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#pragma once

#include "defaults.h"

#include <util/generic/flags.h> 
 
//on some systems (not win, freebd, linux, but darwin (Mac OS X)
//multiple mlock calls on the same address range
//require the corresponding number of munlock calls to actually unlock the pages

//on some systems you must have privilege and resource limit

void LockMemory(const void* addr, size_t len);
void UnlockMemory(const void* addr, size_t len);

enum ELockAllMemoryFlag { 
    /** Lock all pages which are currently mapped into the address space of the process. */ 
    LockCurrentMemory = 1, 
 
    /** Lock all pages which will become mapped into the address space of the process in the future. */ 
    LockFutureMemory = 2, 

    /** Since Linux 4.4, with LockCurrentMemory or LockFutureMemory or both, lock only pages that are or once they are present in memory. */
    LockMemoryOnFault = 4,
};
Y_DECLARE_FLAGS(ELockAllMemoryFlags, ELockAllMemoryFlag) 
Y_DECLARE_OPERATORS_FOR_FLAGS(ELockAllMemoryFlags) 

/** 
 * Performs provided locking operation. 
 * 
 * Does nothing on windows. 
 * 
 * \param flags                         Locking operation to perform. 
 */ 
void LockAllMemory(ELockAllMemoryFlags flags); 

/** 
 * Unlocks whatever was locked with a previous call to `LockAllMemory`. 
 * 
 * Does nothing on windows. 
 */ 
void UnlockAllMemory();