v8/test/unittests/api/deserialize-unittest.cc
Seth Brenith 766b2a4d52 Reland "Background merging of deserialized scripts"
This is a reland of commit e895b7af73

The unit test has been updated to work correctly when
--stress-incremental-marking is enabled.

Original change's description:
> Background merging of deserialized scripts
>
> Recently, https://crrev.com/c/v8/v8/+/3681880 added new API functions
> with which an embedder could request that V8 merge newly deserialized
> script data into an existing Script from the Isolate's compilation
> cache. This change implements those new functions. This functionality is
> still disabled by default due to the flag
> merge_background_deserialized_script_with_compilation_cache.
>
> The goal of this new functionality is to reduce memory usage when
> multiple frames load the same script with a long delay between (long
> enough for the script to have been evicted from Blink's in-memory cache
> and for the top-level SharedFunctionInfo to be flushed). In that case,
> there are two Script objects for the same script: one which was found in
> the Isolate compilation cache (the "old" script), and one which was
> recently deserialized (the "new" script). The new script's object graph
> is essentially standalone: it may point to internalized strings and
> readonly objects such as the empty feedback metadata, but otherwise
> it is unconnected to the rest of the heap. The merging logic takes any
> useful data from the new script's object graph and attaches it into the
> old script's object graph, so that the new Script object and any other
> duplicated objects can be discarded. More specifically:
>
> 1. If the new Script has a SharedFunctionInfo for a particular function
>    literal, and the old Script does not, then the old Script is updated
>    to refer to the new SharedFunctionInfo.
> 2. If the new Script has a compiled SharedFunctionInfo for a particular
>    function literal, and the old Script has an uncompiled
>    SharedFunctionInfo, then the old SharedFunctionInfo is updated to
>    point to the function_data and feedback_metadata from the new
>    SharedFunctionInfo.
> 3. If any used object from the new object graph points to a
>    SharedFunctionInfo, where the old object graph contains a matching
>    SharedFunctionInfo for the same function literal, then that pointer
>    is updated to point to the old SharedFunctionInfo.
>
> The document at [0] includes diagrams showing an example merge on a very
> small script.
>
> Steps 1 and 2 above are pretty simple, but step 3 requires walking a
> possibly large set of objects, so this new API lets the embedder run
> step 3 from a background thread. Steps 1 and 2 are performed later, on
> the main thread.
>
> The next important question is: in what ways can the old script's object
> graph be modified during the background execution of step 3, or during
> the time after step 3 but before steps 1 and 2?
>
> A. SharedFunctionInfos can go from compiled to uncompiled due to
>    flushing. This is okay; the worst outcome is that the function would
>    need to be compiled again later. Such a risk is already present,
>    since V8 doesn't keep IsCompiledScopes for every compiled function in
>    a background-deserialized script.
> B. SharedFunctionInfos can go from uncompiled to compiled due to lazy
>    compilation. This is also okay; the merge completion logic on the
>    main thread will just keep this lazily compiled data rather than
>    inserting compiled data from the newly deserialized object graph.
> C. SharedFunctionInfos can be cleared from the Script's weak array if
>    they are no longer referenced. This is mostly okay, because any
>    SharedFunctionInfo that is needed by the background merge is strongly
>    referenced and therefore can't be cleared. The only problem arises if
>    the top-level SharedFunctionInfo gets cleared, so the merge task must
>    deliberately keep a reference to that one.
> D. SharedFunctionInfos can be created if they are needed due to lazy
>    compilation of a parent function. This change is somewhat troublesome
>    because it invalidates the background thread's work and requires a
>    re-traversal on the main thread to update any pointers that should
>    point to this lazily compiled SharedFunctionInfo.
>
> At a high level, this change implements three previously unimplemented
> functions in BackgroundDeserializeTask (in compiler.cc) and updates one:
>
> - BackgroundDeserializeTask::SourceTextAvailable, run on the main
>   thread, checks whether there is a matching Script in the Isolate
>   compilation cache which doesn't already have a top-level
>   SharedFunctionInfo. If so, it saves that Script in a persistent
>   handle.
> - BackgroundDeserializeTask::ShouldMergeWithExistingScript checks
>   whether the persistent handle from the first step exists (a fast
>   operation which can be called from any thread).
