mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-18 05:32:52 +00:00
34 lines
504 B
C
34 lines
504 B
C
|
#define _DEFAULT_SOURCE
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <sys/random.h>
|
||
|
|
#include <pthread.h>
|
||
|
|
#include <errno.h>
|
||
|
|
|
||
|
|
int getentropy(void *buffer, size_t len)
|
||
|
|
{
|
||
|
|
int cs, ret = 0;
|
||
|
|
char *pos = buffer;
|
||
|
|
|
||
|
|
if (len > 256) {
|
||
|
|
errno = EIO;
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
|
||
|
|
|
||
|
|
while (len) {
|
||
|
|
ret = getrandom(pos, len, 0);
|
||
|
|
if (ret < 0) {
|
||
|
|
if (errno == EINTR) continue;
|
||
|
|
else break;
|
||
|
|
}
|
||
|
|
pos += ret;
|
||
|
|
len -= ret;
|
||
|
|
ret = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
pthread_setcancelstate(cs, 0);
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|