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authorGravatar Abseil Team <absl-team@google.com>2020-02-21 12:51:36 -0800
committerGravatar CJ Johnson <johnsoncj@google.com>2020-02-21 15:56:04 -0500
commitb69c7d880caddfc25bf348dbcfe9d45fdd8bc6e6 (patch)
tree0ceef2d75071fdfdf7a47c2978a4df5b422001ed /absl/synchronization/internal
parent2a5633fc077a58528cdbfe78720f3f6bfdc6044d (diff)
Export of internal Abseil changes
-- 00f5301405423005d9129935c05f20155536cc1a by CJ Johnson <johnsoncj@google.com>: Removes usage of std::aligned_storage from Abseil implementation details PiperOrigin-RevId: 296492301 -- fc11d15f91764612fba080669d2381dc181df52b by Abseil Team <absl-team@google.com>: Fix absl::bind_front documentation. PiperOrigin-RevId: 296482945 -- 0164c595c129c46bf21ae74eba5399a1da5f140b by Gennadiy Rozental <rogeeff@google.com>: Automated g4 rollback of changelist 296320700. PiperOrigin-RevId: 296439968 -- 1eb295700758ca0894d872b2de7c675b4ad679af by Abseil Team <absl-team@google.com>: Removes duplicate comments. PiperOrigin-RevId: 296433214 -- c30c01caae02d2fa4ef783d988de6bebb9757c39 by Derek Mauro <dmauro@google.com>: Merge GitHub #621: Add RISCV support to GetProgramCounter() Fixes #621 PiperOrigin-RevId: 296351174 -- 95d4498167596fd7543e025bdfe9a8da9e2ca3c8 by Abseil Team <absl-team@google.com>: Automated g4 rollback of changelist 296320700. PiperOrigin-RevId: 296348701 -- b193f0543e0cec54dddb2ed51f45dc489c8d06d5 by Gennadiy Rozental <rogeeff@google.com>: Change TryParse interface to return managed value. In addition introduce companion StoreValue routine which consumes pointer to source value and stores the value inside of FlagImpl. In a follow up CL we will change StoreValue implementation to behave differently depending on "value storage kind". We also rename default_src_ to default_value_. PiperOrigin-RevId: 296320700 -- 57e942b485d12912a0a8d0d0b35fa2a62847020f by Derek Mauro <dmauro@google.com>: Merge GitHub #622 * Add missing #ifdef conditionals for ABSL_HAVE_VDSO_SUPPORT PiperOrigin-RevId: 296272830 GitOrigin-RevId: 00f5301405423005d9129935c05f20155536cc1a Change-Id: I1b05eeaf1280f95fb0a2c5f3654995a87c792893
Diffstat (limited to 'absl/synchronization/internal')
-rw-r--r--absl/synchronization/internal/mutex_nonprod.inc4
-rw-r--r--absl/synchronization/internal/waiter.cc34
-rw-r--r--absl/synchronization/internal/waiter.h13
3 files changed, 22 insertions, 29 deletions
diff --git a/absl/synchronization/internal/mutex_nonprod.inc b/absl/synchronization/internal/mutex_nonprod.inc
index 85dae0ff..a1502e72 100644
--- a/absl/synchronization/internal/mutex_nonprod.inc
+++ b/absl/synchronization/internal/mutex_nonprod.inc
@@ -252,8 +252,8 @@ class SynchronizationStorage {
absl::once_flag once_;
- // An aligned space for T.
- typename std::aligned_storage<sizeof(T), alignof(T)>::type space_;
+ // An aligned space for the T.
