Build out backoff as a library

1 files changed, 107 insertions, 0 deletions

diff --git a/test/core/support/backoff_test.c b/test/core/support/backoff_test.c
new file mode 100644
index 0000000000..870b60b2d5
--- /dev/null
+++ b/test/core/support/backoff_test.c
@@ -0,0 +1,107 @@
+/*
+ *
+ * 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/support/backoff.h"
+
+#include <grpc/support/log.h>
+
+#include "test/core/util/test_config.h"
+
+static void test_constant_backoff(void) {
+  gpr_backoff backoff;
+  gpr_backoff_init(&backoff, 1.0, 0.0, 1000, 1000);
+
+  gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
+  gpr_timespec next = gpr_backoff_begin(&backoff, now);
+  GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 1000);
+  for (int i = 0; i < 10000; i++) {
+    next = gpr_backoff_step(&backoff, now);
+    GPR_ASSERT(gpr_time_to_millis(gpr_time_sub(next, now)) == 1000);
+    now = next;
+  }
+}
+
+static void test_no_jitter_backoff(void) {
+  gpr_backoff backoff;
+  gpr_backoff_init(&backoff, 2.0, 0.0, 1, 513);
+
+  gpr_timespec now = gpr_time_0(GPR_TIMESPAN);
+  gpr_timespec next = gpr_backoff_begin(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(3, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(7, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(15, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(31, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(63, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(127, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(255, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(511, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1023, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(1536, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2049, GPR_TIMESPAN), next) == 0);
+  now = next;
+  next = gpr_backoff_step(&backoff, now);
+  GPR_ASSERT(gpr_time_cmp(gpr_time_from_millis(2562, GPR_TIMESPAN), next) == 0);
+}
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  gpr_time_init();
+
+  test_constant_backoff();
+  test_no_jitter_backoff();
+
+  return 0;
+}