Edit: /usr/include/oneapi/tbb/concurrent_priority_queue.h (19531B)
/*
Copyright (c) 2005-2021 Intel Corporation
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#ifndef __TBB_concurrent_priority_queue_H
#define __TBB_concurrent_priority_queue_H
#include "detail/_namespace_injection.h"
#include "detail/_aggregator.h"
#include "detail/_template_helpers.h"
#include "detail/_allocator_traits.h"
#include "detail/_range_common.h"
#include "detail/_exception.h"
#include "detail/_utils.h"
#include "detail/_containers_helpers.h"
#include "cache_aligned_allocator.h"
#include
#include
#include
#include
#include
#include
namespace tbb {
namespace detail {
namespace d1 {
template , typename Allocator = cache_aligned_allocator>
class concurrent_priority_queue {
public:
using value_type = T;
using reference = T&;
using const_reference = const T&;
using size_type = std::size_t;
using difference_type = std::ptrdiff_t;
using allocator_type = Allocator;
concurrent_priority_queue() : concurrent_priority_queue(allocator_type{}) {}
explicit concurrent_priority_queue( const allocator_type& alloc )
: mark(0), my_size(0), my_compare(), data(alloc)
{
my_aggregator.initialize_handler(functor{this});
}
explicit concurrent_priority_queue( const Compare& compare, const allocator_type& alloc = allocator_type() )
: mark(0), my_size(0), my_compare(compare), data(alloc)
{
my_aggregator.initialize_handler(functor{this});
}
explicit concurrent_priority_queue( size_type init_capacity, const allocator_type& alloc = allocator_type() )
: mark(0), my_size(0), my_compare(), data(alloc)
{
data.reserve(init_capacity);
my_aggregator.initialize_handler(functor{this});
}
explicit concurrent_priority_queue( size_type init_capacity, const Compare& compare, const allocator_type& alloc = allocator_type() )
: mark(0), my_size(0), my_compare(compare), data(alloc)
{
data.reserve(init_capacity);
my_aggregator.initialize_handler(functor{this});
}
template
concurrent_priority_queue( InputIterator begin, InputIterator end, const Compare& compare, const allocator_type& alloc = allocator_type() )
: mark(0), my_compare(compare), data(begin, end, alloc)
{
my_aggregator.initialize_handler(functor{this});
heapify();
my_size.store(data.size(), std::memory_order_relaxed);
}
template
concurrent_priority_queue( InputIterator begin, InputIterator end, const allocator_type& alloc = allocator_type() )
: concurrent_priority_queue(begin, end, Compare(), alloc) {}
concurrent_priority_queue( std::initializer_list init, const Compare& compare, const allocator_type& alloc = allocator_type() )
: concurrent_priority_queue(init.begin(), init.end(), compare, alloc) {}
concurrent_priority_queue( std::initializer_list init, const allocator_type& alloc = allocator_type() )
: concurrent_priority_queue(init, Compare(), alloc) {}
concurrent_priority_queue( const concurrent_priority_queue& other )
: mark(other.mark), my_size(other.my_size.load(std::memory_order_relaxed)), my_compare(other.my_compare),
data(other.data)
{
my_aggregator.initialize_handler(functor{this});
}
concurrent_priority_queue( const concurrent_priority_queue& other, const allocator_type& alloc )
: mark(other.mark), my_size(other.my_size.load(std::memory_order_relaxed)), my_compare(other.my_compare),
data(other.data, alloc)
{
my_aggregator.initialize_handler(functor{this});
}
concurrent_priority_queue( concurrent_priority_queue&& other )
: mark(other.mark), my_size(other.my_size.load(std::memory_order_relaxed)), my_compare(other.my_compare),
data(std::move(other.data))
{
my_aggregator.initialize_handler(functor{this});
}
concurrent_priority_queue( concurrent_priority_queue&& other, const allocator_type& alloc )
: mark(other.mark), my_size(other.my_size.load(std::memory_order_relaxed)), my_compare(other.my_compare),
data(std::move(other.data), alloc)
{
my_aggregator.initialize_handler(functor{this});
}
concurrent_priority_queue& operator=( const concurrent_priority_queue& other ) {
if (this != &other) {
data = other.data;
mark = other.mark;
my_size.store(other.my_size.load(std::memory_order_relaxed), std::memory_order_relaxed);
}
return *this;
}
concurrent_priority_queue& operator=( concurrent_priority_queue&& other ) {
if (this != &other) {
// TODO: check if exceptions from std::vector::operator=(vector&&) should be handled separately
data = std::move(other.data);
mark = other.mark;
my_size.store(other.my_size.load(std::memory_order_relaxed), std::memory_order_relaxed);
}
return *this;
}
concurrent_priority_queue& operator=( std::initializer_list init ) {
assign(init.begin(), init.end());
return *this;
}
template
void assign( InputIterator begin, InputIterator end ) {
data.assign(begin, end);
mark = 0;
my_size.store(data.size(), std::memory_order_relaxed);
heapify();
}
void assign( std::initializer_list init ) {
assign(init.begin(), init.end());
}
/* Returned value may not reflect results of pending operations.