+ alignas(T) unsigned char space_[sizeof(T)];
};
} // namespace synchronization_internal
diff --git a/absl/synchronization/internal/waiter.cc b/absl/synchronization/internal/waiter.cc
index ddd6081e..2949f5a8 100644
--- a/absl/synchronization/internal/waiter.cc
+++ b/absl/synchronization/internal/waiter.cc
@@ -368,31 +368,29 @@ class Waiter::WinHelper {
return reinterpret_cast<CONDITION_VARIABLE *>(&w->cv_storage_);
}
- static_assert(sizeof(SRWLOCK) == sizeof(Waiter::SRWLockStorage),
- "SRWLockStorage does not have the same size as SRWLOCK");
+ static_assert(sizeof(SRWLOCK) == sizeof(void *),
+ "`mu_storage_` does not have the same size as SRWLOCK");
+ static_assert(alignof(SRWLOCK) == alignof(void *),
+ "`mu_storage_` does not have the same alignment as SRWLOCK");
+
+ static_assert(sizeof(CONDITION_VARIABLE) == sizeof(void *),
+ "`ABSL_CONDITION_VARIABLE_STORAGE` does not have the same size "
+ "as `CONDITION_VARIABLE`");
static_assert(
- alignof(SRWLOCK) == alignof(Waiter::SRWLockStorage),
- "SRWLockStorage does not have the same alignment as SRWLOCK");
-
- static_assert(sizeof(CONDITION_VARIABLE) ==
- sizeof(Waiter::ConditionVariableStorage),
- "ABSL_CONDITION_VARIABLE_STORAGE does not have the same size "
- "as CONDITION_VARIABLE");
- static_assert(alignof(CONDITION_VARIABLE) ==
- alignof(Waiter::ConditionVariableStorage),
- "ConditionVariableStorage does not have the same "
- "alignment as CONDITION_VARIABLE");
+ alignof(CONDITION_VARIABLE) == alignof(void *),
+ "`cv_storage_` does not have the same alignment as `CONDITION_VARIABLE`");
// The SRWLOCK and CONDITION_VARIABLE types must be trivially constructible
// and destructible because we never call their constructors or destructors.
static_assert(std::is_trivially_constructible<SRWLOCK>::value,
- "The SRWLOCK type must be trivially constructible");
- static_assert(std::is_trivially_constructible<CONDITION_VARIABLE>::value,
- "The CONDITION_VARIABLE type must be trivially constructible");
+ "The `SRWLOCK` type must be trivially constructible");
+ static_assert(
+ std::is_trivially_constructible<CONDITION_VARIABLE>::value,
+ "The `CONDITION_VARIABLE` type must be trivially constructible");
static_assert(std::is_trivially_destructible<SRWLOCK>::value,
- "The SRWLOCK type must be trivially destructible");
+ "The `SRWLOCK` type must be trivially destructible");
static_assert(std::is_trivially_destructible<CONDITION_VARIABLE>::value,
- "The CONDITION_VARIABLE type must be trivially destructible");
+ "The `CONDITION_VARIABLE` type must be trivially destructible");
};
class LockHolder {
diff --git a/absl/synchronization/internal/waiter.h b/absl/synchronization/internal/waiter.h
index 5af5c282..a6e6d4c7 100644
--- a/absl/synchronization/internal/waiter.h
+++ b/absl/synchronization/internal/waiter.h
@@ -133,13 +133,6 @@ class Waiter {
std::atomic<int> wakeups_;
#elif ABSL_WAITER_MODE == ABSL_WAITER_MODE_WIN32
- // 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 =
- typename std::aligned_storage<sizeof(void*), alignof(void*)>::type;
-
// WinHelper - Used to define utilities for accessing the lock and
// condition variable storage once the types are complete.
class WinHelper;
@@ -147,8 +140,10 @@ class Waiter {
// REQUIRES: WinHelper::GetLock(this) must be held.
void InternalCondVarPoke();
- SRWLockStorage mu_storage_;
- ConditionVariableStorage cv_storage_;
+ // We can't include Windows.h in our headers, so we use aligned charachter
+ // buffers to define the storage of SRWLOCK and CONDITION_VARIABLE.
+ alignas(void*) unsigned char mu_storage_[sizeof(void*)];
+ alignas(void*) unsigned char cv_storage_[sizeof(void*)];
int waiter_count_;
int wakeup_count_;