1 files changed, 59 insertions, 0 deletions
diff --git a/test/util/save_util.cc b/test/util/save_util.cc
new file mode 100644
index 000000000..71f4078a7
--- /dev/null
+++ b/test/util/save_util.cc
@@ -0,0 +1,59 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "test/util/save_util.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <atomic>
+#include <cerrno>
+
+#define GVISOR_COOPERATIVE_SAVE_TEST "GVISOR_COOPERATIVE_SAVE_TEST"
+
+namespace gvisor {
+namespace testing {
+namespace {
+
+bool CooperativeSaveEnabled() {
+  static bool enabled = getenv(GVISOR_COOPERATIVE_SAVE_TEST) != nullptr;
+  return enabled;
+}
+
+std::atomic<int> save_disable;
+
+}  // namespace
+
+DisableSave::DisableSave() { save_disable++; }
+
+DisableSave::~DisableSave() { reset(); }
+
+void DisableSave::reset() {
+  if (!reset_) {
+    reset_ = true;
+    save_disable--;
+  }
+}
+
+void MaybeSave() {
+  if (CooperativeSaveEnabled() && !save_disable.load()) {
+    int orig_errno = errno;
+    syscall(SYS_create_module, nullptr, 0);
+    errno = orig_errno;
+  }
+}
+
+}  // namespace testing
+}  // namespace gvisor