mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-27 01:51:59 +00:00
106 lines
2.4 KiB
C
106 lines
2.4 KiB
C
#include <errno.h>
|
|
#include <stdint.h>
|
|
#include <time.h>
|
|
#include "atomic.h"
|
|
#include "syscall.h"
|
|
|
|
#ifdef VDSO_CGT_SYM
|
|
|
|
static void *volatile vdso_func;
|
|
|
|
#ifdef VDSO_CGT32_SYM
|
|
static void *volatile vdso_func_32;
|
|
static int cgt_time32_wrap(clockid_t clk, struct timespec *ts)
|
|
{
|
|
long ts32[2];
|
|
int (*f)(clockid_t, long[2]) =
|
|
(int (*)(clockid_t, long[2]))vdso_func_32;
|
|
int r = f(clk, ts32);
|
|
if (!r) {
|
|
/* Fallback to syscalls if time32 overflowed. Maybe
|
|
* we lucked out and somehow migrated to a kernel with
|
|
* time64 syscalls available. */
|
|
if (ts32[0] < 0) {
|
|
a_cas_p(&vdso_func, (void *)cgt_time32_wrap, 0);
|
|
return -ENOSYS;
|
|
}
|
|
ts->tv_sec = ts32[0];
|
|
ts->tv_nsec = ts32[1];
|
|
}
|
|
return r;
|
|
}
|
|
#endif
|
|
|
|
static int cgt_init(clockid_t clk, struct timespec *ts)
|
|
{
|
|
void *p = __vdsosym(VDSO_CGT_VER, VDSO_CGT_SYM);
|
|
#ifdef VDSO_CGT32_SYM
|
|
if (!p) {
|
|
void *q = __vdsosym(VDSO_CGT32_VER, VDSO_CGT32_SYM);
|
|
if (q) {
|
|
a_cas_p(&vdso_func_32, 0, q);
|
|
p = cgt_time32_wrap;
|
|
}
|
|
}
|
|
#endif
|
|
int (*f)(clockid_t, struct timespec *) =
|
|
(int (*)(clockid_t, struct timespec *))p;
|
|
a_cas_p(&vdso_func, (void *)cgt_init, p);
|
|
return f ? f(clk, ts) : -ENOSYS;
|
|
}
|
|
|
|
static void *volatile vdso_func = (void *)cgt_init;
|
|
|
|
#endif
|
|
|
|
int clock_gettime(clockid_t clk, struct timespec *ts)
|
|
{
|
|
int r;
|
|
|
|
#ifdef VDSO_CGT_SYM
|
|
int (*f)(clockid_t, struct timespec *) =
|
|
(int (*)(clockid_t, struct timespec *))vdso_func;
|
|
if (f) {
|
|
r = f(clk, ts);
|
|
if (!r) return r;
|
|
if (r == -EINVAL) return __syscall_ret(r);
|
|
/* Fall through on errors other than EINVAL. Some buggy
|
|
* vdso implementations return ENOSYS for clocks they
|
|
* can't handle, rather than making the syscall. This
|
|
* also handles the case where cgt_init fails to find
|
|
* a vdso function to use. */
|
|
}
|
|
#endif
|
|
|
|
#ifdef SYS_clock_gettime64
|
|
r = -ENOSYS;
|
|
if (sizeof(time_t) > 4)
|
|
r = __syscall(SYS_clock_gettime64, clk, ts);
|
|
if (SYS_clock_gettime == SYS_clock_gettime64 || r!=-ENOSYS)
|
|
return __syscall_ret(r);
|
|
long ts32[2];
|
|
r = __syscall(SYS_clock_gettime, clk, ts32);
|
|
if (r==-ENOSYS && clk==CLOCK_REALTIME) {
|
|
r = __syscall(SYS_gettimeofday, ts32, 0);
|
|
ts32[1] *= 1000;
|
|
}
|
|
if (!r) {
|
|
ts->tv_sec = ts32[0];
|
|
ts->tv_nsec = ts32[1];
|
|
return r;
|
|
}
|
|
return __syscall_ret(r);
|
|
#else
|
|
r = __syscall(SYS_clock_gettime, clk, ts);
|
|
if (r == -ENOSYS) {
|
|
if (clk == CLOCK_REALTIME) {
|
|
__syscall(SYS_gettimeofday, ts, 0);
|
|
ts->tv_nsec = (int)ts->tv_nsec * 1000;
|
|
return 0;
|
|
}
|
|
r = -EINVAL;
|
|
}
|
|
return __syscall_ret(r);
|
|
#endif
|
|
}
|