Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Appearance settings

Commit 6bf816f

Browse filesBrowse files
ulanMylesBorins
ulan
authored and
MylesBorins
committed
src: limit foreground tasks draining loop
Foreground tasks that repost themselves can force the draining loop to run indefinitely long without giving other tasks chance to run. This limits the foreground task draining loop to run only the tasks that were in the tasks queue at the beginning of the loop. PR-URL: #19987 Fixes: #19937 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Yang Guo <yangguo@chromium.org> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com> Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl> Reviewed-By: Anatoli Papirovski <apapirovski@mac.com> Reviewed-By: Khaidi Chu <i@2333.moe>
1 parent 99e0b91 commit 6bf816f
Copy full SHA for 6bf816f

File tree

Expand file treeCollapse file tree

5 files changed

+83
-7
lines changed
Open diff view settings
Filter options
Expand file treeCollapse file tree

5 files changed

+83
-7
lines changed
Open diff view settings
Collapse file

‎node.gyp‎

Copy file name to clipboardExpand all lines: node.gyp
+1Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -961,6 +961,7 @@
961961
'test/cctest/test_base64.cc',
962962
'test/cctest/test_node_postmortem_metadata.cc',
963963
'test/cctest/test_environment.cc',
964+
'test/cctest/test_platform.cc',
964965
'test/cctest/test_util.cc',
965966
'test/cctest/test_url.cc'
966967
],
Collapse file

‎src/inspector_agent.cc‎

Copy file name to clipboardExpand all lines: src/inspector_agent.cc
+1-1Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -316,7 +316,7 @@ class NodeInspectorClient : public V8InspectorClient {
316316
terminated_ = false;
317317
running_nested_loop_ = true;
318318
while (!terminated_ && channel_->waitForFrontendMessage()) {
319-
platform_->FlushForegroundTasks(env_->isolate());
319+
while (platform_->FlushForegroundTasks(env_->isolate())) {}
320320
}
321321
terminated_ = false;
322322
running_nested_loop_ = false;
Collapse file

‎src/node_platform.cc‎

Copy file name to clipboardExpand all lines: src/node_platform.cc
+18-4Lines changed: 18 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -95,7 +95,7 @@ void PerIsolatePlatformData::PostDelayedTask(
9595
}
9696

9797
PerIsolatePlatformData::~PerIsolatePlatformData() {
98-
FlushForegroundTasksInternal();
98+
while (FlushForegroundTasksInternal()) {}
9999
CancelPendingDelayedTasks();
100100

101101
uv_close(reinterpret_cast<uv_handle_t*>(flush_tasks_),
@@ -223,7 +223,13 @@ bool PerIsolatePlatformData::FlushForegroundTasksInternal() {
223223
});
224224
});
225225
}
226-
while (std::unique_ptr<Task> task = foreground_tasks_.Pop()) {
226+
// Move all foreground tasks into a separate queue and flush that queue.
227+
// This way tasks that are posted while flushing the queue will be run on the
228+
// next call of FlushForegroundTasksInternal.
229+
std::queue<std::unique_ptr<Task>> tasks = foreground_tasks_.PopAll();
230+
while (!tasks.empty()) {
231+
std::unique_ptr<Task> task = std::move(tasks.front());
232+
tasks.pop();
227233
did_work = true;
228234
RunForegroundTask(std::move(task));
229235
}
@@ -254,8 +260,8 @@ void NodePlatform::CallDelayedOnForegroundThread(Isolate* isolate,
254260
std::unique_ptr<Task>(task), delay_in_seconds);
255261
}
256262

257-
void NodePlatform::FlushForegroundTasks(v8::Isolate* isolate) {
258-
ForIsolate(isolate)->FlushForegroundTasksInternal();
263+
bool NodePlatform::FlushForegroundTasks(v8::Isolate* isolate) {
264+
return ForIsolate(isolate)->FlushForegroundTasksInternal();
259265
}
260266

261267
void NodePlatform::CancelPendingDelayedTasks(v8::Isolate* isolate) {
@@ -348,4 +354,12 @@ void TaskQueue<T>::Stop() {
348354
tasks_available_.Broadcast(scoped_lock);
349355
}
350356

