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/***
*heapprm.c - Set/report heap parameters
*
* Copyright (c) 1991, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Set or report the values of certain parameters in the heap.
*
*Revision History:
* 03-04-91 GJF Module created.
*
*******************************************************************************/
#include <cruntime.h>
#include <heap.h>
#include <malloc.h>
#include <os2dll.h>
/***
*_heap_param(int flag, int param_id, void *pparam) - set or report the values
* of the specified heap parameter.
*
*Purpose:
* Get or set certain parameters which affect the behavior of the heap.
* The supported parameters vary implementation to implementation and
* version to version. See description of entry conditions for the
* currently supported parameters.
*
*Entry:
* int flag - _HP_GETPARAM, to get a parameter value, or _HP_SETPARAM,
* to set a parameter value
*
* int param_id - identifier for the heap parameter. values supported in
* this release are:
*
* _HP_AMBLKSIZ - _amblksiz (aka _heap_growsize) parameter
* _HP_GROWSIZE - same as _HP_AMBLKSIZ
* _HP_RESETSIZE - _heap_resetsize parameter
*
* void *pparam - pointer to variable of appropriate type for the heap
* parameter to be fetched/set
*
*Exit:
* 0 = no error has occurred
* -1 = an error has occurred (errno is set)
*
*Exceptions:
*
*******************************************************************************/
int _CALLTYPE1 _heap_param (
int flag,
int param_id,
void *pparam
)
{
switch ( param_id ) {
case _HP_RESETSIZE:
if ( flag == _HP_SETPARAM ) {
_mlock(_HEAP_LOCK);
_heap_resetsize = *(unsigned *)pparam;
_munlock(_HEAP_LOCK);
}
else
*(unsigned *)pparam = _heap_resetsize;
break;
case _HP_AMBLKSIZ:
if ( flag == _HP_SETPARAM )
/*
* the only references to _amblksiz (aka
* _heap_growsize) are atomic. therefore, the
* heap does not need to be locked.
*/
_amblksiz = *(unsigned *)pparam;
else
*(unsigned *)pparam = _amblksiz;
break;
default:
return -1;
}
return 0;
}
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