Reland #2 "Run Target::OnResolve() on background threads"
This reverts commit 54169531ed6da64425ad6e8e9535945c8f6220d0.
Reason for reland: Removed the PointerSet that was triggering an
infinite loop in HashTableBase::NodeLookup(). I'll fix that bug
separately.
Bug: chromium:398002893
Original change's description:
> Revert "Reland "Run Target::OnResolve() on background threads""
>
> This reverts commit 0fcc64f7d006474a026d8f78f3a95dac84cd97ea.
>
> Reason for revert: Failing to roll into chromium:
> https://chromium-review.googlesource.com/c/chromium/src/+/6641508
>
> Bug: chromium:398002893
> Original change's description:
> > Reland "Run Target::OnResolve() on background threads"
> >
> > This reverts commit 8ea3af9118a65387fe4d8428db6f59c5927dd55a.
> >
> > Reason for reland: Fixed test
> >
> > Bug: chromium:398002893
> > Original change's description:
> > > Revert "Run Target::OnResolve() on background threads"
> > >
> > > This reverts commit 3ef7da38dcfb63212d97a987d5c60374134e1007.
> > >
> > > Reason for revert: Failing tests /w asan (and on release bots)
> > >
> > > Bug: chromium:398002893
> > > Original change's description:
> > > > Run Target::OnResolve() on background threads
> > > >
> > > > OnResolve() is often trivial, but it can also not be, as there are a lot
> > > > of possible checks that it can do.
> > > >
> > > > "gn --tracelog gen" now shows all threads being always busy.
> > > >
> > > > Hyperfine Benchmark from Chromium:
> > > > Before:
> > > > Time (mean ± σ): 7.349 s ± 0.251 s [User: 66.903 s, System: 50.486 s]
> > > > Range (min … max): 6.974 s … 7.655 s 10 runs
> > > >
> > > > After:
> > > > Time (mean ± σ): 6.563 s ± 0.313 s [User: 67.873 s, System: 53.023 s]
> > > > Range (min … max): 6.186 s … 7.281 s 10 runs
> > > > Bug: chromium:398002893
> > > > Change-Id: I30bd9b7541a961b1d0cef80c229b0a3f24752d3e
> > > > Reviewed-on: https://gn-review.googlesource.com/c/gn/+/19020
> > > > Reviewed-by: David Turner <digit@google.com>
> > > > Commit-Queue: David Turner <digit@google.com>
> > > > Reviewed-by: Takuto Ikuta <tikuta@google.com>
> > >
> > > # Not skipping CQ checks because original CL landed > 1 day ago.
> > >
> > > Bug: chromium:398002893
> > > Change-Id: I4ca499e210288b46a91209967a635004c9d0ad68
> > > Reviewed-on: https://gn-review.googlesource.com/c/gn/+/19060
> > > Reviewed-by: Andrew Grieve <agrieve@google.com>
> > > Commit-Queue: Roland McGrath <mcgrathr@google.com>
> > > Reviewed-by: Roland McGrath <mcgrathr@google.com>
> >
> > # Not skipping CQ checks because this is a reland.
> >
> > Bug: chromium:398002893
> > Change-Id: Ia052c4fb4182bf879e418effcf17f27868131be2
> > Reviewed-on: https://gn-review.googlesource.com/c/gn/+/19080
> > Commit-Queue: Andrew Grieve <agrieve@google.com>
> > Reviewed-by: David Turner <digit@google.com>
>
> TBR=mcgrathr@google.com,tikuta@google.com,agrieve@google.com,digit@google.com,gn-scoped@luci-project-accounts.iam.gserviceaccount.com
>
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: chromium:398002893
> Change-Id: I85d6f9b25463afddb8e9c31dd7568170c12c0232
> Reviewed-on: https://gn-review.googlesource.com/c/gn/+/19120
> Commit-Queue: Andrew Grieve <agrieve@google.com>
> Reviewed-by: Andrew Grieve <agrieve@google.com>
> Reviewed-by: David Turner <digit@google.com>
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: chromium:398002893
Change-Id: I7122869f620b2a9e8e9c8d5a224ee46431e3c9c2
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/19140
Reviewed-by: Takuto Ikuta <tikuta@google.com>
Commit-Queue: Andrew Grieve <agrieve@google.com>
Reviewed-by: David Turner <digit@google.com>
diff --git a/src/gn/analyzer_unittest.cc b/src/gn/analyzer_unittest.cc
index dfd1486..5952562 100644
--- a/src/gn/analyzer_unittest.cc
+++ b/src/gn/analyzer_unittest.cc
@@ -15,6 +15,7 @@
#include "gn/source_file.h"
#include "gn/substitution_list.h"
#include "gn/target.h"
+#include "gn/test_with_scheduler.h"
#include "gn/tool.h"
#include "gn/toolchain.h"
#include "util/test/test.h"
@@ -43,7 +44,7 @@
~MockLoader() override = default;
};
-class AnalyzerTest : public testing::Test {
+class AnalyzerTest : public TestWithScheduler {
public:
AnalyzerTest()
: loader_(new MockLoader),
@@ -90,6 +91,8 @@
void RunAnalyzerTest(const std::string& input,
const std::string& expected_output) {
+ // Wait for any async OnResolve() to happen.
