pkg/fuzzer: introduce a request restarter layer

Make Result statuses more elaborate.
Instead of retrying inputs directly in rpc.go, extract this logic to a
separate entity in pkg/fuzzer/queue.

1 files changed, 37 insertions, 0 deletions

diff --git a/pkg/fuzzer/queue/retry.go b/pkg/fuzzer/queue/retry.go
new file mode 100644
index 000000000..0b2e02ba5
--- /dev/null
+++ b/pkg/fuzzer/queue/retry.go
@@ -0,0 +1,37 @@
+// 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
+
+type retryer struct {
+	pq   *PlainQueue
+	base Source
+}
+
+// Retry adds a layer that resends results with Status=Restarted.
+func Retry(base Source) Source {
+	return &retryer{
+		base: base,
+		pq:   Plain(),
+	}
+}
+
+func (r *retryer) Next() *Request {
+	req := r.pq.tryNext()
+	if req == nil {
+		req = r.base.Next()
+	}
+	if req != nil {
+		req.OnDone(r.done)
+	}
+	return req
+}
+
+func (r *retryer) done(req *Request, res *Result) bool {
+	// The input was on a restarted VM.
+	if res.Status == Restarted {
+		r.pq.Submit(req)
+		return false
+	}
+	return true
+}