Basic work on a publish/subscribe abstraction

The goal here is to provide a way to decouple pieces of the code
that want to learn "when something happens" from those that realize
that it has happened.

The implementation here consists of a generic backend, plus a set of
macros to define and implement a set of type-safe frontends.

1 files changed, 85 insertions, 0 deletions

diff --git a/src/test/test_pubsub.c b/src/test/test_pubsub.c
new file mode 100644
index 0000000000..547d6c6b32
--- /dev/null
+++ b/src/test/test_pubsub.c
@@ -0,0 +1,85 @@
+/* Copyright (c) 2016, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file test_pubsub.c
+ * \brief Unit tests for publish-subscribe abstraction.
+ **/
+
+#include "or.h"
+#include "test.h"
+#include "pubsub.h"
+
+DECLARE_PUBSUB_STRUCT_TYPES(foobar)
+DECLARE_PUBSUB_TOPIC(foobar)
+DECLARE_NOTIFY_PUBSUB_TOPIC(static, foobar)
+IMPLEMENT_PUBSUB_TOPIC(static, foobar)
+
+struct foobar_event_data_t {
+  unsigned u;
+  const char *s;
+};
+
+struct foobar_subscriber_data_t {
+  const char *name;
+  long l;
+};
+
+static int
+foobar_sub1(foobar_event_data_t *ev, foobar_subscriber_data_t *mine)
+{
+  ev->u += 10;
+  mine->l += 100;
+  return 0;
+}
+
+static int
+foobar_sub2(foobar_event_data_t *ev, foobar_subscriber_data_t *mine)
+{
+  ev->u += 5;
+  mine->l += 50;
+  return 0;
+}
+
+static void
+test_pubsub_basic(void *arg)
+{
+  (void)arg;
+  foobar_subscriber_data_t subdata1 = { "hi", 0 };
+  foobar_subscriber_data_t subdata2 = { "wow", 0 };
+  const foobar_subscriber_t *sub1;
+  const foobar_subscriber_t *sub2;
+  foobar_event_data_t ed = { 0, "x" };
+  foobar_event_data_t ed2 = { 0, "y" };
+  sub1 = foobar_subscribe(foobar_sub1, &subdata1, SUBSCRIBE_ATSTART, 100);
+  tt_assert(sub1);
+
+  foobar_notify(&ed, 0);
+  tt_int_op(subdata1.l, OP_EQ, 100);
+  tt_int_op(subdata2.l, OP_EQ, 0);
+  tt_int_op(ed.u, OP_EQ, 10);
+
+  sub2 = foobar_subscribe(foobar_sub2, &subdata2, 0, 5);
+  tt_assert(sub2);
+
+  foobar_notify(&ed2, 0);
+  tt_int_op(subdata1.l, OP_EQ, 200);
+  tt_int_op(subdata2.l, OP_EQ, 50);
+  tt_int_op(ed2.u, OP_EQ, 15);
+
+  foobar_unsubscribe(sub1);
+
+  foobar_notify(&ed, 0);
+  tt_int_op(subdata1.l, OP_EQ, 200);
+  tt_int_op(subdata2.l, OP_EQ, 100);
+  tt_int_op(ed.u, OP_EQ, 15);
+
+ done:
+  foobar_clear();
+}
+
+struct testcase_t pubsub_tests[] = {
+  { "pubsub_basic", test_pubsub_basic, TT_FORK, NULL, NULL },
+  END_OF_TESTCASES
+};
+