Add command line option for changing the max number of SPDY sessions per

domain.  The default remains at 1.

Command line usage to set it to 13:
   chrome.exe --use-spdy --max-spdy-sessions-per-domain=13

BUG=none
TEST=none


Review URL: http://codereview.chromium.org/669169

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@40775 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 25 insertions, 2 deletions

diff --git a/chrome/browser/browser_main.cc b/chrome/browser/browser_main.cc
index 4d9803c..0d76b8e 100644
--- a/chrome/browser/browser_main.cc
+++ b/chrome/browser/browser_main.cc
@@ -67,6 +67,7 @@
 #include "net/http/http_network_session.h"
 #include "net/http/http_network_transaction.h"
 #include "net/socket/client_socket_pool_base.h"
+#include "net/spdy/spdy_session_pool.h"
 
 #if defined(OS_POSIX)
 // TODO(port): get rid of this include. It's used just to provide declarations
@@ -674,6 +675,14 @@ int BrowserMain(const MainFunctionParams& parameters) {
   if (parsed_command_line.HasSwitch(switches::kIgnoreCertificateErrors))
     net::HttpNetworkTransaction::IgnoreCertificateErrors(true);
 
+  if (parsed_command_line.HasSwitch(switches::kMaxSpdySessionsPerDomain)) {
+    int value = StringToInt(
+        parsed_command_line.GetSwitchValueASCII(
+            switches::kMaxSpdySessionsPerDomain));
+    net::SpdySessionPool::set_max_sessions_per_domain(value);
+  }
+
+
   // Initialize histogram statistics gathering system.
   StatisticsRecorder statistics;
 
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index ac8ee7b..31e3ae3 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -699,6 +699,9 @@ const char kFixedHttpsPort[]                = "testing-fixed-https-port";
 // Ignore certificate related errors.
 const char kIgnoreCertificateErrors[]       = "ignore-certificate-errors";
 
+// Set the maximum SPDY sessions per domain.
+const char kMaxSpdySessionsPerDomain[]      = "max-spdy-sessions-per-domain";
+
 // Use the low fragmentation heap for the CRT.
 const char kUseLowFragHeapCrt[]             = "use-lf-heap";
 
diff --git a/chrome/common/chrome_switches.h b/chrome/common/chrome_switches.h
index 5ceb5fb..0e463a6 100644
--- a/chrome/common/chrome_switches.h
+++ b/chrome/common/chrome_switches.h
@@ -198,6 +198,7 @@ extern const char kUseSpdy[];
 extern const char kFixedHttpPort[];
 extern const char kFixedHttpsPort[];
 extern const char kIgnoreCertificateErrors[];
+extern const char kMaxSpdySessionsPerDomain[];
 extern const char kUseLowFragHeapCrt[];
 extern const char kUserAgent[];
 extern const char kUserDataDir[];
diff --git a/net/spdy/spdy_session_pool.cc b/net/spdy/spdy_session_pool.cc
index 0f012fb..5cfd62c 100644
--- a/net/spdy/spdy_session_pool.cc
+++ b/net/spdy/spdy_session_pool.cc
@@ -12,6 +12,8 @@ namespace net {
 // The maximum number of sessions to open to a single domain.
 static const size_t kMaxSessionsPerDomain = 1;
 
+int SpdySessionPool::g_max_sessions_per_domain = kMaxSessionsPerDomain;
+
 SpdySessionPool::SpdySessionPool() {}
 SpdySessionPool::~SpdySessionPool() {
   CloseAllSessions();
@@ -22,7 +24,7 @@ scoped_refptr<SpdySession> SpdySessionPool::Get(
   scoped_refptr<SpdySession> spdy_session;
   SpdySessionList* list = GetSessionList(host_port_pair);
   if (list) {
-    if (list->size() >= kMaxSessionsPerDomain) {
+    if (list->size() >= static_cast<unsigned int>(g_max_sessions_per_domain)) {
       spdy_session = list->front();
       list->pop_front();
     }
@@ -36,7 +38,7 @@ scoped_refptr<SpdySession> SpdySessionPool::Get(
 
   DCHECK(spdy_session);
   list->push_back(spdy_session);
-  DCHECK(list->size() <= kMaxSessionsPerDomain);
+  DCHECK_LE(list->size(), static_cast<unsigned int>(g_max_sessions_per_domain));
   return spdy_session;
 }
 
diff --git a/net/spdy/spdy_session_pool.h b/net/spdy/spdy_session_pool.h
index 8cf8c60..8c50577 100644
--- a/net/spdy/spdy_session_pool.h
+++ b/net/spdy/spdy_session_pool.h
@@ -47,6 +47,12 @@ class SpdySessionPool : public base::RefCounted<SpdySessionPool> {
   scoped_refptr<SpdySession> Get(
       const HostPortPair& host_port_pair, HttpNetworkSession* session);
 
+  // Set the maximum concurrent sessions per domain.
+  static void set_max_sessions_per_domain(int max) {
+    if (max >= 1)
+      g_max_sessions_per_domain = max;
+  }
+
   // Builds a SpdySession from an existing SSL socket.  Users should try
   // calling Get() first to use an existing SpdySession so we don't get
   // multiple SpdySessions per domain.  Note that ownership of |connection| is
@@ -86,6 +92,8 @@ class SpdySessionPool : public base::RefCounted<SpdySessionPool> {
   // This is our weak session pool - one session per domain.
   SpdySessionsMap sessions_;
 
+  static int g_max_sessions_per_domain;
+
   DISALLOW_COPY_AND_ASSIGN(SpdySessionPool);
 };