SIGTERM should cause the application to exit on the Mac.

BUG=23551
TEST=Send SIGTERM to the browser process.  It should exit cleanly.
Review URL: http://codereview.chromium.org/269048

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@28695 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 75 insertions, 8 deletions

diff --git a/chrome/browser/automation/automation_provider.cc b/chrome/browser/automation/automation_provider.cc
index 89a8ec9..e0b6b1a 100644
--- a/chrome/browser/automation/automation_provider.cc
+++ b/chrome/browser/automation/automation_provider.cc
@@ -1699,7 +1699,7 @@ TestingAutomationProvider::~TestingAutomationProvider() {
 }
 
 void TestingAutomationProvider::OnChannelError() {
-  BrowserList::CloseAllBrowsers(true);
+  BrowserList::CloseAllBrowsersAndExit();
   AutomationProvider::OnChannelError();
 }
 
diff --git a/chrome/browser/browser.cc b/chrome/browser/browser.cc
index ab32402..78191f7 100644
--- a/chrome/browser/browser.cc
+++ b/chrome/browser/browser.cc
@@ -891,7 +891,7 @@ void Browser::ToggleFullscreenMode() {
 
 void Browser::Exit() {
   UserMetrics::RecordAction(L"Exit", profile_);
-  BrowserList::CloseAllBrowsers(true);
+  BrowserList::CloseAllBrowsersAndExit();
 }
 
 void Browser::BookmarkCurrentPage() {
diff --git a/chrome/browser/browser_list.cc b/chrome/browser/browser_list.cc
index 24b796c..8db7b46 100644
--- a/chrome/browser/browser_list.cc
+++ b/chrome/browser/browser_list.cc
@@ -17,6 +17,10 @@
 #include "chrome/common/notification_service.h"
 #include "chrome/common/result_codes.h"
 
+#if defined(OS_MACOSX)
+#include "chrome/browser/chrome_application_mac.h"
+#endif
+
 namespace {
 
 // This object is instantiated when the first Browser object is added to the
@@ -186,6 +190,19 @@ void BrowserList::CloseAllBrowsers(bool use_post) {
 }
 
 // static
+void BrowserList::CloseAllBrowsersAndExit() {
+#if !defined(OS_MACOSX)
+  // On most platforms, closing all windows causes the application to exit.
+  CloseAllBrowsers(true);
+#else
+  // On the Mac, the application continues to run once all windows are closed.
+  // Terminate will result in a CloseAllBrowsers(true) call, and additionally,
+  // will cause the application to exit cleanly.
+  CrApplicationCC::Terminate();
+#endif
+}
+
+// static
 void BrowserList::WindowsSessionEnding() {
   // EndSession is invoked once per frame. Only do something the first time.
   static bool already_ended = false;
diff --git a/chrome/browser/browser_list.h b/chrome/browser/browser_list.h
index de07b9a..b510b8c 100644
--- a/chrome/browser/browser_list.h
+++ b/chrome/browser/browser_list.h
@@ -78,6 +78,12 @@ class BrowserList {
   // the session. use_post should only be false when invoked from end session.
   static void CloseAllBrowsers(bool use_post);
 
+  // Closes all browsers and exits.  This is equivalent to
+  // CloseAllBrowsers(true) on platforms where the application exits when no
+  // more windows are remaining.  On other platforms (the Mac), this will
+  // additionally exit the application.
+  static void CloseAllBrowsersAndExit();
+
   // Begins shutdown of the application when the Windows session is ending.
   static void WindowsSessionEnding();
 
diff --git a/chrome/browser/browser_main.cc b/chrome/browser/browser_main.cc
index 2bb6981..9dd411f 100644
--- a/chrome/browser/browser_main.cc
+++ b/chrome/browser/browser_main.cc
@@ -155,26 +155,49 @@ void RunUIMessageLoop(BrowserProcess* browser_process) {
 }
 
