mirror of https://github.com/trapexit/mergerfs.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
582 lines
21 KiB
582 lines
21 KiB
// Provides an efficient blocking version of moodycamel::ConcurrentQueue.
|
|
// ©2015-2020 Cameron Desrochers. Distributed under the terms of the simplified
|
|
// BSD license, available at the top of concurrentqueue.h.
|
|
// Also dual-licensed under the Boost Software License (see LICENSE.md)
|
|
// Uses Jeff Preshing's semaphore implementation (under the terms of its
|
|
// separate zlib license, see lightweightsemaphore.h).
|
|
|
|
#pragma once
|
|
|
|
#include "concurrentqueue.h"
|
|
#include "lightweightsemaphore.h"
|
|
|
|
#include <type_traits>
|
|
#include <cerrno>
|
|
#include <memory>
|
|
#include <chrono>
|
|
#include <ctime>
|
|
|
|
namespace moodycamel
|
|
{
|
|
// This is a blocking version of the queue. It has an almost identical interface to
|
|
// the normal non-blocking version, with the addition of various wait_dequeue() methods
|
|
// and the removal of producer-specific dequeue methods.
|
|
template<typename T, typename Traits = ConcurrentQueueDefaultTraits>
|
|
class BlockingConcurrentQueue
|
|
{
|
|
private:
|
|
typedef ::moodycamel::ConcurrentQueue<T, Traits> ConcurrentQueue;
|
|
typedef ::moodycamel::LightweightSemaphore LightweightSemaphore;
|
|
|
|
public:
|
|
typedef typename ConcurrentQueue::producer_token_t producer_token_t;
|
|
typedef typename ConcurrentQueue::consumer_token_t consumer_token_t;
|
|
|
|
typedef typename ConcurrentQueue::index_t index_t;
|
|
typedef typename ConcurrentQueue::size_t size_t;
|
|
typedef typename std::make_signed<size_t>::type ssize_t;
|
|
|
|
static const size_t BLOCK_SIZE = ConcurrentQueue::BLOCK_SIZE;
|
|
static const size_t EXPLICIT_BLOCK_EMPTY_COUNTER_THRESHOLD = ConcurrentQueue::EXPLICIT_BLOCK_EMPTY_COUNTER_THRESHOLD;
|
|
static const size_t EXPLICIT_INITIAL_INDEX_SIZE = ConcurrentQueue::EXPLICIT_INITIAL_INDEX_SIZE;
|
|
static const size_t IMPLICIT_INITIAL_INDEX_SIZE = ConcurrentQueue::IMPLICIT_INITIAL_INDEX_SIZE;
|
|
static const size_t INITIAL_IMPLICIT_PRODUCER_HASH_SIZE = ConcurrentQueue::INITIAL_IMPLICIT_PRODUCER_HASH_SIZE;
|
|
static const std::uint32_t EXPLICIT_CONSUMER_CONSUMPTION_QUOTA_BEFORE_ROTATE = ConcurrentQueue::EXPLICIT_CONSUMER_CONSUMPTION_QUOTA_BEFORE_ROTATE;
|
|
static const size_t MAX_SUBQUEUE_SIZE = ConcurrentQueue::MAX_SUBQUEUE_SIZE;
|
|
|
|
public:
|
|
// Creates a queue with at least `capacity` element slots; note that the
|
|
// actual number of elements that can be inserted without additional memory
|
|
// allocation depends on the number of producers and the block size (e.g. if
|
|
// the block size is equal to `capacity`, only a single block will be allocated
|
|
// up-front, which means only a single producer will be able to enqueue elements
|
|
// without an extra allocation -- blocks aren't shared between producers).
|
|
// This method is not thread safe -- it is up to the user to ensure that the
|
|
// queue is fully constructed before it starts being used by other threads (this
|
|
// includes making the memory effects of construction visible, possibly with a
|
|
// memory barrier).
