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authorGravatar Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>2007-03-09 16:56:38 +0000
committerGravatar Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>2007-03-09 16:56:38 +0000
commit71bc71a7dc2601b1d9beb73ee1f178da1733788e (patch)
tree0dba091508cc1a72f77a0c6eae2afed1d0d550aa /miscutils/chrt.c
parent339f5eb2e0676da591150015e157c38c4ab52a3e (diff)
downloadbusybox-71bc71a7dc2601b1d9beb73ee1f178da1733788e.tar.gz
busybox-71bc71a7dc2601b1d9beb73ee1f178da1733788e.tar.bz2
- add chrt applet.
text data bss dec hex filename 769 0 0 769 301 miscutils/chrt.o and could use some further shrinkage
Diffstat (limited to 'miscutils/chrt.c')
-rw-r--r--miscutils/chrt.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/miscutils/chrt.c b/miscutils/chrt.c
new file mode 100644
index 000000000..75d77d536
--- /dev/null
+++ b/miscutils/chrt.c
@@ -0,0 +1,124 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * chrt - manipulate real-time attributes of a process
+ * Copyright (c) 2006-2007 Bernhard Fischer
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "busybox.h"
+#include <unistd.h>
+#include <sched.h>
+#include <getopt.h> /* optind */
+#ifndef _POSIX_PRIORITY_SCHEDULING
+#warning your system may be foobared
+#endif
+static const struct {
+ const int policy;
+ const char const name[12];
+} policies[] = {
+ {SCHED_OTHER, "SCHED_OTHER"},
+ {SCHED_FIFO, "SCHED_FIFO"},
+ {SCHED_RR, "SCHED_RR"}
+};
+
+static void show_min_max(int pol) {
+ const char *fmt = "%s min/max priority\t: %d/%d\n\0%s not supported?\n";
+ int max, min;
+ max = sched_get_priority_max(pol);
+ min = sched_get_priority_min(pol);
+ if (max >= 0 && min >= 0)
+ printf(fmt, policies[pol].name, min, max);
+ else {
+ fmt += 29;
+ printf(fmt, policies[pol].name);
+ }
+}
+
+#define OPT_m (1<<0)
+#define OPT_p (1<<1)
+#define OPT_r (1<<2)
+#define OPT_f (1<<3)
+#define OPT_o (1<<4)
+
+int chrt_main(int argc, char** argv);
+int chrt_main(int argc, char** argv)
+{
+ pid_t pid = 0;
+ unsigned opt;
+ struct sched_param sp;
+ char *p_opt = NULL, *priority = NULL;
+ const char *state = "current\0new";
+ int prio = 0, policy = SCHED_RR;
+
+ opt_complementary = "r--fo:f--ro:r--fo"; /* only one policy accepted */
+ opt = getopt32(argc, argv, "+mp:rfo", &p_opt);
+ if (opt & OPT_r)
+ policy = SCHED_RR;
+ if (opt & OPT_f)
+ policy = SCHED_FIFO;
+ if (opt & OPT_o)
+ policy = SCHED_OTHER;
+
+ if (opt & OPT_m) { /* print min/max */
+ show_min_max(SCHED_FIFO);
+ show_min_max(SCHED_RR);
+ show_min_max(SCHED_OTHER);
+ fflush_stdout_and_exit(EXIT_SUCCESS);
+ }
+ if (opt & OPT_p) {
+ if (argc == optind+1) { /* -p <priority> <pid> */
+ priority = p_opt;
+ p_opt = argv[optind];
+ }
+ argv += optind; /* me -p <arg> */
+ pid = xatoul_range(p_opt, 1, ULONG_MAX); /* -p <pid> */
+ } else {
+ argv += optind; /* me -p <arg> */
+ priority = *argv;
+ }
+ if (priority) {
+ /* from the manpage of sched_getscheduler:
+ [...] sched_priority can have a value
+ in the range 0 to 99.
+ [...] SCHED_OTHER or SCHED_BATCH must be assigned
+ the static priority 0. [...] SCHED_FIFO or
+ SCHED_RR can have a static priority in the range 1 to 99.
+ */
+ prio = xstrtol_range(priority, 0, policy == SCHED_OTHER
+ ? 0 : 1, 99);
+ }
+
+ if (opt & OPT_p) {
+ int pol = 0;
+print_rt_info:
+ pol = sched_getscheduler(pid);
+ if (pol < 0)
+ bb_perror_msg_and_die("failed to %cet pid %d's policy", 'g', pid);
+ printf("pid %d's %s scheduling policy: %s\n",
+ pid, state, policies[pol].name);
+ if (sched_getparam(pid, &sp))
+ bb_perror_msg_and_die("failed to get pid %d's attributes", pid);
+ printf("pid %d's %s scheduling priority: %d\n",
+ pid, state, sp.sched_priority);
+ if (!*argv) /* no new prio given or we did print already, done. */
+ return EXIT_SUCCESS;
+ }
+
+ sp.sched_priority = prio;
+ if (sched_setscheduler(pid, policy, &sp) < 0)
+ bb_perror_msg_and_die("failed to %cet pid %d's policy", 's', pid);
+ if (opt & OPT_p) {
+ state += 8;
+ ++argv;
+ goto print_rt_info;
+ }
+ ++argv;
+ BB_EXECVP(*argv, argv);
+ bb_perror_msg_and_die("%s", *argv);
+}
+#undef OPT_p
+#undef OPT_r
+#undef OPT_f
+#undef OPT_o
+#undef OPT_m