folly::parking_lot_detail::Bucket Struct Reference

#include <ParkingLot.h>

Public Member Functions
void	push_back (WaitNodeBase *node)
void	erase (WaitNodeBase *node)

Static Public Member Functions
static Bucket &	bucketFor (uint64_t key)

Public Attributes
std::mutex	mutex_
WaitNodeBase *	head_
WaitNodeBase *	tail_
std::atomic< uint64_t >	count_

Detailed Description

Definition at line 79 of file ParkingLot.h.

Member Function Documentation

Bucket & folly::parking_lot_detail::Bucket::bucketFor ( uint64_t  key )

static

Definition at line 23 of file ParkingLot.cpp.

References folly::kIsMobile.

Referenced by folly::ParkingLot< Data >::park_until(), and folly::ParkingLot< Data >::unpark().

                                      {
  constexpr size_t const kNumBuckets = kIsMobile ? 256 : 4096;

  // Statically allocating this lets us use this in allocation-sensitive
  // contexts. This relies on the assumption that std::mutex won't dynamically
  // allocate memory, which we assume to be the case on Linux and iOS.
  static Indestructible<std::array<Bucket, kNumBuckets>> gBuckets;
  return (*gBuckets)[key % kNumBuckets];
}

void folly::parking_lot_detail::Bucket::erase ( WaitNodeBase *  node )

inline

Definition at line 99 of file ParkingLot.h.

References FOLLY_SAFE_DCHECK, folly::parking_lot_detail::WaitNodeBase::next_, and folly::parking_lot_detail::WaitNodeBase::prev_.

                                 {
    FOLLY_SAFE_DCHECK(count_.load(std::memory_order_relaxed) >= 1, "");
    if (head_ == node && tail_ == node) {
      FOLLY_SAFE_DCHECK(node->prev_ == nullptr, "");
      FOLLY_SAFE_DCHECK(node->next_ == nullptr, "");
      head_ = nullptr;
      tail_ = nullptr;
    } else if (head_ == node) {
      FOLLY_SAFE_DCHECK(node->prev_ == nullptr, "");
      FOLLY_SAFE_DCHECK(node->next_, "");
      head_ = node->next_;
      head_->prev_ = nullptr;
    } else if (tail_ == node) {
      FOLLY_SAFE_DCHECK(node->next_ == nullptr, "");
      FOLLY_SAFE_DCHECK(node->prev_, "");
      tail_ = node->prev_;
      tail_->next_ = nullptr;
    } else {
      FOLLY_SAFE_DCHECK(node->next_, "");
      FOLLY_SAFE_DCHECK(node->prev_, "");
      node->next_->prev_ = node->prev_;
      node->prev_->next_ = node->next_;
    }
    count_.fetch_sub(1, std::memory_order_relaxed);
  }

void folly::parking_lot_detail::Bucket::push_back ( WaitNodeBase *  node )

inline

Definition at line 87 of file ParkingLot.h.

References FOLLY_SAFE_DCHECK, folly::parking_lot_detail::WaitNodeBase::next_, and folly::parking_lot_detail::WaitNodeBase::prev_.

                                     {
    if (tail_) {
      FOLLY_SAFE_DCHECK(head_, "");
      node->prev_ = tail_;
      tail_->next_ = node;
      tail_ = node;
    } else {
      tail_ = node;
      head_ = node;
    }
  }

Member Data Documentation

std::atomic<uint64_t> folly::parking_lot_detail::Bucket::count_

Definition at line 83 of file ParkingLot.h.

WaitNodeBase* folly::parking_lot_detail::Bucket::head_

Definition at line 81 of file ParkingLot.h.

std::mutex folly::parking_lot_detail::Bucket::mutex_

Definition at line 80 of file ParkingLot.h.

WaitNodeBase* folly::parking_lot_detail::Bucket::tail_

Definition at line 82 of file ParkingLot.h.

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

• proxygen/folly/folly/synchronization/ParkingLot.h
• proxygen/folly/folly/synchronization/ParkingLot.cpp