opendev/gerrit
Code Issues Proposed changes

Use listeners to manage server startup/shutdown

Browse Source 
Instead of enumerating the startup/shutdown sequence inside of the
WebAppInitializer we now use listeners which are bound and managed
by Guice.  The listeners are fired in the order they are registered
within the injector modules.

By using Guice we are more easily able to track the need to start
(or gracefully stop) a component alongside its explicit binding
in the injector.  We can also conditionally include start or stop
rules by controlling which modules are included in the injection.

Change-Id: I93590c666d46e13fdce9aa05100489f9f6d94615
Signed-off-by: Shawn O. Pearce <sop@google.com>
This commit is contained in:
Shawn O. Pearce
2009-11-11 14:46:19 -08:00
parent 58120ab4e9
commit 17a30c3703
14 changed files with 369 additions and 125 deletions
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121
gerrit-war/src/main/java/com/google/gerrit/httpd/WebAppInitializer.java
View File

@@ -16,38 +16,30 @@ package com.google.gerrit.httpd;
import static com.google.inject.Stage.PRODUCTION;
import com.google.gerrit.server.cache.CachePool;
import com.google.gerrit.lifecycle.LifecycleManager;
import com.google.gerrit.server.config.CanonicalWebUrlModule;
import com.google.gerrit.server.config.DatabaseModule;
import com.google.gerrit.server.config.GerritGlobalModule;
import com.google.gerrit.server.git.PushAllProjectsOp;
import com.google.gerrit.server.git.ReloadSubmitQueueOp;
import com.google.gerrit.server.git.WorkQueue;
import com.google.gerrit.sshd.SshDaemon;
import com.google.gerrit.server.config.MasterNodeStartup;
import com.google.gerrit.sshd.SshModule;
import com.google.gerrit.sshd.commands.MasterCommandModule;
import com.google.inject.ConfigurationException;
import com.google.inject.CreationException;
import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.Module;
import com.google.inject.Provider;
import com.google.inject.ProvisionException;
import com.google.inject.servlet.GuiceServletContextListener;
import com.google.inject.spi.Message;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.TimeUnit;
import javax.servlet.ServletContextEvent;
import javax.servlet.http.HttpServletRequest;
import javax.sql.DataSource;
/** Configures the web application environment for Gerrit Code Review. */
public class WebAppInitializer extends GuiceServletContextListener {
@@ -58,9 +50,10 @@ public class WebAppInitializer extends GuiceServletContextListener {
private Injector sysInjector;
private Injector webInjector;
private Injector sshInjector;
private LifecycleManager manager;
private synchronized void init() {
if (sysInjector == null) {
if (manager == null) {
try {
dbInjector = Guice.createInjector(PRODUCTION, new DatabaseModule());
} catch (CreationException ce) {
@@ -105,12 +98,21 @@ public class WebAppInitializer extends GuiceServletContextListener {
sysInjector.getInstance(HttpCanonicalWebUrlProvider.class)
.setHttpServletRequest(
webInjector.getProvider(HttpServletRequest.class));
manager = new LifecycleManager();
manager.add(dbInjector);
manager.add(sysInjector);
manager.add(sshInjector);
manager.add(webInjector);
}
}
private Injector createSshInjector() {
return sysInjector.createChildInjector(new SshModule(),
new MasterCommandModule());
final List<Module> modules = new ArrayList<Module>();
modules.add(new SshModule());
modules.add(new MasterCommandModule());
modules.add(new MasterNodeStartup());
return sysInjector.createChildInjector(modules);
}
private Injector createWebInjector() {
@@ -129,100 +131,15 @@ public class WebAppInitializer extends GuiceServletContextListener {
public void contextInitialized(final ServletContextEvent event) {
super.contextInitialized(event);
init();
try {
sysInjector.getInstance(CachePool.class).start();
} catch (ConfigurationException e) {
log.error("Unable to start CachePool", e);
} catch (ProvisionException e) {
log.error("Unable to start CachePool", e);
}
try {
sysInjector.getInstance(PushAllProjectsOp.Factory.class).create(null)
.start(30, TimeUnit.SECONDS);
} catch (ConfigurationException e) {
log.error("Unable to restart replication queue", e);
} catch (ProvisionException e) {
log.error("Unable to restart replication queue", e);
}
try {
sysInjector.getInstance(ReloadSubmitQueueOp.Factory.class).create()
.start(15, TimeUnit.SECONDS);
} catch (ConfigurationException e) {
log.error("Unable to restart merge queue", e);
} catch (ProvisionException e) {
log.error("Unable to restart merge queue", e);
}
try {
sshInjector.getInstance(SshDaemon.class).start();
} catch (ConfigurationException e) {
log.error("Unable to start SSHD", e);
} catch (ProvisionException e) {
log.error("Unable to start SSHD", e);
} catch (IOException e) {
log.error("Unable to start SSHD", e);
}
manager.start();
}
@Override
public void contextDestroyed(final ServletContextEvent event) {
try {
if (sshInjector != null) {
sshInjector.getInstance(SshDaemon.class).stop();
}
} catch (ConfigurationException e) {
} catch (ProvisionException e) {
if (manager != null) {
manager.stop();
manager = null;
}
try {
if (sysInjector != null) {
sysInjector.getInstance(WorkQueue.class).shutdown();
}
} catch (ConfigurationException e) {
} catch (ProvisionException e) {
}
try {
if (sysInjector != null) {
sysInjector.getInstance(CachePool.class).stop();
}
} catch (ConfigurationException e) {
} catch (ProvisionException e) {
}
try {
if (dbInjector != null) {
closeDataSource(dbInjector.getInstance(DatabaseModule.DS));
}
} catch (ConfigurationException ce) {
} catch (ProvisionException ce) {
}
super.contextDestroyed(event);
}
private void closeDataSource(final DataSource ds) {
try {
Class<?> type = Class.forName("org.apache.commons.dbcp.BasicDataSource");
if (type.isInstance(ds)) {
type.getMethod("close").invoke(ds);
return;
}
} catch (Throwable bad) {
// Oh well, its not a Commons DBCP pooled connection.
}
try {
Class<?> type = Class.forName("com.mchange.v2.c3p0.DataSources");
if (type.isInstance(ds)) {
type.getMethod("destroy", DataSource.class).invoke(null, ds);
return;
}
} catch (Throwable bad) {
// Oh well, its not a c3p0 pooled connection.
}
}
}