我正在开发一个确定性实时项目，该项目每次迭代的执行周期为几百微秒。
我面临的问题是，随机推送操作std::priority_queue需要大量时间。推送操作通常需要大约 5-25 微秒，但随机需要 300 微秒到 5 毫秒。
为了解决这个问题，我决定为我的预先分配内存std::priority_queue。
我参考了以下答案：https://stackoverflow.com/a/29236236/6319901。
开发操作系统：Ubuntu 24.04 LTS。
我的目标操作系统：vxWorks 7
语言：C++17 请在下方找到我的代码和生成的错误。
代码 ：
#include <queue>
#include <array>
#include <vector>
#include <cstdint>
#include <iostream>
#include <functional>
struct ipc_receive_t
{
std::uint32_t priority;
int data1;
float data2;
bool operator<(const ipc_receive_t& object) const //Check if greater
{
return this->priority < object.priority;
}
};
int main(int argc, char const *argv[])
{
std::cout << "Hello, World!!!\n";
std::vector<ipc_receive_t> container;
container.reserve(1000);
std::priority_queue<ipc_receive_t, std::vector<ipc_receive_t>> pq (
std::greater<ipc_receive_t>(), std::move(container)
);
return 0;
}
输出 ：
g++ -std=c++17 main.cpp -o main
main.cpp: In function ‘int main(int, const char**)’:
main.cpp:27:9: error: no matching function for call to ‘std::priority_queue<ipc_receive_t, std::vector<ipc_receive_t> >::priority_queue(std::greater<ipc_receive_t>, std::remove_reference<std::vector<ipc_receive_t>&>::type)’
27 | );
| ^
In file included from /usr/include/c++/14/queue:66,
from main.cpp:1:
/usr/include/c++/14/bits/stl_queue.h:691:9: note: candidate: ‘template<class _InputIterator, class _Alloc, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(_InputIterator, _InputIterator, const _Compare&, _Sequence&&, const _Alloc&) [with _Alloc = _InputIterator; _Requires = _Alloc; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
691 | priority_queue(_InputIterator __first, _InputIterator __last,
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:691:9: note: candidate expects 5 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:679:9: note: candidate: ‘template<class _InputIterator, class _Alloc, class, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(_InputIterator, _InputIterator, const _Compare&, const _Sequence&, const _Alloc&) [with _Alloc = _InputIterator; <template-parameter-2-3> = _Alloc; _Requires = <template-parameter-1-3>; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
679 | priority_queue(_InputIterator __first, _InputIterator __last,
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:679:9: note: candidate expects 5 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:671:9: note: candidate: ‘template<class _InputIterator, class _Alloc, class, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(_InputIterator, _InputIterator, const _Compare&, const _Alloc&) [with _Alloc = _InputIterator; <template-parameter-2-3> = _Alloc; _Requires = <template-parameter-1-3>; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
671 | priority_queue(_InputIterator __first, _InputIterator __last,
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:671:9: note: candidate expects 4 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:663:9: note: candidate: ‘template<class _InputIterator, class _Alloc, class, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(_InputIterator, _InputIterator, const _Alloc&) [with _Alloc = _InputIterator; <template-parameter-2-3> = _Alloc; _Requires = <template-parameter-1-3>; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
663 | priority_queue(_InputIterator __first, _InputIterator __last,
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:663:9: note: candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:649:9: note: candidate: ‘template<class _InputIterator, class> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(_InputIterator, _InputIterator, const _Compare&, _Sequence&&) [with <template-parameter-2-2> = _InputIterator; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
649 | priority_queue(_InputIterator __first, _InputIterator __last,
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:649:9: note: candidate expects 4 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:638:9: note: candidate: ‘template<class _InputIterator, class> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(_InputIterator, _InputIterator, const _Compare&, const _Sequence&) [with <template-parameter-2-2> = _InputIterator; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
638 | priority_queue(_InputIterator __first, _InputIterator __last,
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:638:9: note: candidate expects 4 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:629:9: note: candidate: ‘template<class _InputIterator, class> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(_InputIterator, _InputIterator, const _Compare&) [with <template-parameter-2-2> = _InputIterator; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
629 | priority_queue(_InputIterator __first, _InputIterator __last,
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:629:9: note: template argument deduction/substitution failed:
main.cpp:27:9: note: deduced conflicting types for parameter ‘_InputIterator’ (‘std::greater<ipc_receive_t>’ and ‘std::vector<ipc_receive_t>’)
27 | );
| ^
/usr/include/c++/14/bits/stl_queue.h:594:9: note: candidate: ‘template<class _Alloc, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(std::priority_queue<_Tp, _Sequence, _Compare>&&, const _Alloc&) [with _Requires = _Alloc; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
