memory_pool.h

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/*
    Copyright 2005-2016 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks. Threading Building Blocks is free software;
    you can redistribute it and/or modify it under the terms of the GNU General Public License
    version 2  as  published  by  the  Free Software Foundation.  Threading Building Blocks is
    distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
    implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    See  the GNU General Public License for more details.   You should have received a copy of
    the  GNU General Public License along with Threading Building Blocks; if not, write to the
    Free Software Foundation, Inc.,  51 Franklin St,  Fifth Floor,  Boston,  MA 02110-1301 USA

    As a special exception,  you may use this file  as part of a free software library without
    restriction.  Specifically,  if other files instantiate templates  or use macros or inline
    functions from this file, or you compile this file and link it with other files to produce
    an executable,  this file does not by itself cause the resulting executable to be covered
    by the GNU General Public License. This exception does not however invalidate any other
    reasons why the executable file might be covered by the GNU General Public License.
*/

#ifndef __TBB_memory_pool_H
#define __TBB_memory_pool_H

#if !TBB_PREVIEW_MEMORY_POOL
#error Set TBB_PREVIEW_MEMORY_POOL to include memory_pool.h
#endif

#include "scalable_allocator.h"
#include <new> // std::bad_alloc
#include <stdexcept> // std::runtime_error, std::invalid_argument
// required in C++03 to construct std::runtime_error and std::invalid_argument
#include <string>
#if __TBB_ALLOCATOR_CONSTRUCT_VARIADIC
#include <utility> // std::forward
#endif

#if __TBB_EXTRA_DEBUG
#define __TBBMALLOC_ASSERT ASSERT
#else
#define __TBBMALLOC_ASSERT(a,b) ((void)0)
#endif

namespace tbb {
namespace interface6 {
namespace internal {

class pool_base : tbb::internal::no_copy {
    // Pool interface is separate from standard allocator classes because it has
    // to maintain internal state, no copy or assignment. Move and swap are possible.
public:
    void recycle() { rml::pool_reset(my_pool); }

    void *malloc(size_t size) { return rml::pool_malloc(my_pool, size); }

    void free(void* ptr) { rml::pool_free(my_pool, ptr); }

    // Enables some low-level optimization possibilities
    void *realloc(void* ptr, size_t size) {
        return rml::pool_realloc(my_pool, ptr, size);
    }

protected:
    void destroy() { rml::pool_destroy(my_pool); }

    rml::MemoryPool *my_pool;
};

} // namespace internal

#if _MSC_VER && !defined(__INTEL_COMPILER)
    // Workaround for erroneous "unreferenced parameter" warning in method destroy.
    #pragma warning (push)
    #pragma warning (disable: 4100)
#endif


template<typename T, typename P = internal::pool_base>
class memory_pool_allocator {
protected:
    typedef P pool_type;
    pool_type *my_pool;
    template<typename U, typename R>
    friend class memory_pool_allocator;
    template<typename V, typename U, typename R>
    friend bool operator==( const memory_pool_allocator<V,R>& a, const memory_pool_allocator<U,R>& b);
    template<typename V, typename U, typename R>
    friend bool operator!=( const memory_pool_allocator<V,R>& a, const memory_pool_allocator<U,R>& b);
public:
    typedef typename tbb::internal::allocator_type<T>::value_type value_type;
    typedef value_type* pointer;
    typedef const value_type* const_pointer;
    typedef value_type& reference;
    typedef const value_type& const_reference;
    typedef size_t size_type;
    typedef ptrdiff_t difference_type;
    template<typename U> struct rebind {
        typedef memory_pool_allocator<U, P> other;
    };

    memory_pool_allocator(pool_type &pool) throw() : my_pool(&pool) {}
    memory_pool_allocator(const memory_pool_allocator& src) throw() : my_pool(src.my_pool) {}
    template<typename U>
    memory_pool_allocator(const memory_pool_allocator<U,P>& src) throw() : my_pool(src.my_pool) {}

    pointer address(reference x) const { return &x; }
    const_pointer address(const_reference x) const { return &x; }

    pointer allocate( size_type n, const void* /*hint*/ = 0) {
        pointer p = static_cast<pointer>( my_pool->malloc( n*sizeof(value_type) ) );
        if (!p)
            tbb::internal::throw_exception(std::bad_alloc());
        return p;
    }
    void deallocate( pointer p, size_type ) {
        my_pool->free(p);
    }
    size_type max_size() const throw() {
        size_type max = static_cast<size_type>(-1) / sizeof (value_type);
        return (max > 0 ? max : 1);
    }
#if __TBB_ALLOCATOR_CONSTRUCT_VARIADIC
    template<typename U, typename... Args>
    void construct(U *p, Args&&... args)
        { ::new((void *)p) U(std::forward<Args>(args)...); }
#else // __TBB_ALLOCATOR_CONSTRUCT_VARIADIC
#if __TBB_CPP11_RVALUE_REF_PRESENT
    void construct( pointer p, value_type&& value ) {::new((void*)(p)) value_type(std::move(value));}
#endif
    void construct( pointer p, const value_type& value ) { ::new((void*)(p)) value_type(value); }
#endif // __TBB_ALLOCATOR_CONSTRUCT_VARIADIC

    void destroy( pointer p ) { p->~value_type(); }

};

