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Date: Mon, 01 Sep 2014 00:46:05 +0200
From: Jens Gustedt <Jens.Gustedt@...ia.fr>
To: musl@...ts.openwall.com
Subject: [PATCH 2/9] additions to src/time and some implied minor changes
here and there
This refactors clock_gettime and adds two functions, thrd_sleep and
timespec_get.
The refactoring of clock_gettime introduces a function " clock_gettime"
that has the same signature as clock_gettime, but that returns an
eventual error instead of returning -1 and setting errno. All places that
use clock_gettime functionality internally in musl do this
unconditionally, so there is no reason to mess around with errno.
As an additional fallout for kernels that don't implement the
clock_gettime syscall (yet!), the syscall that results in ENOSYS is
effected only once (instead, as previously, for every call) and a
fallback to gettimeofday is used.
The two newly introduced C11 functions have easy functional equivalences
in POSIX, but these have subtle differences in the handling of errors.
thrd_sleep forces concrete numerical values as error return
timespec_get has a call interface that is incompatible with POSIX because
it has a bogus coding for its clock constants, and also this clock
constants must be returned in case of success. For the moment we only
implement one single clock, TIME_UTC, and map this to
CLOCK_REALTIME. This is the clock that we later need to measure time for
the timedlock and timedwait.
Also, the error handling is different than the one for clock_gettime: the
possible reason for failure are returned and not set in errno.
---
src/aio/aio_suspend.c | 4 +++-
src/network/res_mkquery.c | 4 +++-
src/network/res_msend.c | 4 +++-
src/time/__clock_gettime.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
src/time/clock_gettime.c | 41 +++++++----------------------------------
src/time/ftime.c | 4 +++-
src/time/gettimeofday.c | 4 +++-
src/time/thrd_sleep.c | 26 ++++++++++++++++++++++++++
src/time/timespec_get.c | 12 ++++++++++++
9 files changed, 104 insertions(+), 39 deletions(-)
create mode 100644 src/time/__clock_gettime.c
create mode 100644 src/time/thrd_sleep.c
create mode 100644 src/time/timespec_get.c
diff --git a/src/aio/aio_suspend.c b/src/aio/aio_suspend.c
index 39a1d3a..1e3b7d2 100644
--- a/src/aio/aio_suspend.c
+++ b/src/aio/aio_suspend.c
@@ -2,6 +2,8 @@
#include <errno.h>
#include "pthread_impl.h"
+int __clock_gettime(clockid_t clk, struct timespec *ts);
+
/* Due to the requirement that aio_suspend be async-signal-safe, we cannot
* use any locks, wait queues, etc. that would make it more efficient. The
* only obviously-correct algorithm is to generate a wakeup every time any
@@ -35,7 +37,7 @@ int aio_suspend(const struct aiocb *const cbs[], int cnt, const struct timespec
}
if (first && ts) {
- clock_gettime(CLOCK_MONOTONIC, &at);
+ __clock_gettime(CLOCK_MONOTONIC, &at);
at.tv_sec += ts->tv_sec;
if ((at.tv_nsec += ts->tv_nsec) >= 1000000000) {
at.tv_nsec -= 1000000000;
diff --git a/src/network/res_mkquery.c b/src/network/res_mkquery.c
