From ca8ccb5b43d18882dad79b655a6ae2ea791684cd Mon Sep 17 00:00:00 2001
From: Yingxin <yingxin.cheng@intel.com>
Date: Mon, 20 Aug 2018 16:05:46 +0800
Subject: [PATCH] crimson/test: improve test_config with observers

Signed-off-by: Yingxin <yingxin.cheng@intel.com>
---
 src/test/crimson/test_config.cc | 59 ++++++++++++++++++++++++++++++---
 1 file changed, 54 insertions(+), 5 deletions(-)

diff --git a/src/test/crimson/test_config.cc b/src/test/crimson/test_config.cc
index 5d0c104b8fc31..fd81d328bde6b 100644
--- a/src/test/crimson/test_config.cc
+++ b/src/test/crimson/test_config.cc
@@ -1,26 +1,75 @@
 #include <chrono>
+#include <string>
 #include <numeric>
 #include <seastar/core/app-template.hh>
 #include <seastar/core/sharded.hh>
+#include "common/config_obs.h"
 #include "crimson/common/config_proxy.h"
 
 using Config = ceph::common::ConfigProxy;
+const std::string test_uint_option = "osd_max_pgls";
+const uint64_t INVALID_VALUE = (uint64_t)(-1);
+
+class ConfigObs : public ceph::internal::md_config_obs_impl<Config> {
+  uint64_t last_change = INVALID_VALUE;
+  uint64_t num_changes = 0;
+
+  const char** get_tracked_conf_keys() const override {
+    static const char* keys[] = {
+      test_uint_option.c_str(),
+      nullptr,
+    };
+    return keys;
+  }
+  void handle_conf_change(const Config& conf,
+                          const std::set <std::string> &changes) override{
+    if (changes.count(test_uint_option)) {
+      last_change = conf.get_val<uint64_t>(test_uint_option);
+      num_changes += 1;
+    }
+  }
+public:
+  ConfigObs() {
+    ceph::common::local_conf().add_observer(this);
+  }
+
+  uint64_t get_last_change() const { return last_change; }
+  uint64_t get_num_changes() const { return num_changes; }
+  seastar::future<> stop() {
+    ceph::common::local_conf().remove_observer(this);
+    return seastar::now();
+  }
+};
+
+seastar::sharded<ConfigObs> sharded_cobs;
 
 static seastar::future<> test_config()
 {
   return ceph::common::sharded_conf().start().then([] {
     return ceph::common::sharded_conf().invoke_on(0, &Config::start);
+  }).then([] {
+    return sharded_cobs.start();
   }).then([] {
     return ceph::common::sharded_conf().invoke_on_all([](Config& config) {
-      return config.set_val("osd_tracing", "true");
+      return config.set_val(test_uint_option,
+                            std::to_string(seastar::engine().cpu_id()));
     });
   }).then([] {
-    return ceph::common::sharded_conf().invoke_on_all([](Config& config) {
-      if (!config.get_val<bool>("osd_tracing")) {
-        throw std::runtime_error("run osd_tracing");
+    auto expected = ceph::common::local_conf().get_val<uint64_t>(test_uint_option);
+    return ceph::common::sharded_conf().invoke_on_all([expected](Config& config) {
+      if (expected != config.get_val<uint64_t>(test_uint_option)) {
+        throw std::runtime_error("configurations don't match");
+      }
+      if (expected != sharded_cobs.local().get_last_change()) {
+        throw std::runtime_error("last applied changes don't match the latest config");
+      }
+      if (seastar::smp::count != sharded_cobs.local().get_num_changes()) {
+        throw std::runtime_error("num changes don't match actual changes");
       }
     });
-  }).then([] {
+  }).finally([] {
+    return sharded_cobs.stop();
+  }).finally([] {
     return ceph::common::sharded_conf().stop();
   });
 }
-- 
2.39.5