#if _MSC_VER && !defined(__INTEL_COMPILER)
    #pragma warning (pop)
#endif // warning 4100 is back


template<typename P>
class memory_pool_allocator<void, P> {
public:
    typedef P pool_type;
    typedef void* pointer;
    typedef const void* const_pointer;
    typedef void value_type;
    template<typename U> struct rebind {
        typedef memory_pool_allocator<U, P> other;
    };

    memory_pool_allocator( pool_type &pool) throw() : my_pool(&pool) {}
    memory_pool_allocator( const memory_pool_allocator& src) throw() : my_pool(src.my_pool) {}
    template<typename U>
    memory_pool_allocator(const memory_pool_allocator<U,P>& src) throw() : my_pool(src.my_pool) {}

protected:
    pool_type *my_pool;
    template<typename U, typename R>
    friend class memory_pool_allocator;
    template<typename V, typename U, typename R>
    friend bool operator==( const memory_pool_allocator<V,R>& a, const memory_pool_allocator<U,R>& b);
    template<typename V, typename U, typename R>
    friend bool operator!=( const memory_pool_allocator<V,R>& a, const memory_pool_allocator<U,R>& b);
};

template<typename T, typename U, typename P>
inline bool operator==( const memory_pool_allocator<T,P>& a, const memory_pool_allocator<U,P>& b) {return a.my_pool==b.my_pool;}

template<typename T, typename U, typename P>
inline bool operator!=( const memory_pool_allocator<T,P>& a, const memory_pool_allocator<U,P>& b) {return a.my_pool!=b.my_pool;}


template <typename Alloc>
class memory_pool : public internal::pool_base {
    Alloc my_alloc; // TODO: base-class optimization
    static void *allocate_request(intptr_t pool_id, size_t & bytes);
    static int deallocate_request(intptr_t pool_id, void*, size_t raw_bytes);

public:
    memory_pool(const Alloc &src = Alloc());

    ~memory_pool() { destroy(); } // call the callbacks first and destroy my_alloc latter

};

class fixed_pool : public internal::pool_base {
    void *my_buffer;
    size_t my_size;
    inline static void *allocate_request(intptr_t pool_id, size_t & bytes);

public:
    inline fixed_pool(void *buf, size_t size);
    ~fixed_pool() { destroy(); }
};


template <typename Alloc>
memory_pool<Alloc>::memory_pool(const Alloc &src) : my_alloc(src) {
    rml::MemPoolPolicy args(allocate_request, deallocate_request,
                            sizeof(typename Alloc::value_type));
    rml::MemPoolError res = rml::pool_create_v1(intptr_t(this), &args, &my_pool);
    if (res!=rml::POOL_OK)
        tbb::internal::throw_exception(std::runtime_error("Can't create pool"));
}
template <typename Alloc>
void *memory_pool<Alloc>::allocate_request(intptr_t pool_id, size_t & bytes) {
    memory_pool<Alloc> &self = *reinterpret_cast<memory_pool<Alloc>*>(pool_id);
    const size_t unit_size = sizeof(typename Alloc::value_type);
    __TBBMALLOC_ASSERT( 0 == bytes%unit_size, NULL);
    void *ptr;
    __TBB_TRY { ptr = self.my_alloc.allocate( bytes/unit_size ); }
    __TBB_CATCH(...) { return 0; }
    return ptr;
}
#if __TBB_MSVC_UNREACHABLE_CODE_IGNORED
    // Workaround for erroneous "unreachable code" warning in the template below.
    // Specific for VC++ 17-18 compiler
    #pragma warning (push)
    #pragma warning (disable: 4702)
#endif
template <typename Alloc>
int memory_pool<Alloc>::deallocate_request(intptr_t pool_id, void* raw_ptr, size_t raw_bytes) {
    memory_pool<Alloc> &self = *reinterpret_cast<memory_pool<Alloc>*>(pool_id);
    const size_t unit_size = sizeof(typename Alloc::value_type);
    __TBBMALLOC_ASSERT( 0 == raw_bytes%unit_size, NULL);
    self.my_alloc.deallocate( static_cast<typename Alloc::value_type*>(raw_ptr), raw_bytes/unit_size );
    return 0;
}
#if __TBB_MSVC_UNREACHABLE_CODE_IGNORED
    #pragma warning (pop)
#endif
inline fixed_pool::fixed_pool(void *buf, size_t size) : my_buffer(buf), my_size(size) {
    if (!buf || !size)
        // TODO: improve support for mode with exceptions disabled
        tbb::internal::throw_exception(std::invalid_argument("Zero in parameter is invalid"));
    rml::MemPoolPolicy args(allocate_request, 0, size, /*fixedPool=*/true);
    rml::MemPoolError res = rml::pool_create_v1(intptr_t(this), &args, &my_pool);
    if (res!=rml::POOL_OK)
        tbb::internal::throw_exception(std::runtime_error("Can't create pool"));
}
inline void *fixed_pool::allocate_request(intptr_t pool_id, size_t & bytes) {
    fixed_pool &self = *reinterpret_cast<fixed_pool*>(pool_id);
    __TBBMALLOC_ASSERT(0 != self.my_size, "The buffer must not be used twice.");
    bytes = self.my_size;
    self.my_size = 0; // remember that buffer has been used
    return self.my_buffer;
}

} //namespace interface6
using interface6::memory_pool_allocator;
using interface6::memory_pool;
using interface6::fixed_pool;
} //namespace tbb

#undef __TBBMALLOC_ASSERT
#endif// __TBB_memory_pool_H