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-rw-r--r--absl/container/inlined_vector.h13
-rw-r--r--absl/container/inlined_vector_test.cc24
-rw-r--r--absl/container/internal/inlined_vector.h138
-rw-r--r--absl/container/internal/raw_hash_set.h2
-rw-r--r--absl/debugging/symbolize_win32.inc4
-rw-r--r--absl/flags/flag.h70
-rw-r--r--absl/memory/memory.h9
-rw-r--r--absl/synchronization/internal/create_thread_identity.cc4
-rw-r--r--absl/synchronization/internal/create_thread_identity.h4
-rw-r--r--absl/synchronization/internal/per_thread_sem.cc6
-rw-r--r--absl/synchronization/internal/per_thread_sem.h5
-rw-r--r--absl/synchronization/internal/waiter.cc77
-rw-r--r--absl/synchronization/internal/waiter.h27
13 files changed, 239 insertions, 144 deletions
diff --git a/absl/container/inlined_vector.h b/absl/container/inlined_vector.h
index 5138348a..d5c67db5 100644
--- a/absl/container/inlined_vector.h
+++ b/absl/container/inlined_vector.h
@@ -69,9 +69,10 @@ class InlinedVector {
static_assert(N > 0, "`absl::InlinedVector` requires an inlined capacity.");
using Storage = inlined_vector_internal::Storage<T, N, A>;
- using rvalue_reference = typename Storage::rvalue_reference;
- using MoveIterator = typename Storage::MoveIterator;
+
using AllocatorTraits = typename Storage::AllocatorTraits;
+ using RValueReference = typename Storage::RValueReference;
+ using MoveIterator = typename Storage::MoveIterator;
using IsMemcpyOk = typename Storage::IsMemcpyOk;
template <typename Iterator>
@@ -92,10 +93,10 @@ class InlinedVector {
using value_type = typename Storage::value_type;
using pointer = typename Storage::pointer;
using const_pointer = typename Storage::const_pointer;
- using reference = typename Storage::reference;
- using const_reference = typename Storage::const_reference;
using size_type = typename Storage::size_type;
using difference_type = typename Storage::difference_type;
+ using reference = typename Storage::reference;
+ using const_reference = typename Storage::const_reference;
using iterator = typename Storage::iterator;
using const_iterator = typename Storage::const_iterator;
using reverse_iterator = typename Storage::reverse_iterator;
@@ -563,7 +564,7 @@ class InlinedVector {
// Overload of `InlinedVector::insert(...)` that inserts `v` at `pos` using
// move semantics, returning an `iterator` to the newly inserted element.
- iterator insert(const_iterator pos, rvalue_reference v) {
+ iterator insert(const_iterator pos, RValueReference v) {
return emplace(pos, std::move(v));
}
@@ -660,7 +661,7 @@ class InlinedVector {
// Overload of `InlinedVector::push_back(...)` for inserting `v` at `end()`
// using move semantics.
- void push_back(rvalue_reference v) {
+ void push_back(RValueReference v) {
static_cast<void>(emplace_back(std::move(v)));
}
diff --git a/absl/container/inlined_vector_test.cc b/absl/container/inlined_vector_test.cc
index 080ea956..2c9b0d0e 100644
--- a/absl/container/inlined_vector_test.cc
+++ b/absl/container/inlined_vector_test.cc
@@ -1754,6 +1754,30 @@ TEST(AllocatorSupportTest, SizeAllocConstructor) {
}
}
+TEST(InlinedVectorTest, MinimumAllocatorCompilesUsingTraits) {
+ using T = int;
+ using A = std::allocator<T>;
+ using ATraits = absl::allocator_traits<A>;
+
+ struct MinimumAllocator {
+ using value_type = T;
+
+ value_type* allocate(size_t n) {
+ A a;
+ return ATraits::allocate(a, n);
+ }
+
+ void deallocate(value_type* p, size_t n) {
+ A a;
+ ATraits::deallocate(a, p, n);
+ }
+ };
+
+ absl::InlinedVector<T, 1, MinimumAllocator> vec;
+ vec.emplace_back();
+ vec.resize(0);
+}
+
TEST(InlinedVectorTest, AbslHashValueWorks) {
using V = absl::InlinedVector<int, 4>;
std::vector<V> cases;
diff --git a/absl/container/internal/inlined_vector.h b/absl/container/internal/inlined_vector.h
index f678c88d..84aa785a 100644
--- a/absl/container/internal/inlined_vector.h
+++ b/absl/container/internal/inlined_vector.h
@@ -37,16 +37,17 @@ using IsAtLeastForwardIterator = std::is_convertible<
typename std::iterator_traits<Iterator>::iterator_category,
std::forward_iterator_tag>;
-template <typename AllocatorType>
-using IsMemcpyOk = absl::conjunction<
- std::is_same<std::allocator<typename AllocatorType::value_type>,
- AllocatorType>,
- absl::is_trivially_copy_constructible<typename AllocatorType::value_type>,
- absl::is_trivially_copy_assignable<typename AllocatorType::value_type>,