This operation reads shared data and will trigger a race condition. */
__TBB_nodiscard bool empty() const { return size() == 0; }
// Returns the current number of elements contained in the queue
/* Returned value may not reflect results of pending operations.
This operation reads shared data and will trigger a race condition. */
size_type size() const { return my_size.load(std::memory_order_relaxed); }
/* This operation can be safely used concurrently with other push, try_pop or emplace operations. */
void push( const value_type& value ) {
cpq_operation op_data(value, PUSH_OP);
my_aggregator.execute(&op_data);
if (op_data.status == FAILED)
throw_exception(exception_id::bad_alloc);
}
/* This operation can be safely used concurrently with other push, try_pop or emplace operations. */
void push( value_type&& value ) {
cpq_operation op_data(value, PUSH_RVALUE_OP);
my_aggregator.execute(&op_data);
if (op_data.status == FAILED)
throw_exception(exception_id::bad_alloc);
}
/* This operation can be safely used concurrently with other push, try_pop or emplace operations. */
template
void emplace( Args&&... args ) {
// TODO: support uses allocator construction in this place
push(value_type(std::forward(args)...));
}
// Gets a reference to and removes highest priority element
/* If a highest priority element was found, sets elem and returns true,
otherwise returns false.
This operation can be safely used concurrently with other push, try_pop or emplace operations. */
bool try_pop( value_type& value ) {
cpq_operation op_data(value, POP_OP);
my_aggregator.execute(&op_data);
return op_data.status == SUCCEEDED;
}
// This operation affects the whole container => it is not thread-safe
void clear() {
data.clear();
mark = 0;
my_size.store(0, std::memory_order_relaxed);
}
// This operation affects the whole container => it is not thread-safe
void swap( concurrent_priority_queue& other ) {
if (this != &other) {
using std::swap;
swap(data, other.data);
swap(mark, other.mark);
size_type sz = my_size.load(std::memory_order_relaxed);
my_size.store(other.my_size.load(std::memory_order_relaxed), std::memory_order_relaxed);
other.my_size.store(sz, std::memory_order_relaxed);
}
}
allocator_type get_allocator() const { return data.get_allocator(); }
private:
enum operation_type {INVALID_OP, PUSH_OP, POP_OP, PUSH_RVALUE_OP};
enum operation_status {WAIT = 0, SUCCEEDED, FAILED};
class cpq_operation : public aggregated_operation {
public:
operation_type type;
union {
value_type* elem;
size_type sz;
};
cpq_operation( const value_type& value, operation_type t )
: type(t), elem(const_cast(&value)) {}
}; // class cpq_operation
class functor {
concurrent_priority_queue* my_cpq;
public:
functor() : my_cpq(nullptr) {}
functor( concurrent_priority_queue* cpq ) : my_cpq(cpq) {}
void operator()(cpq_operation* op_list) {
__TBB_ASSERT(my_cpq != nullptr, "Invalid functor");
my_cpq->handle_operations(op_list);
}
}; // class functor
void handle_operations( cpq_operation* op_list ) {
call_itt_notify(acquired, this);
cpq_operation* tmp, *pop_list = nullptr;
__TBB_ASSERT(mark == data.size(), NULL);
// First pass processes all constant (amortized; reallocation may happen) time pushes and pops.