> - BackgroundDeserializeTask::MergeWithExistingScript, run on a
>   background thread, performs step 3 of the merge described above and
>   generates lists of persistent data describing how the main thread can
>   complete the merge.
> - BackgroundDeserializeTask::Finish is updated to perform the merge
>   steps 1 and 2 listed above, as well as a possible re-traversal of the
>   graph if required due to newly created SharedFunctionInfos in the old
>   Script.
>
> The merge logic has nothing to do with deserialization, and indeed I
> hope to reuse it for background compilation tasks as well, so it is all
> contained within a new class BackgroundMergeTask (in compiler.h,cc). It
> uses a second class, ForwardPointersVisitor (in compiler.cc) to perform
> the object visitation that updates pointers to SharedFunctionInfos.
>
> [0] https://docs.google.com/document/d/1UksB5Vm7TT1-f3S9W1dK_rP9jKn_ly0WVm_UDPpWuBw/edit
>
> Bug: v8:12808
> Change-Id: Id405869e9d5b106ca7afd9c4b08cb5813e6852c6
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3739232
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/main@{#81941}

Bug: v8:12808
Change-Id: Id2036dfa4eba8670cac899773d7a906825fa2c50
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3787266
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#82045}
2022-07-28 17:02:55 +00:00

621 lines
25 KiB
C++

// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "include/v8-context.h"
#include "include/v8-function.h"
#include "include/v8-isolate.h"
#include "include/v8-local-handle.h"
#include "include/v8-platform.h"
#include "include/v8-primitive.h"
#include "include/v8-script.h"
#include "test/unittests/test-utils.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace v8 {
class DeserializeTest : public TestWithPlatform {
public:
class IsolateAndContextScope {
public:
explicit IsolateAndContextScope(DeserializeTest* test)
: test_(test),
isolate_wrapper_(kNoCounters),
isolate_scope_(isolate_wrapper_.isolate()),
handle_scope_(isolate_wrapper_.isolate()),
context_(Context::New(isolate_wrapper_.isolate())),
context_scope_(context_) {
CHECK_NULL(test->isolate_);
CHECK(test->context_.IsEmpty());
test->isolate_ = isolate_wrapper_.isolate();
test->context_ = context_;
}
~IsolateAndContextScope() {
test_->isolate_ = nullptr;
test_->context_ = {};
}
private:
DeserializeTest* test_;
v8::IsolateWrapper isolate_wrapper_;
v8::Isolate::Scope isolate_scope_;
v8::HandleScope handle_scope_;
v8::Local<v8::Context> context_;
v8::Context::Scope context_scope_;
};
Local<String> NewString(const char* val) {
return String::NewFromUtf8(isolate(), val).ToLocalChecked();
}
Local<Value> RunGlobalFunc(const char* name) {
Local<Value> func_val =
context()->Global()->Get(context(), NewString(name)).ToLocalChecked();
CHECK(func_val->IsFunction());
Local<Function> func = Local<Function>::Cast(func_val);
return func->Call(context(), Undefined(isolate()), 0, nullptr)
.ToLocalChecked();
}
Isolate* isolate() { return isolate_; }
v8::Local<v8::Context> context() { return context_.ToLocalChecked(); }
private:
Isolate* isolate_ = nullptr;
v8::MaybeLocal<v8::Context> context_;
};
// Check that deserialization works.
TEST_F(DeserializeTest, Deserialize) {
std::unique_ptr<v8::ScriptCompiler::CachedData> cached_data;
{
IsolateAndContextScope scope(this);
Local<String> source_code = NewString("function foo() { return 42; }");
Local<Script> script =
Script::Compile(context(), source_code).ToLocalChecked();
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("foo"), Integer::New(isolate(), 42));
cached_data.reset(
ScriptCompiler::CreateCodeCache(script->GetUnboundScript()));
}
{
IsolateAndContextScope scope(this);
Local<String> source_code = NewString("function foo() { return 42; }");
ScriptCompiler::Source source(source_code, cached_data.release());
Local<Script> script =
ScriptCompiler::Compile(context(), &source,
ScriptCompiler::kConsumeCodeCache)
.ToLocalChecked();
CHECK(!source.GetCachedData()->rejected);
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("foo"), v8::Integer::New(isolate(), 42));
}
}
// Check that deserialization with a different script rejects the cache but
// still works via standard compilation.