- absl::is_trivially_destructible<typename AllocatorType::value_type>>;
-
-template <typename AllocatorType, typename ValueType, typename SizeType>
-void DestroyElements(AllocatorType* alloc_ptr, ValueType* destroy_first,
+template <typename AllocatorType,
+ typename ValueType =
+ typename absl::allocator_traits<AllocatorType>::value_type>
+using IsMemcpyOk =
+ absl::conjunction<std::is_same<AllocatorType, std::allocator<ValueType>>,
+ absl::is_trivially_copy_constructible<ValueType>,
+ absl::is_trivially_copy_assignable<ValueType>,
+ absl::is_trivially_destructible<ValueType>>;
+
+template <typename AllocatorType, typename Pointer, typename SizeType>
+void DestroyElements(AllocatorType* alloc_ptr, Pointer destroy_first,
SizeType destroy_size) {
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
@@ -57,20 +58,25 @@ void DestroyElements(AllocatorType* alloc_ptr, ValueType* destroy_first,
}
#if !defined(NDEBUG)
- // Overwrite unused memory with `0xab` so we can catch uninitialized usage.
- //
- // Cast to `void*` to tell the compiler that we don't care that we might be
- // scribbling on a vtable pointer.
- auto* memory_ptr = static_cast<void*>(destroy_first);
- auto memory_size = sizeof(ValueType) * destroy_size;
- std::memset(memory_ptr, 0xab, memory_size);
+ {
+ using ValueType = typename AllocatorTraits::value_type;
+
+ // Overwrite unused memory with `0xab` so we can catch uninitialized
+ // usage.
+ //
+ // Cast to `void*` to tell the compiler that we don't care that we might
+ // be scribbling on a vtable pointer.
+ void* memory_ptr = destroy_first;
+ auto memory_size = destroy_size * sizeof(ValueType);
+ std::memset(memory_ptr, 0xab, memory_size);
+ }
#endif // !defined(NDEBUG)
}
}
-template <typename AllocatorType, typename ValueType, typename ValueAdapter,
+template <typename AllocatorType, typename Pointer, typename ValueAdapter,
typename SizeType>
-void ConstructElements(AllocatorType* alloc_ptr, ValueType* construct_first,
+void ConstructElements(AllocatorType* alloc_ptr, Pointer construct_first,
ValueAdapter* values_ptr, SizeType construct_size) {
for (SizeType i = 0; i < construct_size; ++i) {
ABSL_INTERNAL_TRY {
@@ -83,8 +89,8 @@ void ConstructElements(AllocatorType* alloc_ptr, ValueType* construct_first,
}
}
-template <typename ValueType, typename ValueAdapter, typename SizeType>
-void AssignElements(ValueType* assign_first, ValueAdapter* values_ptr,
+template <typename Pointer, typename ValueAdapter, typename SizeType>
+void AssignElements(Pointer assign_first, ValueAdapter* values_ptr,
SizeType assign_size) {
for (SizeType i = 0; i < assign_size; ++i) {
values_ptr->AssignNext(assign_first + i);
@@ -93,28 +99,29 @@ void AssignElements(ValueType* assign_first, ValueAdapter* values_ptr,
template <typename AllocatorType>
struct StorageView {
- using pointer = typename AllocatorType::pointer;
- using size_type = typename AllocatorType::size_type;
+ using AllocatorTraits = absl::allocator_traits<AllocatorType>;
+ using Pointer = typename AllocatorTraits::pointer;
+ using SizeType = typename AllocatorTraits::size_type;
- pointer data;
- size_type size;
- size_type capacity;
+ Pointer data;
+ SizeType size;
+ SizeType capacity;
};
template <typename AllocatorType, typename Iterator>
class IteratorValueAdapter {
- using pointer = typename AllocatorType::pointer;
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
+ using Pointer = typename AllocatorTraits::pointer;
public:
explicit IteratorValueAdapter(const Iterator& it) : it_(it) {}
- void ConstructNext(AllocatorType* alloc_ptr, pointer construct_at) {
+ void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) {
AllocatorTraits::construct(*alloc_ptr, construct_at, *it_);
++it_;
}
- void AssignNext(pointer assign_at) {
+ void AssignNext(Pointer assign_at) {
*assign_at = *it_;
++it_;
}
@@ -125,46 +132,45 @@ class IteratorValueAdapter {
template <typename AllocatorType>
class CopyValueAdapter {
- using pointer = typename AllocatorType::pointer;
- using const_pointer = typename AllocatorType::const_pointer;
- using const_reference = typename AllocatorType::const_reference;
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
+ using ValueType = typename AllocatorTraits::value_type;
+ using Pointer = typename AllocatorTraits::pointer;
+ using ConstPointer = typename AllocatorTraits::const_pointer;
public:
- explicit CopyValueAdapter(const_reference v) : ptr_(std::addressof(v)) {}
