| Current File : //usr/include/lzma/hardware.h |
/**
* \file lzma/hardware.h
* \brief Hardware information
*
* Since liblzma can consume a lot of system resources, it also provides
* ways to limit the resource usage. Applications linking against liblzma
* need to do the actual decisions how much resources to let liblzma to use.
* To ease making these decisions, liblzma provides functions to find out
* the relevant capabilities of the underlaying hardware. Currently there
* is only a function to find out the amount of RAM, but in the future there
* will be also a function to detect how many concurrent threads the system
* can run.
*
* \note On some operating systems, these function may temporarily
* load a shared library or open file descriptor(s) to find out
* the requested hardware information. Unless the application
* assumes that specific file descriptors are not touched by
* other threads, this should have no effect on thread safety.
* Possible operations involving file descriptors will restart
* the syscalls if they return EINTR.
*/
/*
* Author: Lasse Collin
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*
* See ../lzma.h for information about liblzma as a whole.
*/
#ifndef LZMA_H_INTERNAL
# error Never include this file directly. Use <lzma.h> instead.
#endif
/**
* \brief Get the total amount of physical memory (RAM) in bytes
*
* This function may be useful when determining a reasonable memory
* usage limit for decompressing or how much memory it is OK to use
* for compressing.
*
* \return On success, the total amount of physical memory in bytes
* is returned. If the amount of RAM cannot be determined,
* zero is returned. This can happen if an error occurs
* or if there is no code in liblzma to detect the amount
* of RAM on the specific operating system.
*/
extern LZMA_API(uint64_t) lzma_physmem(void) lzma_nothrow;
/**
* \brief Get the number of processor cores or threads
*
* This function may be useful when determining how many threads to use.
* If the hardware supports more than one thread per CPU core, the number
* of hardware threads is returned if that information is available.
*
* \brief On success, the number of available CPU threads or cores is
* returned. If this information isn't available or an error
* occurs, zero is returned.
*/
extern LZMA_API(uint32_t) lzma_cputhreads(void) lzma_nothrow;