Snap for 9671667 from 6ca68eb96d6bdea3f7c565168e5b93ea1a234a33 to mainline-networking-releaseaml_net_331812010aml_net_331710000android13-mainline-networking-release

Change-Id: Ib7f4c5fbfbc6958911550a9cf5e68b545356f6cd

4 files changed, 279 insertions, 24 deletions

diff --git a/libartbase/base/metrics/metrics.h b/libartbase/base/metrics/metrics.h
index 9d92ed904c..fd0ae54dac 100644
--- a/libartbase/base/metrics/metrics.h
+++ b/libartbase/base/metrics/metrics.h
@@ -29,6 +29,7 @@
 
 #include "android-base/logging.h"
 #include "base/bit_utils.h"
+#include "base/macros.h"
 #include "base/time_utils.h"
 #include "tinyxml2.h"
 
@@ -106,6 +107,17 @@ class Runtime;
 struct RuntimeArgumentMap;
 
 namespace metrics {
+template <typename value_t>
+class MetricsBase;
+}  // namespace metrics
+
+namespace gc {
+class HeapTest_GCMetrics_Test;
+template <typename T>
+bool AnyIsNonNull(const metrics::MetricsBase<T>* x, const metrics::MetricsBase<T>* y);
+}  // namespace gc
+
+namespace metrics {
 
 /**
  * An enumeration of all ART counters and histograms.
@@ -285,6 +297,15 @@ class MetricsBase {
  public:
   virtual void Add(value_t value) = 0;
   virtual ~MetricsBase() { }
+
+ private:
+  // Is the metric "null", i.e. never updated or freshly reset?
+  // Used for testing purpose only.
+  virtual bool IsNull() const = 0;
+
+  ART_FRIEND_TEST(gc::HeapTest, GCMetrics);
+  template <typename T>
+  friend bool gc::AnyIsNonNull(const MetricsBase<T>* x, const MetricsBase<T>* y);
 };
 
 template <DatumId counter_type, typename T = uint64_t>
@@ -300,7 +321,9 @@ class MetricsCounter : public MetricsBase<T> {
   }
 
   void AddOne() { Add(1u); }
-  void Add(value_t value) { value_.fetch_add(value, std::memory_order::memory_order_relaxed); }
+  void Add(value_t value) override {
+    value_.fetch_add(value, std::memory_order::memory_order_relaxed);
+  }
 
   void Report(const std::vector<MetricsBackend*>& backends) const {
     for (MetricsBackend* backend : backends) {
@@ -313,6 +336,8 @@ class MetricsCounter : public MetricsBase<T> {
   value_t Value() const { return value_.load(std::memory_order::memory_order_relaxed); }
 
  private:
+  bool IsNull() const override { return Value() == 0; }
+
   std::atomic<value_t> value_;
   static_assert(std::atomic<value_t>::is_always_lock_free);
 
@@ -341,7 +366,7 @@ class MetricsAverage final : public MetricsCounter<datum_id, T> {
   // 1. The metric eventually becomes consistent.
   // 2. For sufficiently large count_, a few data points which are off shouldn't
   // make a huge difference to the reporter.
-  void Add(value_t value) {
+  void Add(value_t value) override {
     MetricsCounter<datum_id, value_t>::Add(value);
     count_.fetch_add(1, std::memory_order::memory_order_release);
   }
@@ -363,6 +388,10 @@ class MetricsAverage final : public MetricsCounter<datum_id, T> {
   }
 
  private:
+  count_t Count() const { return count_.load(std::memory_order::memory_order_relaxed); }
+
+  bool IsNull() const override { return Count() == 0; }
+
   std::atomic<count_t> count_;
   static_assert(std::atomic<count_t>::is_always_lock_free);
 
@@ -397,6 +426,10 @@ class MetricsDeltaCounter : public MetricsBase<T> {
   void Reset() { value_ = 0; }
 
  private:
+  value_t Value() const { return value_.load(std::memory_order::memory_order_relaxed); }
+
+  bool IsNull() const override { return Value() == 0; }
+
   std::atomic<value_t> value_;
   static_assert(std::atomic<value_t>::is_always_lock_free);
 
@@ -422,7 +455,7 @@ class MetricsHistogram final : public MetricsBase<int64_t> {
                   == RoundUp(sizeof(intptr_t) + sizeof(value_t) * num_buckets_, sizeof(uint64_t)));
   }
 
