jpayne@69: /* SPDX-License-Identifier: 0BSD */
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \file        lzma/hardware.h
jpayne@69:  * \brief       Hardware information
jpayne@69:  * \note        Never include this file directly. Use <lzma.h> instead.
jpayne@69:  *
jpayne@69:  * Since liblzma can consume a lot of system resources, it also provides
jpayne@69:  * ways to limit the resource usage. Applications linking against liblzma
jpayne@69:  * need to do the actual decisions how much resources to let liblzma to use.
jpayne@69:  * To ease making these decisions, liblzma provides functions to find out
jpayne@69:  * the relevant capabilities of the underlying hardware. Currently there
jpayne@69:  * is only a function to find out the amount of RAM, but in the future there
jpayne@69:  * will be also a function to detect how many concurrent threads the system
jpayne@69:  * can run.
jpayne@69:  *
jpayne@69:  * \note        On some operating systems, these function may temporarily
jpayne@69:  *              load a shared library or open file descriptor(s) to find out
jpayne@69:  *              the requested hardware information. Unless the application
jpayne@69:  *              assumes that specific file descriptors are not touched by
jpayne@69:  *              other threads, this should have no effect on thread safety.
jpayne@69:  *              Possible operations involving file descriptors will restart
jpayne@69:  *              the syscalls if they return EINTR.
jpayne@69:  */
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Author: Lasse Collin
jpayne@69:  */
jpayne@69: 
jpayne@69: #ifndef LZMA_H_INTERNAL
jpayne@69: #	error Never include this file directly. Use <lzma.h> instead.
jpayne@69: #endif
jpayne@69: 
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \brief       Get the total amount of physical memory (RAM) in bytes
jpayne@69:  *
jpayne@69:  * This function may be useful when determining a reasonable memory
jpayne@69:  * usage limit for decompressing or how much memory it is OK to use
jpayne@69:  * for compressing.
jpayne@69:  *
jpayne@69:  * \return      On success, the total amount of physical memory in bytes
jpayne@69:  *              is returned. If the amount of RAM cannot be determined,
jpayne@69:  *              zero is returned. This can happen if an error occurs
jpayne@69:  *              or if there is no code in liblzma to detect the amount
jpayne@69:  *              of RAM on the specific operating system.
jpayne@69:  */
jpayne@69: extern LZMA_API(uint64_t) lzma_physmem(void) lzma_nothrow;
jpayne@69: 
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \brief       Get the number of processor cores or threads
jpayne@69:  *
jpayne@69:  * This function may be useful when determining how many threads to use.
jpayne@69:  * If the hardware supports more than one thread per CPU core, the number
jpayne@69:  * of hardware threads is returned if that information is available.
jpayne@69:  *
jpayne@69:  * \return      On success, the number of available CPU threads or cores is
jpayne@69:  *              returned. If this information isn't available or an error
jpayne@69:  *              occurs, zero is returned.
jpayne@69:  */
jpayne@69: extern LZMA_API(uint32_t) lzma_cputhreads(void) lzma_nothrow;