v8/test/cctest/cctest.cc
Alex Kodat 76217f5708 [cpu-profiler] Ensure sampled thread has Isolate lock under Windows
While the sampler checked if the sampled thread had the Isolate locked
(if locks are being used) under Linux, the check was not done under
Windows (or Fuchsia) which meant that in a multi-threading application
under Windows, thread locking was not checked making it prone to seg
faults and the like as the profiler would be using isolate->js_entry_sp
to determine the stack to walk but isolate->js_entry_sp is the stack
pointer for the thread that currently has the Isolate lock so, if the
sampled thread does not have the lock, the sampler woud be iterating
over the wrong stack, one that might actually be actively changing on
another thread. The fix was to move the lock check into CpuSampler
and Ticker (--prof) so all OSes would do the correct check.

The basic concept is that on all operating systems a CpuProfiler, and
so its corresponding CpuCampler, the profiler is tied to a thread.
This is not based on first principles or anything, it's simply the
way it works in V8, though it is a useful conceit as it makes
visualization and interpretation of profile data much easier.

To collect a sample on a thread associated with a profiler the thread
must be stopped for obvious reasons -- walking the stack of a running
thread is a formula for disaster. The mechanism for stopping a thread
is OS-specific and is done in sample.cc. There are currently three
basic approaches, one for Linux/Unix variants, one for Windows and one
for Fuchsia. The approaches vary as to which thread actually collects
the sample -- under Linux the sample is actually collected on the
(interrupted) sampled thread whereas under Fuchsia/Windows it's on
a separate thread.

However, in a multi-threaded environment (where Locker is used), it's
not sufficient for the sampled thread to be stopped. Because the stack
walk involves looking in the Isolate heap, no other thread can be
messing with the heap while the sample is collected. The only ways to
ensure this would be to either stop all threads whenever collecting a
sample, or to ensure that the thread being sampled holds the Isolate
lock so prevents other threads from messing with the heap. While there
might be something to be said for the "stop all threads" approach, the
current approach in V8 is to only stop the sampled thread so, if in a
multi-threaded environment, the profiler must check if the thread being
sampled holds the Isolate lock.

Since this check must be done, independent of which thread the sample
is being collected on (since it varies from OS to OS), the approach is
to save the thread id of the thread to be profiled/sampled when the
CpuSampler is instantiated (on all OSes it is instantiated on the
sampled thread) and then check that thread id against the Isolate lock
holder thread id before collecting a sample. If it matches, we know
sample.cc has stop the sampled thread, one way or another, and we know
that no other thread can mess with the heap (since the stopped thread
holds the Isolate lock) so it's safe to walk the stack and collect data
from the heap so the sample can be taken. It it doesn't match, we can't
safely collect the sample so we don't.

Bug: v8:10850
Change-Id: Iba6cabcd3e11a19c261c004103e37e806934dc6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2411343
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69952}
2020-09-16 16:17:39 +00:00

