.size());
}

WaitForWorkResult result = WaitForWorkResult.CALLER_SHOULD_CLOSE;
try {
result = waitForWork(); // Wait here for work - read or close connection
while (result == WaitForWorkResult.READ_RESPONSE) {
if (readResponse()) {
// shouldCloseConnection is set to true by readResponse(). Close the connection
result = WaitForWorkResult.CALLER_SHOULD_CLOSE;
} else {
result = waitForWork();
}
while (waitForWork()) { // Wait here for work - read or close connection
readResponse();
}
} catch (InterruptedException t) {
if (LOG.isTraceEnabled()) {
LOG.trace(getName() + ": interrupted while waiting for call responses");
}
if (markClosed(ExceptionUtil.asInterrupt(t))) {
// shouldCloseConnection is set to true. Close connection
result = WaitForWorkResult.CALLER_SHOULD_CLOSE;
}
markClosed(ExceptionUtil.asInterrupt(t));
} catch (Throwable t) {
if (LOG.isDebugEnabled()) {
LOG.debug(getName() + ": unexpected throwable while waiting for call responses", t);
}
if (markClosed(new IOException("Unexpected throwable while waiting call responses", t))) {
// shouldCloseConnection is set to true. Close connection
result = WaitForWorkResult.CALLER_SHOULD_CLOSE;
}
}
if (result == WaitForWorkResult.CALLER_SHOULD_CLOSE) {
close();
markClosed(new IOException("Unexpected throwable while waiting call responses", t));
}

close();

if (LOG.isTraceEnabled()) {
LOG.trace(getName() + ": stopped, connections " + connections.size());
}
Expand Down Expand Up @@ -735,9 +704,8 @@ protected synchronized void setupIOstreams() throws IOException {
}
IOException e = new FailedServerException(
"This server is in the failed servers list: " + server);
if (markClosed(e)) {
close();
}
markClosed(e);
close();
throw e;
}

Expand Down Expand Up @@ -815,9 +783,8 @@ public Boolean run() throws IOException {
e = new IOException("Could not set up IO Streams to " + server, t);
}
}
if (markClosed(e)) {
close();
}
markClosed(e);
close();
throw e;
}
}
Expand Down Expand Up @@ -948,9 +915,8 @@ private void writeRequest(Call call, final int priority, Span span) throws IOExc
} catch (IOException e) {
// We set the value inside the synchronized block, this way the next in line
// won't even try to write
if (markClosed(e)) {
close();
}
markClosed(e);
close();
writeException = e;
interrupt();
}
Expand All @@ -968,10 +934,9 @@ private void writeRequest(Call call, final int priority, Span span) throws IOExc

/* Receive a response.
* Because only one receiver, so no synchronization on in.
* @return true if connection should be closed by caller
*/
protected boolean readResponse() {
if (shouldCloseConnection.get()) return false;
protected void readResponse() {
if (shouldCloseConnection.get()) return;
Call call = null;
boolean expectedCall = false;
try {
Expand All @@ -993,14 +958,14 @@ protected boolean readResponse() {
int readSoFar = IPCUtil.getTotalSizeWhenWrittenDelimited(responseHeader);
int whatIsLeftToRead = totalSize - readSoFar;
IOUtils.skipFully(in, whatIsLeftToRead);
return false;
return;
}
if (responseHeader.hasException()) {
ExceptionResponse exceptionResponse = responseHeader.getException();
RemoteException re = createRemoteException(exceptionResponse);
call.setException(re);
if (isFatalConnectionException(exceptionResponse)) {
return markClosed(re);
markClosed(re);
}
} else {
Message value = null;
Expand All @@ -1027,12 +992,11 @@ protected boolean readResponse() {
if (LOG.isTraceEnabled()) LOG.trace("ignored", e);
} else {
// Treat this as a fatal condition and close this connection
return markClosed(e);
markClosed(e);
}
} finally {
cleanupCalls(false);
}
return false;
}

/**
Expand All @@ -1058,22 +1022,18 @@ private RemoteException createRemoteException(final ExceptionResponse e) {
e.getStackTrace(), doNotRetry);
}

/*
* @return true if shouldCloseConnection is set true by this thread; false otherwise
*/
protected boolean markClosed(IOException e) {
protected synchronized void markClosed(IOException e) {
if (e == null) throw new NullPointerException();

boolean ret = shouldCloseConnection.compareAndSet(false, true);
if (ret) {
if (shouldCloseConnection.compareAndSet(false, true)) {
if (LOG.isTraceEnabled()) {
LOG.trace(getName() + ": marking at should close, reason: " + e.getMessage());
}
if (callSender != null) {
callSender.close();
}
notifyAll();
}
return ret;
}


Expand Down Expand Up @@ -1161,6 +1121,7 @@ public void close() {
if (LOG.isDebugEnabled()) LOG.debug("Stopping rpc client");
if (!running.compareAndSet(true, false)) return;

Set<Connection> connsToClose = null;
// wake up all connections
synchronized (connections) {
for (Connection conn : connections.values()) {
Expand All @@ -1172,13 +1133,19 @@ public void close() {
// In case the CallSender did not setupIOStreams() yet, the Connection may not be started
// at all (if CallSender has a cancelled Call it can happen). See HBASE-13851
if (!conn.isAlive()) {
if (conn.markClosed(new InterruptedIOException("RpcClient is closing"))) {
conn.close();
if (connsToClose == null) {
connsToClose = new HashSet<Connection>();
}
connsToClose.add(conn);
}
}
}

if (connsToClose != null) {
for (Connection conn : connsToClose) {
conn.markClosed(new InterruptedIOException("RpcClient is closing"));
conn.close();
}
}
// wait until all connections are closed
while (!connections.isEmpty()) {
try {
Expand Down

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