github.com/nicocha30/gvisor-ligolo@v0.0.0-20230726075806-989fa2c0a413/pkg/sentry/usage/cpu.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 (
    18  	"time"
    19  )
    20  
    21  // CPUStats contains the subset of struct rusage fields that relate to CPU
    22  // scheduling.
    23  //
    24  // +stateify savable
    25  type CPUStats struct {
    26  	// UserTime is the amount of time spent executing application code.
    27  	UserTime time.Duration
    28  
    29  	// SysTime is the amount of time spent executing sentry code.
    30  	SysTime time.Duration
    31  
    32  	// VoluntarySwitches is the number of times control has been voluntarily
    33  	// ceded due to blocking, etc.
    34  	VoluntarySwitches uint64
    35  
    36  	// InvoluntarySwitches (struct rusage::ru_nivcsw) is unsupported, since
    37  	// "preemptive" scheduling is managed by the Go runtime, which doesn't
    38  	// provide this information.
    39  }
    40  
    41  // Accumulate adds s2 to s.
    42  func (s *CPUStats) Accumulate(s2 CPUStats) {
    43  	s.UserTime += s2.UserTime
    44  	s.SysTime += s2.SysTime
    45  	s.VoluntarySwitches += s2.VoluntarySwitches
    46  }
    47  
    48  // DifferenceSince computes s - earlierSample.
    49  //
    50  // Precondition: s >= earlierSample.
    51  func (s *CPUStats) DifferenceSince(earlierSample CPUStats) CPUStats {
    52  	return CPUStats{
    53  		UserTime:          s.UserTime - earlierSample.UserTime,
    54  		SysTime:           s.SysTime - earlierSample.SysTime,
    55  		VoluntarySwitches: s.VoluntarySwitches - earlierSample.VoluntarySwitches,
    56  	}
    57  }