|
|
explicit BlockingConcurrentQueue(size_t capacity = 6 * BLOCK_SIZE)
|
|
: inner(capacity), sema(create<LightweightSemaphore, ssize_t, int>(0, (int)Traits::MAX_SEMA_SPINS), &BlockingConcurrentQueue::template destroy<LightweightSemaphore>)
|
|
{
|
|
assert(reinterpret_cast<ConcurrentQueue*>((BlockingConcurrentQueue*)1) == &((BlockingConcurrentQueue*)1)->inner && "BlockingConcurrentQueue must have ConcurrentQueue as its first member");
|
|
if (!sema) {
|
|
MOODYCAMEL_THROW(std::bad_alloc());
|
|
}
|
|
}
|
|
|
|
BlockingConcurrentQueue(size_t minCapacity, size_t maxExplicitProducers, size_t maxImplicitProducers)
|
|
: inner(minCapacity, maxExplicitProducers, maxImplicitProducers), sema(create<LightweightSemaphore, ssize_t, int>(0, (int)Traits::MAX_SEMA_SPINS), &BlockingConcurrentQueue::template destroy<LightweightSemaphore>)
|
|
{
|
|
assert(reinterpret_cast<ConcurrentQueue*>((BlockingConcurrentQueue*)1) == &((BlockingConcurrentQueue*)1)->inner && "BlockingConcurrentQueue must have ConcurrentQueue as its first member");
|
|
if (!sema) {
|
|
MOODYCAMEL_THROW(std::bad_alloc());
|
|
}
|
|
}
|
|
|
|
// Disable copying and copy assignment
|
|
BlockingConcurrentQueue(BlockingConcurrentQueue const&) MOODYCAMEL_DELETE_FUNCTION;
|
|
BlockingConcurrentQueue& operator=(BlockingConcurrentQueue const&) MOODYCAMEL_DELETE_FUNCTION;
|
|
|
|
// Moving is supported, but note that it is *not* a thread-safe operation.
|
|
// Nobody can use the queue while it's being moved, and the memory effects
|
|
// of that move must be propagated to other threads before they can use it.
|
|
// Note: When a queue is moved, its tokens are still valid but can only be
|
|
// used with the destination queue (i.e. semantically they are moved along
|
|
// with the queue itself).
|
|
BlockingConcurrentQueue(BlockingConcurrentQueue&& other) MOODYCAMEL_NOEXCEPT
|
|
: inner(std::move(other.inner)), sema(std::move(other.sema))
|
|
{ }
|
|
|
|
inline BlockingConcurrentQueue& operator=(BlockingConcurrentQueue&& other) MOODYCAMEL_NOEXCEPT
|
|
{
|
|
return swap_internal(other);
|
|
}
|
|
|
|
// Swaps this queue's state with the other's. Not thread-safe.
|
|
// Swapping two queues does not invalidate their tokens, however
|
|
// the tokens that were created for one queue must be used with
|
|
// only the swapped queue (i.e. the tokens are tied to the
|
|
// queue's movable state, not the object itself).
|
|
inline void swap(BlockingConcurrentQueue& other) MOODYCAMEL_NOEXCEPT
|
|
{
|
|
swap_internal(other);
|
|
}
|
|
|
|
private:
|
|
BlockingConcurrentQueue& swap_internal(BlockingConcurrentQueue& other)
|
|
{
|
|
if (this == &other) {
|
|
return *this;
|
|
}
|
|
|
|
inner.swap(other.inner);
|
|
sema.swap(other.sema);
|
|
return *this;
|
|
}
|
|
|
|
public:
|
|
// Enqueues a single item (by copying it).
|
|
// Allocates memory if required. Only fails if memory allocation fails (or implicit
|
|
// production is disabled because Traits::INITIAL_IMPLICIT_PRODUCER_HASH_SIZE is 0,
|
|
// or Traits::MAX_SUBQUEUE_SIZE has been defined and would be surpassed).
|
|
// Thread-safe.
|
|
inline bool enqueue(T const& item)
|
|
{
|
|
if ((details::likely)(inner.enqueue(item))) {
|
|
sema->signal();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues a single item (by moving it, if possible).
|
|
// Allocates memory if required. Only fails if memory allocation fails (or implicit
|
|
// production is disabled because Traits::INITIAL_IMPLICIT_PRODUCER_HASH_SIZE is 0,
|
|
// or Traits::MAX_SUBQUEUE_SIZE has been defined and would be surpassed).
|
|
// Thread-safe.
|
|
inline bool enqueue(T&& item)
|
|
{
|
|
if ((details::likely)(inner.enqueue(std::move(item)))) {
|
|
sema->signal();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues a single item (by copying it) using an explicit producer token.
|
|
// Allocates memory if required. Only fails if memory allocation fails (or
|
|
// Traits::MAX_SUBQUEUE_SIZE has been defined and would be surpassed).