409 lines
14 KiB
C++

// Copyright 2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "test/cctest/cctest.h"
#include "include/libplatform/libplatform.h"
#include "include/v8.h"
#include "src/codegen/compiler.h"
#include "src/codegen/optimized-compilation-info.h"
#include "src/compiler/pipeline.h"
#include "src/debug/debug.h"
#include "src/flags/flags.h"
#include "src/objects/objects-inl.h"
#include "src/trap-handler/trap-handler.h"
#include "test/cctest/print-extension.h"
#include "test/cctest/profiler-extension.h"
#include "test/cctest/trace-extension.h"
#ifdef V8_USE_PERFETTO
#include "src/tracing/trace-event.h"
#endif // V8_USE_PERFETTO
#if V8_OS_WIN
#include <windows.h> // NOLINT
#if V8_CC_MSVC
#include <crtdbg.h>
#endif
#endif
enum InitializationState { kUnset, kUninitialized, kInitialized };
static InitializationState initialization_state_ = kUnset;
static bool disable_automatic_dispose_ = false;
CcTest* CcTest::last_ = nullptr;
bool CcTest::initialize_called_ = false;
v8::base::Atomic32 CcTest::isolate_used_ = 0;
v8::ArrayBuffer::Allocator* CcTest::allocator_ = nullptr;
v8::Isolate* CcTest::isolate_ = nullptr;
CcTest::CcTest(TestFunction* callback, const char* file, const char* name,
bool enabled, bool initialize)
: callback_(callback),
name_(name),
enabled_(enabled),
initialize_(initialize),
prev_(last_) {
// Find the base name of this test (const_cast required on Windows).
char *basename = strrchr(const_cast<char *>(file), '/');
if (!basename) {
basename = strrchr(const_cast<char *>(file), '\\');
}
if (!basename) {
basename = v8::internal::StrDup(file);
} else {
basename = v8::internal::StrDup(basename + 1);
}
// Drop the extension, if there is one.
char *extension = strrchr(basename, '.');
if (extension) *extension = 0;
// Install this test in the list of tests
file_ = basename;
prev_ = last_;
last_ = this;
}
void CcTest::Run() {
if (!initialize_) {
CHECK_NE(initialization_state_, kInitialized);
initialization_state_ = kUninitialized;
CHECK_NULL(CcTest::isolate_);
} else {
CHECK_NE(initialization_state_, kUninitialized);
initialization_state_ = kInitialized;
if (isolate_ == nullptr) {
v8::Isolate::CreateParams create_params;
create_params.array_buffer_allocator = allocator_;
isolate_ = v8::Isolate::New(create_params);
}
isolate_->Enter();
}
#ifdef DEBUG
const size_t active_isolates = i::Isolate::non_disposed_isolates();
#endif // DEBUG
callback_();
#ifdef DEBUG
// This DCHECK ensures that all Isolates are properly disposed after finishing
// the test. Stray Isolates lead to stray tasks in the platform which can
// interact weirdly when swapping in new platforms (for testing) or during
// shutdown.
DCHECK_EQ(active_isolates, i::Isolate::non_disposed_isolates());
#endif // DEBUG
if (initialize_) {
if (v8::Locker::IsActive()) {
v8::Locker locker(isolate_);
EmptyMessageQueues(isolate_);
} else {
EmptyMessageQueues(isolate_);
}
isolate_->Exit();
}
}
i::Heap* CcTest::heap() { return i_isolate()->heap(); }
i::ReadOnlyHeap* CcTest::read_only_heap() {
return i_isolate()->read_only_heap();
}
void CcTest::AddGlobalFunction(v8::Local<v8::Context> env, const char* name,
v8::FunctionCallback callback) {
v8::Local<v8::FunctionTemplate> func_template =
v8::FunctionTemplate::New(isolate_, callback);
v8::Local<v8::Function> func =
func_template->GetFunction(env).ToLocalChecked();
func->SetName(v8_str(name));
env->Global()->Set(env, v8_str(name), func).FromJust();
}
void CcTest::CollectGarbage(i::AllocationSpace space, i::Isolate* isolate) {
i::Isolate* iso = isolate ? isolate : i_isolate();
iso->heap()->CollectGarbage(space, i::GarbageCollectionReason::kTesting);
}
void CcTest::CollectAllGarbage(i::Isolate* isolate) {
i::Isolate* iso = isolate ? isolate : i_isolate();
iso->heap()->CollectAllGarbage(i::Heap::kNoGCFlags,
i::GarbageCollectionReason::kTesting);
}
void CcTest::CollectAllAvailableGarbage(i::Isolate* isolate) {
i::Isolate* iso = isolate ? isolate : i_isolate();
