Implement the WindowsLogoffRace finch experiment.
[email protected],[email protected]
[email protected]
BUG=388741
Review URL: https://codereview.chromium.org/385123004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283282 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 27b7c5b..27f05b9 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -15,6 +15,7 @@
#include "base/debug/alias.h"
#include "base/debug/leak_annotations.h"
#include "base/files/file_path.h"
+#include "base/metrics/field_trial.h"
#include "base/path_service.h"
#include "base/prefs/json_pref_store.h"
#include "base/prefs/pref_registry_simple.h"
@@ -441,9 +442,25 @@
return waitable_event_.TimedWait(max_time);
}
+bool ExperimentUseBrokenSynchronization() {
+ // The logoff behavior used to have a race, whereby it would perform profile
+ // IO writes on the blocking thread pool, but would sycnhronize to the FILE
+ // thread. Windows feels free to terminate any process that's hidden or
+ // destroyed all it's windows, and sometimes Chrome would be terminated
+ // with pending profile IO due to this mis-synchronization.
+ // Under the "WindowsLogoffRace" experiment group, the broken behavior is
+ // emulated, in order to allow measuring what fraction of unclean shutdowns
+ // are due to this bug.
+ const std::string group_name =
+ base::FieldTrialList::FindFullName("WindowsLogoffRace");
+ return group_name == "BrokenSynchronization";
+}
+
} // namespace
void BrowserProcessImpl::EndSession() {
+ bool use_broken_synchronization = ExperimentUseBrokenSynchronization();
+
// Mark all the profiles as clean.
ProfileManager* pm = profile_manager();
std::vector<Profile*> profiles(pm->GetLoadedProfiles());
@@ -452,7 +469,8 @@
Profile* profile = profiles[i];
profile->SetExitType(Profile::EXIT_SESSION_ENDED);
- rundown_counter->Post(profile->GetIOTaskRunner());
+ if (!use_broken_synchronization)
+ rundown_counter->Post(profile->GetIOTaskRunner());
}
// Tell the metrics service it was cleanly shutdown.
@@ -465,7 +483,8 @@
// commit metrics::prefs::kStabilitySessionEndCompleted change immediately.
local_state()->CommitPendingWrite();
- rundown_counter->Post(local_state_task_runner_);
+ if (!use_broken_synchronization)
+ rundown_counter->Post(local_state_task_runner_);
#endif
}
@@ -479,6 +498,11 @@
// If you change the condition here, be sure to also change
// ProfileBrowserTests to match.
#if defined(USE_X11) || defined(OS_WIN)
+ if (use_broken_synchronization) {
+ rundown_counter->Post(
+ BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
+ }
+
// Do a best-effort wait on the successful countdown of rundown tasks. Note
// that if we don't complete "quickly enough", Windows will terminate our
// process.