index ec4568a..8bbaf23 100644
--- a/src/network/res_mkquery.c
+++ b/src/network/res_mkquery.c
@@ -3,6 +3,8 @@
#include <time.h>
#include "libc.h"
+int __clock_gettime(clockid_t clk, struct timespec *ts);
+
int __res_mkquery(int op, const char *dname, int class, int type,
const unsigned char *data, int datalen,
const unsigned char *newrr, unsigned char *buf, int buflen)
@@ -32,7 +34,7 @@ int __res_mkquery(int op, const char *dname, int class, int type,
q[i+3] = class;
/* Make a reasonably unpredictable id */
- clock_gettime(CLOCK_REALTIME, &ts);
+ __clock_gettime(CLOCK_REALTIME, &ts);
id = ts.tv_nsec + ts.tv_nsec/65536UL & 0xffff;
q[0] = id/256;
q[1] = id;
diff --git a/src/network/res_msend.c b/src/network/res_msend.c
index 35f106d..eff968a 100644
--- a/src/network/res_msend.c
+++ b/src/network/res_msend.c
@@ -14,6 +14,8 @@
#include "syscall.h"
#include "lookup.h"
+int __clock_gettime(clockid_t clk, struct timespec *ts);
+
static void cleanup(void *p)
{
__syscall(SYS_close, (intptr_t)p);
@@ -22,7 +24,7 @@ static void cleanup(void *p)
static unsigned long mtime()
{
struct timespec ts;
- clock_gettime(CLOCK_REALTIME, &ts);
+ __clock_gettime(CLOCK_REALTIME, &ts);
return (unsigned long)ts.tv_sec * 1000
+ ts.tv_nsec / 1000000;
}
diff --git a/src/time/__clock_gettime.c b/src/time/__clock_gettime.c
new file mode 100644
index 0000000..adbd4e6
--- /dev/null
+++ b/src/time/__clock_gettime.c
@@ -0,0 +1,44 @@
+#include <time.h>
+#include <errno.h>
+#include <stdint.h>
+#include "syscall.h"
+#include "libc.h"
+#include "atomic.h"
+
+static int sc_clock_gettime(clockid_t clk, struct timespec *ts)
+{
+ return __syscall(SYS_clock_gettime, clk, ts);
+}
+
+static int sc_gettimeofday(clockid_t clk, struct timespec *ts)
+{
+ if (clk != CLOCK_REALTIME)
+ return EINVAL;
+ __syscall(SYS_gettimeofday, ts, 0);
+ ts->tv_nsec = (int)ts->tv_nsec * 1000;
+ return 0;
+}
+
+void *__vdsosym(const char *, const char *);
+
+int __clock_gettime(clockid_t clk, struct timespec *ts)
+{
+ static int (*cgt)(clockid_t, struct timespec *);
+ if (!cgt) {
+ int (*f)(clockid_t, struct timespec *) = 0;
+#ifdef VDSO_CGT_SYM
+ f = __vdsosym(VDSO_CGT_VER, VDSO_CGT_SYM);
+#endif
+ if (!f) {
+ int r = sc_clock_gettime(clk, ts);
+ if (r == -ENOSYS) {
+ f = sc_gettimeofday;
+ } else {
+ a_cas_p(&cgt, 0, sc_clock_gettime);
+ return r;
+ }
+ }
+ a_cas_p(&cgt, 0, f);
+ }
+ return cgt(clk, ts);
+}
diff --git a/src/time/clock_gettime.c b/src/time/clock_gettime.c
index 799251d..13ddb89 100644
--- a/src/time/clock_gettime.c
+++ b/src/time/clock_gettime.c
@@ -1,41 +1,14 @@
#include <time.h>
#include <errno.h>
-#include <stdint.h>
-#include "syscall.h"
-#include "libc.h"
-#include "atomic.h"
-static int sc_clock_gettime(clockid_t clk, struct timespec *ts)
+int __clock_gettime(clockid_t clk, struct timespec *ts);
+
+int clock_gettime(clockid_t clk, struct timespec *ts)
{
- int r = __syscall(SYS_clock_gettime, clk, ts);
- if (!r) return r;
- if (r == -ENOSYS) {
- if (clk == CLOCK_REALTIME) {
- __syscall(SYS_gettimeofday, ts, 0);
- ts->tv_nsec = (int)ts->tv_nsec * 1000;
- return 0;
- }