iso->heap()->CollectAllAvailableGarbage(i::GarbageCollectionReason::kTesting);
}
void CcTest::PreciseCollectAllGarbage(i::Isolate* isolate) {
i::Isolate* iso = isolate ? isolate : i_isolate();
iso->heap()->PreciseCollectAllGarbage(i::Heap::kNoGCFlags,
i::GarbageCollectionReason::kTesting);
}
i::Handle<i::String> CcTest::MakeString(const char* str) {
i::Isolate* isolate = CcTest::i_isolate();
i::Factory* factory = isolate->factory();
return factory->InternalizeUtf8String(str);
}
i::Handle<i::String> CcTest::MakeName(const char* str, int suffix) {
i::EmbeddedVector<char, 128> buffer;
SNPrintF(buffer, "%s%d", str, suffix);
return CcTest::MakeString(buffer.begin());
}
v8::base::RandomNumberGenerator* CcTest::random_number_generator() {
return InitIsolateOnce()->random_number_generator();
}
v8::Local<v8::Object> CcTest::global() {
return isolate()->GetCurrentContext()->Global();
}
void CcTest::InitializeVM() {
CHECK(!v8::base::Relaxed_Load(&isolate_used_));
CHECK(!initialize_called_);
initialize_called_ = true;
v8::HandleScope handle_scope(CcTest::isolate());
v8::Context::New(CcTest::isolate())->Enter();
}
void CcTest::TearDown() {
if (isolate_ != nullptr) isolate_->Dispose();
}
v8::Local<v8::Context> CcTest::NewContext(CcTestExtensionFlags extension_flags,
v8::Isolate* isolate) {
const char* extension_names[kMaxExtensions];
int extension_count = 0;
for (int i = 0; i < kMaxExtensions; ++i) {
if (!extension_flags.contains(static_cast<CcTestExtensionId>(i))) continue;
extension_names[extension_count] = kExtensionName[i];
++extension_count;
}
v8::ExtensionConfiguration config(extension_count, extension_names);
v8::Local<v8::Context> context = v8::Context::New(isolate, &config);
CHECK(!context.IsEmpty());
return context;
}
void CcTest::DisableAutomaticDispose() {
CHECK_EQ(kUninitialized, initialization_state_);
disable_automatic_dispose_ = true;
}
LocalContext::~LocalContext() {
v8::HandleScope scope(isolate_);
v8::Local<v8::Context>::New(isolate_, context_)->Exit();
context_.Reset();
}
void LocalContext::Initialize(v8::Isolate* isolate,
v8::ExtensionConfiguration* extensions,
v8::Local<v8::ObjectTemplate> global_template,
v8::Local<v8::Value> global_object) {
v8::HandleScope scope(isolate);
v8::Local<v8::Context> context =
v8::Context::New(isolate, extensions, global_template, global_object);
context_.Reset(isolate, context);
context->Enter();
// We can't do this later perhaps because of a fatal error.
isolate_ = isolate;
}
// This indirection is needed because HandleScopes cannot be heap-allocated, and
// we don't want any unnecessary #includes in cctest.h.
class InitializedHandleScopeImpl {
public:
explicit InitializedHandleScopeImpl(i::Isolate* isolate)
: handle_scope_(isolate) {}
private:
i::HandleScope handle_scope_;
};
InitializedHandleScope::InitializedHandleScope()
: main_isolate_(CcTest::InitIsolateOnce()),
initialized_handle_scope_impl_(
new InitializedHandleScopeImpl(main_isolate_)) {}
InitializedHandleScope::~InitializedHandleScope() = default;
HandleAndZoneScope::HandleAndZoneScope(bool support_zone_compression)
: main_zone_(
new i::Zone(&allocator_, ZONE_NAME, support_zone_compression)) {}
HandleAndZoneScope::~HandleAndZoneScope() = default;
i::Handle<i::JSFunction> Optimize(
i::Handle<i::JSFunction> function, i::Zone* zone, i::Isolate* isolate,
uint32_t flags, std::unique_ptr<i::compiler::JSHeapBroker>* out_broker) {
i::Handle<i::SharedFunctionInfo> shared(function->shared(), isolate);
i::IsCompiledScope is_compiled_scope(shared->is_compiled_scope(isolate));
CHECK(is_compiled_scope.is_compiled() ||
i::Compiler::Compile(function, i::Compiler::CLEAR_EXCEPTION,
&is_compiled_scope));
CHECK_NOT_NULL(zone);
i::OptimizedCompilationInfo info(zone, isolate, shared, function,
i::CodeKind::OPTIMIZED_FUNCTION);
if (flags & i::OptimizedCompilationInfo::kInlining) {
info.set_inlining();
}
CHECK(info.shared_info()->HasBytecodeArray());
i::JSFunction::EnsureFeedbackVector(function, &is_compiled_scope);
i::Handle<i::Code> code =