+ scheduler().Run();
Analyzer analyzer(builder_, SourceFile("//build/config/BUILDCONFIG.gn"),
SourceFile("//.gn"),
{SourceFile("//out/debug/args.gn"),
diff --git a/src/gn/builder.cc b/src/gn/builder.cc
index 1f3ecd8..17f5101 100644
--- a/src/gn/builder.cc
+++ b/src/gn/builder.cc
@@ -497,6 +497,7 @@
if (record->type() == BuilderRecord::ITEM_TARGET) {
Target* target = record->item()->AsTarget();
+ // All deps must be resolved before OnResolved can be called.
if (!ResolveDeps(&target->public_deps(), err) ||
!ResolveDeps(&target->private_deps(), err) ||
!ResolveDeps(&target->data_deps(), err) ||
@@ -505,6 +506,10 @@
!ResolveConfigs(&target->public_configs(), err) ||
!ResolvePool(target, err) || !ResolveToolchain(target, err))
return false;
+
+ // Offload Target::OnResolved to a worker thread.
+ ScheduleTargetOnResolve(record);
+ return true;
} else if (record->type() == BuilderRecord::ITEM_CONFIG) {
Config* config = record->item()->AsConfig();
if (!ResolveConfigs(&config->configs(), err))
@@ -516,11 +521,44 @@
if (!ResolvePools(toolchain, err))
return false;
}
-
- record->set_resolved(true);
-
if (!record->item()->OnResolved(err))
return false;
+
+ return CompleteItemResolution(record, err);
+}
+
+void Builder::ScheduleTargetOnResolve(BuilderRecord* record) {
+ DCHECK(g_scheduler);
+
+ g_scheduler->IncrementWorkCount();
+ g_scheduler->ScheduleWork([this, record]() {
+ Err err;
+ bool success = record->item()->AsTarget()->OnResolved(&err);
+ DCHECK(success == !err.has_error());
+
+ g_scheduler->task_runner()->PostTask(
+ [this, record, err]() {
+ CompleteAsyncTargetResolution(record, err);
+ });
+ });
+}
+
+void Builder::CompleteAsyncTargetResolution(
+ BuilderRecord* record, const Err& err) {
+ if (err.has_error()) {
+ g_scheduler->FailWithError(err);
+ } else {
+ Err next_err;
+ if (!CompleteItemResolution(record, &next_err)) {
+ g_scheduler->FailWithError(next_err);
+ }
+ }
+ g_scheduler->DecrementWorkCount();
+}
+
+bool Builder::CompleteItemResolution(BuilderRecord* record, Err* err) {
+ record->set_resolved(true);
+
if (record->should_generate() && resolved_and_generated_callback_)
resolved_and_generated_callback_(record);
diff --git a/src/gn/builder.h b/src/gn/builder.h
index a9c01aa..6776363 100644
--- a/src/gn/builder.h
+++ b/src/gn/builder.h
@@ -121,6 +121,9 @@
// This takes a BuilderRecord with resolved dependencies, and fills in the
// target's Label*Vectors with the resolved pointers.
bool ResolveItem(BuilderRecord* record, Err* err);
+ void ScheduleTargetOnResolve(BuilderRecord* record);
+ void CompleteAsyncTargetResolution(BuilderRecord* record, const Err& err);
+ bool CompleteItemResolution(BuilderRecord* record, Err* err);
// Fills in the pointers in the given vector based on the labels. We assume
// that everything should be resolved by this point, so will return an error
diff --git a/src/gn/builder_unittest.cc b/src/gn/builder_unittest.cc
index 59068a6..59b58f8 100644
--- a/src/gn/builder_unittest.cc
+++ b/src/gn/builder_unittest.cc
@@ -166,6 +166,7 @@
b->set_output_type(Target::SHARED_LIBRARY);
b->visibility().SetPublic();
builder_.ItemDefined(std::unique_ptr<Item>(b));
+ scheduler().Run();
// B depends only on the already-loaded C and toolchain so we shouldn't have
// requested anything else.
