提高::集装箱的集装箱间不共享内存 [英] boost::interprocess Containers of containers NOT in shared memory
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问题描述
我有一个<一个例子演示程序href=\"http://www.boost.org/doc/libs/1_56_0/doc/html/interprocess/allocators_containers.html#interprocess.allocators_containers.containers_explained.containers_of_containers\"相对=nofollow>的boost ::集装箱类型的集装箱间。
但我喜欢用我的进程内存中的类也正常类。
谁能帮我写一个构造函数，不带任何参数有类我目前的进程内存初始化。
的#include＆LT;升压/间/集装箱/ vector.hpp＆GT;
＃包括LT＆;升压/间/分配器/ allocator.hpp＆GT;
＃包括LT＆;升压/间/ managed_shared_memory.hpp＆GT;
＃包括LT＆;升压/存档/ xml_oarchive.hpp＆GT;
＃包括LT＆;升压/存档/ xml_iarchive.hpp＆GT;
＃包括LT＆; shmfw /系列化/ interprocess_vector.hpp＆GT;
＃包括LT＆;＆stdlib.h中GT; / *函数srand，兰特* /
＃包括LT＆;＆time.h中GT; /* 时间 */
使用空间boost ::进程间;
//别名整数的STL样分配，从该段分配整数
typedef的分配器＆LT; INT，managed_shared_memory :: segment_manager＆GT; ShmemAllocator;//别名，它使用previous STL般分配器矢量
typedef的矢量＆lt;整型，ShmemAllocator＆GT; MyVector;typedef的分配器＆LT;无效，managed_shared_memory :: segment_manager＆GT; void_allocator;类MYSTRUCT {
上市：
MyVector myVector;
//由于void_allocator可以转换为任何其他分配器＆LT;吨＆gt;中我们可以简化
//初始化服用只是一个分配器为所有内部容器。
MYSTRUCT（常量void_allocator＆安培; void_alloc）
：myVector（void_alloc）
{}
//那是什么我喜欢
// MYSTRUCT（）
//：myVector（??）
// {}
};诠释主（）{ //我想有类似的东西的工作和也低于SHM东西
// MYSTRUCT X;
managed_shared_memory段;
//一个管理的共享内存，我们可以构造对象
//与C字符串相关
尝试{
段= managed_shared_memory（create_only，MySharedMemory，65536）;
}赶上（...）{
段= managed_shared_memory（open_onlyMySharedMemory）;
} //初始化STL般分配器
常量ShmemAllocator alloc_inst（segment.get_segment_manager（））; MYSTRUCT * myStruct_src = segment.find_or_construct＆LT;＆MYSTRUCT GT; （MYSTRUCT）（alloc_inst）;
函数srand（时间（NULL））;
myStruct_src-＆GT; myVector.push_back（RAND（））; MYSTRUCT * myStruct_des = segment.find_or_construct＆LT;＆MYSTRUCT GT; （MYSTRUCT）（alloc_inst）; 用于（为size_t我= 0; I＆LT; myStruct_src-＆GT; myVector.size（）;我++）{
性病::法院LT＆;＆LT; I＆LT;＆LT; ：＆所述;＆下; myStruct_src-＆GT; myVector [1] - ;＆下; =＆所述;＆下; myStruct_des-＆GT; myVector [1] - ;＆下;的std :: ENDL;
如果（myStruct_src-＆GT; myVector [i] = myStruct_des-＆GT;！myVector [i]）{
性病::法院LT＆;＆LT; 出了些问题！ ＆LT;＆LT;的std :: ENDL;
}
}
//segment.destroy<MyVector> （MyVector）;
返回0;
}
解决方案
如果您更改分配器类型，你改变容器（比如，编译时模板实例化的本质）。
从技术上讲，你可以设计一个类型擦除分配器（点菜的std ::功能或的boost :: any_iterator ），但这可能会导致糟糕的性能。此外，它仍然需要所有的分配器中的所有静态已知的属性对应，减少了灵活性。
在现实中，我建议只templatizing MYSTRUCT 在分配器键入要用于任何嵌入式容器。然后特意采取这种分配器在构造函数中：
//变种堆使用：
使用HeapStruct = MYSTRUCT＆LT;的std ::分配器取代;
//变到共享内存中使用：
使用ShmemStruct = MYSTRUCT＆LT; BoundShmemAllocator取代;
演示程序：
的#include＆LT;升压/间/集装箱/ vector.hpp＆GT;
＃包括LT＆;升压/间/分配器/ allocator.hpp＆GT;
＃包括LT＆;升压/间/ managed_shared_memory.hpp＆GT;
＃包括LT＆;升压/范围/ algorithm.hpp＆GT;
＃包括LT＆;＆iostream的GT;
＃包括LT＆;＆了cassert GT;命名空间BIP =的boost ::进程间;
模板＆LT; typename的T＆GT;
使用BoundShmemAllocator = BIP ::分配器＆LT; T，BIP :: managed_shared_memory :: segment_manager取代;////////////////////////////////////////////////// /////////////
//你MYSTRUCT，模板化的一个分配器类模板模板＆LT;模板＆LT; typename的...＆GT;类分配器＆GT;
类MYSTRUCT {
上市：
BIP ::矢量＆lt; INT，分配器＆LT; INT＆GT; ＆GT;整型;
