gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/pkg/sentry/usage/io.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 usage
    16  
    17  import "gvisor.dev/gvisor/pkg/atomicbitops"
    18  
    19  // IO contains I/O-related statistics.
    20  //
    21  // +stateify savable
    22  type IO struct {
    23  	// CharsRead is the number of bytes read by read syscalls.
    24  	CharsRead atomicbitops.Uint64
    25  
    26  	// CharsWritten is the number of bytes written by write syscalls.
    27  	CharsWritten atomicbitops.Uint64
    28  
    29  	// ReadSyscalls is the number of read syscalls.
    30  	ReadSyscalls atomicbitops.Uint64
    31  
    32  	// WriteSyscalls is the number of write syscalls.
    33  	WriteSyscalls atomicbitops.Uint64
    34  
    35  	// The following counter is only meaningful when Sentry has internal
    36  	// pagecache.
    37  
    38  	// BytesRead is the number of bytes actually read into pagecache.
    39  	BytesRead atomicbitops.Uint64
    40  
    41  	// BytesWritten is the number of bytes actually written from pagecache.
    42  	BytesWritten atomicbitops.Uint64
    43  
    44  	// BytesWriteCancelled is the number of bytes not written out due to
    45  	// truncation.
    46  	BytesWriteCancelled atomicbitops.Uint64
    47  }
    48  
    49  // Clone turns other into a clone of i.
    50  func (i *IO) Clone(other *IO) {
    51  	other.CharsRead.Store(i.CharsRead.Load())
    52  	other.CharsWritten.Store(i.CharsWritten.Load())
    53  	other.ReadSyscalls.Store(i.ReadSyscalls.Load())
    54  	other.WriteSyscalls.Store(i.WriteSyscalls.Load())
    55  	other.BytesRead.Store(i.BytesRead.Load())
    56  	other.BytesWritten.Store(i.BytesWritten.Load())
    57  	other.BytesWriteCancelled.Store(i.BytesWriteCancelled.Load())
    58  }
    59  
    60  // AccountReadSyscall does the accounting for a read syscall.
    61  func (i *IO) AccountReadSyscall(bytes int64) {
    62  	i.ReadSyscalls.Add(1)
    63  	if bytes > 0 {
    64  		i.CharsRead.Add(uint64(bytes))
    65  	}
    66  }
    67  
    68  // AccountWriteSyscall does the accounting for a write syscall.
    69  func (i *IO) AccountWriteSyscall(bytes int64) {
    70  	i.WriteSyscalls.Add(1)
    71  	if bytes > 0 {
    72  		i.CharsWritten.Add(uint64(bytes))
    73  	}
    74  }
    75  
    76  // AccountReadIO does the accounting for a read IO into the file system.
    77  func (i *IO) AccountReadIO(bytes int64) {
    78  	if bytes > 0 {
    79  		i.BytesRead.Add(uint64(bytes))
    80  	}
    81  }
    82  
    83  // AccountWriteIO does the accounting for a write IO into the file system.
    84  func (i *IO) AccountWriteIO(bytes int64) {
    85  	if bytes > 0 {
    86  		i.BytesWritten.Add(uint64(bytes))
    87  	}
    88  }
    89  
    90  // Accumulate adds up io usages.
    91  func (i *IO) Accumulate(io *IO) {
    92  	i.CharsRead.Add(io.CharsRead.Load())
    93  	i.CharsWritten.Add(io.CharsWritten.Load())
    94  	i.ReadSyscalls.Add(io.ReadSyscalls.Load())
    95  	i.WriteSyscalls.Add(io.WriteSyscalls.Load())
    96  	i.BytesRead.Add(io.BytesRead.Load())
    97  	i.BytesWritten.Add(io.BytesWritten.Load())
    98  	i.BytesWriteCancelled.Add(io.BytesWriteCancelled.Load())
    99  }