-  void Add(int64_t value) {
+  void Add(int64_t value) override {
     const size_t i = FindBucketId(value);
     buckets_[i].fetch_add(1u, std::memory_order::memory_order_relaxed);
   }
@@ -462,6 +495,11 @@ class MetricsHistogram final : public MetricsBase<int64_t> {
     return std::vector<value_t>{buckets_.begin(), buckets_.end()};
   }
 
+  bool IsNull() const override {
+    std::vector<value_t> buckets = GetBuckets();
+    return std::all_of(buckets.cbegin(), buckets.cend(), [](value_t i) { return i == 0; });
+  }
+
   std::array<std::atomic<value_t>, num_buckets_> buckets_;
   static_assert(std::atomic<value_t>::is_always_lock_free);
 
@@ -479,7 +517,7 @@ class MetricsAccumulator final : MetricsBase<T> {
                   RoundUp(sizeof(intptr_t) + sizeof(T), sizeof(uint64_t)));
   }
 
-  void Add(T value) {
+  void Add(T value) override {
     T current = value_.load(std::memory_order::memory_order_relaxed);
     T new_value;
     do {
@@ -505,6 +543,8 @@ class MetricsAccumulator final : MetricsBase<T> {
  private:
   T Value() const { return value_.load(std::memory_order::memory_order_relaxed); }
 
+  bool IsNull() const override { return Value() == 0; }
+
   std::atomic<T> value_;
 
   friend class ArtMetrics;
diff --git a/runtime/gc/collector/mark_compact.cc b/runtime/gc/collector/mark_compact.cc
index f262b66f7a..8aba47fb3f 100644
--- a/runtime/gc/collector/mark_compact.cc
+++ b/runtime/gc/collector/mark_compact.cc
@@ -353,6 +353,24 @@ MarkCompact::MarkCompact(Heap* heap)
   CHECK_EQ(*conc_compaction_termination_page_, 0);
   // In most of the cases, we don't expect more than one LinearAlloc space.
   linear_alloc_spaces_data_.reserve(1);
+
+  // Initialize GC metrics.
+  metrics::ArtMetrics* metrics = GetMetrics();
+  // The mark-compact collector supports only full-heap collections at the moment.
+  gc_time_histogram_ = metrics->FullGcCollectionTime();
+  metrics_gc_count_ = metrics->FullGcCount();
+  metrics_gc_count_delta_ = metrics->FullGcCountDelta();
+  gc_throughput_histogram_ = metrics->FullGcThroughput();
+  gc_tracing_throughput_hist_ = metrics->FullGcTracingThroughput();
+  gc_throughput_avg_ = metrics->FullGcThroughputAvg();
+  gc_tracing_throughput_avg_ = metrics->FullGcTracingThroughputAvg();
+  gc_scanned_bytes_ = metrics->FullGcScannedBytes();
+  gc_scanned_bytes_delta_ = metrics->FullGcScannedBytesDelta();
+  gc_freed_bytes_ = metrics->FullGcFreedBytes();
+  gc_freed_bytes_delta_ = metrics->FullGcFreedBytesDelta();
+  gc_duration_ = metrics->FullGcDuration();
+  gc_duration_delta_ = metrics->FullGcDurationDelta();
+  are_metrics_initialized_ = true;
 }
 
 void MarkCompact::AddLinearAllocSpaceData(uint8_t* begin, size_t len) {
diff --git a/runtime/gc/heap_test.cc b/runtime/gc/heap_test.cc
index 5e8c1e368a..e8a0f711fa 100644
--- a/runtime/gc/heap_test.cc
+++ b/runtime/gc/heap_test.cc
@@ -14,6 +14,9 @@
  * limitations under the License.
  */
 
+#include <algorithm>
+
+#include "base/metrics/metrics.h"
 #include "class_linker-inl.h"
 #include "common_runtime_test.h"
 #include "gc/accounting/card_table-inl.h"
@@ -99,6 +102,148 @@ TEST_F(HeapTest, DumpGCPerformanceOnShutdown) {
   Runtime::Current()->SetDumpGCPerformanceOnShutdown(true);
 }
 