TEST_F(DeserializeTest, DeserializeRejectsDifferentSource) {
std::unique_ptr<v8::ScriptCompiler::CachedData> cached_data;
{
IsolateAndContextScope scope(this);
Local<String> source_code = NewString("function foo() { return 42; }");
Local<Script> script =
Script::Compile(context(), source_code).ToLocalChecked();
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("foo"), Integer::New(isolate(), 42));
cached_data.reset(
ScriptCompiler::CreateCodeCache(script->GetUnboundScript()));
}
{
IsolateAndContextScope scope(this);
// The source hash is based on the source length, so have to make sure that
// this is different here.
Local<String> source_code = NewString("function bar() { return 142; }");
ScriptCompiler::Source source(source_code, cached_data.release());
Local<Script> script =
ScriptCompiler::Compile(context(), &source,
ScriptCompiler::kConsumeCodeCache)
.ToLocalChecked();
CHECK(source.GetCachedData()->rejected);
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("bar"), v8::Integer::New(isolate(), 142));
}
}
class DeserializeThread : public base::Thread {
public:
explicit DeserializeThread(ScriptCompiler::ConsumeCodeCacheTask* task)
: Thread(base::Thread::Options("DeserializeThread")), task_(task) {}
void Run() override { task_->Run(); }
std::unique_ptr<ScriptCompiler::ConsumeCodeCacheTask> TakeTask() {
return std::move(task_);
}
private:
std::unique_ptr<ScriptCompiler::ConsumeCodeCacheTask> task_;
};
// Check that off-thread deserialization works.
TEST_F(DeserializeTest, OffThreadDeserialize) {
std::unique_ptr<v8::ScriptCompiler::CachedData> cached_data;
{
IsolateAndContextScope scope(this);
Local<String> source_code = NewString("function foo() { return 42; }");
Local<Script> script =
Script::Compile(context(), source_code).ToLocalChecked();
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("foo"), Integer::New(isolate(), 42));
cached_data.reset(
ScriptCompiler::CreateCodeCache(script->GetUnboundScript()));
}
{
IsolateAndContextScope scope(this);
DeserializeThread deserialize_thread(
ScriptCompiler::StartConsumingCodeCache(
isolate(), std::make_unique<ScriptCompiler::CachedData>(
cached_data->data, cached_data->length,
ScriptCompiler::CachedData::BufferNotOwned)));
CHECK(deserialize_thread.Start());
deserialize_thread.Join();
Local<String> source_code = NewString("function foo() { return 42; }");
ScriptCompiler::Source source(source_code, cached_data.release(),
deserialize_thread.TakeTask().release());
Local<Script> script =
ScriptCompiler::Compile(context(), &source,
ScriptCompiler::kConsumeCodeCache)
.ToLocalChecked();
CHECK(!source.GetCachedData()->rejected);
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("foo"), v8::Integer::New(isolate(), 42));
}
}
// Check that off-thread deserialization works.
TEST_F(DeserializeTest, OffThreadDeserializeRejectsDifferentSource) {
std::unique_ptr<v8::ScriptCompiler::CachedData> cached_data;
{
IsolateAndContextScope scope(this);
Local<String> source_code = NewString("function foo() { return 42; }");
Local<Script> script =
Script::Compile(context(), source_code).ToLocalChecked();
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("foo"), Integer::New(isolate(), 42));
cached_data.reset(
ScriptCompiler::CreateCodeCache(script->GetUnboundScript()));
}
{
IsolateAndContextScope scope(this);
DeserializeThread deserialize_thread(
ScriptCompiler::StartConsumingCodeCache(
isolate(), std::make_unique<ScriptCompiler::CachedData>(
cached_data->data, cached_data->length,
ScriptCompiler::CachedData::BufferNotOwned)));
CHECK(deserialize_thread.Start());
deserialize_thread.Join();
Local<String> source_code = NewString("function bar() { return 142; }");
ScriptCompiler::Source source(source_code, cached_data.release(),
deserialize_thread.TakeTask().release());
Local<Script> script =
ScriptCompiler::Compile(context(), &source,
ScriptCompiler::kConsumeCodeCache)
.ToLocalChecked();
CHECK(source.GetCachedData()->rejected);
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("bar"), v8::Integer::New(isolate(), 142));
}
}
class MergeDeserializedCodeTest : public DeserializeTest {
protected:
// The source code used in these tests.