|
|
// Thread-safe.
|
|
inline bool enqueue(producer_token_t const& token, T const& item)
|
|
{
|
|
if ((details::likely)(inner.enqueue(token, item))) {
|
|
sema->signal();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues a single item (by moving it, if possible) using an explicit producer token.
|
|
// Allocates memory if required. Only fails if memory allocation fails (or
|
|
// Traits::MAX_SUBQUEUE_SIZE has been defined and would be surpassed).
|
|
// Thread-safe.
|
|
inline bool enqueue(producer_token_t const& token, T&& item)
|
|
{
|
|
if ((details::likely)(inner.enqueue(token, std::move(item)))) {
|
|
sema->signal();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues several items.
|
|
// Allocates memory if required. Only fails if memory allocation fails (or
|
|
// implicit production is disabled because Traits::INITIAL_IMPLICIT_PRODUCER_HASH_SIZE
|
|
// is 0, or Traits::MAX_SUBQUEUE_SIZE has been defined and would be surpassed).
|
|
// Note: Use std::make_move_iterator if the elements should be moved instead of copied.
|
|
// Thread-safe.
|
|
template<typename It>
|
|
inline bool enqueue_bulk(It itemFirst, size_t count)
|
|
{
|
|
if ((details::likely)(inner.enqueue_bulk(std::forward<It>(itemFirst), count))) {
|
|
sema->signal((LightweightSemaphore::ssize_t)(ssize_t)count);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues several items using an explicit producer token.
|
|
// Allocates memory if required. Only fails if memory allocation fails
|
|
// (or Traits::MAX_SUBQUEUE_SIZE has been defined and would be surpassed).
|
|
// Note: Use std::make_move_iterator if the elements should be moved
|
|
// instead of copied.
|
|
// Thread-safe.
|
|
template<typename It>
|
|
inline bool enqueue_bulk(producer_token_t const& token, It itemFirst, size_t count)
|
|
{
|
|
if ((details::likely)(inner.enqueue_bulk(token, std::forward<It>(itemFirst), count))) {
|
|
sema->signal((LightweightSemaphore::ssize_t)(ssize_t)count);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues a single item (by copying it).
|
|
// Does not allocate memory. Fails if not enough room to enqueue (or implicit
|
|
// production is disabled because Traits::INITIAL_IMPLICIT_PRODUCER_HASH_SIZE
|
|
// is 0).
|
|
// Thread-safe.
|
|
inline bool try_enqueue(T const& item)
|
|
{
|
|
if (inner.try_enqueue(item)) {
|
|
sema->signal();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues a single item (by moving it, if possible).
|
|
// Does not allocate memory (except for one-time implicit producer).
|
|
// Fails if not enough room to enqueue (or implicit production is
|
|
// disabled because Traits::INITIAL_IMPLICIT_PRODUCER_HASH_SIZE is 0).
|
|
// Thread-safe.
|
|
inline bool try_enqueue(T&& item)
|
|
{
|
|
if (inner.try_enqueue(std::move(item))) {
|
|
sema->signal();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues a single item (by copying it) using an explicit producer token.
|
|
// Does not allocate memory. Fails if not enough room to enqueue.
|
|
// Thread-safe.
|
|
inline bool try_enqueue(producer_token_t const& token, T const& item)
|
|
{
|
|
if (inner.try_enqueue(token, item)) {
|
|
sema->signal();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues a single item (by moving it, if possible) using an explicit producer token.
|
|
// Does not allocate memory. Fails if not enough room to enqueue.
|
|
// Thread-safe.
|
|
inline bool try_enqueue(producer_token_t const& token, T&& item)
|
|
{
|
|
if (inner.try_enqueue(token, std::move(item))) {
|
|
sema->signal();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues several items.
|
|
// Does not allocate memory (except for one-time implicit producer).
|
|
// Fails if not enough room to enqueue (or implicit production is
|
|
// disabled because Traits::INITIAL_IMPLICIT_PRODUCER_HASH_SIZE is 0).
|
|
// Note: Use std::make_move_iterator if the elements should be moved
|
|
// instead of copied.
|
|
// Thread-safe.
|
|
template<typename It>
|
|
inline bool try_enqueue_bulk(It itemFirst, size_t count)
|
|
{
|
|
if (inner.try_enqueue_bulk(std::forward<It>(itemFirst), count)) {
|
|
sema->signal((LightweightSemaphore::ssize_t)(ssize_t)count);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Enqueues several items using an explicit producer token.
