Files
routewatch/internal/routetable/routetable_internal_test.go
T
sneak 6b02cee68b
check / check (push) Canceled after 0s
Keep taking messages while a peer's session goes down (closes #216)
The table's PeerDown visits every prefix under the write lock, which
takes over a second on a full table. The prefix handler called it
inline, so its queue filled and the streamer dropped updates.

PeerDown now lets the lock go after every 10,000 prefixes. The handler
runs it on a goroutine of its own, one peer at a time, and holds back
the down peer's later messages until it returns, then applies them in
order. Stop waits for this before its last flush, and logs the
held-back messages it could not apply.

Model: opus-5-5
2026-11-02 00:18:03 +00:00

70 lines
1.4 KiB
Go

package routetable
import (
"net/netip"
"runtime"
"testing"
"time"
)
// TestPeerDownLetsReadsIn reads the table's counts again and again while a peer
// that carries more than two batches of prefixes goes down. PeerDown lets the
// lock go after every walkBatch prefixes, so a read must get in while the peer
// still carries some of its prefixes but no longer all.
func TestPeerDownLetsReadsIn(t *testing.T) {
t.Parallel()
const (
asn = 1000
peer = "192.0.2.1"
// prefixCount is more prefixes than two of walkBatch.
prefixCount = 2*walkBatch + 1
)
routeTime := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
table := New(Params{})
addr := netip.MustParseAddr("1.0.0.0")
for range prefixCount {
prefix := netip.PrefixFrom(addr, addr.BitLen())
table.Announce(prefix, asn, Route{Peer: peer, Time: routeTime})
addr = addr.Next()
}
// Hold a read lock until PeerDown waits for the lock, so that the first
// read below starts once PeerDown holds it. TryRLock fails once a writer
// waits.
table.mu.RLock()
peerDownDone := make(chan struct{})
go func() {
defer close(peerDownDone)
table.PeerDown(peer)
}()
for table.mu.TryRLock() {
table.mu.RUnlock()
runtime.Gosched()
}
table.mu.RUnlock()
for {
routes := table.Counts().IPv4Routes
if routes > 0 && routes < prefixCount {
break
}
select {
case <-peerDownDone:
t.Fatal("no read got in while PeerDown ran")
default:
}
}
<-peerDownDone
}