+template <typename T>
+bool AnyIsNonNull(const metrics::MetricsBase<T>* x, const metrics::MetricsBase<T>* y) {
+  return !x->IsNull() || !y->IsNull();
+}
+
+TEST_F(HeapTest, GCMetrics) {
+  // Allocate a few string objects (to be collected), then trigger garbage
+  // collection, and check that GC metrics are updated (where applicable).
+  {
+    constexpr const size_t kNumObj = 128;
+    ScopedObjectAccess soa(Thread::Current());
+    StackHandleScope<kNumObj> hs(soa.Self());
+    for (size_t i = 0u; i < kNumObj; ++i) {
+      Handle<mirror::String> string [[maybe_unused]] (
+          hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "test")));
+    }
+  }
+  Heap* heap = Runtime::Current()->GetHeap();
+  heap->CollectGarbage(/* clear_soft_references= */ false);
+
+  // ART Metrics.
+  metrics::ArtMetrics* metrics = Runtime::Current()->GetMetrics();
+  // ART full-heap GC metrics.
+  metrics::MetricsBase<int64_t>* full_gc_collection_time = metrics->FullGcCollectionTime();
+  metrics::MetricsBase<uint64_t>* full_gc_count = metrics->FullGcCount();
+  metrics::MetricsBase<uint64_t>* full_gc_count_delta = metrics->FullGcCountDelta();
+  metrics::MetricsBase<int64_t>* full_gc_throughput = metrics->FullGcThroughput();
+  metrics::MetricsBase<int64_t>* full_gc_tracing_throughput = metrics->FullGcTracingThroughput();
+  metrics::MetricsBase<uint64_t>* full_gc_throughput_avg = metrics->FullGcThroughputAvg();
+  metrics::MetricsBase<uint64_t>* full_gc_tracing_throughput_avg =
+      metrics->FullGcTracingThroughputAvg();
+  metrics::MetricsBase<uint64_t>* full_gc_scanned_bytes = metrics->FullGcScannedBytes();
+  metrics::MetricsBase<uint64_t>* full_gc_scanned_bytes_delta = metrics->FullGcScannedBytesDelta();
+  metrics::MetricsBase<uint64_t>* full_gc_freed_bytes = metrics->FullGcFreedBytes();
+  metrics::MetricsBase<uint64_t>* full_gc_freed_bytes_delta = metrics->FullGcFreedBytesDelta();
+  metrics::MetricsBase<uint64_t>* full_gc_duration = metrics->FullGcDuration();
+  metrics::MetricsBase<uint64_t>* full_gc_duration_delta = metrics->FullGcDurationDelta();
+  // ART young-generation GC metrics.
+  metrics::MetricsBase<int64_t>* young_gc_collection_time = metrics->YoungGcCollectionTime();
+  metrics::MetricsBase<uint64_t>* young_gc_count = metrics->YoungGcCount();
+  metrics::MetricsBase<uint64_t>* young_gc_count_delta = metrics->YoungGcCountDelta();
+  metrics::MetricsBase<int64_t>* young_gc_throughput = metrics->YoungGcThroughput();
+  metrics::MetricsBase<int64_t>* young_gc_tracing_throughput = metrics->YoungGcTracingThroughput();
+  metrics::MetricsBase<uint64_t>* young_gc_throughput_avg = metrics->YoungGcThroughputAvg();
+  metrics::MetricsBase<uint64_t>* young_gc_tracing_throughput_avg =
+      metrics->YoungGcTracingThroughputAvg();
+  metrics::MetricsBase<uint64_t>* young_gc_scanned_bytes = metrics->YoungGcScannedBytes();
+  metrics::MetricsBase<uint64_t>* young_gc_scanned_bytes_delta =
+      metrics->YoungGcScannedBytesDelta();
+  metrics::MetricsBase<uint64_t>* young_gc_freed_bytes = metrics->YoungGcFreedBytes();
+  metrics::MetricsBase<uint64_t>* young_gc_freed_bytes_delta = metrics->YoungGcFreedBytesDelta();
+  metrics::MetricsBase<uint64_t>* young_gc_duration = metrics->YoungGcDuration();
+  metrics::MetricsBase<uint64_t>* young_gc_duration_delta = metrics->YoungGcDurationDelta();
+
+  CollectorType fg_collector_type = heap->GetForegroundCollectorType();
+  if (fg_collector_type == kCollectorTypeCC || fg_collector_type == kCollectorTypeCMC) {
+    // Only the Concurrent Copying and Concurrent Mark-Compact collectors enable
+    // GC metrics at the moment.
+    if (heap->GetUseGenerationalCC()) {
+      // Check that full-heap and/or young-generation GC metrics are non-null
+      // after trigerring the collection.
+      EXPECT_PRED2(AnyIsNonNull<int64_t>, full_gc_collection_time, young_gc_collection_time);
+      EXPECT_PRED2(AnyIsNonNull<uint64_t>, full_gc_count, young_gc_count);
+      EXPECT_PRED2(AnyIsNonNull<uint64_t>, full_gc_count_delta, young_gc_count_delta);
+      EXPECT_PRED2(AnyIsNonNull<int64_t>, full_gc_throughput, young_gc_throughput);
+      EXPECT_PRED2(AnyIsNonNull<int64_t>, full_gc_tracing_throughput, young_gc_tracing_throughput);
+      EXPECT_PRED2(AnyIsNonNull<uint64_t>, full_gc_throughput_avg, young_gc_throughput_avg);