|
|
// Does not allocate memory. Fails if not enough room to enqueue.
|
|
// Note: Use std::make_move_iterator if the elements should be moved
|
|
// instead of copied.
|
|
// Thread-safe.
|
|
template<typename It>
|
|
inline bool try_enqueue_bulk(producer_token_t const& token, It itemFirst, size_t count)
|
|
{
|
|
if (inner.try_enqueue_bulk(token, std::forward<It>(itemFirst), count)) {
|
|
sema->signal((LightweightSemaphore::ssize_t)(ssize_t)count);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
// Attempts to dequeue from the queue.
|
|
// Returns false if all producer streams appeared empty at the time they
|
|
// were checked (so, the queue is likely but not guaranteed to be empty).
|
|
// Never allocates. Thread-safe.
|
|
template<typename U>
|
|
inline bool try_dequeue(U& item)
|
|
{
|
|
if (sema->tryWait()) {
|
|
while (!inner.try_dequeue(item)) {
|
|
continue;
|
|
}
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Attempts to dequeue from the queue using an explicit consumer token.
|
|
// Returns false if all producer streams appeared empty at the time they
|
|
// were checked (so, the queue is likely but not guaranteed to be empty).
|
|
// Never allocates. Thread-safe.
|
|
template<typename U>
|
|
inline bool try_dequeue(consumer_token_t& token, U& item)
|
|
{
|
|
if (sema->tryWait()) {
|
|
while (!inner.try_dequeue(token, item)) {
|
|
continue;
|
|
}
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Attempts to dequeue several elements from the queue.
|
|
// Returns the number of items actually dequeued.
|
|
// Returns 0 if all producer streams appeared empty at the time they
|
|
// were checked (so, the queue is likely but not guaranteed to be empty).
|
|
// Never allocates. Thread-safe.
|
|
template<typename It>
|
|
inline size_t try_dequeue_bulk(It itemFirst, size_t max)
|
|
{
|
|
size_t count = 0;
|
|
max = (size_t)sema->tryWaitMany((LightweightSemaphore::ssize_t)(ssize_t)max);
|
|
while (count != max) {
|
|
count += inner.template try_dequeue_bulk<It&>(itemFirst, max - count);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
// Attempts to dequeue several elements from the queue using an explicit consumer token.
|
|
// Returns the number of items actually dequeued.
|
|
// Returns 0 if all producer streams appeared empty at the time they
|
|
// were checked (so, the queue is likely but not guaranteed to be empty).
|
|
// Never allocates. Thread-safe.
|
|
template<typename It>
|
|
inline size_t try_dequeue_bulk(consumer_token_t& token, It itemFirst, size_t max)
|
|
{
|
|
size_t count = 0;
|
|
max = (size_t)sema->tryWaitMany((LightweightSemaphore::ssize_t)(ssize_t)max);
|
|
while (count != max) {
|
|
count += inner.template try_dequeue_bulk<It&>(token, itemFirst, max - count);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
|
|
|
|
// Blocks the current thread until there's something to dequeue, then
|
|
// dequeues it.
|
|
// Never allocates. Thread-safe.
|
|
template<typename U>
|
|
inline void wait_dequeue(U& item)
|
|
{
|
|
while (!sema->wait()) {
|
|
continue;
|
|
}
|
|
while (!inner.try_dequeue(item)) {
|
|
continue;
|
|
}
|
|
}
|
|
|
|
// Blocks the current thread until either there's something to dequeue
|
|
// or the timeout (specified in microseconds) expires. Returns false
|
|
// without setting `item` if the timeout expires, otherwise assigns
|
|
// to `item` and returns true.
|
|
// Using a negative timeout indicates an indefinite timeout,
|
|
// and is thus functionally equivalent to calling wait_dequeue.
|
|
// Never allocates. Thread-safe.
|
|
template<typename U>
|
|
inline bool wait_dequeue_timed(U& item, std::int64_t timeout_usecs)
|
|
{
|
|
if (!sema->wait(timeout_usecs)) {
|
|
return false;
|
|
}
|
|
while (!inner.try_dequeue(item)) {
|
|
continue;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Blocks the current thread until either there's something to dequeue
|
|
// or the timeout expires. Returns false without setting `item` if the
|
|
// timeout expires, otherwise assigns to `item` and returns true.
