Speed up the Task Manager on linux.

- Unify the calls to get shared memory and private memory. On Linux, these call the same API and on Linux, it takes >10ms to fetch both values each time it is called.
- Cache the returned memory values. While sorting the task manager by memory, it would make the expensive memory call for each row on each sort operation.

BUG=40033
TEST=Existing task manager tests.

Review URL: http://codereview.chromium.org/2047009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@46938 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 41 insertions, 15 deletions

diff --git a/chrome/browser/task_manager.cc b/chrome/browser/task_manager.cc
index a604b70..1d2907a 100644
--- a/chrome/browser/task_manager.cc
+++ b/chrome/browser/task_manager.cc
@@ -404,25 +404,34 @@ double TaskManagerModel::GetCPUUsage(TaskManager::Resource* resource) const {
 }
 
 bool TaskManagerModel::GetPrivateMemory(int index, size_t* result) const {
-  *result = 0;
-  base::ProcessMetrics* process_metrics;
-  if (!GetProcessMetricsForRow(index, &process_metrics))
-    return false;
-  *result = process_metrics->GetPrivateBytes();
-  if (*result == 0)
-    return false;
+  base::ProcessHandle handle = resources_[index]->GetProcess();
+  MemoryUsageMap::const_iterator iter = memory_usage_map_.find(handle);
+  if (iter == memory_usage_map_.end()) {
+    std::pair<size_t, size_t> usage;
+    if (!GetAndCacheMemoryMetrics(handle, &usage))
+      return false;
+
+    *result = usage.first;
+  } else {
+    *result = iter->second.first;
+  }
+
   return true;
 }
 
 bool TaskManagerModel::GetSharedMemory(int index, size_t* result) const {
-  *result = 0;
-  base::ProcessMetrics* process_metrics;
-  if (!GetProcessMetricsForRow(index, &process_metrics))
-    return false;
-  base::WorkingSetKBytes ws_usage;
-  if (!process_metrics->GetWorkingSetKBytes(&ws_usage))
-    return false;
-  *result = ws_usage.shared * 1024;
+  base::ProcessHandle handle = resources_[index]->GetProcess();
+  MemoryUsageMap::const_iterator iter = memory_usage_map_.find(handle);
+  if (iter == memory_usage_map_.end()) {
+    std::pair<size_t, size_t> usage;
+    if (!GetAndCacheMemoryMetrics(handle, &usage))
+      return false;
+
+    *result = usage.second;
+  } else {
+    *result = iter->second.second;
+  }
+
   return true;
 }
 
@@ -718,6 +727,9 @@ void TaskManagerModel::Refresh() {
     cpu_usage_map_[process] = metrics_iter->second->GetCPUUsage();
   }
 
+  // Clear the memory values so they can be querried lazily.
+  memory_usage_map_.clear();
+
   // Compute the new network usage values.
   displayed_network_usage_map_.clear();
   for (ResourceValueMap::iterator iter = current_byte_count_map_.begin();
@@ -952,3 +964,17 @@ void TaskManager::OpenAboutMemory() {
     browser->window()->Show();
   }
 }
+
+bool TaskManagerModel::GetAndCacheMemoryMetrics(
+    base::ProcessHandle handle,
+    std::pair<size_t, size_t>* usage) const {
+  MetricsMap::const_iterator iter = metrics_map_.find(handle);
+  if (iter == metrics_map_.end())
+    return false;
+
+  if (!iter->second->GetMemoryBytes(&usage->first, &usage->second))
+    return false;
+
+  memory_usage_map_.insert(std::make_pair(handle, *usage));
+  return true;
+}