static constexpr char kSourceCode[] = R"(
// Looks like an IIFE but isn't, to get eagerly parsed:
var eager = (function () {
// Actual IIFE, also eagerly parsed:
return (function iife() {
return 42;
})();
});
// Lazily parsed:
var lazy = function () { return eager(); };
)";
// Objects from the Script's object graph whose lifetimes and connectedness
// are useful to track.
enum ScriptObject {
kScript,
kToplevelSfi,
kToplevelFunctionData,
kToplevelFeedbackMetadata,
kEagerSfi,
kEagerFunctionData,
kEagerFeedbackMetadata,
kIifeSfi,
kIifeFunctionData,
kIifeFeedbackMetadata,
kLazySfi,
kScriptObjectsCount
};
enum ScriptObjectFlag {
kNone,
kScriptFlag = 1 << kScript,
kToplevelSfiFlag = 1 << kToplevelSfi,
kToplevelFunctionDataFlag = 1 << kToplevelFunctionData,
kToplevelFeedbackMetadataFlag = 1 << kToplevelFeedbackMetadata,
kEagerSfiFlag = 1 << kEagerSfi,
kEagerFunctionDataFlag = 1 << kEagerFunctionData,
kEagerFeedbackMetadataFlag = 1 << kEagerFeedbackMetadata,
kIifeSfiFlag = 1 << kIifeSfi,
kIifeFunctionDataFlag = 1 << kIifeFunctionData,
kIifeFeedbackMetadataFlag = 1 << kIifeFeedbackMetadata,
kLazySfiFlag = 1 << kLazySfi,
kAllScriptObjects = (1 << kScriptObjectsCount) - 1,
kAllCompiledSfis = kToplevelSfiFlag | kEagerSfiFlag | kIifeSfiFlag,
kAllSfis = kAllCompiledSfis | kLazySfiFlag,
kEagerAndLazy = kLazySfiFlag | kEagerSfiFlag,
kToplevelEagerAndLazy = kToplevelSfiFlag | kEagerAndLazy,
kToplevelAndEager = kToplevelSfiFlag | kEagerSfiFlag,
};
template <typename T>
static i::SharedFunctionInfo GetSharedFunctionInfo(
Local<T> function_or_script) {
i::Handle<i::JSFunction> i_function =
i::Handle<i::JSFunction>::cast(Utils::OpenHandle(*function_or_script));
return i_function->shared();
}
static i::MaybeObject WeakOrSmi(i::Object obj) {
return obj.IsSmi()
? i::MaybeObject::FromSmi(i::Smi::cast(obj))
: i::MaybeObject::MakeWeak(i::MaybeObject::FromObject(obj));
}
void ValidateStandaloneGraphAndPopulateArray(
i::SharedFunctionInfo toplevel_sfi, i::WeakFixedArray array,
bool lazy_should_be_compiled = false,
bool eager_should_be_compiled = true) {
i::DisallowGarbageCollection no_gc;
CHECK(toplevel_sfi.is_compiled());
array.Set(kToplevelSfi, WeakOrSmi(toplevel_sfi));
array.Set(kToplevelFunctionData,
WeakOrSmi(toplevel_sfi.function_data(kAcquireLoad)));
array.Set(kToplevelFeedbackMetadata,
WeakOrSmi(toplevel_sfi.feedback_metadata()));
i::Script script = i::Script::cast(toplevel_sfi.script());
array.Set(kScript, WeakOrSmi(script));
i::WeakFixedArray sfis = script.shared_function_infos();
CHECK_EQ(sfis.length(), 4);
CHECK_EQ(sfis.Get(0), WeakOrSmi(toplevel_sfi));
i::SharedFunctionInfo eager =
i::SharedFunctionInfo::cast(sfis.Get(1).GetHeapObjectAssumeWeak());
CHECK_EQ(eager.is_compiled(), eager_should_be_compiled);
array.Set(kEagerSfi, WeakOrSmi(eager));
if (eager_should_be_compiled) {
array.Set(kEagerFunctionData,
WeakOrSmi(eager.function_data(kAcquireLoad)));
array.Set(kEagerFeedbackMetadata, WeakOrSmi(eager.feedback_metadata()));
i::SharedFunctionInfo iife =
i::SharedFunctionInfo::cast(sfis.Get(2).GetHeapObjectAssumeWeak());
CHECK(iife.is_compiled());