i::compiler::Pipeline::GenerateCodeForTesting(&info, isolate, out_broker)
.ToHandleChecked();
info.native_context().AddOptimizedCode(*code);
function->set_code(*code);
return function;
}
static void PrintTestList(CcTest* current) {
if (current == nullptr) return;
PrintTestList(current->prev());
printf("%s/%s\n", current->file(), current->name());
}
static void SuggestTestHarness(int tests) {
if (tests == 0) return;
printf("Running multiple tests in sequence is deprecated and may cause "
"bogus failure. Consider using tools/run-tests.py instead.\n");
}
int main(int argc, char* argv[]) {
#if V8_OS_WIN
UINT new_flags =
SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX | SEM_NOOPENFILEERRORBOX;
UINT existing_flags = SetErrorMode(new_flags);
SetErrorMode(existing_flags | new_flags);
#if V8_CC_MSVC
_CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
_CrtSetReportFile(_CRT_WARN, _CRTDBG_FILE_STDERR);
_CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
_CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
_CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_DEBUG | _CRTDBG_MODE_FILE);
_CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDERR);
_set_error_mode(_OUT_TO_STDERR);
#endif // V8_CC_MSVC
#endif // V8_OS_WIN
std::string usage = "Usage: " + std::string(argv[0]) + " [--list]" +
" [[V8_FLAGS] CCTEST]\n\n" + "Options:\n" +
" --list: list all cctests\n" +
" CCTEST: cctest identfier returned by --list\n" +
" V8_FLAGS: see V8 options below\n\n\n";
#ifdef V8_USE_PERFETTO
// Set up the in-process backend that the tracing controller will connect to.
perfetto::TracingInitArgs init_args;
init_args.backends = perfetto::BackendType::kInProcessBackend;
perfetto::Tracing::Initialize(init_args);
#endif // V8_USE_PERFETTO
v8::V8::InitializeICUDefaultLocation(argv[0]);
std::unique_ptr<v8::Platform> platform(v8::platform::NewDefaultPlatform());
v8::V8::InitializePlatform(platform.get());
using HelpOptions = v8::internal::FlagList::HelpOptions;
v8::internal::FlagList::SetFlagsFromCommandLine(
&argc, argv, true, HelpOptions(HelpOptions::kExit, usage.c_str()));
v8::V8::Initialize();
v8::V8::InitializeExternalStartupData(argv[0]);
if (V8_TRAP_HANDLER_SUPPORTED && i::FLAG_wasm_trap_handler) {
constexpr bool use_default_signal_handler = true;
CHECK(v8::V8::EnableWebAssemblyTrapHandler(use_default_signal_handler));
}
CcTest::set_array_buffer_allocator(
v8::ArrayBuffer::Allocator::NewDefaultAllocator());
v8::RegisterExtension(std::make_unique<i::PrintExtension>());
v8::RegisterExtension(std::make_unique<i::ProfilerExtension>());
v8::RegisterExtension(std::make_unique<i::TraceExtension>());
int tests_run = 0;
bool print_run_count = true;
for (int i = 1; i < argc; i++) {
char* arg = argv[i];
if (strcmp(arg, "--list") == 0) {
PrintTestList(CcTest::last());
print_run_count = false;
} else {
char* arg_copy = v8::internal::StrDup(arg);
char* testname = strchr(arg_copy, '/');
if (testname) {
// Split the string in two by nulling the slash and then run
// exact matches.
*testname = 0;
char* file = arg_copy;
char* name = testname + 1;
CcTest* test = CcTest::last();
while (test != nullptr) {
if (test->enabled()
&& strcmp(test->file(), file) == 0
&& strcmp(test->name(), name) == 0) {
SuggestTestHarness(tests_run++);
test->Run();
}
test = test->prev();
}
} else {
// Run all tests with the specified file or test name.
char* file_or_name = arg_copy;
CcTest* test = CcTest::last();
while (test != nullptr) {
if (test->enabled()
&& (strcmp(test->file(), file_or_name) == 0
|| strcmp(test->name(), file_or_name) == 0)) {
SuggestTestHarness(tests_run++);
test->Run();
}
test = test->prev();
}
}
v8::internal::DeleteArray<char>(arg_copy);
}
}
if (print_run_count && tests_run != 1)
printf("Ran %i tests.\n", tests_run);
CcTest::TearDown();
if (!disable_automatic_dispose_) v8::V8::Dispose();
v8::V8::ShutdownPlatform();
return 0;
}
RegisterThreadedTest* RegisterThreadedTest::first_ = nullptr;
int RegisterThreadedTest::count_ = 0;