fix: use small buffers to make tests more efficient

conn/batchsize_default.go

@@ -0,0 +1,12 @@
+//go:build !testsmallbuffers
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ */
+
+package conn
+
+const (
+	IdealBatchSize = 128 // maximum number of packets handled per read and write
+)

conn/batchsize_testsmall.go

@@ -0,0 +1,16 @@
+//go:build testsmallbuffers
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ *
+ * Modified by Coder for test environments to reduce memory usage.
+ */
+
+package conn
+
+// IdealBatchSize is reduced for tests to minimize memory usage.
+// In production, this is 128 (see batchsize_default.go), but tests don't need
+// the full batch capacity and this significantly reduces memory overhead
+// from wireguard buffer pools (~8MB per connection down to ~256KB).
+const IdealBatchSize = 4

conn/conn.go

@@ -15,10 +15,6 @@ import (
 	"strings"
 )
 
-const (
-	IdealBatchSize = 128 // maximum number of packets handled per read and write
-)
-
 // A ReceiveFunc receives at least one packet from the network and writes them
 // into packets. On a successful read it returns the number of elements of
 // sizes, packets, and endpoints that should be evaluated. Some elements of

device/queueconstants_android.go

@@ -1,3 +1,5 @@
+//go:build android && !testsmallbuffers
+
 /* SPDX-License-Identifier: MIT
  *
  * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.

device/queueconstants_default.go

@@ -1,4 +1,4 @@
-//go:build !android && !ios && !windows
+//go:build !android && !ios && !windows && !testsmallbuffers
 
 /* SPDX-License-Identifier: MIT
  *

device/queueconstants_ios.go

@@ -1,4 +1,4 @@
-//go:build ios
+//go:build ios && !testsmallbuffers
 
 /* SPDX-License-Identifier: MIT
  *

device/queueconstants_testsmall.go

@@ -0,0 +1,21 @@
+//go:build testsmallbuffers
+
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
+ *
+ * Modified by Coder for test environments to reduce memory usage.
+ */
+
+package device
+
+import "github.com/tailscale/wireguard-go/conn"
+
+const (
+	QueueStagedSize            = conn.IdealBatchSize
+	QueueOutboundSize          = 64   // Reduced from 1024 for tests
+	QueueInboundSize           = 64   // Reduced from 1024 for tests
+	QueueHandshakeSize         = 64   // Reduced from 1024 for tests
+	MaxSegmentSize             = 2048 // Reduced from 65535 for tests (enough for typical packets)
+	PreallocatedBuffersPerPool = 0    // Disable and allow for infinite memory growth
+)

device/queueconstants_windows.go

@@ -1,3 +1,5 @@
+//go:build !testsmallbuffers
+
 /* SPDX-License-Identifier: MIT
  *
  * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.