github.com/primecitizens/pcz/std@v0.2.1/core/atomic/stubs.go (about)

     1  // SPDX-License-Identifier: Apache-2.0
     2  // Copyright 2023 The Prime Citizens
     3  //
     4  // Copyright 2015 The Go Authors. All rights reserved.
     5  // Use of this source code is governed by a BSD-style
     6  // license that can be found in the LICENSE file.
     7  
     8  //go:build !wasm
     9  
    10  package atomic
    11  
    12  import "unsafe"
    13  
    14  // PublicationBarrier performs a store/store barrier (a "publication"
    15  // or "export" barrier). Some form of synchronization is required
    16  // between initializing an object and making that object accessible to
    17  // another processor. Without synchronization, the initialization
    18  // writes and the "publication" write may be reordered, allowing the
    19  // other processor to follow the pointer and observe an uninitialized
    20  // object. In general, higher-level synchronization should be used,
    21  // such as locking or an atomic pointer write. publicationBarrier is
    22  // for when those aren't an option, such as in the implementation of
    23  // the memory manager.
    24  //
    25  // There's no corresponding barrier for the read side because the read
    26  // side naturally has a data dependency order. All architectures that
    27  // Go supports or seems likely to ever support automatically enforce
    28  // data dependency ordering.
    29  func PublicationBarrier()
    30  
    31  //
    32  // Store
    33  //
    34  
    35  //go:noescape
    36  func StoreInt32(ptr *int32, new int32)
    37  
    38  //go:noescape
    39  func StoreInt64(ptr *int64, new int64)
    40  
    41  //go:noescape
    42  func StoreUintptr(ptr *uintptr, new uintptr)
    43  
    44  // TODO(matloob): Should these functions have the go:noescape annotation?
    45  
    46  //
    47  // Load
    48  //
    49  
    50  //go:noescape
    51  func LoadUintptr(ptr *uintptr) uintptr
    52  
    53  //go:noescape
    54  func LoadUint(ptr *uint) uint
    55  
    56  //go:noescape
    57  func LoadInt32(ptr *int32) int32
    58  
    59  //go:noescape
    60  func LoadInt64(ptr *int64) int64
    61  
    62  //
    63  // Swap
    64  //
    65  
    66  //go:noescape
    67  func SwapInt32(ptr *int32, new int32) int32
    68  
    69  //go:noescape
    70  func SwapInt64(ptr *int64, new int64) int64
    71  
    72  //
    73  // Add
    74  //
    75  
    76  //go:noescape
    77  func AddInt32(ptr *int32, delta int32) int32
    78  
    79  //go:noescape
    80  func AddInt64(ptr *int64, delta int64) int64
    81  
    82  //
    83  // Compare and swap
    84  //
    85  
    86  //go:noescape
    87  func Cas32(ptr *uint32, old, new uint32) bool
    88  
    89  //go:noescape
    90  func CasUintptr(ptr *uintptr, old, new uintptr) bool
    91  
    92  // NO go:noescape annotation; see atomic_pointer.go.
    93  func CasUnsafePointer(ptr *unsafe.Pointer, old, new unsafe.Pointer) bool
    94  
    95  //go:noescape
    96  func CasInt32(ptr *int32, old, new int32) bool
    97  
    98  //go:noescape
    99  func CasInt64(ptr *int64, old, new int64) bool