From: Tobias Klauser <tklauser@distanz.ch>
Date: Wed, 18 Nov 2020 10:08:43 +0000 (+0100)
Subject: runtime: use clock_gettime instead of gettimeofday on darwin
X-Git-Tag: go1.16beta1~209
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=ae76f6e96216f352cc5021a4c8a7d879c4cb6873;p=gostls13.git

runtime: use clock_gettime instead of gettimeofday on darwin

clock_gettime has higher resolution than gettimeofday and is available
since macOS 10.12. Go 1.15 already requires at least macOS 10.12 and
thus clock_gettime can be used unconditionally (also see
https://golang.org/doc/go1.15#darwin)

Fixes #25633

Change-Id: I46305387212735e5d3a13e5f02ec90f3e6d546a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/270918
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
---

diff --git a/src/runtime/sys_darwin.go b/src/runtime/sys_darwin.go
index e4f19bbf41..a7983be2ef 100644
--- a/src/runtime/sys_darwin.go
+++ b/src/runtime/sys_darwin.go
@@ -303,9 +303,9 @@ func nanotime_trampoline()
 //go:nosplit
 //go:cgo_unsafe_args
 func walltime1() (int64, int32) {
-	var t timeval
+	var t timespec
 	libcCall(unsafe.Pointer(funcPC(walltime_trampoline)), unsafe.Pointer(&t))
-	return int64(t.tv_sec), 1000 * t.tv_usec
+	return t.tv_sec, int32(t.tv_nsec)
 }
 func walltime_trampoline()
 
@@ -470,7 +470,7 @@ func setNonblock(fd int32) {
 
 //go:cgo_import_dynamic libc_mach_timebase_info mach_timebase_info "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_mach_absolute_time mach_absolute_time "/usr/lib/libSystem.B.dylib"
-//go:cgo_import_dynamic libc_gettimeofday gettimeofday "/usr/lib/libSystem.B.dylib"
+//go:cgo_import_dynamic libc_clock_gettime clock_gettime "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_sigaction sigaction "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_pthread_sigmask pthread_sigmask "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_sigaltstack sigaltstack "/usr/lib/libSystem.B.dylib"
diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s
index 825852d673..129e1e1a96 100644
--- a/src/runtime/sys_darwin_amd64.s
+++ b/src/runtime/sys_darwin_amd64.s
@@ -10,6 +10,8 @@
 #include "go_tls.h"
 #include "textflag.h"
 
+#define CLOCK_REALTIME		0
+
 // Exit the entire program (like C exit)
 TEXT runtime·exit_trampoline(SB),NOSPLIT,$0
 	PUSHQ	BP
@@ -137,9 +139,9 @@ initialized:
 TEXT runtime·walltime_trampoline(SB),NOSPLIT,$0
 	PUSHQ	BP			// make a frame; keep stack aligned
 	MOVQ	SP, BP
-	// DI already has *timeval
-	XORL	SI, SI // no timezone needed
-	CALL	libc_gettimeofday(SB)
+	MOVQ	DI, SI			// arg 2 timespec
+	MOVL	$CLOCK_REALTIME, DI	// arg 1 clock_id
+	CALL	libc_clock_gettime(SB)
 	POPQ	BP
 	RET
 
diff --git a/src/runtime/sys_darwin_arm64.s b/src/runtime/sys_darwin_arm64.s
index fd713b7902..88cdb281d4 100644
--- a/src/runtime/sys_darwin_arm64.s
+++ b/src/runtime/sys_darwin_arm64.s
@@ -10,6 +10,8 @@
 #include "go_tls.h"
 #include "textflag.h"
 
+#define CLOCK_REALTIME		0
+
 TEXT notok<>(SB),NOSPLIT,$0
 	MOVD	$0, R8
 	MOVD	R8, (R8)
@@ -126,9 +128,9 @@ TEXT runtime·setitimer_trampoline(SB),NOSPLIT,$0
 	RET
 
 TEXT runtime·walltime_trampoline(SB),NOSPLIT,$0
-	// R0 already has *timeval
-	MOVD	$0, R1 // no timezone needed
-	BL	libc_gettimeofday(SB)
+	MOVD	R0, R1			// arg 2 timespec
+	MOVW	$CLOCK_REALTIME, R0 	// arg 1 clock_id
+	BL	libc_clock_gettime(SB)
 	RET
 
 GLOBL timebase<>(SB),NOPTR,$(machTimebaseInfo__size)