Introduce an artificial 2 second delay after network IP address changes before re-running proxy auto-config.

During this time network requests will be stalled.

This is to work around a problem where DNS gives transient failures shortly after IP address changes.

BUG=50779
TEST=On a linux laptop switch between wireless networks while using auto-detect. When you switch to a network that contains the host 'wpad' verify that when InitProxyResolver runs it does not get a DNS error resolving 'wpad'. (Use about:net-internals to view this information).

Review URL: http://codereview.chromium.org/3151040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57471 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 42 insertions, 1 deletions

diff --git a/net/proxy/init_proxy_resolver.cc b/net/proxy/init_proxy_resolver.cc
index 04f828b..9cffa67 100644
--- a/net/proxy/init_proxy_resolver.cc
+++ b/net/proxy/init_proxy_resolver.cc
@@ -36,6 +36,7 @@ InitProxyResolver::~InitProxyResolver() {
 }
 
 int InitProxyResolver::Init(const ProxyConfig& config,
+                            const base::TimeDelta wait_delay,
                             CompletionCallback* callback) {
   DCHECK_EQ(STATE_NONE, next_state_);
   DCHECK(callback);
@@ -43,10 +44,15 @@ int InitProxyResolver::Init(const ProxyConfig& config,
 
   net_log_.BeginEvent(NetLog::TYPE_INIT_PROXY_RESOLVER, NULL);
 
+  // Save the |wait_delay| as a non-negative value.
+  wait_delay_ = wait_delay;
+  if (wait_delay_ < base::TimeDelta())
+    wait_delay_ = base::TimeDelta();
+
   pac_urls_ = BuildPacUrlsFallbackList(config);
   DCHECK(!pac_urls_.empty());
 
-  next_state_ = GetStartState();
+  next_state_ = STATE_WAIT;
 
   int rv = DoLoop(OK);
   if (rv == ERR_IO_PENDING)
@@ -86,6 +92,13 @@ int InitProxyResolver::DoLoop(int result) {
     State state = next_state_;
     next_state_ = STATE_NONE;
     switch (state) {
+      case STATE_WAIT:
+        DCHECK_EQ(OK, rv);
+        rv = DoWait();
+        break;
+      case STATE_WAIT_COMPLETE:
+        rv = DoWaitComplete(rv);
+        break;
       case STATE_FETCH_PAC_SCRIPT:
         DCHECK_EQ(OK, rv);
         rv = DoFetchPacScript();
@@ -115,6 +128,27 @@ void InitProxyResolver::DoCallback(int result) {
   user_callback_->Run(result);
 }
 
+int InitProxyResolver::DoWait() {
+  next_state_ = STATE_WAIT_COMPLETE;
+
+  // If no waiting is required, continue on to the next state.
+  if (wait_delay_.ToInternalValue() == 0)
+    return OK;
+
+  // Otherwise wait the specified amount of time.
+  wait_timer_.Start(wait_delay_, this, &InitProxyResolver::OnWaitTimerFired);
+  net_log_.BeginEvent(NetLog::TYPE_INIT_PROXY_RESOLVER_WAIT, NULL);
+  return ERR_IO_PENDING;
+}
+
+int InitProxyResolver::DoWaitComplete(int result) {
+  DCHECK_EQ(OK, result);
+  if (wait_delay_.ToInternalValue() != 0)
+    net_log_.EndEvent(NetLog::TYPE_INIT_PROXY_RESOLVER_WAIT, NULL);
+  next_state_ = GetStartState();
+  return OK;
+}
+
 int InitProxyResolver::DoFetchPacScript() {
   DCHECK(resolver_->expects_pac_bytes());
 
@@ -217,6 +251,10 @@ const InitProxyResolver::PacURL& InitProxyResolver::current_pac_url() const {
   return pac_urls_[current_pac_url_index_];
 }
 
+void InitProxyResolver::OnWaitTimerFired() {
+  OnIOCompletion(OK);
+}
+
 void InitProxyResolver::DidCompleteInit() {
   net_log_.EndEvent(NetLog::TYPE_INIT_PROXY_RESOLVER, NULL);
 }
@@ -227,6 +265,9 @@ void InitProxyResolver::Cancel() {
   net_log_.AddEvent(NetLog::TYPE_CANCELLED, NULL);
 
   switch (next_state_) {
+    case STATE_WAIT_COMPLETE:
+      wait_timer_.Stop();
+      break;
     case STATE_FETCH_PAC_SCRIPT_COMPLETE:
       proxy_script_fetcher_->Cancel();
       break;