while(op_list) {
// ITT note: &(op_list->status) tag is used to cover accesses to op_list
// node. This thread is going to handle the operation, and so will acquire it
// and perform the associated operation w/o triggering a race condition; the
// thread that created the operation is waiting on the status field, so when
// this thread is done with the operation, it will perform a
// store_with_release to give control back to the waiting thread in
// aggregator::insert_operation.
// TODO: enable
call_itt_notify(acquired, &(op_list->status));
__TBB_ASSERT(op_list->type != INVALID_OP, NULL);
tmp = op_list;
op_list = op_list->next.load(std::memory_order_relaxed);
if (tmp->type == POP_OP) {
if (mark < data.size() &&
my_compare(data[0], data.back()))
{
// there are newly pushed elems and the last one is higher than top
*(tmp->elem) = std::move(data.back());
my_size.store(my_size.load(std::memory_order_relaxed) - 1, std::memory_order_relaxed);
tmp->status.store(uintptr_t(SUCCEEDED), std::memory_order_release);
data.pop_back();
__TBB_ASSERT(mark <= data.size(), NULL);
} else { // no convenient item to pop; postpone
tmp->next.store(pop_list, std::memory_order_relaxed);
pop_list = tmp;
}
} else { // PUSH_OP or PUSH_RVALUE_OP
__TBB_ASSERT(tmp->type == PUSH_OP || tmp->type == PUSH_RVALUE_OP, "Unknown operation");
#if TBB_USE_EXCEPTIONS
try
#endif
{
if (tmp->type == PUSH_OP) {
push_back_helper(*(tmp->elem));
} else {
data.push_back(std::move(*(tmp->elem)));
}
my_size.store(my_size.load(std::memory_order_relaxed) + 1, std::memory_order_relaxed);
tmp->status.store(uintptr_t(SUCCEEDED), std::memory_order_release);
}
#if TBB_USE_EXCEPTIONS
catch(...) {
tmp->status.store(uintptr_t(FAILED), std::memory_order_release);
}
#endif
}
}
// Second pass processes pop operations
while(pop_list) {
tmp = pop_list;
pop_list = pop_list->next.load(std::memory_order_relaxed);
__TBB_ASSERT(tmp->type == POP_OP, NULL);
if (data.empty()) {
tmp->status.store(uintptr_t(FAILED), std::memory_order_release);
} else {
__TBB_ASSERT(mark <= data.size(), NULL);
if (mark < data.size() &&
my_compare(data[0], data.back()))
{
// there are newly pushed elems and the last one is higher than top
*(tmp->elem) = std::move(data.back());
my_size.store(my_size.load(std::memory_order_relaxed) - 1, std::memory_order_relaxed);
tmp->status.store(uintptr_t(SUCCEEDED), std::memory_order_release);
data.pop_back();
} else { // extract top and push last element down heap
*(tmp->elem) = std::move(data[0]);
my_size.store(my_size.load(std::memory_order_relaxed) - 1, std::memory_order_relaxed);
tmp->status.store(uintptr_t(SUCCEEDED), std::memory_order_release);
reheap();
}
}
}
// heapify any leftover pushed elements before doing the next
// batch of operations
if (mark < data.size()) heapify();
__TBB_ASSERT(mark == data.size(), NULL);
call_itt_notify(releasing, this);
}
// Merge unsorted elements into heap
void heapify() {
if (!mark && data.size() > 0) mark = 1;
for (; mark < data.size(); ++mark) {
// for each unheapified element under size
size_type cur_pos = mark;
value_type to_place = std::move(data[mark]);
do { // push to_place up the heap
size_type parent = (cur_pos - 1) >> 1;
if (!my_compare(data[parent], to_place))
break;
data[cur_pos] = std::move(data[parent]);
cur_pos = parent;
} while(cur_pos);
data[cur_pos] = std::move(to_place);
}
}
// Re-heapify after an extraction
// Re-heapify by pushing last element down the heap from the root.
