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Diffstat (limited to 'pkg/atomicbitops/atomic_bitops.go')
-rw-r--r-- | pkg/atomicbitops/atomic_bitops.go | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/pkg/atomicbitops/atomic_bitops.go b/pkg/atomicbitops/atomic_bitops.go new file mode 100644 index 000000000..63aa2b7f1 --- /dev/null +++ b/pkg/atomicbitops/atomic_bitops.go @@ -0,0 +1,59 @@ +// Copyright 2018 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// +build amd64 + +// Package atomicbitops provides basic bitwise operations in an atomic way. +// The implementation on amd64 leverages the LOCK prefix directly instead of +// relying on the generic cas primitives. +// +// WARNING: the bitwise ops provided in this package doesn't imply any memory +// ordering. Using them to construct locks must employ proper memory barriers. +package atomicbitops + +// AndUint32 atomically applies bitwise and operation to *addr with val. +func AndUint32(addr *uint32, val uint32) + +// OrUint32 atomically applies bitwise or operation to *addr with val. +func OrUint32(addr *uint32, val uint32) + +// XorUint32 atomically applies bitwise xor operation to *addr with val. +func XorUint32(addr *uint32, val uint32) + +// CompareAndSwapUint32 is like sync/atomic.CompareAndSwapUint32, but returns +// the value previously stored at addr. +func CompareAndSwapUint32(addr *uint32, old, new uint32) uint32 + +// AndUint64 atomically applies bitwise and operation to *addr with val. +func AndUint64(addr *uint64, val uint64) + +// OrUint64 atomically applies bitwise or operation to *addr with val. +func OrUint64(addr *uint64, val uint64) + +// XorUint64 atomically applies bitwise xor operation to *addr with val. +func XorUint64(addr *uint64, val uint64) + +// CompareAndSwapUint64 is like sync/atomic.CompareAndSwapUint64, but returns +// the value previously stored at addr. +func CompareAndSwapUint64(addr *uint64, old, new uint64) uint64 + +// IncUnlessZeroInt32 increments the value stored at the given address and +// returns true; unless the value stored in the pointer is zero, in which case +// it is left unmodified and false is returned. +func IncUnlessZeroInt32(addr *int32) bool + +// DecUnlessOneInt32 decrements the value stored at the given address and +// returns true; unless the value stored in the pointer is 1, in which case it +// is left unmodified and false is returned. +func DecUnlessOneInt32(addr *int32) bool |