|
|
// Never allocates. Thread-safe.
|
|
template<typename U, typename Rep, typename Period>
|
|
inline bool wait_dequeue_timed(U& item, std::chrono::duration<Rep, Period> const& timeout)
|
|
{
|
|
return wait_dequeue_timed(item, std::chrono::duration_cast<std::chrono::microseconds>(timeout).count());
|
|
}
|
|
|
|
// Blocks the current thread until there's something to dequeue, then
|
|
// dequeues it using an explicit consumer token.
|
|
// Never allocates. Thread-safe.
|
|
template<typename U>
|
|
inline void wait_dequeue(consumer_token_t& token, U& item)
|
|
{
|
|
while (!sema->wait()) {
|
|
continue;
|
|
}
|
|
while (!inner.try_dequeue(token, item)) {
|
|
continue;
|
|
}
|
|
}
|
|
|
|
// Blocks the current thread until either there's something to dequeue
|
|
// or the timeout (specified in microseconds) expires. Returns false
|
|
// without setting `item` if the timeout expires, otherwise assigns
|
|
// to `item` and returns true.
|
|
// Using a negative timeout indicates an indefinite timeout,
|
|
// and is thus functionally equivalent to calling wait_dequeue.
|
|
// Never allocates. Thread-safe.
|
|
template<typename U>
|
|
inline bool wait_dequeue_timed(consumer_token_t& token, U& item, std::int64_t timeout_usecs)
|
|
{
|
|
if (!sema->wait(timeout_usecs)) {
|
|
return false;
|
|
}
|
|
while (!inner.try_dequeue(token, item)) {
|
|
continue;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Blocks the current thread until either there's something to dequeue
|
|
// or the timeout expires. Returns false without setting `item` if the
|
|
// timeout expires, otherwise assigns to `item` and returns true.
|
|
// Never allocates. Thread-safe.
|
|
template<typename U, typename Rep, typename Period>
|
|
inline bool wait_dequeue_timed(consumer_token_t& token, U& item, std::chrono::duration<Rep, Period> const& timeout)
|
|
{
|
|
return wait_dequeue_timed(token, item, std::chrono::duration_cast<std::chrono::microseconds>(timeout).count());
|
|
}
|
|
|
|
// Attempts to dequeue several elements from the queue.
|
|
// Returns the number of items actually dequeued, which will
|
|
// always be at least one (this method blocks until the queue
|
|
// is non-empty) and at most max.
|
|
// Never allocates. Thread-safe.
|
|
template<typename It>
|
|
inline size_t wait_dequeue_bulk(It itemFirst, size_t max)
|
|
{
|
|
size_t count = 0;
|
|
max = (size_t)sema->waitMany((LightweightSemaphore::ssize_t)(ssize_t)max);
|
|
while (count != max) {
|
|
count += inner.template try_dequeue_bulk<It&>(itemFirst, max - count);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
// Attempts to dequeue several elements from the queue.
|
|
// Returns the number of items actually dequeued, which can
|
|
// be 0 if the timeout expires while waiting for elements,
|
|
// and at most max.
|
|
// Using a negative timeout indicates an indefinite timeout,
|
|
// and is thus functionally equivalent to calling wait_dequeue_bulk.
|
|
// Never allocates. Thread-safe.
|
|
template<typename It>
|
|
inline size_t wait_dequeue_bulk_timed(It itemFirst, size_t max, std::int64_t timeout_usecs)
|
|
{
|
|
size_t count = 0;
|
|
max = (size_t)sema->waitMany((LightweightSemaphore::ssize_t)(ssize_t)max, timeout_usecs);
|
|
while (count != max) {
|
|
count += inner.template try_dequeue_bulk<It&>(itemFirst, max - count);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
// Attempts to dequeue several elements from the queue.
|
|
// Returns the number of items actually dequeued, which can
|
|
// be 0 if the timeout expires while waiting for elements,
|
|
// and at most max.
|
|
// Never allocates. Thread-safe.
|
|
template<typename It, typename Rep, typename Period>
|
|
inline size_t wait_dequeue_bulk_timed(It itemFirst, size_t max, std::chrono::duration<Rep, Period> const& timeout)
|
|
{
|
|
return wait_dequeue_bulk_timed<It&>(itemFirst, max, std::chrono::duration_cast<std::chrono::microseconds>(timeout).count());
|
|
}
|
|
|
|
// Attempts to dequeue several elements from the queue using an explicit consumer token.
