Added command line switches "crash-on-hang-threads" and "crash-on-hang-seconds"

chrome/browser/metrics/thread_watcher.h

Index: chrome/browser/metrics/thread_watcher.h
===================================================================
--- chrome/browser/metrics/thread_watcher.h	(revision 88502)
+++ chrome/browser/metrics/thread_watcher.h	(working copy)
@@ -32,10 +32,12 @@
 #define CHROME_BROWSER_METRICS_THREAD_WATCHER_H_
 
 #include <map>
+#include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/command_line.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ -158,16 +160,13 @@
   // It increments unresponsive_count_ by 1.
   void GotNoResponse();
 
+  // Helper method to get |unresponsive_count_|.
+  uint32 unresponsive_count() const { return unresponsive_count_; }
+
   // This is the number of ping messages to be sent when the user is idle.
   // ping_count_ will be initialized to kPingCount whenever user becomes active.
   static const int kPingCount;
 
-  // This value is used to determine if the watched thread is responsive or not.
-  // If unresponsive_count_ is less than kUnresponsiveCount then watched thread
-  // is considered as responsive (in responsive_count_histogram_) otherwise it
-  // is considered as unresponsive (in unresponsive_count_histogram_).
-  static const int kUnresponsiveCount;
-
   // The thread_id of the thread being watched. Only one instance can exist for
   // the given thread_id of the thread being watched.
   const BrowserThread::ID thread_id_;
@@ -223,7 +222,7 @@
   // is zero then watched thread has responded with a pong message. This is
   // incremented by 1 when we got no response (GotNoResponse) from the watched
   // thread.
-  int unresponsive_count_;
+  uint32 unresponsive_count_;
 
   // This is set to true when we would have crashed the browser because the
   // watched thread hasn't responded atleast 6 times. It is reset to false when
@@ -248,7 +247,7 @@
   typedef std::map<BrowserThread::ID, ThreadWatcher*> RegistrationList;
 
   // This singleton holds the global list of registered ThreadWatchers.
-  ThreadWatcherList();
+  explicit ThreadWatcherList(const CommandLine& command_line);
   // Destructor deletes all registered ThreadWatcher instances.
   virtual ~ThreadWatcherList();
 
@@ -273,8 +272,19 @@
   // This method is accessible on UI thread.
   static void RemoveNotifications();
 
+  // Returns true if watched thread's |unresponsive_count_| is less than
+  // |crash_on_unresponsive_count_|. A watched thread is considered as
+  // unresponsive if it has not responded with a pong message for
+  // |crash_on_unresponsive_count_| number of ping messages.
+  static bool IsResponsive(ThreadWatcher* watcher);
+
+  // Returns true if the watched thread is not responsive and is listed
+  // as one of the threads in "--crash-on-hang-threads" command line switch.
+  static bool CrashOnHang(ThreadWatcher* watcher);
+
   // This method returns number of watched threads that have responded and
-  // threads that have not responded with a pong message.
+  // threads that have not responded with a pong message for
+  // |crash_on_unresponsive_count_| number of ping messages.
   static void GetStatusOfThreads(int* no_of_responding_threads,
                                  int* no_of_unresponding_threads);
 
@@ -316,6 +326,11 @@
   // received pong message or not.
   static const int kUnresponsiveSeconds;
 
+  // This is used to initialize |crash_on_unresponsive_count_|.
+  // |crash_on_unresponsive_count_| is used to determine if the watched thread
+  // is responsive or not.

[jar (doing other things), 2011/06/10 00:38:33]

nit: Don't bother explaining the variable... since it has its own comment.  All
you need is:

// Default values for |crash_on_unresponsive_count_|.

[ramant (doing other things), 2011/06/13 03:26:02]

Done.

+  static const int kUnresponsiveCount;
+
   // Lock for access to registered_.
   base::Lock lock_;
 
@@ -328,6 +343,19 @@
   // This is the last time when woke all thread watchers up.
   base::TimeTicks last_wakeup_time_;
 
+  // This is used to determine if the watched thread is responsive or not. If
+  // watched thread's |unresponsive_count_| is greater than or equal to
+  // |crash_on_unresponsive_count_| then we could crash the browser if the
+  // watched thread is listed in the "--crash-on-hang-threads" command line
+  // switch. It is initialized with |kUnresponsiveCount|, but can be overwritten
+  // by the command line switch "--crash-on-hang-seconds".
+  uint32 crash_on_unresponsive_count_;
+
+  // This is the set of watched thread's names that are to be crashed if they
+  // have not responded with a pong message for |crash_on_unresponsive_count_|
+  // number of ping messages.
+  std::set<std::string> crash_on_hang_thread_names_;
+
   DISALLOW_COPY_AND_ASSIGN(ThreadWatcherList);
 };