Refine nstime_update().

Add missing #include <time.h>.  The critical time facilities appear to
have been transitively included via unistd.h and sys/time.h, but in
principle this omission was capable of having caused
clock_gettime(CLOCK_MONOTONIC, ...) to have been overlooked in favor of
gettimeofday(), which in turn could cause spurious non-monotonic time
updates.

Refactor nstime_get() out of nstime_update() and add configure tests for
all variants.

Add CLOCK_MONOTONIC_RAW support (Linux-specific) and
mach_absolute_time() support (OS X-specific).

Do not fall back to clock_gettime(CLOCK_REALTIME, ...).  This was a
fragile Linux-specific workaround, which we're unlikely to use at all
now that clock_gettime(CLOCK_MONOTONIC_RAW, ...) is supported, and if we
have no choice besides non-monotonic clocks, gettimeofday() is only
incrementally worse.
This commit is contained in:
Jason Evans 2016-10-07 08:47:16 -07:00
parent b6c0867142
commit e0164bc63c
5 changed files with 109 additions and 38 deletions

View File

@ -345,11 +345,11 @@ dnl
dnl Define cpp macros in CPPFLAGS, rather than doing AC_DEFINE(macro), since the
dnl definitions need to be seen before any headers are included, which is a pain
dnl to make happen otherwise.
CFLAGS="$CFLAGS"
default_munmap="1"
maps_coalesce="1"
case "${host}" in
*-*-darwin* | *-*-ios*)
CFLAGS="$CFLAGS"
abi="macho"
AC_DEFINE([JEMALLOC_PURGE_MADVISE_FREE], [ ])
RPATH=""
@ -362,30 +362,26 @@ case "${host}" in
sbrk_deprecated="1"
;;
*-*-freebsd*)
CFLAGS="$CFLAGS"
abi="elf"
AC_DEFINE([JEMALLOC_SYSCTL_VM_OVERCOMMIT], [ ])
AC_DEFINE([JEMALLOC_PURGE_MADVISE_FREE], [ ])
force_lazy_lock="1"
;;
*-*-dragonfly*)
CFLAGS="$CFLAGS"
abi="elf"
AC_DEFINE([JEMALLOC_PURGE_MADVISE_FREE], [ ])
;;
*-*-openbsd*)
CFLAGS="$CFLAGS"
abi="elf"
AC_DEFINE([JEMALLOC_PURGE_MADVISE_FREE], [ ])
force_tls="0"
;;
*-*-bitrig*)
CFLAGS="$CFLAGS"
abi="elf"
AC_DEFINE([JEMALLOC_PURGE_MADVISE_FREE], [ ])
;;
*-*-linux*)
CFLAGS="$CFLAGS"
dnl secure_getenv() is exposed by _GNU_SOURCE.
CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"
abi="elf"
AC_DEFINE([JEMALLOC_HAS_ALLOCA_H])
@ -404,13 +400,12 @@ case "${host}" in
#error aout
#endif
]])],
[CFLAGS="$CFLAGS"; abi="elf"],
[abi="elf"],
[abi="aout"])
AC_MSG_RESULT([$abi])
AC_DEFINE([JEMALLOC_PURGE_MADVISE_FREE], [ ])
;;
*-*-solaris2*)
CFLAGS="$CFLAGS"
abi="elf"
AC_DEFINE([JEMALLOC_PURGE_MADVISE_FREE], [ ])
RPATH='-Wl,-R,$(1)'
@ -1309,6 +1304,44 @@ if test "x$je_cv_cray_prgenv_wrapper" = "xyes" ; then
fi
fi
dnl check for CLOCK_MONOTONIC_RAW (Linux-specific).
JE_COMPILABLE([clock_gettime(CLOCK_MONOTONIC_RAW, ...)], [
#include <time.h>
], [
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
], [je_cv_clock_monotonic_raw])
if test "x${je_cv_clock_monotonic_raw}" = "xyes" ; then
AC_DEFINE([JEMALLOC_HAVE_CLOCK_MONOTONIC_RAW])
fi
dnl check for CLOCK_MONOTONIC.
JE_COMPILABLE([clock_gettime(CLOCK_MONOTONIC, ...)], [
#include <unistd.h>
#include <time.h>
], [
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
#if !defined(_POSIX_MONOTONIC_CLOCK) || _POSIX_MONOTONIC_CLOCK < 0
# error _POSIX_MONOTONIC_CLOCK missing/invalid
#endif
], [je_cv_clock_monotonic])
if test "x${je_cv_clock_monotonic}" = "xyes" ; then
AC_DEFINE([JEMALLOC_HAVE_CLOCK_MONOTONIC])
fi
dnl Check for mach_absolute_time().
JE_COMPILABLE([mach_absolute_time()], [
#include <mach/mach_time.h>
], [
mach_absolute_time();
], [je_cv_mach_absolute_time])
if test "x${je_cv_mach_absolute_time}" = "xyes" ; then
AC_DEFINE([JEMALLOC_HAVE_MACH_ABSOLUTE_TIME])
fi
dnl Check if the GNU-specific secure_getenv function exists.
AC_CHECK_FUNC([secure_getenv],
[have_secure_getenv="1"],

