folly::threadlocal_detail::PthreadKeyUnregister Class Reference

#include <ThreadLocalDetail.h>

Public Member Functions
	~PthreadKeyUnregister ()

Static Public Member Functions
static void	registerKey (pthread_key_t key)

Static Public Attributes
static constexpr size_t	kMaxKeys = 1UL << 16

Private Member Functions
constexpr	PthreadKeyUnregister ()
void	registerKeyImpl (pthread_key_t key)

Private Attributes
MicroSpinLock	lock_
size_t	size_
pthread_key_t	keys_ [kMaxKeys]

Static Private Attributes
static PthreadKeyUnregister	instance_

Friends
struct	folly::threadlocal_detail::PthreadKeyUnregisterTester

Detailed Description

We want to disable onThreadExit call at the end of shutdown, we don't care about leaking memory at that point.

Otherwise if ThreadLocal is used in a shared library, onThreadExit may be called after dlclose().

This class has one single static instance; however since it's so widely used, directly or indirectly, by so many classes, we need to take care to avoid problems stemming from the Static Initialization/Destruction Order Fiascos. Therefore this class needs to be constexpr-constructible, so as to avoid the need for this to participate in init/destruction order.

Definition at line 256 of file ThreadLocalDetail.h.

Constructor & Destructor Documentation

folly::threadlocal_detail::PthreadKeyUnregister::~PthreadKeyUnregister ( )

inline

Definition at line 260 of file ThreadLocalDetail.h.

                          {
    // If static constructor priorities are not supported then
    // ~PthreadKeyUnregister logic is not safe.
#if !defined(__APPLE__) && !defined(_MSC_VER)
    MSLGuard lg(lock_);
    while (size_) {
      pthread_key_delete(keys_[--size_]);
    }
#endif
  }

constexpr folly::threadlocal_detail::PthreadKeyUnregister::PthreadKeyUnregister ( )

inlineprivate

Only one global instance should exist, hence this is private. See also the important note at the top of this class about constexpr usage.

Definition at line 281 of file ThreadLocalDetail.h.

: lock_(), size_(0), keys_() {}

Member Function Documentation

static void folly::threadlocal_detail::PthreadKeyUnregister::registerKey ( pthread_key_t  key )

inlinestatic

Definition at line 271 of file ThreadLocalDetail.h.

Referenced by folly::threadlocal_detail::StaticMetaBase::getThreadEntryList(), and folly::threadlocal_detail::StaticMetaBase::StaticMetaBase().

                                             {
    instance_.registerKeyImpl(key);
  }

void folly::threadlocal_detail::PthreadKeyUnregister::registerKeyImpl ( pthread_key_t  key )

inlineprivate

Definition at line 284 of file ThreadLocalDetail.h.

                                          {
    MSLGuard lg(lock_);
    if (size_ == kMaxKeys) {
      throw std::logic_error("pthread_key limit has already been reached");
    }
    keys_[size_++] = key;
  }

Friends And Related Function Documentation

friend struct folly::threadlocal_detail::PthreadKeyUnregisterTester

friend

Definition at line 282 of file ThreadLocalDetail.h.

Member Data Documentation

FOLLY_STATIC_CTOR_PRIORITY_MAX PthreadKeyUnregister folly::threadlocal_detail::PthreadKeyUnregister::instance_

staticprivate

Definition at line 296 of file ThreadLocalDetail.h.

Referenced by folly::threadlocal_detail::StaticMetaBase::pushBackUnlocked().

pthread_key_t folly::threadlocal_detail::PthreadKeyUnregister::keys_[kMaxKeys]

private

Definition at line 294 of file ThreadLocalDetail.h.

constexpr size_t folly::threadlocal_detail::PthreadKeyUnregister::kMaxKeys = 1UL << 16

static

Definition at line 258 of file ThreadLocalDetail.h.

MicroSpinLock folly::threadlocal_detail::PthreadKeyUnregister::lock_

private

Definition at line 292 of file ThreadLocalDetail.h.

size_t folly::threadlocal_detail::PthreadKeyUnregister::size_

private

Definition at line 293 of file ThreadLocalDetail.h.

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The documentation for this class was generated from the following files:

• proxygen/folly/folly/detail/ThreadLocalDetail.h
• proxygen/folly/folly/detail/ThreadLocalDetail.cpp