array.Set(kIifeSfi, WeakOrSmi(iife));
array.Set(kIifeFunctionData, WeakOrSmi(iife.function_data(kAcquireLoad)));
array.Set(kIifeFeedbackMetadata, WeakOrSmi(iife.feedback_metadata()));
}
i::SharedFunctionInfo lazy =
i::SharedFunctionInfo::cast(sfis.Get(3).GetHeapObjectAssumeWeak());
CHECK_EQ(lazy.is_compiled(), lazy_should_be_compiled);
array.Set(kLazySfi, WeakOrSmi(lazy));
}
void AgeBytecodeAndGC(ScriptObjectFlag sfis_to_age,
i::Handle<i::WeakFixedArray> original_objects,
i::Isolate* i_isolate) {
for (int index = 0; index < kScriptObjectsCount; ++index) {
if ((sfis_to_age & (1 << index)) == (1 << index)) {
i::BytecodeArray bytecode =
i::SharedFunctionInfo::cast(
original_objects->Get(index).GetHeapObjectAssumeWeak())
.GetBytecodeArray(i_isolate);
const int kAgingThreshold = 6;
for (int j = 0; j < kAgingThreshold; ++j) {
bytecode.MakeOlder();
}
}
}
i_isolate->heap()->CollectAllGarbage(i::Heap::kNoGCFlags,
i::GarbageCollectionReason::kTesting);
// A second round of GC is necessary in case incremental marking had already
// started before the bytecode was aged.
i_isolate->heap()->CollectAllGarbage(i::Heap::kNoGCFlags,
i::GarbageCollectionReason::kTesting);
}
class MergeThread : public base::Thread {
public:
explicit MergeThread(ScriptCompiler::ConsumeCodeCacheTask* task)
: Thread(base::Thread::Options("MergeThread")), task_(task) {}
void Run() override { task_->MergeWithExistingScript(); }
private:
ScriptCompiler::ConsumeCodeCacheTask* task_;
};
void RetainObjects(ScriptObjectFlag to_retain,
i::WeakFixedArray original_objects,
i::FixedArray retained_original_objects,
i::Isolate* i_isolate) {
for (int index = 0; index < kScriptObjectsCount; ++index) {
if ((to_retain & (1 << index)) == (1 << index)) {
i::MaybeObject maybe = original_objects.Get(index);
if (i::HeapObject heap_object;
maybe.GetHeapObjectIfWeak(&heap_object)) {
retained_original_objects.set(index, heap_object);
continue;
}
}
retained_original_objects.set(
index, i::ReadOnlyRoots(i_isolate).undefined_value());
}
}
void TestOffThreadMerge(ScriptObjectFlag retained_before_background_merge,
ScriptObjectFlag aged_before_background_merge,
bool run_code_after_background_merge,
ScriptObjectFlag retained_after_background_merge,
ScriptObjectFlag aged_after_background_merge,
bool lazy_should_be_compiled = false,
bool eager_should_be_compiled = true) {
i::FLAG_merge_background_deserialized_script_with_compilation_cache = true;
std::unique_ptr<v8::ScriptCompiler::CachedData> cached_data;
IsolateAndContextScope scope(this);
i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate());
ScriptOrigin default_origin(isolate(), NewString(""));
i::Handle<i::WeakFixedArray> original_objects =
i_isolate->factory()->NewWeakFixedArray(kScriptObjectsCount);
i::Handle<i::FixedArray> retained_original_objects =
i_isolate->factory()->NewFixedArray(kScriptObjectsCount);
i::Handle<i::WeakFixedArray> new_objects =
i_isolate->factory()->NewWeakFixedArray(kScriptObjectsCount);
Local<Script> original_script;
// Compile the script for the first time, to both populate the Isolate
// compilation cache and produce code cache data.