357+
template <class T>
358+
std::queue<std::unique_ptr<T>> TaskQueue<T>::PopAll() {
359+
Mutex::ScopedLock scoped_lock(lock_);
360+
std::queue<std::unique_ptr<T>> result;
361+
result.swap(task_queue_);
362+
return result;
363+
}
364+
351365
} // namespace node
Collapse file

‎src/node_platform.h‎

Copy file name to clipboardExpand all lines: src/node_platform.h
+8-2Lines changed: 8 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -26,6 +26,7 @@ class TaskQueue {
2626
void Push(std::unique_ptr<T> task);
2727
std::unique_ptr<T> Pop();
2828
std::unique_ptr<T> BlockingPop();
29+
std::queue<std::unique_ptr<T>> PopAll();
2930
void NotifyOfCompletion();
3031
void BlockingDrain();
3132
void Stop();
@@ -65,7 +66,9 @@ class PerIsolatePlatformData :
6566
void ref();
6667
int unref();
6768

68-
// Returns true iff work was dispatched or executed.
69+
// Returns true if work was dispatched or executed. New tasks that are
70+
// posted during flushing of the queue are postponed until the next
71+
// flushing.
6972
bool FlushForegroundTasksInternal();
7073
void CancelPendingDelayedTasks();
7174

@@ -130,7 +133,10 @@ class NodePlatform : public MultiIsolatePlatform {
130133
double CurrentClockTimeMillis() override;
131134
v8::TracingController* GetTracingController() override;
132135

133-
void FlushForegroundTasks(v8::Isolate* isolate);
136+
// Returns true if work was dispatched or executed. New tasks that are
137+
// posted during flushing of the queue are postponed until the next
138+
// flushing.
139+
bool FlushForegroundTasks(v8::Isolate* isolate);
134140

135141
void RegisterIsolate(IsolateData* isolate_data, uv_loop_t* loop) override;
136142
void UnregisterIsolate(IsolateData* isolate_data) override;
Collapse file

‎test/cctest/test_platform.cc‎

Copy file name to clipboard
+55Lines changed: 55 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,55 @@
1+
#include "node_internals.h"
2+
#include "libplatform/libplatform.h"
3+
4+
#include <string>
5+
#include "gtest/gtest.h"
6+
#include "node_test_fixture.h"
7+
8+
// This task increments the given run counter and reposts itself until the
9+
// repost counter reaches zero.
10+
class RepostingTask : public v8::Task {
11+
public:
12+
explicit RepostingTask(int repost_count,
13+
int* run_count,
14+
v8::Isolate* isolate,
15+
node::NodePlatform* platform)
16+
: repost_count_(repost_count),
17+
run_count_(run_count),
18+
isolate_(isolate),
19+
platform_(platform) {}
20+
21+
// v8::Task implementation
22+
void Run() final {
23+
++*run_count_;
24+
if (repost_count_ > 0) {
25+
--repost_count_;
26+
platform_->CallOnForegroundThread(isolate_,
27+
new RepostingTask(repost_count_, run_count_, isolate_, platform_));
28+
}
29+
}
30+
31+
private:
32+
int repost_count_;
33+
int* run_count_;
34+
v8::Isolate* isolate_;
35+
node::NodePlatform* platform_;
36+
};
37+
38+
class PlatformTest : public EnvironmentTestFixture {};
39+
40+
TEST_F(PlatformTest, SkipNewTasksInFlushForegroundTasks) {
41+
v8::Isolate::Scope isolate_scope(isolate_);
42+
const v8::HandleScope handle_scope(isolate_);
43+
const Argv argv;
44+
Env env {handle_scope, argv};
45+
int run_count = 0;
46+
platform->CallOnForegroundThread(
47+
isolate_, new RepostingTask(2, &run_count, isolate_, platform.get()));
48+
EXPECT_TRUE(platform->FlushForegroundTasks(isolate_));
49+
EXPECT_EQ(1, run_count);
50+
EXPECT_TRUE(platform->FlushForegroundTasks(isolate_));
51+
EXPECT_EQ(2, run_count);
52+
EXPECT_TRUE(platform->FlushForegroundTasks(isolate_));
53+
EXPECT_EQ(3, run_count);
54+
EXPECT_FALSE(platform->FlushForegroundTasks(isolate_));
55+
}

0 commit comments

Comments
0 (0)
Morty Proxy This is a proxified and sanitized view of the page, visit original site.