+ explicit CopyValueAdapter(const ValueType& v) : ptr_(std::addressof(v)) {}
- void ConstructNext(AllocatorType* alloc_ptr, pointer construct_at) {
+ void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) {
AllocatorTraits::construct(*alloc_ptr, construct_at, *ptr_);
}
- void AssignNext(pointer assign_at) { *assign_at = *ptr_; }
+ void AssignNext(Pointer assign_at) { *assign_at = *ptr_; }
private:
- const_pointer ptr_;
+ ConstPointer ptr_;
};
template <typename AllocatorType>
class DefaultValueAdapter {
- using pointer = typename AllocatorType::pointer;
- using value_type = typename AllocatorType::value_type;
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
+ using ValueType = typename AllocatorTraits::value_type;
+ using Pointer = typename AllocatorTraits::pointer;
public:
explicit DefaultValueAdapter() {}
- void ConstructNext(AllocatorType* alloc_ptr, pointer construct_at) {
+ void ConstructNext(AllocatorType* alloc_ptr, Pointer construct_at) {
AllocatorTraits::construct(*alloc_ptr, construct_at);
}
- void AssignNext(pointer assign_at) { *assign_at = value_type(); }
+ void AssignNext(Pointer assign_at) { *assign_at = ValueType(); }
};
template <typename AllocatorType>
class AllocationTransaction {
- using value_type = typename AllocatorType::value_type;
- using pointer = typename AllocatorType::pointer;
- using size_type = typename AllocatorType::size_type;
using AllocatorTraits = absl::allocator_traits<AllocatorType>;
+ using Pointer = typename AllocatorTraits::pointer;
+ using SizeType = typename AllocatorTraits::size_type;
public:
explicit AllocationTransaction(AllocatorType* alloc_ptr)
@@ -180,11 +186,11 @@ class AllocationTransaction {
void operator=(const AllocationTransaction&) = delete;
AllocatorType& GetAllocator() { return alloc_data_.template get<0>(); }
- pointer& GetData() { return alloc_data_.template get<1>(); }
- size_type& GetCapacity() { return capacity_; }
+ Pointer& GetData() { return alloc_data_.template get<1>(); }
+ SizeType& GetCapacity() { return capacity_; }
bool DidAllocate() { return GetData() != nullptr; }
- pointer Allocate(size_type capacity) {
+ Pointer Allocate(SizeType capacity) {
GetData() = AllocatorTraits::allocate(GetAllocator(), capacity);
GetCapacity() = capacity;
return GetData();
@@ -196,14 +202,15 @@ class AllocationTransaction {
}
private:
- container_internal::CompressedTuple<AllocatorType, pointer> alloc_data_;
- size_type capacity_ = 0;
+ container_internal::CompressedTuple<AllocatorType, Pointer> alloc_data_;
+ SizeType capacity_ = 0;
};
template <typename AllocatorType>
class ConstructionTransaction {
- using pointer = typename AllocatorType::pointer;
- using size_type = typename AllocatorType::size_type;
+ using AllocatorTraits = absl::allocator_traits<AllocatorType>;
+ using Pointer = typename AllocatorTraits::pointer;
+ using SizeType = typename AllocatorTraits::size_type;
public:
explicit ConstructionTransaction(AllocatorType* alloc_ptr)
@@ -220,12 +227,12 @@ class ConstructionTransaction {
void operator=(const ConstructionTransaction&) = delete;
AllocatorType& GetAllocator() { return alloc_data_.template get<0>(); }
- pointer& GetData() { return alloc_data_.template get<1>(); }
- size_type& GetSize() { return size_; }
+ Pointer& GetData() { return alloc_data_.template get<1>(); }
+ SizeType& GetSize() { return size_; }
bool DidConstruct() { return GetData() != nullptr; }
template <typename ValueAdapter>
- void Construct(pointer data, ValueAdapter* values_ptr, size_type size) {
+ void Construct(Pointer data, ValueAdapter* values_ptr, SizeType size) {
inlined_vector_internal::ConstructElements(std::addressof(GetAllocator()),
data, values_ptr, size);
GetData() = data;
@@ -237,28 +244,29 @@ class ConstructionTransaction {
}
private:
- container_internal::CompressedTuple<AllocatorType, pointer> alloc_data_;
- size_type size_ = 0;
+ container_internal::CompressedTuple<AllocatorType, Pointer> alloc_data_;
+ SizeType size_ = 0;
};
template <typename T, size_t N, typename A>
class Storage {
public:
- using allocator_type = A;
- using value_type = typename allocator_type::value_type;
- using pointer = typename allocator_type::pointer;
- using const_pointer = typename allocator_type::const_pointer;
- using reference = typename allocator_type::reference;
- using const_reference = typename allocator_type::const_reference;
- using rvalue_reference = typename allocator_type::value_type&&;
