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#include "stack_utils.h" 
 
#include <contrib/libs/linux-headers/asm-generic/errno-base.h> 
#include <util/generic/scope.h> 
#include <util/system/yassert.h> 
 
#ifdef _linux_ 
#include <sys/mman.h> 
#endif 
 
#include <cerrno> 
#include <cstdlib> 
#include <cstring> 
 
 
namespace NCoro::NStack { 
 
#ifdef _linux_ 
    bool GetAlignedMemory(uint64_t sizeInPages, char*& rawPtr, char*& alignedPtr) noexcept { 
        Y_ASSERT(sizeInPages); 
 
        void* ptr = nullptr; 
        int error = posix_memalign(&ptr, PageSize, sizeInPages * PageSize); 
        alignedPtr = rawPtr = (char*)ptr; 
        return rawPtr && alignedPtr && !error; 
    } 
#else 
    bool GetAlignedMemory(uint64_t sizeInPages, char*& rawPtr, char*& alignedPtr) noexcept { 
        Y_ASSERT(sizeInPages); 
 
        rawPtr = (char*) malloc((sizeInPages + 1) * PageSize); // +1 in case result would be unaligned 
        alignedPtr = (char*)( ((uint64_t)rawPtr + PageSize - 1) & ~PageSizeMask); 
        return rawPtr && alignedPtr; 
    } 
#endif 
 
#ifdef _linux_ 
    void ReleaseRss(char* alignedPtr, uint64_t numOfPages) noexcept { 
        Y_VERIFY( !((uint64_t)alignedPtr & PageSizeMask), "Not aligned pointer to release RSS memory"); 
        if (!numOfPages) { 
            return; 
        } 
        if (auto res = madvise((void*) alignedPtr, numOfPages * PageSize, MADV_DONTNEED); res) { 
            Y_VERIFY(errno == EAGAIN || errno == ENOMEM, "Failed to release memory"); 
        } 
    } 
#else 
    void ReleaseRss(char*, uint64_t) noexcept { 
    } 
#endif 
 
#ifdef _linux_ 
    uint64_t CountMapped(char* alignedPtr, uint64_t numOfPages) noexcept { 
        Y_VERIFY( !((uint64_t)alignedPtr & PageSizeMask) ); 
        Y_ASSERT(numOfPages); 
 
        uint64_t result = 0; 
        unsigned char* mappedPages = (unsigned char*) calloc(numOfPages, numOfPages); 
        Y_VERIFY(mappedPages); 
        Y_DEFER { 
            free(mappedPages); 
        }; 
 
        if (!mincore((void*)alignedPtr, numOfPages * PageSize, mappedPages)) { 
            for (uint64_t i = 0; i < numOfPages; ++i) { 
                if (mappedPages[i] & 1) { 
                    ++result; 
                } 
            } 
        } else { 
            Y_ASSERT(false); 
            return 0; 
        } 
 
        return result; 
    } 
 
#else 
    uint64_t CountMapped(char*, uint64_t) noexcept { 
        return 0; // stub for Windows tests 
    } 
#endif 
 
}