View File

@ -19,6 +19,10 @@
# include <pthread.h>
# include <errno.h>
# include <sys/time.h>
# include <time.h>
# ifdef JEMALLOC_HAVE_MACH_ABSOLUTE_TIME
# include <mach/mach_time.h>
# endif
#endif
#include <sys/types.h>

View File

@ -76,6 +76,21 @@
*/
#undef JEMALLOC_HAVE_ISSETUGID
/*
* Defined if clock_gettime(CLOCK_MONOTONIC_RAW, ...) is available.
*/
#undef JEMALLOC_HAVE_CLOCK_MONOTONIC_RAW
/*
* Defined if clock_gettime(CLOCK_MONOTONIC, ...) is available.
*/
#undef JEMALLOC_HAVE_CLOCK_MONOTONIC
/*
* Defined if mach_absolute_time() is available.
*/
#undef JEMALLOC_HAVE_MACH_ABSOLUTE_TIME
/*
* Defined if _malloc_thread_cleanup() exists. At least in the case of
* FreeBSD, pthread_key_create() allocates, which if used during malloc

View File

@ -1,9 +1,6 @@
/******************************************************************************/
#ifdef JEMALLOC_H_TYPES
#define JEMALLOC_CLOCK_GETTIME defined(_POSIX_MONOTONIC_CLOCK) \
&& _POSIX_MONOTONIC_CLOCK >= 0
typedef struct nstime_s nstime_t;
/* Maximum supported number of seconds (~584 years). */

View File

@ -97,6 +97,54 @@ nstime_divide(const nstime_t *time, const nstime_t *divisor)
return (time->ns / divisor->ns);
}
#ifdef _WIN32
static void
nstime_get(nstime_t *time)
{
FILETIME ft;
uint64_t ticks_100ns;
GetSystemTimeAsFileTime(&ft);
ticks_100ns = (((uint64_t)ft.dwHighDateTime) << 32) | ft.dwLowDateTime;
nstime_init(time, ticks_100ns * 100);
}
#elif JEMALLOC_HAVE_CLOCK_MONOTONIC_RAW
static void
nstime_get(nstime_t *time)
{
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
nstime_init2(time, ts.tv_sec, ts.tv_nsec);
}
#elif JEMALLOC_HAVE_CLOCK_MONOTONIC
static void
nstime_get(nstime_t *time)
{
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
nstime_init2(time, ts.tv_sec, ts.tv_nsec);
}
#elif JEMALLOC_HAVE_MACH_ABSOLUTE_TIME
static void
nstime_get(nstime_t *time)
{
nstime_init(time, mach_absolute_time());
}
#else
static void
nstime_get(nstime_t *time)
{
struct timeval tv;
gettimeofday(&tv, NULL);
nstime_init2(time, tv.tv_sec, tv.tv_usec * 1000);
}
#endif
#ifdef JEMALLOC_JET
#undef nstime_update
#define nstime_update JEMALLOC_N(n_nstime_update)
@ -107,33 +155,7 @@ nstime_update(nstime_t *time)
nstime_t old_time;
nstime_copy(&old_time, time);
#ifdef _WIN32
{
FILETIME ft;
uint64_t ticks;
GetSystemTimeAsFileTime(&ft);
ticks = (((uint64_t)ft.dwHighDateTime) << 32) |
ft.dwLowDateTime;
time->ns = ticks * 100;
}
#elif JEMALLOC_CLOCK_GETTIME
{
struct timespec ts;
if (sysconf(_SC_MONOTONIC_CLOCK) > 0)
clock_gettime(CLOCK_MONOTONIC, &ts);
else
clock_gettime(CLOCK_REALTIME, &ts);
time->ns = ts.tv_sec * BILLION + ts.tv_nsec;
}
#else
{
struct timeval tv;
gettimeofday(&tv, NULL);
time->ns = tv.tv_sec * BILLION + tv.tv_usec * 1000;
}
#endif
nstime_get(time);
/* Handle non-monotonic clocks. */
if (unlikely(nstime_compare(&old_time, time) > 0)) {