- using size_type = typename allocator_type::size_type;
- using difference_type = typename allocator_type::difference_type;
+ using AllocatorTraits = absl::allocator_traits<A>;
+ using allocator_type = typename AllocatorTraits::allocator_type;
+ using value_type = typename AllocatorTraits::value_type;
+ using pointer = typename AllocatorTraits::pointer;
+ using const_pointer = typename AllocatorTraits::const_pointer;
+ using size_type = typename AllocatorTraits::size_type;
+ using difference_type = typename AllocatorTraits::difference_type;
+
+ using reference = value_type&;
+ using const_reference = const value_type&;
+ using RValueReference = value_type&&;
using iterator = pointer;
using const_iterator = const_pointer;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
using MoveIterator = std::move_iterator<iterator>;
- using AllocatorTraits = absl::allocator_traits<allocator_type>;
using IsMemcpyOk = inlined_vector_internal::IsMemcpyOk<allocator_type>;
using StorageView = inlined_vector_internal::StorageView<allocator_type>;
diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index 9079a73e..bf0c03c4 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -615,7 +615,7 @@ class raw_hash_set {
// PRECONDITION: not an end() iterator.
reference operator*() const {
- /* To be enabled: assert_is_full(); */
+ assert_is_full();
return PolicyTraits::element(slot_);
}
diff --git a/absl/debugging/symbolize_win32.inc b/absl/debugging/symbolize_win32.inc
index 0fb4b803..b0fb3b9a 100644
--- a/absl/debugging/symbolize_win32.inc
+++ b/absl/debugging/symbolize_win32.inc
@@ -17,10 +17,10 @@
#include <windows.h>
-// MSVC header DbgHelp.h has a warning for an ignored typedef.
+// MSVC header dbghelp.h has a warning for an ignored typedef.
#pragma warning(push)
#pragma warning(disable:4091)
-#include <DbgHelp.h>
+#include <dbghelp.h>
#pragma warning(pop)
#pragma comment(lib, "dbghelp.lib")
diff --git a/absl/flags/flag.h b/absl/flags/flag.h
index c0060b44..356ddb61 100644
--- a/absl/flags/flag.h
+++ b/absl/flags/flag.h
@@ -67,17 +67,20 @@ namespace absl {
template <typename T>
using Flag = flags_internal::Flag<T>;
#else
-// MSVC debug builds do not implement constexpr correctly for classes with
-// virtual methods. To work around this we adding level of indirection, so that
-// the class `absl::Flag` contains an `internal::Flag*` (instead of being an
-// alias to that class) and dynamically allocates an instance when necessary.
-// We also forward all calls to internal::Flag methods via trampoline methods.
-// In this setup the `absl::Flag` class does not have virtual methods and thus
-// MSVC is able to initialize it at link time. To deal with multiple threads
-// accessing the flag for the first time concurrently we use an atomic boolean
-// indicating if flag object is constructed. We also employ the double-checked
-// locking pattern where the second level of protection is a global Mutex, so
-// if two threads attempt to construct the flag concurrently only one wins.
+// MSVC debug builds do not implement initialization with constexpr constructors
+// correctly. To work around this we add a level of indirection, so that the
+// class `absl::Flag` contains an `internal::Flag*` (instead of being an alias
+// to that class) and dynamically allocates an instance when necessary. We also
+// forward all calls to internal::Flag methods via trampoline methods. In this
+// setup the `absl::Flag` class does not have constructor and virtual methods,
+// all the data members are public and thus MSVC is able to initialize it at
+// link time. To deal with multiple threads accessing the flag for the first
+// time concurrently we use an atomic boolean indicating if flag object is
+// initialized. We also employ the double-checked locking pattern where the
+// second level of protection is a global Mutex, so if two threads attempt to
+// construct the flag concurrently only one wins.
+// This solution is based on a recomendation here:
+// https://developercommunity.visualstudio.com/content/problem/336946/class-with-constexpr-constructor-not-using-static.html?childToView=648454#comment-648454
namespace flags_internal {
absl::Mutex* GetGlobalConstructionGuard();
@@ -86,16 +89,23 @@ absl::Mutex* GetGlobalConstructionGuard();
template <typename T>
class Flag {
public:
+ // No constructor and destructor to ensure this is an aggregate type.