 #if defined(OS_POSIX)
-// See comment below, where sigaction is called.
+// See comment in BrowserMain, where sigaction is called.
 void SIGCHLDHandler(int signal) {
 }
 
-// See comment below, where sigaction is called.
+// See comment in BrowserMain, where sigaction is called.
 void SIGTERMHandler(int signal) {
   DCHECK_EQ(signal, SIGTERM);
   LOG(WARNING) << "Addressing SIGTERM on " << PlatformThread::CurrentId();
+
   MessageLoop* main_loop = ChromeThread::GetMessageLoop(ChromeThread::UI);
   if (main_loop) {
-    main_loop->PostTask(FROM_HERE,
-                        NewRunnableFunction(
-                            BrowserList::CloseAllBrowsers, true));
+    // Post the exit task to the main thread.
+    main_loop->PostTask(
+        FROM_HERE, NewRunnableFunction(BrowserList::CloseAllBrowsersAndExit));
+    LOG(WARNING) << "Posted task to UI thread; resetting SIGTERM handler";
   }
+
   // Reinstall the default handler.  We had one shot at graceful shutdown.
-  LOG(WARNING) << "Posted task to UI thread; resetting SIGTERM handler.";
   struct sigaction term_action;
   memset(&term_action, 0, sizeof(term_action));
   term_action.sa_handler = SIG_DFL;
   CHECK(sigaction(SIGTERM, &term_action, NULL) == 0);
+
+  if (!main_loop) {
+    // Without a UI thread to post the exit task to, there aren't many
+    // options.  Raise the signal again.  The default handler will pick it up
+    // and cause an ungraceful exit.
+    LOG(WARNING) << "No UI thread, exiting ungracefully";
+    kill(getpid(), signal);
+
+    // The signal may be handled on another thread.  Give that a chance to
+    // happen.
+    sleep(3);
+
+    // We really should be dead by now.  For whatever reason, we're not. Exit
+    // immediately, with the exit status set to the signal number with bit 8
+    // set.  On the systems that we care about, this exit status is what is
+    // normally used to indicate an exit by this signal's default handler.
+    // This mechanism isn't a de jure standard, but even in the worst case, it
+    // should at least result in an immediate exit.
+    LOG(WARNING) << "Still here, exiting really ungracefully";
+    _exit(signal | (1 << 7));
+  }
 }
 
 // Sets the file descriptor soft limit to |max_descriptors| or the OS hard
diff --git a/chrome/browser/chrome_application_mac.h b/chrome/browser/chrome_application_mac.h
index b09af38..6d5d95f 100644
--- a/chrome/browser/chrome_application_mac.h
+++ b/chrome/browser/chrome_application_mac.h
@@ -5,9 +5,22 @@
 #ifndef CHROME_BROWSER_CHROME_APPLICATION_MAC_H_
 #define CHROME_BROWSER_CHROME_APPLICATION_MAC_H_
 
+#ifdef __OBJC__
+
 #import <AppKit/AppKit.h>
 
 @interface CrApplication : NSApplication
 @end
 
+#endif  // __OBJC__
+
+// CrApplicationCC provides access to CrApplication Objective-C selectors from
+// C++ code.
+namespace CrApplicationCC {
+
+// Calls -[NSApp terminate:].
+void Terminate();
+
+}  // namespace CrApplicationCC
+
 #endif  // CHROME_BROWSER_CHROME_APPLICATION_MAC_H_
diff --git a/chrome/browser/chrome_application_mac.mm b/chrome/browser/chrome_application_mac.mm
index a94d3aa..a81326f 100644
--- a/chrome/browser/chrome_application_mac.mm
+++ b/chrome/browser/chrome_application_mac.mm
@@ -84,3 +84,11 @@
 }
 
 @end
+
+namespace CrApplicationCC {
+
+void Terminate() {
+  [NSApp terminate:nil];
+}
+
+}  // namespace CrApplicationCC