{
v8::EscapableHandleScope handle_scope(isolate());
Local<Script> script =
Script::Compile(context(), NewString(kSourceCode), &default_origin)
.ToLocalChecked();
ValidateStandaloneGraphAndPopulateArray(GetSharedFunctionInfo(script),
*original_objects);
RetainObjects(retained_before_background_merge, *original_objects,
*retained_original_objects, i_isolate);
cached_data.reset(
ScriptCompiler::CreateCodeCache(script->GetUnboundScript()));
if (run_code_after_background_merge) {
// We must retain the v8::Script (a JSFunction) so we can run it later.
original_script = handle_scope.Escape(script);
// It doesn't make any sense to configure a test case which says it
// doesn't want to retain the toplevel SFI but does want to run the
// script later.
CHECK(retained_before_background_merge & kToplevelSfiFlag);
}
}
AgeBytecodeAndGC(aged_before_background_merge, original_objects, i_isolate);
DeserializeThread deserialize_thread(
ScriptCompiler::StartConsumingCodeCache(
isolate(), std::make_unique<ScriptCompiler::CachedData>(
cached_data->data, cached_data->length,
ScriptCompiler::CachedData::BufferNotOwned)));
CHECK(deserialize_thread.Start());
deserialize_thread.Join();
std::unique_ptr<ScriptCompiler::ConsumeCodeCacheTask> task =
deserialize_thread.TakeTask();
task->SourceTextAvailable(isolate(), NewString(kSourceCode),
default_origin);
// If the top-level SFI was retained and not flushed, then no merge is
// necessary because the results from the deserialization will be discarded.
// If nothing at all was retained, then no merge is necessary because the
// original Script is no longer in the compilation cache. Otherwise, a merge
// is necessary.
bool merge_expected =
(retained_before_background_merge != kNone) &&
(!(retained_before_background_merge & kToplevelSfiFlag) ||
(aged_before_background_merge & kToplevelSfiFlag));
CHECK_EQ(merge_expected, task->ShouldMergeWithExistingScript());
if (merge_expected) {
MergeThread merge_thread(task.get());
CHECK(merge_thread.Start());
merge_thread.Join();
}
if (run_code_after_background_merge) {
CHECK(!original_script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("lazy"), v8::Integer::New(isolate(), 42));
ValidateStandaloneGraphAndPopulateArray(
GetSharedFunctionInfo(original_script), *original_objects,
true /*lazy_should_be_compiled*/);
}
RetainObjects(retained_after_background_merge, *original_objects,
*retained_original_objects, i_isolate);
AgeBytecodeAndGC(aged_after_background_merge, original_objects, i_isolate);
ScriptCompiler::Source source(NewString(kSourceCode), default_origin,
cached_data.release(), task.release());
Local<Script> script =
ScriptCompiler::Compile(context(), &source,
ScriptCompiler::kConsumeCodeCache)
.ToLocalChecked();
CHECK(!source.GetCachedData()->rejected);
ValidateStandaloneGraphAndPopulateArray(
GetSharedFunctionInfo(script), *new_objects, lazy_should_be_compiled,
eager_should_be_compiled);
// At this point, the original_objects array might still have pointers to
// some old discarded content, such as UncompiledData from flushed
// functions. GC again to clear it all out.
i_isolate->heap()->CollectAllGarbage(i::Heap::kNoGCFlags,
i::GarbageCollectionReason::kTesting);
// All tracked objects from the original Script should have been reused if
// they're still alive.
for (int index = 0; index < kScriptObjectsCount; ++index) {
if (original_objects->Get(index).IsWeak() &&
new_objects->Get(index).IsWeak()) {
CHECK_EQ(original_objects->Get(index), new_objects->Get(index));
}
}
CHECK(!script->Run(context()).IsEmpty());
CHECK_EQ(RunGlobalFunc("lazy"), v8::Integer::New(isolate(), 42));
}
};
TEST_F(MergeDeserializedCodeTest, NoMergeWhenAlreadyCompiled) {
// Retain everything; age nothing.