|
|
// Returns the number of items actually dequeued, which will
|
|
// always be at least one (this method blocks until the queue
|
|
// is non-empty) and at most max.
|
|
// Never allocates. Thread-safe.
|
|
template<typename It>
|
|
inline size_t wait_dequeue_bulk(consumer_token_t& token, It itemFirst, size_t max)
|
|
{
|
|
size_t count = 0;
|
|
max = (size_t)sema->waitMany((LightweightSemaphore::ssize_t)(ssize_t)max);
|
|
while (count != max) {
|
|
count += inner.template try_dequeue_bulk<It&>(token, itemFirst, max - count);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
// Attempts to dequeue several elements from the queue using an explicit consumer token.
|
|
// Returns the number of items actually dequeued, which can
|
|
// be 0 if the timeout expires while waiting for elements,
|
|
// and at most max.
|
|
// Using a negative timeout indicates an indefinite timeout,
|
|
// and is thus functionally equivalent to calling wait_dequeue_bulk.
|
|
// Never allocates. Thread-safe.
|
|
template<typename It>
|
|
inline size_t wait_dequeue_bulk_timed(consumer_token_t& token, It itemFirst, size_t max, std::int64_t timeout_usecs)
|
|
{
|
|
size_t count = 0;
|
|
max = (size_t)sema->waitMany((LightweightSemaphore::ssize_t)(ssize_t)max, timeout_usecs);
|
|
while (count != max) {
|
|
count += inner.template try_dequeue_bulk<It&>(token, itemFirst, max - count);
|
|
}
|
|
return count;
|
|
}
|
|
|
|
// Attempts to dequeue several elements from the queue using an explicit consumer token.
|
|
// Returns the number of items actually dequeued, which can
|
|
// be 0 if the timeout expires while waiting for elements,
|
|
// and at most max.
|
|
// Never allocates. Thread-safe.
|
|
template<typename It, typename Rep, typename Period>
|
|
inline size_t wait_dequeue_bulk_timed(consumer_token_t& token, It itemFirst, size_t max, std::chrono::duration<Rep, Period> const& timeout)
|
|
{
|
|
return wait_dequeue_bulk_timed<It&>(token, itemFirst, max, std::chrono::duration_cast<std::chrono::microseconds>(timeout).count());
|
|
}
|
|
|
|
|
|
// Returns an estimate of the total number of elements currently in the queue. This
|
|
// estimate is only accurate if the queue has completely stabilized before it is called
|
|
// (i.e. all enqueue and dequeue operations have completed and their memory effects are
|
|
// visible on the calling thread, and no further operations start while this method is
|
|
// being called).
|
|
// Thread-safe.
|
|
inline size_t size_approx() const
|
|
{
|
|
return (size_t)sema->availableApprox();
|
|
}
|
|
|
|
|
|
// Returns true if the underlying atomic variables used by
|
|
// the queue are lock-free (they should be on most platforms).
|
|
// Thread-safe.
|
|
static constexpr bool is_lock_free()
|
|
{
|
|
return ConcurrentQueue::is_lock_free();
|
|
}
|
|
|
|
|
|
private:
|
|
template<typename U, typename A1, typename A2>
|
|
static inline U* create(A1&& a1, A2&& a2)
|
|
{
|
|
void* p = (Traits::malloc)(sizeof(U));
|
|
return p != nullptr ? new (p) U(std::forward<A1>(a1), std::forward<A2>(a2)) : nullptr;
|
|
}
|
|
|
|
template<typename U>
|
|
static inline void destroy(U* p)
|
|
{
|
|
if (p != nullptr) {
|
|
p->~U();
|
|
}
|
|
(Traits::free)(p);
|
|
}
|
|
|
|
private:
|
|
ConcurrentQueue inner;
|
|
std::unique_ptr<LightweightSemaphore, void (*)(LightweightSemaphore*)> sema;
|
|
};
|
|
|
|
|
|
template<typename T, typename Traits>
|
|
inline void swap(BlockingConcurrentQueue<T, Traits>& a, BlockingConcurrentQueue<T, Traits>& b) MOODYCAMEL_NOEXCEPT
|
|
{
|
|
a.swap(b);
|
|
}
|
|
|
|
} // end namespace moodycamel
|