X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=lzma%2Fapi%2Flzma%2Fhardware.h;fp=lzma%2Fapi%2Flzma%2Fhardware.h;h=5321d9af8e46d0caa86de68a71e899bd33f7e5ed;hb=32b8a6b26ed8843828e03e505d2256960bda0980;hp=0000000000000000000000000000000000000000;hpb=d48fc23a4bcf8ca3c406d6e8c8a6f8c6b0fa2f1e;p=zpackage diff --git a/lzma/api/lzma/hardware.h b/lzma/api/lzma/hardware.h new file mode 100644 index 0000000..5321d9a --- /dev/null +++ b/lzma/api/lzma/hardware.h @@ -0,0 +1,64 @@ +/** + * \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 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;