1 files changed, 77 insertions, 0 deletions
diff --git a/test/core/transport/pid_controller_test.c b/test/core/transport/pid_controller_test.c
new file mode 100644
index 0000000000..9614983b00
--- /dev/null
+++ b/test/core/transport/pid_controller_test.c
@@ -0,0 +1,77 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/transport/pid_controller.h"
+
+#include <math.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/useful.h>
+#include "src/core/lib/support/string.h"
+#include "test/core/util/test_config.h"
+
+static void test_noop(void) {
+  gpr_log(GPR_INFO, "test_noop");
+  grpc_pid_controller pid;
+  grpc_pid_controller_init(&pid, 1, 1, 1);
+}
+
+static void test_simple_convergence(double gain_p, double gain_i, double gain_d,
+                                    double dt, double set_point, double start) {
+  gpr_log(GPR_INFO,
+          "test_simple_convergence(p=%lf, i=%lf, d=%lf); dt=%lf set_point=%lf "
+          "start=%lf",
+          gain_p, gain_i, gain_d, dt, set_point, start);
+  grpc_pid_controller pid;
+  grpc_pid_controller_init(&pid, 0.2, 0.1, 0.1);
+
+  double current = start;
+
+  for (int i = 0; i < 1000; i++) {
+    current += grpc_pid_controller_update(&pid, set_point - current, 1);
+  }
+
+  GPR_ASSERT(fabs(set_point - current) < 0.1);
+  GPR_ASSERT(fabs(pid.error_integral) < 0.1);
+}
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  test_noop();
+  test_simple_convergence(0.2, 0, 0, 1, 100, 0);
+  test_simple_convergence(0.2, 0.1, 0, 1, 100, 0);
+  test_simple_convergence(0.2, 0.1, 0.1, 1, 100, 0);
+  return 0;
+}