+ // Visual Studio 2015 still requires the constructor for class to be
+ // constexpr initializable.
+#if _MSC_VER <= 1900
constexpr Flag(const char* name, const flags_internal::HelpGenFunc help_gen,
const char* filename,
const flags_internal::FlagMarshallingOpFn marshalling_op,
- const flags_internal::InitialValGenFunc initial_value_gen)
+ const flags_internal::InitialValGenFunc initial_value_gen,
+ bool, void*)
: name_(name),
help_gen_(help_gen),
filename_(filename),
marshalling_op_(marshalling_op),
initial_value_gen_(initial_value_gen),
- inited_(false) {}
+ inited_(false),
+ impl_(nullptr) {}
+#endif
flags_internal::Flag<T>* GetImpl() const {
if (!inited_.load(std::memory_order_acquire)) {
@@ -113,7 +123,8 @@ class Flag {
return impl_;
}
- // absl::Flag API
+ // Public methods of `absl::Flag<T>` are NOT part of the Abseil Flags API.
+ // See https://abseil.io/docs/cpp/guides/flags
bool IsRetired() const { return GetImpl()->IsRetired(); }
bool IsAbseilFlag() const { return GetImpl()->IsAbseilFlag(); }
absl::string_view Name() const { return GetImpl()->Name(); }
@@ -126,9 +137,9 @@ class Flag {
std::string Filename() const { return GetImpl()->Filename(); }
std::string DefaultValue() const { return GetImpl()->DefaultValue(); }
std::string CurrentValue() const { return GetImpl()->CurrentValue(); }
- template <typename T1>
+ template <typename U>
inline bool IsOfType() const {
- return GetImpl()->template IsOfType<T1>();
+ return GetImpl()->template IsOfType<U>();
}
T Get() const { return GetImpl()->Get(); }
bool AtomicGet(T* v) const { return GetImpl()->AtomicGet(v); }
@@ -138,7 +149,8 @@ class Flag {
}
void InvokeCallback() { GetImpl()->InvokeCallback(); }
- private:
+ // The data members are logically private, but they need to be public for
+ // this to be an aggregate type.
const char* name_;
const flags_internal::HelpGenFunc help_gen_;
const char* filename_;
@@ -146,7 +158,7 @@ class Flag {
const flags_internal::InitialValGenFunc initial_value_gen_;
mutable std::atomic<bool> inited_;
- mutable flags_internal::Flag<T>* impl_ = nullptr;
+ mutable flags_internal::Flag<T>* impl_;
};
#endif
@@ -310,17 +322,35 @@ void SetFlag(absl::Flag<T>* flag, const V& v) {
// Note: Name of registrar object is not arbitrary. It is used to "grab"
// global name for FLAGS_no<flag_name> symbol, thus preventing the possibility
// of defining two flags with names foo and nofoo.
+#if !defined(_MSC_VER) || defined(__clang__)
#define ABSL_FLAG_IMPL(Type, name, default_value, help) \
namespace absl /* block flags in namespaces */ {} \
ABSL_FLAG_IMPL_DECLARE_DEF_VAL_WRAPPER(name, Type, default_value) \
ABSL_FLAG_IMPL_DECLARE_HELP_WRAPPER(name, help) \
- ABSL_CONST_INIT absl::Flag<Type> FLAGS_##name( \
+ ABSL_CONST_INIT absl::Flag<Type> FLAGS_##name{ \
ABSL_FLAG_IMPL_FLAGNAME(#name), &AbslFlagsWrapHelp##name, \
ABSL_FLAG_IMPL_FILENAME(), \
&absl::flags_internal::FlagMarshallingOps<Type>, \
- &AbslFlagsInitFlag##name); \
+ &AbslFlagsInitFlag##name}; \
+ extern bool FLAGS_no##name; \
+ bool FLAGS_no##name = ABSL_FLAG_IMPL_REGISTRAR(Type, FLAGS_##name)
+#else
+// MSVC version uses aggregate initialization.
