From 592a645a578d68af3f0f1daae69ee8d91b5ced00 Mon Sep 17 00:00:00 2001
From: Paul Buetow <paul@buetow.org>
Date: Fri, 27 Feb 2026 18:11:19 +0200
Subject: flamegraph: add opt-in live trie stress QA test

---
 internal/flamegraph/livetrie_test.go | 85 ++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)

(limited to 'internal')

diff --git a/internal/flamegraph/livetrie_test.go b/internal/flamegraph/livetrie_test.go
index 6982a86..5d32209 100644
--- a/internal/flamegraph/livetrie_test.go
+++ b/internal/flamegraph/livetrie_test.go
@@ -3,11 +3,16 @@ package flamegraph
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"ior/internal/event"
 	"ior/internal/file"
 	"ior/internal/types"
+	"os"
+	"runtime"
 	"sync"
+	"sync/atomic"
 	"testing"
+	"time"
 )
 
 func TestLiveTrieIngestAndSnapshotRoundTrip(t *testing.T) {
@@ -117,6 +122,86 @@ func TestLiveTrieConcurrentIngestAndSnapshot(t *testing.T) {
 	}
 }
 
+func TestLiveTrieStressHighRateConcurrentSnapshot(t *testing.T) {
+	if os.Getenv("IOR_STRESS_TEST") != "1" {
+		t.Skip("set IOR_STRESS_TEST=1 to run stress test")
+	}
+
+	const (
+		totalEvents     = 50000
+		snapshotReaders = 3
+		maxMemGrowth    = 512 << 20
+	)
+
+	lt := NewLiveTrie([]string{"path", "pid"}, "count")
+	var startMem runtime.MemStats
+	runtime.ReadMemStats(&startMem)
+
+	done := make(chan struct{})
+	var snapshots atomic.Int64
+	errCh := make(chan error, snapshotReaders)
+	var readersWG sync.WaitGroup
+	readersWG.Add(snapshotReaders)
+	for i := 0; i < snapshotReaders; i++ {
+		go func() {
+			defer readersWG.Done()
+			ticker := time.NewTicker(2 * time.Millisecond)
+			defer ticker.Stop()
+			for {
+				select {
+				case <-done:
+					return
+				case <-ticker.C:
+					payload, _ := lt.SnapshotJSON()
+					var snap trieSnapshot
+					if err := json.Unmarshal(payload, &snap); err != nil {
+						errCh <- fmt.Errorf("snapshot json invalid: %w", err)
+						return
+					}
+					snapshots.Add(1)
+				}
+			}
+		}()
+	}
+
+	start := time.Now()
+	for i := 0; i < totalEvents; i++ {
+		pid := uint32(1000 + (i % 32))
+		tid := uint32(100000 + i)
+		path := fmt.Sprintf("/stress/%05d", i)
+		lt.Ingest(newTestPair("qa-load", pid, tid, path, 1, 1, 1))
+	}
+	ingestDuration := time.Since(start)
+
+	close(done)
+	readersWG.Wait()
+	close(errCh)
+	for err := range errCh {
+		t.Fatal(err)
+	}
+
+	if got := lt.Version(); got != totalEvents {
+		t.Fatalf("version = %d, want %d", got, totalEvents)
+	}
+	if snapshots.Load() == 0 {
+		t.Fatalf("expected at least one concurrent snapshot read")
+	}
+
+	final := decodeLiveSnapshot(t, lt)
+	if final.Total != totalEvents {
+		t.Fatalf("final total = %d, want %d", final.Total, totalEvents)
+	}
+
+	var endMem runtime.MemStats
+	runtime.ReadMemStats(&endMem)
+	if endMem.Alloc > startMem.Alloc+maxMemGrowth {
+		t.Fatalf("memory growth too high: start=%d end=%d limit=%d", startMem.Alloc, endMem.Alloc, startMem.Alloc+maxMemGrowth)
+	}
+
+	rate := float64(totalEvents) / ingestDuration.Seconds()
+	t.Logf("stress ingest rate: %.0f events/sec (%d events in %s)", rate, totalEvents, ingestDuration)
+}
+
 func newTestPair(comm string, pid uint32, tid uint32, path string, duration uint64, gap uint64, bytesCnt uint64) *event.Pair {
 	enter := &types.OpenEvent{
 		TraceId: types.SYS_ENTER_OPENAT,
-- 
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