+      EXPECT_PRED2(
+          AnyIsNonNull<uint64_t>, full_gc_tracing_throughput_avg, young_gc_tracing_throughput_avg);
+      EXPECT_PRED2(AnyIsNonNull<uint64_t>, full_gc_scanned_bytes, young_gc_scanned_bytes);
+      EXPECT_PRED2(
+          AnyIsNonNull<uint64_t>, full_gc_scanned_bytes_delta, young_gc_scanned_bytes_delta);
+      EXPECT_PRED2(AnyIsNonNull<uint64_t>, full_gc_freed_bytes, young_gc_freed_bytes);
+      EXPECT_PRED2(AnyIsNonNull<uint64_t>, full_gc_freed_bytes_delta, young_gc_freed_bytes_delta);
+      EXPECT_PRED2(AnyIsNonNull<uint64_t>, full_gc_duration, young_gc_duration);
+      EXPECT_PRED2(AnyIsNonNull<uint64_t>, full_gc_duration_delta, young_gc_duration_delta);
+    } else {
+      // Check that only full-heap GC metrics are non-null after trigerring the collection.
+      EXPECT_FALSE(full_gc_collection_time->IsNull());
+      EXPECT_FALSE(full_gc_count->IsNull());
+      EXPECT_FALSE(full_gc_count_delta->IsNull());
+      EXPECT_FALSE(full_gc_throughput->IsNull());
+      EXPECT_FALSE(full_gc_tracing_throughput->IsNull());
+      EXPECT_FALSE(full_gc_throughput_avg->IsNull());
+      EXPECT_FALSE(full_gc_tracing_throughput_avg->IsNull());
+      if (fg_collector_type != kCollectorTypeCMC) {
+        // TODO(b/270957146): For some reason, these metrics are still null
+        // after running the Concurrent Mark-Compact collector; investigate why.
+        EXPECT_FALSE(full_gc_scanned_bytes->IsNull());
+        EXPECT_FALSE(full_gc_scanned_bytes_delta->IsNull());
+      }
+      EXPECT_FALSE(full_gc_freed_bytes->IsNull());
+      EXPECT_FALSE(full_gc_freed_bytes_delta->IsNull());
+      EXPECT_FALSE(full_gc_duration->IsNull());
+      EXPECT_FALSE(full_gc_duration_delta->IsNull());
+
+      EXPECT_TRUE(young_gc_collection_time->IsNull());
+      EXPECT_TRUE(young_gc_count->IsNull());
+      EXPECT_TRUE(young_gc_count_delta->IsNull());
+      EXPECT_TRUE(young_gc_throughput->IsNull());
+      EXPECT_TRUE(young_gc_tracing_throughput->IsNull());
+      EXPECT_TRUE(young_gc_throughput_avg->IsNull());
+      EXPECT_TRUE(young_gc_tracing_throughput_avg->IsNull());
+      EXPECT_TRUE(young_gc_scanned_bytes->IsNull());
+      EXPECT_TRUE(young_gc_scanned_bytes_delta->IsNull());
+      EXPECT_TRUE(young_gc_freed_bytes->IsNull());
+      EXPECT_TRUE(young_gc_freed_bytes_delta->IsNull());
+      EXPECT_TRUE(young_gc_duration->IsNull());
+      EXPECT_TRUE(young_gc_duration_delta->IsNull());
+    }
+  } else {
+    // Check that all metrics are null after trigerring the collection.
+    EXPECT_TRUE(full_gc_collection_time->IsNull());
+    EXPECT_TRUE(full_gc_count->IsNull());
+    EXPECT_TRUE(full_gc_count_delta->IsNull());
+    EXPECT_TRUE(full_gc_throughput->IsNull());
+    EXPECT_TRUE(full_gc_tracing_throughput->IsNull());
+    EXPECT_TRUE(full_gc_throughput_avg->IsNull());
+    EXPECT_TRUE(full_gc_tracing_throughput_avg->IsNull());
+    EXPECT_TRUE(full_gc_scanned_bytes->IsNull());
+    EXPECT_TRUE(full_gc_scanned_bytes_delta->IsNull());
+    EXPECT_TRUE(full_gc_freed_bytes->IsNull());
+    EXPECT_TRUE(full_gc_freed_bytes_delta->IsNull());
+    EXPECT_TRUE(full_gc_duration->IsNull());
+    EXPECT_TRUE(full_gc_duration_delta->IsNull());
+
+    EXPECT_TRUE(young_gc_collection_time->IsNull());
+    EXPECT_TRUE(young_gc_count->IsNull());
+    EXPECT_TRUE(young_gc_count_delta->IsNull());
+    EXPECT_TRUE(young_gc_throughput->IsNull());
+    EXPECT_TRUE(young_gc_tracing_throughput->IsNull());
+    EXPECT_TRUE(young_gc_throughput_avg->IsNull());
+    EXPECT_TRUE(young_gc_tracing_throughput_avg->IsNull());
+    EXPECT_TRUE(young_gc_scanned_bytes->IsNull());
+    EXPECT_TRUE(young_gc_scanned_bytes_delta->IsNull());
+    EXPECT_TRUE(young_gc_freed_bytes->IsNull());
+    EXPECT_TRUE(young_gc_freed_bytes_delta->IsNull());
+    EXPECT_TRUE(young_gc_duration->IsNull());
+    EXPECT_TRUE(young_gc_duration_delta->IsNull());
+  }
+}
+
 class ZygoteHeapTest : public CommonRuntimeTest {
   void SetUpRuntimeOptions(RuntimeOptions* options) override {
     CommonRuntimeTest::SetUpRuntimeOptions(options);
diff --git a/sigchainlib/sigchain.cc b/sigchainlib/sigchain.cc
index 5bad8568f2..24101c3be1 100644
--- a/sigchainlib/sigchain.cc
+++ b/sigchainlib/sigchain.cc
@@ -27,6 +27,7 @@
 #endif
 