@@ -253,6 +254,7 @@
a->public_deps().push_back(LabelTargetPair(b_label));
a->set_output_type(Target::EXECUTABLE);
builder_.ItemDefined(std::unique_ptr<Item>(a));
+ scheduler().Run();
// A should have the generate bit set since it's in the default toolchain.
BuilderRecord* a_record = builder_.GetRecord(a_label);
@@ -290,6 +292,7 @@
Target* b = new Target(&settings2, b_label);
b->set_output_type(Target::EXECUTABLE);
+ b->visibility().SetPublic(); // Allow 'a' to depend on 'b'
b->gen_deps().push_back(LabelTargetPair(c_label));
builder_.ItemDefined(std::unique_ptr<Item>(b));
@@ -305,6 +308,7 @@
Target* d = new Target(&settings2, d_label);
d->set_output_type(Target::EXECUTABLE);
builder_.ItemDefined(std::unique_ptr<Item>(d));
+ scheduler().Run();
BuilderRecord* a_record = builder_.GetRecord(a_label);
BuilderRecord* b_record = builder_.GetRecord(b_label);
@@ -335,12 +339,14 @@
Target* a = new Target(&settings_, a_label);
a->gen_deps().push_back(LabelTargetPair(b_label));
a->set_output_type(Target::EXECUTABLE);
+ a->visibility().SetPublic(); // Allow 'b' to depend on 'a'
builder_.ItemDefined(std::unique_ptr<Item>(a));
Target* b = new Target(&settings2, b_label);
b->private_deps().push_back(LabelTargetPair(a_label));
b->set_output_type(Target::EXECUTABLE);
builder_.ItemDefined(std::unique_ptr<Item>(b));
+ scheduler().Run();
Err err;
EXPECT_TRUE(builder_.CheckForBadItems(&err));
diff --git a/src/gn/item.h b/src/gn/item.h
index dd1a606..4a6e193 100644
--- a/src/gn/item.h
+++ b/src/gn/item.h
@@ -69,6 +69,7 @@
// Called when this item is resolved, meaning it and all of its dependents
// have no unresolved deps. Returns true on success. Sets the error and
// returns false on failure.
+ // Can be called from any thread, so must not mutate dependencies.
virtual bool OnResolved(Err* err);
private:
diff --git a/src/gn/scheduler.cc b/src/gn/scheduler.cc
index 6525f33..9265b51 100644
--- a/src/gn/scheduler.cc
+++ b/src/gn/scheduler.cc
@@ -25,6 +25,19 @@
}
bool Scheduler::Run() {
+ // Reentrancy check.
+ CHECK(!is_running_);
+
+ // Ensure there is at least one task, (or else this will wait forever).
+ if (is_failed_ || (work_count_.IsZero() && pool_work_count_.IsZero())) {
+ // Flush any posted tasks (that were posted from the UI thread).
+ main_thread_run_loop_->PostQuit();
+ main_thread_run_loop_->Run();
+ return is_failed_;
+ }
+
+ has_been_shutdown_ = false;
+ is_running_ = true;
main_thread_run_loop_->Run();
bool local_is_failed;
{
@@ -35,6 +48,7 @@
// Don't do this while holding |lock_|, since it will block on the workers,
// which may be in turn waiting on the lock.
WaitForPoolTasks();
+ is_running_ = false;
return !local_is_failed;
}
diff --git a/src/gn/scheduler.h b/src/gn/scheduler.h
index cf29fe8..b90814f 100644
--- a/src/gn/scheduler.h
+++ b/src/gn/scheduler.h
@@ -140,6 +140,9 @@
// loop.
bool has_been_shutdown_ = false;
+ // Prevent reentrancy.
+ bool is_running_ = false;
+
// Protected by the lock. See the corresponding Add/Get functions above.
std::vector<base::FilePath> gen_dependencies_;
std::vector<SourceFile> written_files_;