void reheap() {
size_type cur_pos = 0, child = 1;
while(child < mark) {
size_type target = child;
if (child + 1 < mark && my_compare(data[child], data[child + 1]))
++target;
// target now has the higher priority child
if (my_compare(data[target], data.back()))
break;
data[cur_pos] = std::move(data[target]);
cur_pos = target;
child = (cur_pos << 1) + 1;
}
if (cur_pos != data.size() - 1)
data[cur_pos] = std::move(data.back());
data.pop_back();
if (mark > data.size()) mark = data.size();
}
void push_back_helper( const T& value ) {
push_back_helper_impl(value, std::is_copy_constructible{});
}
void push_back_helper_impl( const T& value, /*is_copy_constructible = */std::true_type ) {
data.push_back(value);
}
void push_back_helper_impl( const T&, /*is_copy_constructible = */std::false_type ) {
__TBB_ASSERT(false, "error: calling tbb::concurrent_priority_queue.push(const value_type&) for move-only type");
}
using aggregator_type = aggregator;
aggregator_type my_aggregator;
// Padding added to avoid false sharing
char padding1[max_nfs_size - sizeof(aggregator_type)];
// The point at which unsorted elements begin
size_type mark;
std::atomic my_size;
Compare my_compare;
// Padding added to avoid false sharing
char padding2[max_nfs_size - (2*sizeof(size_type)) - sizeof(Compare)];
//! Storage for the heap of elements in queue, plus unheapified elements
/** data has the following structure:
binary unheapified
heap elements
____|_______|____
| | |
v v v
[_|...|_|_|...|_| |...| ]
0 ^ ^ ^
| | |__capacity
| |__my_size
|__mark
Thus, data stores the binary heap starting at position 0 through
mark-1 (it may be empty). Then there are 0 or more elements
that have not yet been inserted into the heap, in positions
mark through my_size-1. */
using vector_type = std::vector;
vector_type data;
friend bool operator==( const concurrent_priority_queue& lhs,
const concurrent_priority_queue& rhs )
{
return lhs.data == rhs.data;
}
#if !__TBB_CPP20_COMPARISONS_PRESENT
friend bool operator!=( const concurrent_priority_queue& lhs,
const concurrent_priority_queue& rhs )
{
return !(lhs == rhs);
}
#endif
}; // class concurrent_priority_queue
#if __TBB_CPP17_DEDUCTION_GUIDES_PRESENT
template >,
typename Alloc = tbb::cache_aligned_allocator>,
typename = std::enable_if_t>,
typename = std::enable_if_t>,
typename = std::enable_if_t>>
concurrent_priority_queue( It, It, Comp = Comp(), Alloc = Alloc() )
-> concurrent_priority_queue, Comp, Alloc>;
template >,
typename = std::enable_if_t>>
concurrent_priority_queue( It, It, Alloc )
-> concurrent_priority_queue, std::less>, Alloc>;
template ,
typename Alloc = tbb::cache_aligned_allocator,
typename = std::enable_if_t>,
typename = std::enable_if_t>>
concurrent_priority_queue( std::initializer_list, Comp = Comp(), Alloc = Alloc() )
-> concurrent_priority_queue;
template >>
concurrent_priority_queue( std::initializer_list, Alloc )
-> concurrent_priority_queue, Alloc>;
#endif // __TBB_CPP17_DEDUCTION_GUIDES_PRESENT
template
void swap( concurrent_priority_queue& lhs,
concurrent_priority_queue& rhs )
{
lhs.swap(rhs);
}
} // namespace d1
} // namespace detail
inline namespace v1 {
using detail::d1::concurrent_priority_queue;
} // inline namespace v1
} // namespace tbb
#endif // __TBB_concurrent_priority_queue_H