/*

 * POSIX library for Lua 5.1, 5.2 & 5.3.

 * (c) Gary V. Vaughan <gary@vaughan.pe>, 2013-2015

 * (c) Reuben Thomas <rrt@sc3d.org> 2010-2013

 * (c) Natanael Copa <natanael.copa@gmail.com> 2008-2010

 * Clean up and bug fixes by Leo Razoumov <slonik.az@gmail.com> 2006-10-11

 * Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br> 07 Apr 2006 23:17:49

 * Based on original by Claudio Terra for Lua 3.x.

 * With contributions by Roberto Ierusalimschy.

 * With documentation from Steve Donovan 2012

 */

/***

 Control Maximum System Resource Consumption.

@module posix.sys.resource

*/

#include <config.h>

#include <sys/resource.h>

#include "_helpers.c"

/* OpenBSD 5.6 recommends using RLIMIT_DATA in place of missing RLIMIT_AS */

#ifndef RLIMIT_AS

#  define RLIMIT_AS RLIMIT_DATA

#endif

/***

Resource limit record.

@table PosixRlimit

@int rlim_cur current soft limit

@int rlim_max hard limit

*/

static int

pushrlimit(lua_State *L, struct rlimit *lim)

{

	if (!lim)

		return lua_pushnil(L), 1;

	lua_createtable(L, 0, 2);

	setnumberfield(lim, rlim_cur);

	setnumberfield(lim, rlim_max);

	settypemetatable("PosixRlimit");

	return 1;

}

/***

Get resource limits for this process.

@function getrlimit

@int resource one of `RLIMIT_CORE`, `RLIMIT_CPU`, `RLIMIT_DATA`, `RLIMIT_FSIZE`,

  `RLIMIT_NOFILE`, `RLIMIT_STACK` or `RLIMIT_AS`

@treturn[1] int softlimit

@treturn[1] int hardlimit, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see getrlimit(2)

@see setrlimit

*/

static int

Pgetrlimit(lua_State *L)

{

	struct rlimit lim;

	int r;

	checknargs(L, 1);

	r = getrlimit(checkint(L, 1), &lim);

	if (r < 0)

		return pusherror(L, "getrlimit");

	return pushrlimit(L, &lim);

}

/***

Set a resource limit for subsequent child processes.

@function setrlimit

@string resource one of "core", "cpu", "data", "fsize",

 "nofile", "stack" or "as"

@param[opt] softlimit process may receive a signal when reached

@param[opt] hardlimit process may be terminated when reached

@treturn[1] int `0`, if successful

@return[2] nil

@treturn[2] string error message

@treturn[2] int errnum

@see getrlimit(2)

@see limit.lua

@usage P.setrlimit ("nofile", 1000, 2000)

*/

static const char *Srlimit_fields[] = { "rlim_cur", "rlim_max" };

static int

Psetrlimit(lua_State *L)

{

	struct rlimit lim;

	int rid = checkint(L, 1);

	luaL_checktype(L, 2, LUA_TTABLE);

	checknargs(L, 2);

	lim.rlim_cur = checknumberfield(L, 2, "rlim_cur");

	lim.rlim_max = checknumberfield(L, 2, "rlim_max");

	checkfieldnames(L, 2, Srlimit_fields);

	return pushresult(L, setrlimit(rid, &lim), "setrlimit");

}

static const luaL_Reg posix_sys_resource_fns[] =

{

	LPOSIX_FUNC( Pgetrlimit		),

	LPOSIX_FUNC( Psetrlimit		),

	{NULL, NULL}

};

/***

Constants.

@section constants

*/

/***

Rlimit constants.

@table posix.sys.resource

@int RLIM_INFINITY unlimited resource usage

@int RLIM_SAVED_CUR saved current resource soft limit

@int RLIM_SAVED_MAX saved resource hard limit

@int RLIMIT_CORE maximum bytes allowed for a core file

@int RLIMIT_CPU maximum cputime secconds allowed per process

@int RLIMIT_DATA maximum data segment bytes per process

@int RLIMIT_FSIZE maximum bytes in any file

@int RLIMIT_NOFILE maximum number of open files per process

@int RLIMIT_STACK maximum stack segment bytes per process

@int RLIMIT_AS maximum bytes total address space per process

@usage

  -- Print resource constants supported on this host.

  for name, value in pairs (require "posix.sys.resource") do

    if type (value) == "number" then

      print (name, value)

     end

  end

*/

LUALIB_API int

luaopen_posix_sys_resource(lua_State *L)

{

	luaL_register(L, "posix.sys.resource", posix_sys_resource_fns);

	lua_pushliteral(L, "posix.sys.resource for " LUA_VERSION " / " PACKAGE_STRING);

	lua_setfield(L, -2, "version");

	LPOSIX_CONST( RLIM_INFINITY	);

#if defined RLIM_SAVED_CUR

	LPOSIX_CONST( RLIM_SAVED_CUR	);

#endif

#if defined RLIM_SAVED_MAX

	LPOSIX_CONST( RLIM_SAVED_MAX	);

#endif

	LPOSIX_CONST( RLIMIT_CORE	);

	LPOSIX_CONST( RLIMIT_CPU	);

	LPOSIX_CONST( RLIMIT_DATA	);

	LPOSIX_CONST( RLIMIT_FSIZE	);

	LPOSIX_CONST( RLIMIT_NOFILE	);

	LPOSIX_CONST( RLIMIT_STACK	);

	LPOSIX_CONST( RLIMIT_AS		);

	return 1;

}