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 e4f19bbf41f84bf85957d03a1d1c53bbe901712f..a7983be2eff29a462fe0f6846baf4772e3b4d767 100644 (file)
--- 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 825852d673975969ef14a16cb43252d3c4e623bc..129e1e1a96def25ef543268a554582d3bbf22f1d 100644 (file)
--- 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 fd713b7902f7d65347a7255aabc70d08e36f47c6..88cdb281d4c1653774d1db52d28a07fd63d4d01b 100644 (file)
--- 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)