From 3875acf3922501ddbbbdbcd4b18e81ffeb70757f Mon Sep 17 00:00:00 2001
From: Otto van der Schaaf <oschaaf@we-amp.com>
Date: Thu, 5 Mar 2015 13:30:44 +0100
Subject: [PATCH] native-fetcher: fixes

- Native fetching broke in https://github.com/pagespeed/ngx_pagespeed/pull/925
  Make changes so we can do early-stage fetches in the startup process
  to fix that.
- Properly cancel out any pending fetches upon ShutDown()
- Decline fetching after ShutDown(), decline fetching when Init()
  failed.
---
 src/ngx_pagespeed.cc              |  3 ---
 src/ngx_rewrite_driver_factory.cc | 13 +------------
 src/ngx_rewrite_driver_factory.h  |  1 -
 src/ngx_url_async_fetcher.cc      | 17 +++++++++++++++++
 4 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/src/ngx_pagespeed.cc b/src/ngx_pagespeed.cc
index 7b978b637..f6cfbe9f9 100644
--- a/src/ngx_pagespeed.cc
+++ b/src/ngx_pagespeed.cc
@@ -3067,9 +3067,6 @@ ngx_int_t ps_init_child_process(ngx_cycle_t* cycle) {
     }
   }
 
-  if (!cfg_m->driver_factory->InitNgxUrlAsyncFetchers()) {
-    return NGX_ERROR;
-  }
   cfg_m->driver_factory->StartThreads();
   return NGX_OK;
 }
diff --git a/src/ngx_rewrite_driver_factory.cc b/src/ngx_rewrite_driver_factory.cc
index 9bc055a3d..aeef4afc9 100644
--- a/src/ngx_rewrite_driver_factory.cc
+++ b/src/ngx_rewrite_driver_factory.cc
@@ -152,18 +152,6 @@ RewriteOptions* NgxRewriteDriverFactory::NewRewriteOptions() {
   return options;
 }
 
-bool NgxRewriteDriverFactory::InitNgxUrlAsyncFetchers() {
-  log_ = ngx_cycle->log;
-  for (size_t i = 0; i < ngx_url_async_fetchers_.size(); ++i) {
-    // TODO(oschaaf): Can we pass the log from the server{} block here?
-    if (!ngx_url_async_fetchers_[i]->Init(
-      const_cast<ngx_cycle_t*>(ngx_cycle))) {
-      return false;
-    }
-  }
-  return true;
-}
-
 bool NgxRewriteDriverFactory::CheckResolver() {
   if (use_native_fetcher_ && resolver_ == NULL) {
     return false;
@@ -221,6 +209,7 @@ void NgxRewriteDriverFactory::StartThreads() {
 }
 
 void NgxRewriteDriverFactory::LoggingInit(ngx_log_t* log) {
+  log_ = log;
   net_instaweb::log_message_handler::Install(log);
   if (install_crash_handler()) {
     NgxMessageHandler::InstallCrashHandler(log);
diff --git a/src/ngx_rewrite_driver_factory.h b/src/ngx_rewrite_driver_factory.h
index 957d14492..a35cb2532 100644
--- a/src/ngx_rewrite_driver_factory.h
+++ b/src/ngx_rewrite_driver_factory.h
@@ -62,7 +62,6 @@ class NgxRewriteDriverFactory : public SystemRewriteDriverFactory {
   // NgxRewriteOptions.
   virtual RewriteOptions* NewRewriteOptions();
   virtual ServerContext* NewDecodingServerContext();
-  bool InitNgxUrlAsyncFetchers();
   // Check resolver configured or not.
   bool CheckResolver();
 
diff --git a/src/ngx_url_async_fetcher.cc b/src/ngx_url_async_fetcher.cc
index 4a85cc0e5..b90101604 100644
--- a/src/ngx_url_async_fetcher.cc
+++ b/src/ngx_url_async_fetcher.cc
@@ -78,6 +78,12 @@ namespace net_instaweb {
     log_ = log;
     pool_ = NULL;
     resolver_ = resolver;
+    // If init fails, set shutdown_ so no fetches will be attempted.
+    if (!Init(const_cast<ngx_cycle_t*>(ngx_cycle))) {
+      shutdown_ = true;
+      message_handler_->Message(
+          kError, "NgxUrlAsyncFetcher failed to init, fetching disabled.");
+    }
   }
 
   NgxUrlAsyncFetcher::~NgxUrlAsyncFetcher() {
@@ -178,6 +184,11 @@ namespace net_instaweb {
   void NgxUrlAsyncFetcher::ShutDown() {
     shutdown_ = true;
     if (!pending_fetches_.empty()) {
+      for (Pool<NgxFetch>::iterator p = pending_fetches_.begin(),
+           e = pending_fetches_.end(); p != e; p++) {
+        NgxFetch* fetch = *p;
+        fetch->CallbackDone(false);
+      }
       pending_fetches_.DeleteAll();
     }
 
@@ -201,6 +212,12 @@ namespace net_instaweb {
   void NgxUrlAsyncFetcher::Fetch(const GoogleString& url,
                                  MessageHandler* message_handler,
                                  AsyncFetch* async_fetch) {
+    // Don't accept new fetches when shut down. This flow is also entered when
+    // we did not initialize properly in ::Init().
+    if (shutdown_) {
+      async_fetch->Done(false);
+      return;
+    }
     async_fetch = EnableInflation(async_fetch);
     NgxFetch* fetch = new NgxFetch(url, async_fetch,
           message_handler, log_);