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author | Mattias Andrée <maandree@kth.se> | 2024-02-24 20:33:55 +0100 |
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committer | Mattias Andrée <maandree@kth.se> | 2024-02-24 20:33:55 +0100 |
commit | 78ea3f31e616b9da05f8bd61b550abed92f678d9 (patch) | |
tree | c4bee0b1eec9e08930a82627de68101ca18c9831 | |
parent | Add coreupdownd (diff) | |
download | coreupdown-78ea3f31e616b9da05f8bd61b550abed92f678d9.tar.gz coreupdown-78ea3f31e616b9da05f8bd61b550abed92f678d9.tar.bz2 coreupdown-78ea3f31e616b9da05f8bd61b550abed92f678d9.tar.xz |
Add support for SIGHUP
Signed-off-by: Mattias Andrée <maandree@kth.se>
-rw-r--r-- | Makefile | 3 | ||||
-rw-r--r-- | config.mk | 18 | ||||
-rw-r--r-- | coreupdown.c | 48 |
3 files changed, 51 insertions, 18 deletions
@@ -11,7 +11,8 @@ CPPFLAGS_CONFS =\ -D'COREDOWN_THRESHOLD_TIME=$(COREDOWN_THRESHOLD_TIME)'\ -D'COREDOWN_COOLDOWN=$(COREDOWN_COOLDOWN)'\ -D'DAEMON_INTERVAL_SEC=$(DAEMON_INTERVAL_SEC)'\ - -D'DAEMON_INTERVAL_NSEC=$(DAEMON_INTERVAL_NSEC)' + -D'DAEMON_INTERVAL_NSEC=$(DAEMON_INTERVAL_NSEC)'\ + -D'DAEMON_PATH="$(PREFIX)/bin/coreupdownd"' OBJ =\ coreupdown.o @@ -1,14 +1,18 @@ PREFIX = /usr MANPREFIX = $(PREFIX)/share/man +# It is important that PREFIX is properly set when building, not just installing -COREUP_THRESHOLD_CPU = 95 -COREUP_THRESHOLD_TIME = 2 -COREUP_COOLDOWN = 4 -COREDOWN_THRESHOLD_CPU = 50 +# In percent of one CPU (integer) +COREUP_THRESHOLD_CPU = 95 +COREDOWN_THRESHOLD_CPU = 50 +# In multiples of the update interval (integer) +COREUP_THRESHOLD_TIME = 2 COREDOWN_THRESHOLD_TIME = 2 -COREDOWN_COOLDOWN = 4 -DAEMON_INTERVAL_SEC = 1 -DAEMON_INTERVAL_NSEC = 0 +COREUP_COOLDOWN = 4 +COREDOWN_COOLDOWN = 4 +# Update interval (integer) +DAEMON_INTERVAL_SEC = 1 +DAEMON_INTERVAL_NSEC = 0 CC = c99 diff --git a/coreupdown.c b/coreupdown.c index 403bdf6..70015ec 100644 --- a/coreupdown.c +++ b/coreupdown.c @@ -3,6 +3,7 @@ #include <errno.h> #include <fcntl.h> #include <limits.h> +#include <signal.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> @@ -11,6 +12,7 @@ #include <unistd.h> static const char *argv0; +static volatile sig_atomic_t caught_sighup = 0; #define coreup() coreupdown(ULONG_MAX) #define coredown() coreupdown(1) @@ -226,14 +228,25 @@ line_done: #undef IDLE_FIELD } +static void +sighup_handler(int signo) +{ + (void) signo; + caught_sighup = 1; +} + static int -daemon_main(int argc, char **argv) +daemon_main(int argc, char **argv, int orig_argc, char **orig_argv, int reexeced) { uintmax_t total, idle; size_t cpus; - int up_time = 0, down_time = 0, cooldown = 0; + int up_time = 0, down_time = 0, cooldown = 0, err; struct timespec interval, rem; +restart: + if (reexeced) + argv[0] = "coreupdownd"; + if (argc && !strcmp(argv[0], "--")) { argv++; argc--; @@ -244,11 +257,14 @@ daemon_main(int argc, char **argv) return 1; } - /* TODO configurations should be configurable */ + if (!reexeced) { + /* TODO add proper daemonisation */ + } - /* TODO add SIGHUP support */ + /* TODO configurations should be configurable */ - /* TODO add proper daemonisation */ + if (signal(SIGHUP, sighup_handler) == SIG_ERR) + fprintf(stderr, "%s: signal SIGHUP <function>: %s\n", argv0, strerror(errno)); interval.tv_sec = DAEMON_INTERVAL_SEC; interval.tv_nsec = DAEMON_INTERVAL_NSEC; @@ -260,16 +276,26 @@ daemon_main(int argc, char **argv) close(STDOUT_FILENO); for (;;) { - if (clock_nanosleep(CLOCK_REALTIME /* = monotonic */, 0, &interval, &rem)) { + if (caught_sighup) { + caught_sighup = 0; + orig_argv[0] = "coreupdownd "; + execv(DAEMON_PATH, orig_argv); + fprintf(stderr, "%s: execv %s: %s\n", argv0, DAEMON_PATH, strerror(errno)); + reexeced = 1; + argv = &orig_argv[1]; + argc = orig_argc - 1; + goto restart; + } + + if ((err = clock_nanosleep(CLOCK_REALTIME /* = monotonic */, 0, &interval, &rem))) { do { - if (errno != EINTR) { + if (err != EINTR) { fprintf(stderr, "%s: clock_nanosleep CLOCK_REALTIME: %s\n", argv0, strerror(errno)); return 1; } - } while (clock_nanosleep(CLOCK_REALTIME, 0, &rem, &rem)); + } while ((err = clock_nanosleep(CLOCK_REALTIME, 0, &rem, &rem))); } - sleep(1); if (getusage(&total, &idle, &cpus)) return 1; if (cooldown) { @@ -313,7 +339,9 @@ main(int argc, char **argv) if (!strcmp(command, "coredown")) return oneshot_main(argc, argv, 1); if (!strcmp(command, "coreupdownd")) - return daemon_main(argc, argv); + return daemon_main(argc, argv, argc + 1, &argv[-1], 0); + if (!strcmp(command, "coreupdownd ")) + return daemon_main(argc, argv, argc + 1, &argv[-1], 1); } fprintf(stderr, "usage: coreup [count]\n" |