From f064193fe71b8b055d060adb10fbc4e3cca8c604 Mon Sep 17 00:00:00 2001 From: ericrk Date: Wed, 24 Feb 2016 13:17:10 -0800 Subject: Refactor signaling in RWP A previous patch had moved RasterWorkerPool to make heavy use of broadcast in order to simplify logic a bit. It turns out that broadcast is not ideal in performance critical situations, as it increases lock contention (see https://code.google.com/p/chromium/codesearch#chromium/src/base/synchronization/condition_variable.h&l=34). This change removes all uses of broadcast other than in Shutdown, where performance is less of a concern and we actually need all threads to wake up. To achieve this, we need to re-factor RWP to use: - N foreground threads - 1 background thread rather than N threads which may be able to run foreground/background tasks. In order to ensure that we don't overload the system, this change introduces a limiting system where the background priority thread can only run tasks if no other threads are doing so. BUG= CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel Review URL: https://codereview.chromium.org/1666283002 Cr-Commit-Position: refs/heads/master@{#377379} --- cc/raster/task_graph_work_queue.cc | 26 +++++++++++++++++--------- cc/raster/task_graph_work_queue.h | 17 ++++++++++++++++- 2 files changed, 33 insertions(+), 10 deletions(-) (limited to 'cc') diff --git a/cc/raster/task_graph_work_queue.cc b/cc/raster/task_graph_work_queue.cc index 2947402..f4368e1 100644 --- a/cc/raster/task_graph_work_queue.cc +++ b/cc/raster/task_graph_work_queue.cc @@ -97,9 +97,11 @@ void TaskGraphWorkQueue::ScheduleTasks(NamespaceToken token, TaskGraph* graph) { continue; // Skip if already running. - if (std::find(task_namespace.running_tasks.begin(), - task_namespace.running_tasks.end(), - node.task) != task_namespace.running_tasks.end()) + if (std::any_of(task_namespace.running_tasks.begin(), + task_namespace.running_tasks.end(), + [&node](const CategorizedTask& task) { + return task.second == node.task; + })) continue; task_namespace.ready_to_run_tasks[node.category].push_back(PrioritizedTask( @@ -127,9 +129,11 @@ void TaskGraphWorkQueue::ScheduleTasks(NamespaceToken token, TaskGraph* graph) { continue; // Skip if already running. - if (std::find(task_namespace.running_tasks.begin(), - task_namespace.running_tasks.end(), - node.task) != task_namespace.running_tasks.end()) + if (std::any_of(task_namespace.running_tasks.begin(), + task_namespace.running_tasks.end(), + [&node](const CategorizedTask& task) { + return task.second == node.task; + })) continue; DCHECK(std::find(task_namespace.completed_tasks.begin(), @@ -195,7 +199,8 @@ TaskGraphWorkQueue::PrioritizedTask TaskGraphWorkQueue::GetNextTaskToRun( } // Add task to |running_tasks|. - task_namespace->running_tasks.push_back(task.task); + task_namespace->running_tasks.push_back( + std::make_pair(task.category, task.task)); return task; } @@ -205,8 +210,11 @@ void TaskGraphWorkQueue::CompleteTask(const PrioritizedTask& completed_task) { scoped_refptr task(completed_task.task); // Remove task from |running_tasks|. - auto it = std::find(task_namespace->running_tasks.begin(), - task_namespace->running_tasks.end(), task); + auto it = std::find_if(task_namespace->running_tasks.begin(), + task_namespace->running_tasks.end(), + [&completed_task](const CategorizedTask& task) { + return task.second == completed_task.task; + }); DCHECK(it != task_namespace->running_tasks.end()); std::swap(*it, task_namespace->running_tasks.back()); task_namespace->running_tasks.pop_back(); diff --git a/cc/raster/task_graph_work_queue.h b/cc/raster/task_graph_work_queue.h index 95d3c77..7fbd19b 100644 --- a/cc/raster/task_graph_work_queue.h +++ b/cc/raster/task_graph_work_queue.h @@ -46,6 +46,8 @@ class CC_EXPORT TaskGraphWorkQueue { uint16_t priority; }; + using CategorizedTask = std::pair>; + // Helper classes and static methods used by dependent classes. struct TaskNamespace { typedef std::vector Vector; @@ -64,7 +66,7 @@ class CC_EXPORT TaskGraphWorkQueue { Task::Vector completed_tasks; // This set contains all currently running tasks. - Task::Vector running_tasks; + std::vector running_tasks; }; TaskGraphWorkQueue(); @@ -145,6 +147,19 @@ class CC_EXPORT TaskGraphWorkQueue { return ready_to_run_namespaces_; } + size_t NumRunningTasksForCategory(uint16_t category) const { + size_t count = 0; + for (const auto& task_namespace_entry : namespaces_) { + for (const auto& categorized_task : + task_namespace_entry.second.running_tasks) { + if (categorized_task.first == category) { + ++count; + } + } + } + return count; + } + // Helper function which ensures that graph dependencies were correctly // configured. static bool DependencyMismatch(const TaskGraph* graph); -- cgit v1.1