+#define ABSL_FLAG_IMPL(Type, name, default_value, help) \
+ namespace absl /* block flags in namespaces */ {} \
+ ABSL_FLAG_IMPL_DECLARE_DEF_VAL_WRAPPER(name, Type, default_value) \
+ ABSL_FLAG_IMPL_DECLARE_HELP_WRAPPER(name, help) \
+ ABSL_CONST_INIT absl::Flag<Type> FLAGS_##name{ \
+ ABSL_FLAG_IMPL_FLAGNAME(#name), \
+ &AbslFlagsWrapHelp##name, \
+ ABSL_FLAG_IMPL_FILENAME(), \
+ &absl::flags_internal::FlagMarshallingOps<Type>, \
+ &AbslFlagsInitFlag##name, \
+ false, \
+ nullptr}; \
extern bool FLAGS_no##name; \
bool FLAGS_no##name = ABSL_FLAG_IMPL_REGISTRAR(Type, FLAGS_##name)
+#endif
// ABSL_RETIRED_FLAG
//
diff --git a/absl/memory/memory.h b/absl/memory/memory.h
index 5a4a1a1d..243a5dda 100644
--- a/absl/memory/memory.h
+++ b/absl/memory/memory.h
@@ -92,11 +92,12 @@ struct MakeUniqueResult<T[N]> {
} // namespace memory_internal
-// gcc 4.8 has __cplusplus at 201301 but doesn't define make_unique. Other
-// supported compilers either just define __cplusplus as 201103 but have
-// make_unique (msvc), or have make_unique whenever __cplusplus > 201103 (clang)
+// gcc 4.8 has __cplusplus at 201301 but the libstdc++ shipped with it doesn't
+// define make_unique. Other supported compilers either just define __cplusplus
+// as 201103 but have make_unique (msvc), or have make_unique whenever
+// __cplusplus > 201103 (clang).
#if (__cplusplus > 201103L || defined(_MSC_VER)) && \
- !(defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 8)
+ !(defined(__GLIBCXX__) && !defined(__cpp_lib_make_unique))
using std::make_unique;
#else
// -----------------------------------------------------------------------------
diff --git a/absl/synchronization/internal/create_thread_identity.cc b/absl/synchronization/internal/create_thread_identity.cc
index ce3676a8..eef661f2 100644
--- a/absl/synchronization/internal/create_thread_identity.cc
+++ b/absl/synchronization/internal/create_thread_identity.cc
@@ -37,7 +37,7 @@ static base_internal::ThreadIdentity* thread_identity_freelist;
// A per-thread destructor for reclaiming associated ThreadIdentity objects.
// Since we must preserve their storage we cache them for re-use.
-static void ReclaimThreadIdentity(void* v) {
+void ReclaimThreadIdentity(void* v) {
base_internal::ThreadIdentity* identity =
static_cast<base_internal::ThreadIdentity*>(v);
@@ -47,6 +47,8 @@ static void ReclaimThreadIdentity(void* v) {
base_internal::LowLevelAlloc::Free(identity->per_thread_synch.all_locks);
}
+ PerThreadSem::Destroy(identity);
+
// We must explicitly clear the current thread's identity:
// (a) Subsequent (unrelated) per-thread destructors may require an identity.
// We must guarantee a new identity is used in this case (this instructor
diff --git a/absl/synchronization/internal/create_thread_identity.h b/absl/synchronization/internal/create_thread_identity.h
index ebb16c56..97237a6e 100644
--- a/absl/synchronization/internal/create_thread_identity.h
+++ b/absl/synchronization/internal/create_thread_identity.h
@@ -35,6 +35,10 @@ namespace synchronization_internal {
// For private use only.
base_internal::ThreadIdentity* CreateThreadIdentity();
+// A per-thread destructor for reclaiming associated ThreadIdentity objects.
+// For private use only.
+void ReclaimThreadIdentity(void* v);
+
// Returns the ThreadIdentity object representing the calling thread; guaranteed
// to be unique for its lifetime. The returned object will remain valid for the
// program's lifetime; although it may be re-assigned to a subsequent thread.
diff --git a/absl/synchronization/internal/per_thread_sem.cc b/absl/synchronization/internal/per_thread_sem.cc
index b7014fb2..2a78b20f 100644
--- a/absl/synchronization/internal/per_thread_sem.cc
+++ b/absl/synchronization/internal/per_thread_sem.cc
@@ -40,12 +40,16 @@ std::atomic<int> *PerThreadSem::GetThreadBlockedCounter() {
}
void PerThreadSem::Init(base_internal::ThreadIdentity *identity) {
- Waiter::GetWaiter(identity)->Init();
+ new (Waiter::GetWaiter(identity)) Waiter();
identity->ticker.store(0, std::memory_order_relaxed);
identity->wait_start.store(0, std::memory_order_relaxed);
identity->is_idle.store(false, std::memory_order_relaxed);
}
+void PerThreadSem::Destroy(base_internal::ThreadIdentity *identity) {
+ Waiter::GetWaiter(identity)->~Waiter();
+}
+
void PerThreadSem::Tick(base_internal::ThreadIdentity *identity) {
const int ticker =
identity->ticker.fetch_add(1, std::memory_order_relaxed) + 1;
diff --git a/absl/synchronization/internal/per_thread_sem.h b/absl/synchronization/internal/per_thread_sem.h
index e7da070b..113cdfb7 100644
--- a/absl/synchronization/internal/per_thread_sem.h
+++ b/absl/synchronization/internal/per_thread_sem.h
@@ -65,6 +65,10 @@ class PerThreadSem {
// REQUIRES: May only be called by ThreadIdentity.
static void Init(base_internal::ThreadIdentity* identity);
+ // Destroy the PerThreadSem associated with "identity".
