Hadoop源码分析10: IPC流程(5) Atomic
1.Class类的running
用于主线程的Client 和若干 ClientConnection 线程之间 共享Client的running变量
public classClient {
public AtomicBoolean running = newAtomicBoolean(true); // if client runs
public void stop() {
...............
if(!running.compareAndSet(true, false)) {
return;
}
.................
}
private ClientConnectiongetConnection(ClientConnectionId remoteId,
ClientCallcall)
throwsIOException, InterruptedException {
if(!running.get()) {
//the client is stopped
thrownew IOException("The client is stopped");
}
}
public class ClientConnection extends Thread {
private synchronizedboolean waitForWork() {
if(calls.isEmpty() && !shouldCloseConnection.get() &&
client.running.get()) {
long timeout = maxIdleTime-
(System.currentTimeMillis()-lastActivity.get());
if (timeout>0) {
try {
wait(timeout);
} catch (InterruptedExceptione) {}
}
}
if (!calls.isEmpty()&& !shouldCloseConnection.get() &&
client.running.get()) {
return true;
}
。。。。。。。。。。。。。。
}
public class ClientConnectionPingInputStream extendsFilterInputStream {
private voidhandleTimeout(SocketTimeoutException e) throws IOException{
if(clientConnection.shouldCloseConnection.get() ||!clientConnection.client.running.get() ||clientConnection.rpcTimeout > 0) {
throw e;
}else {
sendPing();
}
}
。。。。。。
}
2. ClientConnection的lastActivity
用于若干ClientConnection线程之间共享lastActivity
public class ClientConnection extends Thread {
private AtomicLonglastActivity = new AtomicLong();// last I/O activity time
private voidtouch() {
lastActivity.set(System.currentTimeMillis());
}
private synchronizedboolean waitForWork() {
if(calls.isEmpty() && !shouldCloseConnection.get() && client.running.get()) {
long timeout = maxIdleTime-
(System.currentTimeMillis()-lastActivity.get());
if (timeout>0) {
try {
wait(timeout);
} catch (InterruptedExceptione) {}
}
}
}
}3. ClientConnection 的shouldCloseConnection
用于若干ClientConnection 线程之间共享shouldCloseConnection
public class ClientConnection extends Thread {
AtomicBooleanshouldCloseConnection = new AtomicBoolean();
// indicate if theconnection is closed
public synchronizedboolean addCall(ClientCall call) {
if(shouldCloseConnection.get())
return false;
calls.put(call.id, call);
notify();
return true;
}
public synchronized voidsetupIOstreams() throws InterruptedException {
if(socket != null || shouldCloseConnection.get()) {
return;
}
.........
}
private synchronizedboolean waitForWork() {
if(calls.isEmpty() && !shouldCloseConnection.get() && client.running.get()) {
long timeout = maxIdleTime-
(System.currentTimeMillis()-lastActivity.get());
if (timeout>0) {
try {
wait(timeout);
} catch (InterruptedExceptione) {}
}
}
if(!calls.isEmpty() && !shouldCloseConnection.get()&& client.running.get()) {
return true;
}else if (shouldCloseConnection.get()) {
return false;
}else if (calls.isEmpty()) { // idle connection closed orstopped
markClosed(null);
return false;
}else { // get stopped but there are still pendingrequests
markClosed((IOException)newIOException().initCause(
newInterruptedException()));
return false;
}
}
public voidsendParam(ClientCall call) {
if(shouldCloseConnection.get()) {
return;
}
}
private voidreceiveResponse() {
if(shouldCloseConnection.get()) {
return;
}
touch();
}
private synchronizedvoid markClosed(IOException e) {
if(shouldCloseConnection.compareAndSet(false, true)) {
closeException = e;
notifyAll();
}
}
private synchronizedvoid close() {
if(!shouldCloseConnection.get()) {
return;
}
}
}
publicclass ClientConnectionPingInputStream extendsFilterInputStream {
privatevoid handleTimeout(SocketTimeoutExceptione) throws IOException {
if(clientConnection.shouldCloseConnection.get() ||!clientConnection.client.running.get() ||clientConnection.rpcTimeout > 0) {
throw e;
}else {
sendPing();
}
}
。。。。。。
}