594 | priority_queue(priority_queue&& __q, const _Alloc& __a)
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:594:9: note: template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_queue.h: In substitution of ‘template<class _Tp, class _Sequence, class _Compare> template<class _Alloc> using std::priority_queue<_Tp, _Sequence, _Compare>::_Uses = typename std::enable_if<std::uses_allocator<_Sequence, _Alloc>::value>::type [with _Alloc = std::vector<ipc_receive_t>; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’:
/usr/include/c++/14/bits/stl_queue.h:593:33: required from here
593 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
| ^~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:513:15: error: no type named ‘type’ in ‘struct std::enable_if<false, void>’
513 | using _Uses = typename
| ^~~~~
/usr/include/c++/14/bits/stl_queue.h:590:9: note: candidate: ‘template<class _Alloc, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(const std::priority_queue<_Tp, _Sequence, _Compare>&, const _Alloc&) [with _Requires = _Alloc; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
590 | priority_queue(const priority_queue& __q, const _Alloc& __a)
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:590:9: note: template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_queue.h:585:9: note: candidate: ‘template<class _Alloc, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(const _Compare&, _Sequence&&, const _Alloc&) [with _Requires = _Alloc; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
585 | priority_queue(const _Compare& __x, _Sequence&& __c, const _Alloc& __a)
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:585:9: note: candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:579:9: note: candidate: ‘template<class _Alloc, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(const _Compare&, const _Sequence&, const _Alloc&) [with _Requires = _Alloc; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
579 | priority_queue(const _Compare& __x, const _Sequence& __c,
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:579:9: note: candidate expects 3 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:573:9: note: candidate: ‘template<class _Alloc, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(const _Compare&, const _Alloc&) [with _Requires = _Alloc; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
573 | priority_queue(const _Compare& __x, const _Alloc& __a)
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:573:9: note: template argument deduction/substitution failed:
/usr/include/c++/14/bits/stl_queue.h:569:9: note: candidate: ‘template<class _Alloc, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(const _Alloc&) [with _Requires = _Alloc; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
569 | priority_queue(const _Alloc& __a)
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:569:9: note: candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_queue.h:554:9: note: candidate: ‘template<class _Seq, class _Requires> std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue() [with _Requires = _Seq; _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
554 | priority_queue()
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:554:9: note: candidate expects 0 arguments, 2 provided
/usr/include/c++/14/bits/stl_queue.h:563:7: note: candidate: ‘std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(const _Compare&, _Sequence&&) [with _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
563 | priority_queue(const _Compare& __x, _Sequence&& __s = _Sequence())
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:563:38: note: no known conversion for argument 1 from ‘std::greater<ipc_receive_t>’ to ‘const std::less<ipc_receive_t>&’
563 | priority_queue(const _Compare& __x, _Sequence&& __s = _Sequence())
| ~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_queue.h:558:7: note: candidate: ‘std::priority_queue<_Tp, _Sequence, _Compare>::priority_queue(const _Compare&, const _Sequence&) [with _Tp = ipc_receive_t; _Sequence = std::vector<ipc_receive_t>; _Compare = std::less<ipc_receive_t>]’
558 | priority_queue(const _Compare& __x, const _Sequence& __s)
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:558:38: note: no known conversion for argument 1 from ‘std::greater<ipc_receive_t>’ to ‘const std::less<ipc_receive_t>&’
558 | priority_queue(const _Compare& __x, const _Sequence& __s)
| ~~~~~~~~~~~~~~~~^~~
/usr/include/c++/14/bits/stl_queue.h:496:11: note: candidate: ‘std::priority_queue<ipc_receive_t, std::vector<ipc_receive_t> >::priority_queue(const std::priority_queue<ipc_receive_t, std::vector<ipc_receive_t> >&)’
496 | class priority_queue
| ^~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_queue.h:496:11: note: candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_queue.h:496:11: note: candidate: ‘std::priority_queue<ipc_receive_t, std::vector<ipc_receive_t> >::priority_queue(std::priority_queue<ipc_receive_t, std::vector<ipc_receive_t> >&&)’
/usr/include/c++/14/bits/stl_queue.h:496:11: note: candidate expects 1 argument, 2 provided
a 的第三个模板参数是它的比较器类型，当未指定时，
std::priority_queue则默认为。std::less<T>您的代码无法编译，因为
std::greater<ipc_receive_t>()不是类型std::less<ipc_receive_t>。您将需要此代码。
你需要定义