+ // REQUIRES: May only be called by ThreadIdentity.
+ static void Destroy(base_internal::ThreadIdentity* identity);
+
// Increments "identity"'s count.
static inline void Post(base_internal::ThreadIdentity* identity);
@@ -77,6 +81,7 @@ class PerThreadSem {
friend class PerThreadSemTest;
friend class absl::Mutex;
friend absl::base_internal::ThreadIdentity* CreateThreadIdentity();
+ friend void ReclaimThreadIdentity(void* v);
};
} // namespace synchronization_internal
diff --git a/absl/synchronization/internal/waiter.cc b/absl/synchronization/internal/waiter.cc
index 2f41aa5f..8e713770 100644
--- a/absl/synchronization/internal/waiter.cc
+++ b/absl/synchronization/internal/waiter.cc
@@ -122,10 +122,12 @@ class Futex {
}
};
-void Waiter::Init() {
+Waiter::Waiter() {
futex_.store(0, std::memory_order_relaxed);
}
+Waiter::~Waiter() = default;
+
bool Waiter::Wait(KernelTimeout t) {
// Loop until we can atomically decrement futex from a positive
// value, waiting on a futex while we believe it is zero.
@@ -199,7 +201,7 @@ class PthreadMutexHolder {
pthread_mutex_t *mu_;
};
-void Waiter::Init() {
+Waiter::Waiter() {
const int err = pthread_mutex_init(&mu_, 0);
if (err != 0) {
ABSL_RAW_LOG(FATAL, "pthread_mutex_init failed: %d", err);
@@ -214,6 +216,18 @@ void Waiter::Init() {
wakeup_count_ = 0;
}
+Waiter::~Waiter() {
+ const int err = pthread_mutex_destroy(&mu_);
+ if (err != 0) {
+ ABSL_RAW_LOG(FATAL, "pthread_mutex_destroy failed: %d", err);
+ }
+
+ const int err2 = pthread_cond_destroy(&cv_);
+ if (err2 != 0) {
+ ABSL_RAW_LOG(FATAL, "pthread_cond_destroy failed: %d", err2);
+ }
+}
+
bool Waiter::Wait(KernelTimeout t) {
struct timespec abs_timeout;
if (t.has_timeout()) {
@@ -274,13 +288,19 @@ void Waiter::InternalCondVarPoke() {
#elif ABSL_WAITER_MODE == ABSL_WAITER_MODE_SEM
-void Waiter::Init() {
+Waiter::Waiter() {
if (sem_init(&sem_, 0, 0) != 0) {
ABSL_RAW_LOG(FATAL, "sem_init failed with errno %d\n", errno);
}
wakeups_.store(0, std::memory_order_relaxed);
}
+Waiter::~Waiter() {
+ if (sem_destroy(&sem_) != 0) {
+ ABSL_RAW_LOG(FATAL, "sem_destroy failed with errno %d\n", errno);
+ }
+}
+
bool Waiter::Wait(KernelTimeout t) {
struct timespec abs_timeout;
if (t.has_timeout()) {
@@ -388,39 +408,32 @@ class LockHolder {
SRWLOCK* mu_;
};
-void Waiter::Init() {
+Waiter::Waiter() {
auto *mu = ::new (static_cast<void *>(&mu_storage_)) SRWLOCK;
auto *cv = ::new (static_cast<void *>(&cv_storage_)) CONDITION_VARIABLE;
InitializeSRWLock(mu);
InitializeConditionVariable(cv);
- waiter_count_.store(0, std::memory_order_relaxed);
- wakeup_count_.store(0, std::memory_order_relaxed);
+ waiter_count_ = 0;
+ wakeup_count_ = 0;
}
+// SRW locks and condition variables do not need to be explicitly destroyed.
+// https://docs.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-initializesrwlock
+// https://stackoverflow.com/questions/28975958/why-does-windows-have-no-deleteconditionvariable-function-to-go-together-with
+Waiter::~Waiter() = default;
+
bool Waiter::Wait(KernelTimeout t) {
SRWLOCK *mu = WinHelper::GetLock(this);
CONDITION_VARIABLE *cv = WinHelper::GetCond(this);
LockHolder h(mu);
- waiter_count_.fetch_add(1, std::memory_order_relaxed);
+ ++waiter_count_;
// Loop until we find a wakeup to consume or timeout.