- r = -EINVAL;
- }
+ int r = __clock_gettime(clk, ts);
+ /* In case of -1 lower levels already have already taken care
+ * of setting errno. */
+ if (r >= -1) return r;
errno = -r;
return -1;
}
-
-void *__vdsosym(const char *, const char *);
-
-int __clock_gettime(clockid_t clk, struct timespec *ts)
-{
-#ifdef VDSO_CGT_SYM
- static int (*cgt)(clockid_t, struct timespec *);
- if (!cgt) {
- void *f = __vdsosym(VDSO_CGT_VER, VDSO_CGT_SYM);
- if (!f) f = (void *)sc_clock_gettime;
- a_cas_p(&cgt, 0, f);
- }
- return cgt(clk, ts);
-#else
- return sc_clock_gettime(clk, ts);
-#endif
-}
-
-weak_alias(__clock_gettime, clock_gettime);
diff --git a/src/time/ftime.c b/src/time/ftime.c
index a1734d0..00af1ca 100644
--- a/src/time/ftime.c
+++ b/src/time/ftime.c
@@ -1,10 +1,12 @@
#include <sys/timeb.h>
#include <time.h>
+int __clock_gettime(clockid_t clk, struct timespec *ts);
+
int ftime(struct timeb *tp)
{
struct timespec ts;
- clock_gettime(CLOCK_REALTIME, &ts);
+ __clock_gettime(CLOCK_REALTIME, &ts);
tp->time = ts.tv_sec;
tp->millitm = ts.tv_nsec / 1000000;
tp->timezone = tp->dstflag = 0;
diff --git a/src/time/gettimeofday.c b/src/time/gettimeofday.c
index 691f8e9..375ec0e 100644
--- a/src/time/gettimeofday.c
+++ b/src/time/gettimeofday.c
@@ -2,11 +2,13 @@
#include <sys/time.h>
#include "syscall.h"
+int __clock_gettime(clockid_t clk, struct timespec *ts);
+
int gettimeofday(struct timeval *restrict tv, void *restrict tz)
{
struct timespec ts;
if (!tv) return 0;
- clock_gettime(CLOCK_REALTIME, &ts);
+ __clock_gettime(CLOCK_REALTIME, &ts);
tv->tv_sec = ts.tv_sec;
tv->tv_usec = (int)ts.tv_nsec / 1000;
return 0;
diff --git a/src/time/thrd_sleep.c b/src/time/thrd_sleep.c
new file mode 100644
index 0000000..3dbfe47
--- /dev/null
+++ b/src/time/thrd_sleep.c
@@ -0,0 +1,26 @@
+#include <time.h>
+#include <errno.h>
+#include "syscall.h"
+#include "libc.h"
+#include "threads.h"
+
+/* Roughly __syscall already returns the right thing: 0 if all went
+ well or a negative error indication, otherwise. */
+int thrd_sleep(const struct timespec *req, struct timespec *rem)
+{
+ int ret = __syscall(SYS_nanosleep, req, rem);
+ switch (ret) {
+ case 0:
+ return 0;
+ /* error described by POSIX: */
+ /* EINTR The nanosleep() function was interrupted by a signal. */
+ /* The C11 wording is: */
+ /* -1 if it has been interrupted by a signal */
+ case -EINTR:
+ return -1;
+ /* EINVAL: described by POSIX */
+ /* EFAULT: described for linux */
+ default:
+ return -2;
+ }
+}
diff --git a/src/time/timespec_get.c b/src/time/timespec_get.c
new file mode 100644
index 0000000..601c3cc
--- /dev/null
+++ b/src/time/timespec_get.c
@@ -0,0 +1,12 @@
+#include <time.h>
+
+int __clock_gettime(clockid_t clk, struct timespec *ts);
+
+/* There is no other implemented value than TIME_UTC, all other values
+ are considered erroneous. */
+int timespec_get(struct timespec * ts, int base)
+{
+ if (base != TIME_UTC) return 0;
+ int ret = __clock_gettime(CLOCK_REALTIME, ts);
+ return ret < 0 ? 0 : base;
+}
--
1.7.10.4
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