github.com/c0deoo1/golang1.5@v0.0.0-20220525150107-c87c805d4593/src/runtime/atomic_arm64.go (about)

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package runtime
     6  
     7  import "unsafe"
     8  
     9  //go:noescape
    10  func xadd(ptr *uint32, delta int32) uint32
    11  
    12  //go:noescape
    13  func xadd64(ptr *uint64, delta int64) uint64
    14  
    15  //go:noescape
    16  //go:linkname xadduintptr runtime.xadd64
    17  func xadduintptr(ptr *uintptr, delta uintptr) uintptr
    18  
    19  //go:noescape
    20  func xchg(ptr *uint32, new uint32) uint32
    21  
    22  //go:noescape
    23  func xchg64(ptr *uint64, new uint64) uint64
    24  
    25  // NO go:noescape annotation; see atomic_pointer.go.
    26  func xchgp1(ptr unsafe.Pointer, new unsafe.Pointer) unsafe.Pointer
    27  
    28  //go:noescape
    29  func xchguintptr(ptr *uintptr, new uintptr) uintptr
    30  
    31  //go:noescape
    32  func atomicload(ptr *uint32) uint32
    33  
    34  //go:noescape
    35  func atomicload64(ptr *uint64) uint64
    36  
    37  //go:noescape
    38  func atomicloadp(ptr unsafe.Pointer) unsafe.Pointer
    39  
    40  //go:nosplit
    41  func atomicor8(addr *uint8, v uint8) {
    42  	// TODO(dfc) implement this in asm.
    43  	// Align down to 4 bytes and use 32-bit CAS.
    44  	uaddr := uintptr(unsafe.Pointer(addr))
    45  	addr32 := (*uint32)(unsafe.Pointer(uaddr &^ 3))
    46  	word := uint32(v) << ((uaddr & 3) * 8) // little endian
    47  	for {
    48  		old := *addr32
    49  		if cas(addr32, old, old|word) {
    50  			return
    51  		}
    52  	}
    53  }
    54  
    55  //go:nosplit
    56  func atomicand8(addr *uint8, v uint8) {
    57  	// TODO(dfc) implement this in asm.
    58  	// Align down to 4 bytes and use 32-bit CAS.
    59  	uaddr := uintptr(unsafe.Pointer(addr))
    60  	addr32 := (*uint32)(unsafe.Pointer(uaddr &^ 3))
    61  	word := uint32(v) << ((uaddr & 3) * 8)    // little endian
    62  	mask := uint32(0xFF) << ((uaddr & 3) * 8) // little endian
    63  	word |= ^mask
    64  	for {
    65  		old := *addr32
    66  		if cas(addr32, old, old&word) {
    67  			return
    68  		}
    69  	}
    70  }
    71  
    72  //go:noescape
    73  func cas64(ptr *uint64, old, new uint64) bool
    74  
    75  //go:noescape
    76  func atomicstore(ptr *uint32, val uint32)
    77  
    78  //go:noescape
    79  func atomicstore64(ptr *uint64, val uint64)
    80  
    81  // NO go:noescape annotation; see atomic_pointer.go.
    82  func atomicstorep1(ptr unsafe.Pointer, val unsafe.Pointer)