golang sys_darwin_arm64 代码
文件路径：/src/runtime/sys_darwin_arm64.go
/ Copyright 2020 The Go Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSE file.
package runtime
import (
"internal/abi"
"internal/goarch"
"unsafe"
)
/ libc function wrappers. Must run on system stack.
/go:nosplit
/go:cgo_unsafe_args
func g0_pthread_key_create(k *pthreadkey, destructor uintptr) int32 {
ret := asmcgocall(unsafe.Pointer(abi.FuncPCABI0(pthread_key_create_trampoline)), unsafe.Pointer(&k))
KeepAlive(k)
return ret
}
func pthread_key_create_trampoline()
/go:nosplit
/go:cgo_unsafe_args
func g0_pthread_setspecific(k pthreadkey, value uintptr) int32 {
return asmcgocall(unsafe.Pointer(abi.FuncPCABI0(pthread_setspecific_trampoline)), unsafe.Pointer(&k))
}
func pthread_setspecific_trampoline()
/go:cgo_import_dynamic libc_pthread_key_create pthread_key_create "/usr/lib/libSystem.B.dylib"
/go:cgo_import_dynamic libc_pthread_setspecific pthread_setspecific "/usr/lib/libSystem.B.dylib"
/ tlsinit allocates a thread-local storage slot for g.
/
/ It finds the first available slot using pthread_key_create and uses
/ it as the offset value for runtime.tlsg.
/
/ This runs at startup on g0 stack, but before g is set, so it must
/ not split stack (transitively). g is expected to be nil, so things
/ (e.g. asmcgocall) will skip saving or reading g.
/
/go:nosplit
func tlsinit(tlsg *uintptr, tlsbase *[_PTHREAD_KEYS_MAX]uintptr) {
var k pthreadkey
err := g0_pthread_key_create(&k, 0)
if err != 0 {
abort()
}
const magic = 0xc476c475c47957
err = g0_pthread_setspecific(k, magic)
if err != 0 {
abort()
}
for i, x := range tlsbase {
if x == magic {
*tlsg = uintptr(i * goarch.PtrSize)
g0_pthread_setspecific(k, 0)
return
}
}
abort()
}