{

typedef ::moodycamel::ConcurrentQueue<T, Traits> ConcurrentQueue;

typedef ::moodycamel::LightweightSemaphore LightweightSemaphore;

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;

// 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);

}

BlockingConcurrentQueue& swap_internal(BlockingConcurrentQueue& other)

{

if (this == &other) {

return *this;

}

inner.swap(other.inner);

sema.swap(other.sema);

return *this;

}

// 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();

}

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);

}

ConcurrentQueue inner;

std::unique_ptr<LightweightSemaphore, void (*)(LightweightSemaphore*)> sema;