From 6d625d5e5e06b5a07ab90c37ef6b03b55ca1c00a Mon Sep 17 00:00:00 2001
From: Qi Wang <interwq@gwu.edu>
Date: Fri, 4 Oct 2024 15:25:54 -0700
Subject: [PATCH] Add support for clock_gettime_nsec_np()

Prefer clock_gettime_nsec_np(CLOCK_UPTIME_RAW) to mach_absolute_time().
---
 configure.ac                                        | 10 ++++++++++
 .../jemalloc/internal/jemalloc_internal_defs.h.in   |  5 +++++
 src/nstime.c                                        | 13 ++++++++++++-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 4776aa60..9698997a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2126,6 +2126,16 @@ if test "x${je_cv_clock_realtime}" = "xyes" ; then
   AC_DEFINE([JEMALLOC_HAVE_CLOCK_REALTIME], [ ], [ ])
 fi
 
+dnl Check for clock_gettime_nsec_np().
+JE_COMPILABLE([clock_gettime_nsec_np()], [
+#include <time.h>
+], [
+	clock_gettime_nsec_np(CLOCK_UPTIME_RAW);
+], [je_cv_clock_gettime_nsec_np])
+if test "x${je_cv_clock_gettime_nsec_np}" = "xyes" ; then
+  AC_DEFINE([JEMALLOC_HAVE_CLOCK_GETTIME_NSEC_NP], [ ], [ ])
+fi
+
 dnl Use syscall(2) (if available) by default.
 AC_ARG_ENABLE([syscall],
   [AS_HELP_STRING([--disable-syscall], [Disable use of syscall(2)])],
diff --git a/include/jemalloc/internal/jemalloc_internal_defs.h.in b/include/jemalloc/internal/jemalloc_internal_defs.h.in
index 7ad75a06..f5b1a924 100644
--- a/include/jemalloc/internal/jemalloc_internal_defs.h.in
+++ b/include/jemalloc/internal/jemalloc_internal_defs.h.in
@@ -117,6 +117,11 @@
  */
 #undef JEMALLOC_HAVE_CLOCK_REALTIME
 
+/*
+ * Defined if clock_gettime_nsec_np(CLOCK_UPTIME_RAW) is available.
+ */
+#undef JEMALLOC_HAVE_CLOCK_GETTIME_NSEC_NP
+
 /*
  * Defined if _malloc_thread_cleanup() exists.  At least in the case of
  * FreeBSD, pthread_key_create() allocates, which if used during malloc
diff --git a/src/nstime.c b/src/nstime.c
index 72f04227..15c53330 100644
--- a/src/nstime.c
+++ b/src/nstime.c
@@ -201,11 +201,22 @@ nstime_get(nstime_t *time) {
 	clock_gettime(CLOCK_MONOTONIC, &ts);
 	nstime_init2(time, ts.tv_sec, ts.tv_nsec);
 }
+#elif defined(JEMALLOC_HAVE_CLOCK_GETTIME_NSEC_NP)
+#  define NSTIME_MONOTONIC true
+static void
+nstime_get(nstime_t *time) {
+	nstime_init(time, clock_gettime_nsec_np(CLOCK_UPTIME_RAW));
+}
 #elif defined(JEMALLOC_HAVE_MACH_ABSOLUTE_TIME)
 #  define NSTIME_MONOTONIC true
 static void
 nstime_get(nstime_t *time) {
-	nstime_init(time, mach_absolute_time());
+	static mach_timebase_info_data_t sTimebaseInfo;
+	if (sTimebaseInfo.denom == 0) {
+		(void) mach_timebase_info(&sTimebaseInfo);
+	}
+	nstime_init(time, mach_absolute_time() * sTimebaseInfo.numer
+	    / sTimebaseInfo.denom);
 }
 #else
 #  define NSTIME_MONOTONIC false