BIP ::矢量＆lt;双，分配器＆LT;双＆GT; ＆GT;双打; MYSTRUCT（常量分配器＆LT;无效＆GT;＆安培; void_alloc = {}）
：整型（void_alloc）
双打（void_alloc）
{}
};//变堆中使用：
使用HeapStruct = MYSTRUCT＆LT;的std ::分配器取代;
//变到共享内存中使用：
使用ShmemStruct = MYSTRUCT＆LT; BoundShmemAllocator取代;//
////////////////////////////////////////////////// /////////////诠释主（）{
函数srand（时间（NULL））; //你可以有这样的事情工作：
HeapStruct X; //也是SHM下面的东西
的std :: generate_n（性病:: back_inserter（x.ints），20，＆安培;的std ::兰特）;
的std :: generate_n（性病:: back_inserter（x.doubles），20，＆安培;的std ::兰特）; //一个管理的共享内存，我们可以构造对象
BIP :: managed_shared_memory段= BIP :: managed_shared_memory（BIP :: open_or_create，MySharedMemory，65536）;
BoundShmemAllocator＆LT; INT＆GT;常量shmem_alloc（segment.get_segment_manager（））; 自动SRC = segment.find_or_construct＆所述; ShmemStruct＆GT（MYSTRUCT）（shmem_alloc）;
src-＆GT; ints.insert（src-＆GT; ints.end（），x.ints.begin（），x.ints.end（））;
src-＆GT; doubles.insert（src-＆GT; doubles.end（），x.doubles.begin（），x.doubles.end（））; 汽车DES = segment.find_or_construct＆LT; ShmemStruct＆GT;（MYSTRUCT）（shmem_alloc）; 性病::法院LT＆;＆LT; -------------------------;
提高::复制（src-＆GT;整型，性病:: ostream_iterator＆LT; INT＆GT;（STD ::法院LT＆;＆LT;\\ NSRC整型，））;
提高::复制（沙漠 - ＆GT;整型，性病:: ostream_iterator＆LT; INT＆GT;（STD ::法院LT＆;＆LT;\\濒死体验整型，））;
性病::法院LT＆;＆LT; \\ n -------------------------
提高::复制（src-＆GT;双打的std :: ostream_iterator＆LT;双＆GT;（STD ::法院LT＆;＆LT;\\ NSRC双打，））;
提高::复制（沙漠 - ＆GT;双打的std :: ostream_iterator＆LT;双＆GT;（STD ::法院LT＆;＆LT;\\濒死体验双打，））; 断言（src-＆GT; ints.size（）==沙漠＆GT; ints.size（））;
断言（src-＆GT; doubles.size（）==沙漠＆GT; doubles.size（））;
断言（升压::不匹配（src-＆GT;整型，沙漠 - ＆GT;整型）==的std :: make_pair（src-＆GT; ints.end（），沙漠 - ＆GT; ints.end（）））;
断言（升压::不匹配（src-＆GT;双打，沙漠 - ＆GT;双打）==的std :: make_pair（src-＆GT; doubles.end（），沙漠 - ＆GT; doubles.end（）））; segment.destroy＆所述; ShmemStruct＆GT（MYSTRUCT）;
}
I have the example demo program with a boost::interprocess Containers of containers type. But I like to use the class also a normal class within my process memory. Can someone help me to write a constructor which takes no arguments to have the class initialized in my current process memory.
#include <boost/interprocess/containers/vector.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/archive/xml_oarchive.hpp>
#include <boost/archive/xml_iarchive.hpp>
#include <shmfw/serialization/interprocess_vector.hpp>
#include <stdlib.h> /* srand, rand */
#include <time.h> /* time */
using namespace boost::interprocess;
//Alias an STL-like allocator of ints that allocates ints from the segment
typedef allocator<int, managed_shared_memory::segment_manager> ShmemAllocator;
//Alias a vector that uses the previous STL-like allocator
typedef vector<int, ShmemAllocator> MyVector;
typedef allocator<void, managed_shared_memory::segment_manager > void_allocator;
class MyStruct {
public:
MyVector myVector;
//Since void_allocator is convertible to any other allocator<T>, we can simplify
//the initialization taking just one allocator for all inner containers.
