github.com/nats-io/nats-server/v2@v2.11.0-preview.2/server/pse/pse_test.go (about)

     1  // Copyright 2015-2018 The NATS Authors
     2  // Licensed under the Apache License, Version 2.0 (the "License");
     3  // you may not use this file except in compliance with the License.
     4  // You may obtain a copy of the License at
     5  //
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package pse
    15  
    16  import (
    17  	"fmt"
    18  	"os"
    19  	"os/exec"
    20  	"runtime"
    21  	"testing"
    22  )
    23  
    24  func TestPSEmulation(t *testing.T) {
    25  	if runtime.GOOS == "windows" {
    26  		t.Skipf("Skipping this test on Windows")
    27  	}
    28  	var rss, vss, psRss, psVss int64
    29  	var pcpu, psPcpu float64
    30  
    31  	runtime.GC()
    32  
    33  	// PS version first
    34  	pidStr := fmt.Sprintf("%d", os.Getpid())
    35  	out, err := exec.Command("ps", "o", "pcpu=,rss=,vsz=", "-p", pidStr).Output()
    36  	if err != nil {
    37  		t.Fatalf("Failed to execute ps command: %v\n", err)
    38  	}
    39  
    40  	fmt.Sscanf(string(out), "%f %d %d", &psPcpu, &psRss, &psVss)
    41  	psRss *= 1024 // 1k blocks, want bytes.
    42  	psVss *= 1024 // 1k blocks, want bytes.
    43  
    44  	runtime.GC()
    45  
    46  	// Our internal version
    47  	ProcUsage(&pcpu, &rss, &vss)
    48  
    49  	if pcpu != psPcpu {
    50  		delta := int64(pcpu - psPcpu)
    51  		if delta < 0 {
    52  			delta = -delta
    53  		}
    54  		if delta > 30 { // 30%?
    55  			t.Fatalf("CPUs did not match close enough: %f vs %f", pcpu, psPcpu)
    56  		}
    57  	}
    58  	if rss != psRss {
    59  		delta := rss - psRss
    60  		if delta < 0 {
    61  			delta = -delta
    62  		}
    63  		if delta > 1024*1024 { // 1MB
    64  			t.Fatalf("RSSs did not match close enough: %d vs %d", rss, psRss)
    65  		}
    66  	}
    67  }