gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/pkg/eventfd/eventfd_test.go (about)

     1  // Copyright 2021 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 eventfd
    16  
    17  import (
    18  	"testing"
    19  	"time"
    20  )
    21  
    22  func TestReadWrite(t *testing.T) {
    23  	efd, err := Create()
    24  	if err != nil {
    25  		t.Fatalf("failed to Create(): %v", err)
    26  	}
    27  	defer efd.Close()
    28  
    29  	// Make sure we can read actual values
    30  	const want = 343
    31  	if err := efd.Write(want); err != nil {
    32  		t.Fatalf("failed to write value: %d", want)
    33  	}
    34  
    35  	got, err := efd.Read()
    36  	if err != nil {
    37  		t.Fatalf("failed to read value: %v", err)
    38  	}
    39  	if got != want {
    40  		t.Fatalf("Read(): got %d, but wanted %d", got, want)
    41  	}
    42  }
    43  
    44  func TestWait(t *testing.T) {
    45  	efd, err := Create()
    46  	if err != nil {
    47  		t.Fatalf("failed to Create(): %v", err)
    48  	}
    49  	defer efd.Close()
    50  
    51  	// There's no way to test with certainty that Wait() blocks indefinitely, but
    52  	// as a best-effort we can wait a bit on it.
    53  	errCh := make(chan error)
    54  	go func() {
    55  		errCh <- efd.Wait()
    56  	}()
    57  	select {
    58  	case err := <-errCh:
    59  		t.Fatalf("Wait() returned without a call to Notify(): %v", err)
    60  	case <-time.After(500 * time.Millisecond):
    61  	}
    62  
    63  	// Notify and check that Wait() returned.
    64  	if err := efd.Notify(); err != nil {
    65  		t.Fatalf("Notify() failed: %v", err)
    66  	}
    67  	select {
    68  	case err := <-errCh:
    69  		if err != nil {
    70  			t.Fatalf("Read() failed: %v", err)
    71  		}
    72  	case <-time.After(5 * time.Second):
    73  		t.Fatalf("Read() did not return after Notify()")
    74  	}
    75  }