 #include <algorithm>
+#include <atomic>
 #include <initializer_list>
 #include <mutex>
 #include <type_traits>
@@ -151,38 +152,92 @@ __attribute__((constructor)) static void InitializeSignalChain() {
   });
 }
 
-static pthread_key_t GetHandlingSignalKey() {
-  static pthread_key_t key;
+template <typename T>
+static constexpr bool IsPowerOfTwo(T x) {
+  static_assert(std::is_integral_v<T>, "T must be integral");
+  static_assert(std::is_unsigned_v<T>, "T must be unsigned");
+  return (x & (x - 1)) == 0;
+}
+
+template <typename T>
+static constexpr T RoundUp(T x, T n) {
+  return (x + n - 1) & -n;
+}
+// Use a bitmap to indicate which signal is being handled so that other
+// non-blocked signals are allowed to be handled, if raised.
+static constexpr size_t kSignalSetLength = _NSIG - 1;
+static constexpr size_t kNumSignalsPerKey = std::numeric_limits<uintptr_t>::digits;
+static_assert(IsPowerOfTwo(kNumSignalsPerKey));
+static constexpr size_t kHandlingSignalKeyCount =
+    RoundUp(kSignalSetLength, kNumSignalsPerKey) / kNumSignalsPerKey;
+
+// We rely on bionic's implementation of pthread_(get/set)specific being
+// async-signal safe.
+static pthread_key_t GetHandlingSignalKey(size_t idx) {
+  static pthread_key_t key[kHandlingSignalKeyCount];
   static std::once_flag once;
   std::call_once(once, []() {
-    int rc = pthread_key_create(&key, nullptr);
-    if (rc != 0) {
-      fatal("failed to create sigchain pthread key: %s", strerror(rc));
+    for (size_t i = 0; i < kHandlingSignalKeyCount; i++) {
+      int rc = pthread_key_create(&key[i], nullptr);
+      if (rc != 0) {
+        fatal("failed to create sigchain pthread key: %s", strerror(rc));
+      }
     }
   });
-  return key;
+  return key[idx];
 }
 
