github.com/MerlinKodo/gvisor@v0.0.0-20231110090155-957f62ecf90e/pkg/tcpip/link/sharedmem/pipe/pipe_unsafe.go (about)

     1  // Copyright 2018 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package pipe
    16  
    17  import (
    18  	"unsafe"
    19  
    20  	"github.com/MerlinKodo/gvisor/pkg/atomicbitops"
    21  )
    22  
    23  func (p *pipe) write(idx uint64, v uint64) {
    24  	ptr := (*uint64)(unsafe.Pointer(&p.buffer[idx&offsetMask:][:8][0]))
    25  	*ptr = v
    26  }
    27  
    28  func (p *pipe) writeAtomic(idx uint64, v uint64) {
    29  	ptr := (*atomicbitops.Uint64)(unsafe.Pointer(&p.buffer[idx&offsetMask:][:8][0]))
    30  	ptr.Store(v)
    31  }
    32  
    33  func (p *pipe) readAtomic(idx uint64) uint64 {
    34  	ptr := (*atomicbitops.Uint64)(unsafe.Pointer(&p.buffer[idx&offsetMask:][:8][0]))
    35  	return ptr.Load()
    36  }