CrOS - Memory debug widget shows anonymous memory and renderer kills.

chrome/browser/chromeos/status/memory_menu_button.cc

Index: chrome/browser/chromeos/status/memory_menu_button.cc
diff --git a/chrome/browser/chromeos/status/memory_menu_button.cc b/chrome/browser/chromeos/status/memory_menu_button.cc
index 606ebc16ebc5732c9b2efafd743668ac88466510..634c985098427726eaeb711aae38370010a42ed3 100644
--- a/chrome/browser/chromeos/status/memory_menu_button.cc
+++ b/chrome/browser/chromeos/status/memory_menu_button.cc
@@ -8,6 +8,8 @@
 #include "base/stringprintf.h"
 #include "chrome/browser/chromeos/status/status_area_host.h"
 #include "chrome/browser/memory_purger.h"
+#include "content/browser/renderer_host/render_process_host.h"
+#include "content/common/notification_service.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "views/widget/widget.h"
@@ -33,11 +35,12 @@ const int kUpdateIntervalSeconds = 5;
 
 MemoryMenuButton::MemoryMenuButton(StatusAreaHost* host)
     : StatusAreaButton(host, this),
-      mem_total_(0),
-      shmem_(0),
-      mem_free_(0),
-      mem_buffers_(0),
-      mem_cache_(0) {
+      meminfo_(new base::SystemMemoryInfoKB()),
+      renderer_kills_(0) {
+  // Track renderer kills, as the kernel OOM killer will start to kill our
+  // renderers as we run out of memory.
+  registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CLOSED,
+                 NotificationService::AllSources());
   UpdateTextAndSetNextTimer();
 }
 
@@ -52,17 +55,20 @@ void MemoryMenuButton::UpdateTextAndSetNextTimer() {
 }
 
 void MemoryMenuButton::UpdateText() {
-  base::GetSystemMemoryInfo(&mem_total_, &mem_free_, &mem_buffers_, &mem_cache_,
-                            &shmem_);
-  std::wstring label = base::StringPrintf(L"%d MB", mem_free_ / 1024);
+  base::GetSystemMemoryInfo(meminfo_.get());
+  // "Anonymous" memory, meaning not mapped to a file (which has a name),
+  // represents memory that has been dynamically allocated to a process.
+  // It thus approximates heap memory usage across all processes.
+  int anon_kb = meminfo_->active_anon + meminfo_->inactive_anon;
+  std::wstring label = base::StringPrintf(L"%d MB (%d)",
+                                          anon_kb / 1024,
+                                          renderer_kills_);
   SetText(label);
   std::wstring tooltip = base::StringPrintf(
-      L"%d MB total\n%d MB free\n%d MB buffers\n%d MB cache\n%d MB shmem",
-      mem_total_ / 1024,
-      mem_free_ / 1024,
-      mem_buffers_ / 1024,
-      mem_cache_ / 1024,
-      shmem_ / 1024);
+      L"%d MB allocated (anonymous)\n"
+      L"%d renderer kill(s)",
+      anon_kb / 1024,
+      renderer_kills_);
   SetTooltipText(tooltip);
   SchedulePaint();
 }
@@ -71,15 +77,15 @@ void MemoryMenuButton::UpdateText() {
 std::wstring MemoryMenuButton::GetLabel(int id) const {
   switch (id) {
     case MEM_TOTAL_ITEM:
-      return StringPrintf(L"%d MB total", mem_total_ / 1024);
+      return StringPrintf(L"%d MB total", meminfo_->total / 1024);
     case MEM_FREE_ITEM:
-      return StringPrintf(L"%d MB free", mem_free_ / 1024);
+      return StringPrintf(L"%d MB free", meminfo_->free / 1024);
     case MEM_BUFFERS_ITEM:
-      return StringPrintf(L"%d MB buffers", mem_buffers_ / 1024);
+      return StringPrintf(L"%d MB buffers", meminfo_->buffers / 1024);
     case MEM_CACHE_ITEM:
-      return StringPrintf(L"%d MB cache", mem_cache_ / 1024);
+      return StringPrintf(L"%d MB cache", meminfo_->cached / 1024);
     case SHMEM_ITEM:
-      return StringPrintf(L"%d MB shmem", shmem_ / 1024);
+      return StringPrintf(L"%d MB shmem", meminfo_->shmem / 1024);
     case PURGE_MEMORY_ITEM:
       return L"Purge memory";
     default:
@@ -146,4 +152,28 @@ void MemoryMenuButton::EnsureMenu() {
   menu_->AppendDelegateMenuItem(PURGE_MEMORY_ITEM);
 }
 
+/////////////////////////////////////////////////////////////////////////////
+// NotificationObserver overrides.
+
+void MemoryMenuButton::Observe(int type,
+                               const NotificationSource& source,
+                               const NotificationDetails& details) {
+  switch (type) {
+    case content::NOTIFICATION_RENDERER_PROCESS_CLOSED: {
+      RenderProcessHost::RendererClosedDetails* process_details =
+          Details<RenderProcessHost::RendererClosedDetails>(details).ptr();
+      if (process_details->status ==
+          base::TERMINATION_STATUS_PROCESS_WAS_KILLED) {
+        renderer_kills_++;
+        // A kill is a very interesting event, so repaint immediately.
+        UpdateText();
+      }
+      break;
+    }
+    default:
+      NOTREACHED() << L"Received unexpected notification";
+      break;
+  }
+}
+
 }  // namespace chromeos