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Diffstat (limited to 'shell_cmds/w/proc_compare.c')
| -rw-r--r-- | shell_cmds/w/proc_compare.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/shell_cmds/w/proc_compare.c b/shell_cmds/w/proc_compare.c new file mode 100644 index 0000000..806f571 --- /dev/null +++ b/shell_cmds/w/proc_compare.c @@ -0,0 +1,144 @@ +/*- + * Copyright (c) 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if 0 +#ifndef lint +static char sccsid[] = "@(#)proc_compare.c 8.2 (Berkeley) 9/23/93"; +#endif /* not lint */ +#endif + +#include <sys/cdefs.h> +#ifndef __APPLE__ +__FBSDID("$FreeBSD: src/usr.bin/w/proc_compare.c,v 1.9 2004/04/14 09:34:17 bde Exp $"); +#endif + +#include <sys/param.h> +#ifdef __APPLE__ +#include <sys/time.h> +#endif +#include <sys/proc.h> +#include <sys/time.h> +#include <sys/user.h> + +#include "extern.h" + +/* + * Returns 1 if p2 is "better" than p1 + * + * The algorithm for picking the "interesting" process is thus: + * + * 1) Only foreground processes are eligible - implied. + * 2) Runnable processes are favored over anything else. The runner + * with the highest cpu utilization is picked (p_estcpu). Ties are + * broken by picking the highest pid. + * 3) The sleeper with the shortest sleep time is next. With ties, + * we pick out just "short-term" sleepers (TDF_SINTR == 0). + * 4) Further ties are broken by picking the highest pid. + * + * If you change this, be sure to consider making the change in the kernel + * too (^T in kern/tty.c). + * + * TODO - consider whether pctcpu should be used. + */ + +#if !HAVE_KVM +#define ki_estcpu p_estcpu +#define ki_pid p_pid +#define ki_slptime p_slptime +#define ki_stat p_stat +#define ki_tdflags p_tdflags +#endif + +#define ISRUN(p) (((p)->ki_stat == SRUN) || ((p)->ki_stat == SIDL)) +#define TESTAB(a, b) ((a)<<1 | (b)) +#define ONLYA 2 +#define ONLYB 1 +#define BOTH 3 + +#if HAVE_KVM +int +proc_compare(struct kinfo_proc *p1, struct kinfo_proc *p2) +{ +#else +int +proc_compare(struct kinfo_proc *arg1, struct kinfo_proc *arg2) +{ + struct extern_proc* p1 = &arg1->kp_proc; + struct extern_proc* p2 = &arg2->kp_proc; +#endif + + if (p1 == NULL) + return (1); + /* + * see if at least one of them is runnable + */ + switch (TESTAB(ISRUN(p1), ISRUN(p2))) { + case ONLYA: + return (0); + case ONLYB: + return (1); + case BOTH: + /* + * tie - favor one with highest recent cpu utilization + */ + if (p2->ki_estcpu > p1->ki_estcpu) + return (1); + if (p1->ki_estcpu > p2->ki_estcpu) + return (0); + return (p2->ki_pid > p1->ki_pid); /* tie - return highest pid */ + } + /* + * weed out zombies + */ + switch (TESTAB(p1->ki_stat == SZOMB, p2->ki_stat == SZOMB)) { + case ONLYA: + return (1); + case ONLYB: + return (0); + case BOTH: + return (p2->ki_pid > p1->ki_pid); /* tie - return highest pid */ + } + /* + * pick the one with the smallest sleep time + */ + if (p2->ki_slptime > p1->ki_slptime) + return (0); + if (p1->ki_slptime > p2->ki_slptime) + return (1); +#ifndef __APPLE__ + /* + * favor one sleeping in a non-interruptible sleep + */ + if (p1->ki_tdflags & TDF_SINTR && (p2->ki_tdflags & TDF_SINTR) == 0) + return (1); + if (p2->ki_tdflags & TDF_SINTR && (p1->ki_tdflags & TDF_SINTR) == 0) + return (0); +#endif + return (p2->ki_pid > p1->ki_pid); /* tie - return highest pid */ +} |