MyStruct ( const void_allocator &void_alloc )
: myVector ( void_alloc )
{}
// Thats what I like to have
//MyStruct ()
// : myVector ( ?? )
//{}
};
int main () {
// I would like to have something like that working and also the shm stuff below
// MyStruct x;
managed_shared_memory segment;
//A managed shared memory where we can construct objects
//associated with a c-string
try {
segment = managed_shared_memory( create_only, "MySharedMemory", 65536 );
} catch (...){
segment = managed_shared_memory( open_only, "MySharedMemory" );
}
//Initialize the STL-like allocator
const ShmemAllocator alloc_inst ( segment.get_segment_manager() );
MyStruct *myStruct_src = segment.find_or_construct<MyStruct> ( "MyStruct" ) ( alloc_inst );
srand (time(NULL));
myStruct_src->myVector.push_back ( rand() );
MyStruct *myStruct_des = segment.find_or_construct<MyStruct> ( "MyStruct" ) ( alloc_inst );
for ( size_t i = 0; i < myStruct_src->myVector.size(); i++ ) {
std::cout << i << ": " << myStruct_src->myVector[i] << " = " << myStruct_des->myVector[i] << std::endl;
if(myStruct_src->myVector[i] != myStruct_des->myVector[i]) {
std::cout << "Something went wrong!" << std::endl;
}
}
//segment.destroy<MyVector> ( "MyVector" );
return 0;
}
解决方案
If you change the allocator type, you change the container (such is the nature of compile-time template instantiation).
Technically, you could devise a type-erased allocator (à la std::function or boost::any_iterator) but this would probably result in abysmal performance. Also, it would still require all the allocators to correspond in all the statically known properties, reducing flexibility.
In reality, I suggest just templatizing MyStruct on the Allocator type to be used for any embedded containers. Then specifically take such an allocator in the constructor:
// Variant to use on the heap:
using HeapStruct = MyStruct<std::allocator>;
// Variant to use in shared memory:
using ShmemStruct = MyStruct<BoundShmemAllocator>;
Demo Program:
#include <boost/interprocess/containers/vector.hpp>
#include <boost/interprocess/allocators/allocator.hpp>
#include <boost/interprocess/managed_shared_memory.hpp>
#include <boost/range/algorithm.hpp>
#include <iostream>
#include <cassert>
namespace bip = boost::interprocess;
template <typename T>
using BoundShmemAllocator = bip::allocator<T, bip::managed_shared_memory::segment_manager>;
///////////////////////////////////////////////////////////////
// Your MyStruct, templatized for an Allocator class template
template <template<typename...> class Allocator>
class MyStruct {
public:
bip::vector<int, Allocator<int> > ints;
bip::vector<double, Allocator<double> > doubles;
MyStruct(const Allocator<void>& void_alloc = {})
: ints(void_alloc),
doubles(void_alloc)
{}
};
// Variant to use on the heap:
using HeapStruct = MyStruct<std::allocator>;
// Variant to use in shared memory:
using ShmemStruct = MyStruct<BoundShmemAllocator>;
//
///////////////////////////////////////////////////////////////
int main() {
srand(time(NULL));
// You can have something like this working:
HeapStruct x; // and also the shm stuff below
std::generate_n(std::back_inserter(x.ints), 20, &std::rand);
std::generate_n(std::back_inserter(x.doubles), 20, &std::rand);
// A managed shared memory where we can construct objects
bip::managed_shared_memory segment = bip::managed_shared_memory(bip::open_or_create, "MySharedMemory", 65536);
BoundShmemAllocator<int> const shmem_alloc(segment.get_segment_manager());
auto src = segment.find_or_construct<ShmemStruct>("MyStruct")(shmem_alloc);
src->ints.insert(src->ints.end(), x.ints.begin(), x.ints.end());
src->doubles.insert(src->doubles.end(), x.doubles.begin(), x.doubles.end());
auto des = segment.find_or_construct<ShmemStruct>("MyStruct")(shmem_alloc);
std::cout << "-------------------------";
boost::copy(src->ints, std::ostream_iterator<int>(std::cout << "\nsrc ints: ", "; "));
boost::copy(des->ints, std::ostream_iterator<int>(std::cout << "\ndes ints: ", "; "));
std::cout << "\n-------------------------";
boost::copy(src->doubles, std::ostream_iterator<double>(std::cout << "\nsrc doubles: ", "; "));
boost::copy(des->doubles, std::ostream_iterator<double>(std::cout << "\ndes doubles: ", "; "));
assert(src->ints.size() == des->ints.size());
assert(src->doubles.size() == des->doubles.size());
assert(boost::mismatch(src->ints, des->ints) == std::make_pair(src->ints.end(), des->ints.end()));
assert(boost::mismatch(src->doubles, des->doubles) == std::make_pair(src->doubles.end(), des->doubles.end()));
segment.destroy<ShmemStruct>("MyStruct");
}
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