// Note that, since the thread ticker is just reset, we don't need to check
// whether the thread is idle on the very first pass of the loop.
bool first_pass = true;
- while (true) {
- int x = wakeup_count_.load(std::memory_order_relaxed);
- if (x != 0) {
- if (!wakeup_count_.compare_exchange_weak(x, x - 1,
- std::memory_order_acquire,
- std::memory_order_relaxed)) {
- continue; // Raced with someone, retry.
- }
- // Successfully consumed a wakeup, we're done.
- waiter_count_.fetch_sub(1, std::memory_order_relaxed);
- return true;
- }
-
+ while (wakeup_count_ == 0) {
if (!first_pass) MaybeBecomeIdle();
// No wakeups available, time to wait.
if (!SleepConditionVariableSRW(cv, mu, t.InMillisecondsFromNow(), 0)) {
@@ -429,7 +442,7 @@ bool Waiter::Wait(KernelTimeout t) {
// initialization guarantees this is not a narrowing conversion.
const unsigned long err{GetLastError()}; // NOLINT(runtime/int)
if (err == ERROR_TIMEOUT) {
- waiter_count_.fetch_sub(1, std::memory_order_relaxed);
+ --waiter_count_;
return false;
} else {
ABSL_RAW_LOG(FATAL, "SleepConditionVariableSRW failed: %lu", err);
@@ -437,23 +450,27 @@ bool Waiter::Wait(KernelTimeout t) {
}
first_pass = false;
}
+ // Consume a wakeup and we're done.
+ --wakeup_count_;
+ --waiter_count_;
+ return true;
}
void Waiter::Post() {
- wakeup_count_.fetch_add(1, std::memory_order_release);
- Poke();
+ LockHolder h(WinHelper::GetLock(this));
+ ++wakeup_count_;
+ InternalCondVarPoke();
}
void Waiter::Poke() {
- if (waiter_count_.load(std::memory_order_relaxed) == 0) {
- return;
- }
- // Potentially a waiter. Take the lock and check again.
LockHolder h(WinHelper::GetLock(this));
- if (waiter_count_.load(std::memory_order_relaxed) == 0) {
- return;
+ InternalCondVarPoke();
+}
+
+void Waiter::InternalCondVarPoke() {
+ if (waiter_count_ != 0) {
+ WakeConditionVariable(WinHelper::GetCond(this));
}
- WakeConditionVariable(WinHelper::GetCond(this));
}
#else
diff --git a/absl/synchronization/internal/waiter.h b/absl/synchronization/internal/waiter.h
index c2389700..cac81d5f 100644
--- a/absl/synchronization/internal/waiter.h
+++ b/absl/synchronization/internal/waiter.h
@@ -58,14 +58,15 @@ namespace synchronization_internal {
// Waiter is an OS-specific semaphore.
class Waiter {
public:
- // No constructor, instances use the reserved space in ThreadIdentity.
- // All initialization logic belongs in `Init()`.
- Waiter() = delete;
+ // Prepare any data to track waits.
+ Waiter();
+
+ // Not copyable or movable
Waiter(const Waiter&) = delete;
Waiter& operator=(const Waiter&) = delete;
- // Prepare any data to track waits.
- void Init();
+ // Destroy any data to track waits.
+ ~Waiter();
// Blocks the calling thread until a matching call to `Post()` or
// `t` has passed. Returns `true` if woken (`Post()` called),
@@ -122,13 +123,8 @@ class Waiter {
std::atomic<int> wakeups_;
#elif ABSL_WAITER_MODE == ABSL_WAITER_MODE_WIN32
- // The Windows API has lots of choices for synchronization
- // primivitives. We are using SRWLOCK and CONDITION_VARIABLE
- // because they don't require a destructor to release system
- // resources.
- //
- // However, we can't include Windows.h in our headers, so we use aligned
- // storage buffers to define the storage.
+ // We can't include Windows.h in our headers, so we use aligned storage
+ // buffers to define the storage of SRWLOCK and CONDITION_VARIABLE.
using SRWLockStorage =
typename std::aligned_storage<sizeof(void*), alignof(void*)>::type;
using ConditionVariableStorage =
@@ -138,10 +134,13 @@ class Waiter {
// condition variable storage once the types are complete.
class WinHelper;
+ // REQUIRES: WinHelper::GetLock(this) must be held.
+ void InternalCondVarPoke();
+
SRWLockStorage mu_storage_;
ConditionVariableStorage cv_storage_;
- std::atomic<int> waiter_count_;
- std::atomic<int> wakeup_count_;
+ int waiter_count_;
+ int wakeup_count_;
#else
#error Unknown ABSL_WAITER_MODE
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 11:48:03 +0000