/* -*- c-file-style: "java"; indent-tabs-mode: nil; fill-column: 78 -*-
 *
 * distcc -- A simple distributed compiler system
 *
 * Copyright (C) 2003 by Martin Pool <mbp@samba.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

/* Thanks to Dimitri PAPADOPOULOS-ORFANOS for researching many of the methods
 * in this file. */

#include "common-internal.h"
#include "ncpus.h"
#include "util.h"

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/stat.h>


#define EXIT_DISTCC_FAILED -1

/**
 * Determine number of processors online.
 *
 * We will in the future use this to gauge how many concurrent tasks
 * should run on this machine.  Obviously this is only very rough: the
 * correct number needs to take into account disk buffers, IO
 * bandwidth, other tasks, etc.
**/

#if defined(__hpux__) || defined(__hpux)

#include <sys/param.h>
#include <sys/pstat.h>

int dcc_ncpus(int *ncpus)
{
	struct pst_dynamic psd;
	if (pstat_getdynamic(&psd, sizeof(psd), 1, 0) != -1) {
		*ncpus = psd.psd_proc_cnt;
		return 0;
	} else {
		*ncpus = -1;
		LOG_ERRNO (errno, cherokee_err_error, CHEROKEE_ERROR_NCPUS_PSTAT);
		return EXIT_DISTCC_FAILED;
	}
}


#elif defined(__VOS__)

#ifdef __GNUC__
#define $shortmap
#endif

#include <module_info.h>

extern void s$get_module_info (char_varying *module_name, void *mip, short int *code);

int dcc_ncpus(int *ncpus)
{
	short int code;
	module_info mi;
	char_varying(66) module_name;

	strcpy_vstr_nstr (&module_name, "");
	mi.version = MODULE_INFO_VERSION_1;
	s$get_module_info ((char_varying *)&module_name, (void *)&mi, &code);
	if (code != 0)
		*ncpus = 1;    /* safe guess... */
	else
		*ncpus = mi.n_user_cpus;
	return 0;
}

#elif defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || defined(__APPLE__)

/* http://www.FreeBSD.org/cgi/man.cgi?query=sysctl&sektion=3&manpath=FreeBSD+4.6-stable
 * http://www.openbsd.org/cgi-bin/man.cgi?query=sysctl&sektion=3&manpath=OpenBSD+Current
 * http://www.tac.eu.org/cgi-bin/man-cgi?sysctl+3+NetBSD-current
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/sysctl.h>
int dcc_ncpus(int *ncpus)
{
	int mib[2];
	size_t len = sizeof(*ncpus);
	mib[0] = CTL_HW;
	mib[1] = HW_NCPU;
	if (sysctl(mib, 2, ncpus, &len, NULL, 0) == 0) {
		return 0;
	} else {
		LOG_ERRNO (errno, cherokee_err_error, CHEROKEE_ERROR_NCPUS_HW_NCPU);
		return EXIT_DISTCC_FAILED;
	}
}

#else /* every other system */

/*
 * http://www.opengroup.org/onlinepubs/007904975/functions/sysconf.html
 * http://docs.sun.com/?p=/doc/816-0213/6m6ne38dd&a=view
 * http://www.tru64unix.compaq.com/docs/base_doc/DOCUMENTATION/V40G_HTML/MAN/MAN3/0629____.HTM
 * http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi?coll=0650&db=man&fname=/usr/share/catman/p_man/cat3c/sysconf.z
 */

int dcc_ncpus(int *ncpus)
{
#if defined(_SC_NPROCESSORS_ONLN)
	/* Linux, Solaris, Tru64, UnixWare 7, and Open UNIX 8  */
	*ncpus = sysconf(_SC_NPROCESSORS_ONLN);
#elif defined(_SC_NPROC_ONLN)
	/* IRIX */
	*ncpus = sysconf(_SC_NPROC_ONLN);
#else
#warning "Please port this function"
	*ncpus = -1;                /* unknown */
#endif

	if (*ncpus == -1) {
		LOG_ERRNO_S (errno, cherokee_err_error, CHEROKEE_ERROR_NCPUS_SYSCONF);
		return EXIT_DISTCC_FAILED;
	} else if (*ncpus == 0) {
		/* If there are no cpus, what are we running on ?
		 * NOTE: it has apparently been observed to happen on ARM Linux
		 */
		*ncpus = 1;
	}

	return 0;
}
#endif