pkg/fuzzer/queue: retry inputs from crashed VMs

Mark some requests as Important. The Retry() layer will give them one
more chance even if they were not executed due to a VM crash.

For now, the only important requests are related to triage, candidates
and pkg/vminfo tests.

Add tests for retry.go.

1 files changed, 72 insertions, 0 deletions

diff --git a/pkg/fuzzer/queue/retry_test.go b/pkg/fuzzer/queue/retry_test.go
new file mode 100644
index 000000000..8529779a2
--- /dev/null
+++ b/pkg/fuzzer/queue/retry_test.go
@@ -0,0 +1,72 @@
+// Copyright 2024 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package queue
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRetryerOnRestart(t *testing.T) {
+	q := Plain()
+	retryerObj := Retry(q)
+
+	q.Submit(&Request{Important: true})
+	q.Submit(&Request{Important: false})
+
+	// The requests must be retried forever.
+	req1 := retryerObj.Next()
+	req2 := retryerObj.Next()
+	for i := 0; i < 10; i++ {
+		req1.Done(&Result{Status: Restarted})
+		req2.Done(&Result{Status: Restarted})
+		assert.Equal(t, req1, retryerObj.Next())
+		assert.Equal(t, req2, retryerObj.Next())
+	}
+
+	// Once successful, requests should no longer appear.
+	req1.Done(&Result{Status: Success})
+	req2.Done(&Result{Status: Success})
+
+	assert.Equal(t, Success, req1.Wait(context.Background()).Status)
+	assert.Equal(t, Success, req2.Wait(context.Background()).Status)
+
+	assert.Nil(t, retryerObj.Next())
+	assert.Nil(t, retryerObj.Next())
+}
+
+func TestRetryerOnCrash(t *testing.T) {
+	q := Plain()
+	retryerObj := Retry(q)
+
+	// Unimportant requests will not be retried.
+	req := &Request{Important: false}
+	q.Submit(req)
+	assert.Equal(t, req, retryerObj.Next())
+	req.Done(&Result{Status: Crashed})
+	assert.Nil(t, retryerObj.Next())
+	assert.Equal(t, Crashed, req.Wait(context.Background()).Status)
+
+	// Important requests will be retried once.
+	req = &Request{Important: true}
+	q.Submit(req)
+	assert.Equal(t, req, retryerObj.Next())
+	req.Done(&Result{Status: Crashed})
+	assert.Equal(t, req, retryerObj.Next())
+	req.Done(&Result{Status: Success})
+	assert.Nil(t, retryerObj.Next())
+	assert.Equal(t, Success, req.Wait(context.Background()).Status)
+
+	// .. but not more than once.
+	req = &Request{Important: true}
+	q.Submit(req)
+	assert.Equal(t, req, retryerObj.Next())
+	req.Done(&Result{Status: Crashed})
+	assert.Equal(t, req, retryerObj.Next())
+	req.Done(&Result{Status: Crashed})
+	assert.Nil(t, retryerObj.Next())
+	assert.Equal(t, Crashed, req.Wait(context.Background()).Status)
+}