fixes bug 97833 "http should periodically prune it's idle connection list of

dead connections"
patch=badami@netscape.com
r=dougt@netscape.com
sr=darin@netscape.com

netwerk/build/Makefile.in

@@ -42,6 +42,7 @@ REQUIRES	= xpcom \
 		  intl \
 		  uconv \
 		  caps \
+		  timer \
 		  $(ZLIB_REQUIRES) \
 		  $(NULL)
 

netwerk/build/makefile.win

@@ -34,6 +34,7 @@ REQUIRES	= xpcom \
 		  locale \
 		  intl \
 		  uconv \
+		  timer \
 		  zlib \
 		  caps \
 		  $(NULL)

netwerk/protocol/http/src/Makefile.in

@@ -36,6 +36,7 @@ REQUIRES	= xpcom \
 		  intl \
 		  exthandler \
 		  caps \
+		  timer \
 		  $(NULL)
 
 CPPSRCS		= \

netwerk/protocol/http/src/makefile.win

@@ -29,6 +29,7 @@ REQUIRES	= xpcom \
 		  intl \
 		  exthandler \
 		  caps \
+		  timer \
 		  $(NULL)
 include <$(DEPTH)/config/config.mak>
 

netwerk/protocol/http/src/nsHttpHandler.cpp

@@ -134,6 +134,9 @@ nsHttpHandler::nsHttpHandler()
 
 nsHttpHandler::~nsHttpHandler()
 {
+    // We do not deal with the timer cancellation in the destructor since
+    // it is taken care of in xpcom shutdown event in the Observe method.
+
     LOG(("Deleting nsHttpHandler [this=%x]\n", this));
 
     nsHttp::DestroyAtomTable();
@@ -255,7 +258,17 @@ nsHttpHandler::Init()
     if (observerSvc) {
         observerSvc->AddObserver(this, "profile-before-change", PR_TRUE);
         observerSvc->AddObserver(this, "session-logout", PR_TRUE);
+        observerSvc->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, PR_TRUE);
     }
+
+    mTimer = do_CreateInstance("@mozilla.org/timer;1");
+    // failure to create a timer is not a fatal error, but idle connections
+    // may not be cleaned up as aggressively.
+    if (mTimer)
+        mTimer->Init(DeadConnectionCleanupCB, this, 15*1000, // 15 seconds
+                     NS_PRIORITY_NORMAL,
+                     NS_TYPE_REPEATING_SLACK);
+ 
     return NS_OK;
 }
 
@@ -442,6 +455,21 @@ nsHttpHandler::ReclaimConnection(nsHttpConnection *conn)
     return NS_OK;
 }
 
+nsresult 
+nsHttpHandler::PurgeDeadConnections()
+{
+    nsAutoLock lock(mConnectionLock);
+    for (PRInt32 i = 0; i < mIdleConnections.Count(); ++i) {
+        nsHttpConnection *conn = (nsHttpConnection *) mIdleConnections[i];
+        if (conn && !conn->CanReuse()) {
+            // Dead and idle connection; purge it
+            mIdleConnections.RemoveElement(conn);
+            NS_RELEASE(conn);
+        }
+    }
+    return NS_OK;
+}
+
 // called from the socket thread (see nsHttpConnection::OnDataAvailable)
 nsresult
 nsHttpHandler::ProcessTransactionQ()
@@ -895,6 +923,14 @@ nsHttpHandler::RemovePendingTransaction_Locked(nsHttpTransaction *trans)
     return NS_ERROR_NOT_AVAILABLE;
 }
 
+void 
+nsHttpHandler::DeadConnectionCleanupCB(nsITimer *timer, void *closure)
+{
+    nsHttpHandler *self = NS_STATIC_CAST(nsHttpHandler*, closure);
+    if (self)
+        self->PurgeDeadConnections();
+}
+
 void
 nsHttpHandler::DropConnections(nsVoidArray &connections)
 {
@@ -1875,6 +1911,13 @@ nsHttpHandler::Observe(nsISupports *subject,
         // depend on this value.
         mSessionStartTime = NowInSeconds();
     }
+    else if (!nsCRT::strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
+        if (mTimer) {
+            mTimer->Cancel();
+            mTimer = 0;
+        }
+    }
+
     return NS_OK;
 }
 

netwerk/protocol/http/src/nsHttpHandler.h

@@ -42,6 +42,7 @@
 #include "nsWeakReference.h"
 #include "nsVoidArray.h"
 #include "nsIIDNService.h"
+#include "nsITimer.h"
 
 class nsHttpConnection;
 class nsHttpConnectionInfo;
@@ -123,6 +124,8 @@ public:
     // longer than mMaxRequestDelay.
     nsresult ProcessTransactionQ();
 
+    nsresult PurgeDeadConnections();
+
     //
     // The HTTP handler caches pointers to specific XPCOM services, and
     // provides the following helper routines for accessing those services:
@@ -189,7 +192,8 @@ private:
     nsresult SetAcceptEncodings(const char *);
     nsresult SetAcceptCharsets(const char *);
 
-    static PRInt32 PR_CALLBACK PrefsCallback(const char *, void *);
+    // timer callback for cleansing the idle connection list
+    static void DeadConnectionCleanupCB(nsITimer *, void *);
 
 private:
     static nsHttpHandler *mGlobalInstance;
@@ -202,6 +206,7 @@ private:
     nsCOMPtr<nsIStreamConverterService> mStreamConvSvc;
     nsCOMPtr<nsIMIMEService>            mMimeService;
     nsCOMPtr<nsIIDNService>             mIDNConverter;
+    nsCOMPtr<nsITimer>                  mTimer;
 
     // the authentication credentials cache
     nsHttpAuthCache *mAuthCache;
@@ -234,7 +239,7 @@ private:
     nsCOMPtr<nsICacheSession> mCacheSession_MEM;
     PRUint32                  mLastUniqueID;
     PRUint32                  mSessionStartTime;
-
+ 
     // connection management
     nsVoidArray mActiveConnections; // list of nsHttpConnection objects
     nsVoidArray mIdleConnections;   // list of nsHttpConnection objects