mean.tproj/mean.c

   1 /*
   2  *  mean.c
   3  *  mean - lower process priorities with more force than nice
   4  *
   5  *  Created by Lucia Ballard on 9/16/09.
   6  *  Copyright 2009 Apple Inc. All rights reserved.
   7  *
   8  */
   9
  10 #include <mach/mach.h>
  11 #include <mach/task.h>
  12
  13 #include <sys/resource.h>
  14
  15 #include <errno.h>
  16 #include <getopt.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19
  20 void usage(void);
  21
  22 #ifndef PRIO_DARWIN_PROCESS
  23 #define PRIO_DARWIN_PROCESS 4       /* Second argument is a PID */
  24 #endif
  25
  26 void
  27 usage(void)
  28 {
  29                 fprintf(stderr, "Usage: mean -t <pid>\n");
  30                 fprintf(stderr, "\tthrottle <pid>'s usage of cpu, I/O, and networking\n");
  31                 fprintf(stderr, "mean -u <pid>\n");
  32                 fprintf(stderr,  "\treturn <pid> to normal priority\n");
  33                 fprintf(stderr, "mean -[s|r] <pid>\n");
  34                 fprintf(stderr,  "\tsuspend or resume <pid>\n");
  35                 exit(0);
  36 }
  37
  38 int
  39 main(int argc, char **argv)
  40 {
  41         int pid, err, ch;
  42         mach_port_t task;
  43         int priority = 0;
  44
  45         boolean_t do_resume = 0, do_suspend = 0;
  46         boolean_t do_throttle = 0, do_undo = 0;
  47
  48         if (argc < 2)
  49                 usage();
  50
  51         while ((ch = getopt(argc, argv, "rstu")) != -1)
  52         switch (ch) {
  53                 case 'u':
  54                         do_undo = 1;
  55                         continue;
  56                 case 'r':
  57                         do_resume = 1;
  58                         continue;
  59                 case 's':
  60                         do_suspend = 1;
  61                         continue;
  62                 case 't':
  63                         do_throttle = 1;
  64                         continue;
  65                 default:
  66                         usage();
  67         }
  68
  69         argc -= optind; argv += optind;
  70
  71         if (argc == 0)
  72                 usage();
  73
  74         pid = atoi(*argv);
  75         if (!pid)
  76                 usage();
  77
  78         if (do_throttle || do_undo) {
  79                 priority = PRIO_DARWIN_BG;
  80
  81                 if (do_undo)
  82                         priority = 0;
  83
  84                 err = setpriority(PRIO_DARWIN_PROCESS, pid, priority);
  85                 if (err) {
  86                         fprintf(stderr, "Failed to set priority (%d)\n", errno);
  87                         exit(0);
  88                 }
  89         }
  90
  91         if (do_suspend || do_resume) {
  92                 err = task_for_pid(mach_task_self(), pid, &task);
  93                 if (err) {
  94                         fprintf(stderr, "Failed to get task port (%d)\n", err);
  95                         exit(0);
  96                 }
  97
  98                 if (do_suspend) {
  99                         err = task_suspend(task);
 100                         if (err) {
 101                                 fprintf(stderr, "Failed to suspend task (%d)\n", err);
 102                         }
 103
 104                 }
 105
 106                 if (do_resume) {
 107                         err = task_resume(task);
 108                         if (err) {
 109                                 fprintf(stderr, "Failed to resume task (%d)\n", err);
 110                         }
 111                 }
 112         }
 113
 114         return 0;
 115 }
 116