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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:46:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:46:30 +0000 |
commit | b5896ba9f6047e7031e2bdee0622d543e11a6734 (patch) | |
tree | fd7b460593a2fee1be579bec5697e6d887ea3421 /src/util/rand_sleep.c | |
parent | Initial commit. (diff) | |
download | postfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.tar.xz postfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.zip |
Adding upstream version 3.4.23.upstream/3.4.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/rand_sleep.c')
-rw-r--r-- | src/util/rand_sleep.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/src/util/rand_sleep.c b/src/util/rand_sleep.c new file mode 100644 index 0000000..69a8cc8 --- /dev/null +++ b/src/util/rand_sleep.c @@ -0,0 +1,89 @@ +/*++ +/* NAME +/* rand_sleep 3 +/* SUMMARY +/* sleep for randomized interval +/* SYNOPSIS +/* #include <iostuff.h> +/* +/* void rand_sleep(delay, variation) +/* unsigned delay; +/* unsigned variation; +/* DESCRIPTION +/* rand_sleep() blocks the current process for an amount of time +/* pseudo-randomly chosen from the interval (delay +- variation/2). +/* +/* Arguments: +/* .IP delay +/* Time to sleep in microseconds. +/* .IP variation +/* Variation in microseconds; must not be larger than delay. +/* DIAGNOSTICS +/* Panic: interface violation. All system call errors are fatal. +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <stdlib.h> +#include <unistd.h> +#include <time.h> + +/* Utility library. */ + +#include <msg.h> +#include <myrand.h> +#include <iostuff.h> + +/* rand_sleep - block for random time */ + +void rand_sleep(unsigned delay, unsigned variation) +{ + const char *myname = "rand_sleep"; + unsigned usec; + + /* + * Sanity checks. + */ + if (delay == 0) + msg_panic("%s: bad delay %d", myname, delay); + if (variation > delay) + msg_panic("%s: bad variation %d", myname, variation); + + /* + * Use the semi-crappy random number generator. + */ + usec = (delay - variation / 2) + variation * (double) myrand() / RAND_MAX; + doze(usec); +} + +#ifdef TEST + +#include <msg_vstream.h> + +int main(int argc, char **argv) +{ + int delay; + int variation; + + msg_vstream_init(argv[0], VSTREAM_ERR); + if (argc != 3) + msg_fatal("usage: %s delay variation", argv[0]); + if ((delay = atoi(argv[1])) <= 0) + msg_fatal("bad delay: %s", argv[1]); + if ((variation = atoi(argv[2])) < 0) + msg_fatal("bad variation: %s", argv[2]); + rand_sleep(delay * 1000000, variation * 1000000); + exit(0); +} + +#endif |