TestOffThreadMerge(kAllScriptObjects, // retained_before_background_merge
kNone, // aged_before_background_merge
false, // run_code_after_background_merge
kAllScriptObjects, // retained_after_background_merge
kNone); // aged_after_background_merge
}
TEST_F(MergeDeserializedCodeTest, NoMergeWhenOriginalWasDiscarded) {
// Retain nothing.
TestOffThreadMerge(kNone, // retained_before_background_merge
kNone, // aged_before_background_merge
false, // run_code_after_background_merge
kNone, // retained_after_background_merge
kNone); // aged_after_background_merge
}
TEST_F(MergeDeserializedCodeTest, NoMergeWhenOriginalWasDiscardedLate) {
// The original top-level SFI is retained by the background merge task even
// though other retainers are discarded.
TestOffThreadMerge(kAllScriptObjects, // retained_before_background_merge
kNone, // aged_before_background_merge
false, // run_code_after_background_merge
kNone, // retained_after_background_merge
kNone); // aged_after_background_merge
}
TEST_F(MergeDeserializedCodeTest, MergeIntoFlushedSFIs) {
// Retain all SFIs but age them.
TestOffThreadMerge(kAllSfis, // retained_before_background_merge
kAllCompiledSfis, // aged_before_background_merge
false, // run_code_after_background_merge
kAllSfis, // retained_after_background_merge
kNone); // aged_after_background_merge
}
TEST_F(MergeDeserializedCodeTest, MergeBasic) {
// Retain the eager and lazy functions; discard the top-level SFI.
// This is a common scenario which requires a merge.
TestOffThreadMerge(kEagerAndLazy, // retained_before_background_merge
kToplevelSfiFlag, // aged_before_background_merge
false, // run_code_after_background_merge
kNone, // retained_after_background_merge
kNone); // aged_after_background_merge
}
TEST_F(MergeDeserializedCodeTest, MergeBasicWithFlushing) {
// Retain the eager and lazy functions; discard the top-level SFI.
// Also flush the eager function, which discards the IIFE.
// This is a common scenario which requires a merge.
TestOffThreadMerge(kEagerAndLazy, // retained_before_background_merge
kToplevelAndEager, // aged_before_background_merge
false, // run_code_after_background_merge
kNone, // retained_after_background_merge
kNone); // aged_after_background_merge
}
TEST_F(MergeDeserializedCodeTest, MergeBasicWithLateFlushing) {
// Flush the eager function after the background merge has taken place. In
// this case, the data from the background thread points to the eager SFI but
// not its bytecode, so the end result is that the eager SFI is not compiled
// after completion on the main thread.
TestOffThreadMerge(kEagerAndLazy, // retained_before_background_merge
kToplevelSfiFlag, // aged_before_background_merge
false, // run_code_after_background_merge
kNone, // retained_after_background_merge
kEagerSfiFlag, // aged_after_background_merge
false, // lazy_should_be_compiled
false); // eager_should_be_compiled
}
TEST_F(MergeDeserializedCodeTest, RunScriptButNoReMergeNecessary) {
// The original script is run after the background merge, causing the
// top-level SFI and lazy SFI to become compiled. However, no SFIs are
// created when running the script, so the main thread needn't redo the merge.
TestOffThreadMerge(kToplevelEagerAndLazy, // retained_before_background_merge
kToplevelSfiFlag, // aged_before_background_merge
true, // run_code_after_background_merge
kAllScriptObjects, // retained_after_background_merge
kNone, // aged_after_background_merge
true); // lazy_should_be_compiled
}
TEST_F(MergeDeserializedCodeTest, MainThreadReMerge) {
// By flushing the eager SFI early, we cause the IIFE SFI to disappear
// entirely. When the original script runs after the background merge, the
// IIFE SFI is recreated. Thus, the main thread must redo the merge.
TestOffThreadMerge(kToplevelEagerAndLazy, // retained_before_background_merge
kToplevelAndEager, // aged_before_background_merge
true, // run_code_after_background_merge
kAllScriptObjects, // retained_after_background_merge
kToplevelSfiFlag, // aged_after_background_merge
true); // lazy_should_be_compiled
}
} // namespace v8