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authorRich Felker <dalias@aerifal.cx>2011-07-23 23:45:33 -0400
committerRich Felker <dalias@aerifal.cx>2011-07-23 23:45:33 -0400
commite3eb49321c85e43fcc6842f3f57ee097b32555e4 (patch)
tree126e8f35f23c92fdb7ff8f805c7d59b662c8b7ae /src/time/clock_gettime.c
parentc0fe5b9da9f98b83262717c0090817f1fbb3d8a0 (diff)
downloadmusl-e3eb49321c85e43fcc6842f3f57ee097b32555e4.tar.gz
some preliminaries for vdso clock support
these changes also make it so clock_gettime(CLOCK_REALTIME, &ts) works even on pre-2.6 kernels, emulated via the gettimeofday syscall. there is no cost for the fallback check, as it falls under the error case that already must be checked for storing the error code in errno, but which would normally be hidden inside __syscall_ret.
Diffstat (limited to 'src/time/clock_gettime.c')
-rw-r--r--src/time/clock_gettime.c25
1 files changed, 23 insertions, 2 deletions
diff --git a/src/time/clock_gettime.c b/src/time/clock_gettime.c
index c345c46e..c27c9e9e 100644
--- a/src/time/clock_gettime.c
+++ b/src/time/clock_gettime.c
@@ -1,7 +1,28 @@
#include <time.h>
+#include <errno.h>
+#include <stdint.h>
#include "syscall.h"
+#include "libc.h"
-int clock_gettime(clockid_t clk, struct timespec *ts)
+int __vdso_clock_gettime(clockid_t, struct timespec *) __attribute__((weak));
+static int (*cgt)(clockid_t, struct timespec *) = __vdso_clock_gettime;
+
+int __clock_gettime(clockid_t clk, struct timespec *ts)
{
- return syscall(SYS_clock_gettime, clk, ts);
+ int r;
+ if (cgt) return cgt(clk, ts);
+ r = __syscall(SYS_clock_gettime, clk, ts);
+ if (!r) return r;
+ if (r == -ENOSYS) {
+ if (clk == CLOCK_REALTIME) {
+ __syscall(SYS_gettimeofday, clk, ts, 0);
+ ts->tv_nsec = (int)ts->tv_nsec * 1000;
+ return 0;
+ }
+ r = -EINVAL;
+ }
+ errno = -r;
+ return -1;
}
+
+weak_alias(__clock_gettime, clock_gettime);