host_win.cpp

#include "host.hpp"

#if defined(HOST_SYSTEM_WINDOWS)

#include "errors.hpp"

// Winapi implementation
#include <Windows.h>

#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4191) // warning C4191: 'reinterpret_cast': unsafe conversion from 'FARPROC' to 'propane::method_handle'
#endif

namespace propane
{
    hostmem host::allocate(size_t len)
    {
        ASSERT(len, "Allocation length cannot be zero");

        // Get page size
        SYSTEM_INFO system_info = { 0 };
        GetSystemInfo(&system_info);
        const size_t page_size = static_cast<size_t>(system_info.dwPageSize);
        ASSERT(page_size, "Page size is zero");

        // Round up to page size
        const size_t full_size = ceil_page_size(len, page_size);

        // Allocate
        void* const address = VirtualAlloc(nullptr, full_size, MEM_COMMIT, PAGE_READWRITE);
        return hostmem{ address, full_size };
    }
    bool host::protect(hostmem mem)
    {
        DWORD old_protect;
        const BOOL result = VirtualProtect(mem.address, mem.size, PAGE_READONLY, &old_protect);
        return result;
    }
    void host::free(hostmem mem)
    {
        const BOOL result = VirtualFree(mem.address, 0, MEM_RELEASE);
        ASSERT(result, "Failed to release memory");
    }

    void* host::openlib(const char* path)
    {
        return LoadLibraryA(path);
    }
    void host::closelib(void* handle)
    {
        FreeLibrary((HMODULE)handle);
    }
    method_handle host::loadsym(void* handle, const char* name)
    {
        return reinterpret_cast<method_handle>(GetProcAddress((HMODULE)handle, name));
    }
}

#ifdef _MSC_VER
#pragma warning (pop)
#endif

#endif