 static bool GetHandlingSignal() {
-  void* result = pthread_getspecific(GetHandlingSignalKey());
-  return reinterpret_cast<uintptr_t>(result);
+  for (size_t i = 0; i < kHandlingSignalKeyCount; i++) {
+    void* result = pthread_getspecific(GetHandlingSignalKey(i));
+    if (reinterpret_cast<uintptr_t>(result) != 0) {
+      return true;
+    }
+  }
+  return false;
 }
 
-static void SetHandlingSignal(bool value) {
-  pthread_setspecific(GetHandlingSignalKey(),
-                      reinterpret_cast<void*>(static_cast<uintptr_t>(value)));
+static bool GetHandlingSignal(int signo) {
+  size_t bit_idx = signo - 1;
+  size_t key_idx = bit_idx / kNumSignalsPerKey;
+  uintptr_t bit_mask = static_cast<uintptr_t>(1) << (bit_idx % kNumSignalsPerKey);
+  uintptr_t result =
+      reinterpret_cast<uintptr_t>(pthread_getspecific(GetHandlingSignalKey(key_idx)));
+  return result & bit_mask;
+}
+
+static bool SetHandlingSignal(int signo, bool value) {
+  // Use signal-fence to ensure that compiler doesn't reorder generated code
+  // across signal handlers.
+  size_t bit_idx = signo - 1;
+  size_t key_idx = bit_idx / kNumSignalsPerKey;
+  uintptr_t bit_mask = static_cast<uintptr_t>(1) << (bit_idx % kNumSignalsPerKey);
+  pthread_key_t key = GetHandlingSignalKey(key_idx);
+  std::atomic_signal_fence(std::memory_order_seq_cst);
+  uintptr_t bitmap = reinterpret_cast<uintptr_t>(pthread_getspecific(key));
+  bool ret = bitmap & bit_mask;
+  if (value) {
+    bitmap |= bit_mask;
+  } else {
+    bitmap &= ~bit_mask;
+  }
+  pthread_setspecific(key, reinterpret_cast<void*>(bitmap));
+  std::atomic_signal_fence(std::memory_order_seq_cst);
+  return ret;
 }
 
 class ScopedHandlingSignal {
  public:
-  ScopedHandlingSignal() : original_value_(GetHandlingSignal()) {
-  }
+  ScopedHandlingSignal(int signo, bool set)
+      : signo_(signo),
+        original_value_(set ? SetHandlingSignal(signo, true) : GetHandlingSignal(signo)) {}
 
   ~ScopedHandlingSignal() {
-    SetHandlingSignal(original_value_);
+    SetHandlingSignal(signo_, original_value_);
   }
 
  private:
+  int signo_;
   bool original_value_;
 };
 
@@ -336,14 +391,14 @@ class SignalChain {
 
 // _NSIG is 1 greater than the highest valued signal, but signals start from 1.
 // Leave an empty element at index 0 for convenience.
-static SignalChain chains[_NSIG + 1];
+static SignalChain chains[_NSIG];
 
 static bool is_signal_hook_debuggable = false;
 
 void SignalChain::Handler(int signo, siginfo_t* siginfo, void* ucontext_raw) {
   // Try the special handlers first.
   // If one of them crashes, we'll reenter this handler and pass that crash onto the user handler.
-  if (!GetHandlingSignal()) {
+  if (!GetHandlingSignal(signo)) {
     for (const auto& handler : chains[signo].special_handlers_) {
       if (handler.sc_sigaction == nullptr) {
         break;
@@ -356,10 +411,7 @@ void SignalChain::Handler(int signo, siginfo_t* siginfo, void* ucontext_raw) {
       sigset_t previous_mask;
       linked_sigprocmask(SIG_SETMASK, &handler.sc_mask, &previous_mask);
 
-      ScopedHandlingSignal restorer;
-      if (!handler_noreturn) {
-        SetHandlingSignal(true);
-      }
+      ScopedHandlingSignal restorer(signo, !handler_noreturn);
 
       if (handler.sc_sigaction(signo, siginfo, ucontext_raw)) {
         return;