(HPC) High-performance computing

A high-performance computing library focused on developing useful code blocks and intrusive containers with reduced memory fetches, continuous memory, and improved locality to minimize cache misses. It employs a branchless and lockless approach whenever possible, along with efficient synchronization that scales linearly with CPUs, ensuring efficient execution in userland.

Build

git clone git@github.com:n13l/hpc.git
cd hpc/
./bootstrap.sh          # init submodules (kbuild, liburcu, catch2, bats)
make menuconfig         # or: make defconfig
make -j$(nproc)
make check

bootstrap.sh initializes only what a standalone build needs: vendor/kbuild (the build system — scripts/, arch/ and os/ are committed symlinks into it), vendor/userspace-rcu and vendor/catch2, plus the bats framework that kbuild owns. Both in-tree and out-of-tree (make O=<dir>) builds are supported.

Configuration: sections, attributes and getopt_long

<hpc/conf.h> lets a program declare its knobs once, as attributes grouped into sections, and generates three things that otherwise drift apart by hand:

DEFINE_CONF_SECTION(net_conf, "net", "Networking",
	CONF_STRING('l', "listen",  listen,  0, "ADDR", "Address to bind to"),
	CONF_INT   (0,   "backlog", backlog, 0, "N",    "Listen backlog"),
	CONF_INC   ('v', "verbose", verbose, 0, NULL,   "Increase verbosity"),
	CONF_HELP_OPTION
);

struct conf_ctx *ctx = conf_alloc(NULL);	/* NULL: use mm_libc() */
conf_add(ctx, &net_conf);
int rest = conf_getopt(ctx, argc, argv);	/* or drive the loop yourself */

• the getopt_long() tables — conf_longopts() and conf_shortopts() give back exactly the struct option[] and short-option string you would have written, so a program can keep its own getopt_long() loop and call conf_dispatch() for the options this owns (CONF_USER declares one it handles itself);
• the --help text, grouped under each section's headline;
• the net.listen namespace — -S net.listen=…, conf_set(), a configuration file behind -C, and --dumpconfig.

Option spellings are declared verbatim; a section is a namespace and a help grouping, never a prefix on the command line.

Memory comes from hpc's allocator interface (struct mm, <mem/alloc.h>): the context tracks what it allocated and conf_free() releases it, so any mm works — mm_libc() by default, an arena or pool if one is passed in.

CONFIG_SECTION (Library options) decides how much of this a build pays for. With it off, the section names and the attribute metavars and descriptions stop being struct fields at all — the declaration macros never name the string literals, so they are never linked — and -S, -C and --dumpconfig go with the machinery behind them. What is left is the long name, the short letter, the target and its type: the option parsing is unchanged, the command line is identical, and source that compiled with sections on compiles with them off (conf_set(), conf_load() and conf_dump() become inline stubs and --help lists the options without descriptions).

CONFIG_ENVIRONMENT (Library options) decides the other source a value can come from — the one the program does not choose, since whoever starts it sets it. conf_getenv() and the typed conf_env_str(), conf_env_int(), conf_env_uint(), conf_env_u64(), conf_env_double() and conf_env_bool() readers over it are the single door onto getenv(). With the symbol off that door is closed: conf_getenv() is NULL, each typed reader is the default it was handed, the module behind them is not compiled, and the variable names stop being named by the code that looked them up. Every knob stays reachable from the command line, from -S and from a file, and the source is the same either way — so a build that says N is one whose configuration is a property of the binary rather than of the environment it was started in.