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/*
* Copyright (c) 2014, NORDUnet A/S.
* See COPYING for licensing information.
*/
/* slowdown -- a shared library for introducing delay in read(2) and
write(2) calls to simulate a slow disk */
#define _GNU_SOURCE 1 /* For RTLD_NEXT. */
#include <unistd.h>
#include <dlfcn.h>
#include <stdlib.h>
static
sleepsome (const char *envname)
{
const char *delay_str = secure_getenv(envname);
useconds_t delay = 0;
if (delay_str != NULL)
delay = atoi(delay_str);
usleep (1000 * delay);
}
ssize_t
read (int fd, void *buf, size_t count)
{
ssize_t (*real_read)(int, void*, size_t) = dlsym(RTLD_NEXT, "read");
sleepsome ("SLOWDOWN_READ_DELAY_MS");
return real_read (fd, buf, count);
}
ssize_t
write (int fd, const void *buf, size_t count)
{
ssize_t (*real_write)(int, const void*, size_t) = dlsym(RTLD_NEXT, "write");
sleepsome ("SLOWDOWN_WRITE_DELAY_MS");
return real_write (fd, buf, count);
}
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