Make dbusconfiguration reloadable without reboot

Now that asio is being used instead of threads, we can
reload the fan configuration without having to restart the
application. This moves the ownership of the passive and host
bus outside of the SensorManager so that it can be recreated
each reload.

Tested: Watched logs and saw full fan config get reloaded
after changing fan configuration

Tested: Ran on json configured system and it behaved as
expected.

Change-Id: I00e6b27f75384fd41de2017b723f159c9691ae97
Signed-off-by: James Feist <james.feist@linux.intel.com>

2 files changed, 74 insertions, 40 deletions

diff --git a/dbus/dbusconfiguration.cpp b/dbus/dbusconfiguration.cpp
index 2c9bbc2..870e5e8 100644
--- a/dbus/dbusconfiguration.cpp
+++ b/dbus/dbusconfiguration.cpp
@@ -18,15 +18,16 @@
 #include "util.hpp"
 
 #include <algorithm>
+#include <boost/asio/steady_timer.hpp>
 #include <chrono>
 #include <functional>
 #include <iostream>
+#include <list>
 #include <regex>
 #include <sdbusplus/bus.hpp>
 #include <sdbusplus/bus/match.hpp>
 #include <sdbusplus/exception.hpp>
 #include <set>
-#include <thread>
 #include <unordered_map>
 #include <variant>
 
@@ -139,16 +140,6 @@ void debugPrint(void)
     std::cout << "}\n\n";
 }
 
-int eventHandler(sd_bus_message*, void*, sd_bus_error*)
-{
-    // do a brief sleep as we tend to get a bunch of these events at
-    // once
-    std::this_thread::sleep_for(std::chrono::seconds(5));
-    std::cout << "New configuration detected, restarting\n.";
-    std::exit(EXIT_SUCCESS); // service file should make us restart
-    return 1;
-}
-
 size_t getZoneIndex(const std::string& name, std::vector<std::string>& zones)
 {
     auto it = std::find(zones.begin(), zones.end(), name);
@@ -229,8 +220,74 @@ std::vector<std::string> getSelectedProfiles(sdbusplus::bus::bus& bus)
     return ret;
 }
 
-void init(sdbusplus::bus::bus& bus)
+int eventHandler(sd_bus_message*, void* context, sd_bus_error*)
+{
+
+    if (context == nullptr)
+    {
+        throw std::runtime_error("Invalid match");
+    }
+    boost::asio::steady_timer* timer =
+        static_cast<boost::asio::steady_timer*>(context);
+
+    // do a brief sleep as we tend to get a bunch of these events at
+    // once
+    timer->expires_after(std::chrono::seconds(2));
+    timer->async_wait([](const boost::system::error_code ec) {
+        if (ec == boost::asio::error::operation_aborted)
+        {
+            /* another timer started*/
+            return;
+        }
+
+        std::cout << "New configuration detected, reloading\n.";
+        restartControlLoops();
+    });
+
+    return 1;
+}
+
+void createMatches(sdbusplus::bus::bus& bus, boost::asio::steady_timer& timer)
+{
+    // this is a list because the matches can't be moved
+    static std::list<sdbusplus::bus::match::match> matches;
+
+    const std::array<std::string, 5> interfaces = {
+        thermalControlIface, fanProfileConfigurationIface,
+        pidConfigurationInterface, pidZoneConfigurationInterface,
+        stepwiseConfigurationInterface};
+
+    // this list only needs to be created once
+    if (!matches.empty())
+    {
+        return;
+    }
+
+    // we restart when the configuration changes or there are new sensors
+    for (const auto& interface : interfaces)
+    {
+        matches.emplace_back(
+            bus,
+            "type='signal',member='PropertiesChanged',arg0namespace='" +
+                interface + "'",
+            eventHandler, &timer);
+    }
+    matches.emplace_back(
+        bus,
+        "type='signal',member='InterfacesAdded',arg0path='/xyz/openbmc_project/"
+        "sensors/'",
+        eventHandler, &timer);
+}
+
+bool init(sdbusplus::bus::bus& bus, boost::asio::steady_timer& timer)
 {
+
+    sensorConfig.clear();
+    zoneConfig.clear();
+    zoneDetailsConfig.clear();
+
+    createMatches(bus, timer);
+
     using DbusVariantType =
         std::variant<uint64_t, int64_t, double, std::string,
                      std::vector<std::string>, std::vector<double>>;
@@ -240,27 +297,6 @@ void init(sdbusplus::bus::bus& bus)
         std::unordered_map<std::string,
                            std::unordered_map<std::string, DbusVariantType>>>;
 
-    // restart on configuration properties changed
-    static sdbusplus::bus::match::match configMatch(
-        bus,
-        "type='signal',member='PropertiesChanged',arg0namespace='" +
-            std::string(pidConfigurationInterface) + "'",
-        eventHandler);
-
-    // restart on profile change
-    static sdbusplus::bus::match::match profileMatch(
-        bus,
-        "type='signal',member='PropertiesChanged',arg0namespace='" +
-            std::string(thermalControlIface) + "'",
-        eventHandler);
-
-    // restart on sensors changed
-    static sdbusplus::bus::match::match sensorAdded(
-        bus,
-        "type='signal',member='InterfacesAdded',arg0path='/xyz/openbmc_project/"
-        "sensors/'",
-        eventHandler);
-
     auto mapper =
         bus.new_method_call("xyz.openbmc_project.ObjectMapper",
                             "/xyz/openbmc_project/object_mapper",
@@ -768,12 +804,10 @@ void init(sdbusplus::bus::bus& bus)
     }
     if (zoneConfig.empty() || zoneDetailsConfig.empty())
     {
-        std::cerr << "No fan zones, application pausing until reboot\n";
-        while (1)
-        {
-            bus.process_discard();
-            bus.wait();
-        }
+        std::cerr
+            << "No fan zones, application pausing until new configuration\n";
+        return false;
     }
+    return true;
 }
 } // namespace dbus_configuration
diff --git a/dbus/dbusconfiguration.hpp b/dbus/dbusconfiguration.hpp
index b3032e9..a9b12a9 100644
--- a/dbus/dbusconfiguration.hpp
+++ b/dbus/dbusconfiguration.hpp
@@ -21,5 +21,5 @@
 
 namespace dbus_configuration
 {
-void init(sdbusplus::bus::bus& bus);
+bool init(sdbusplus::bus::bus& bus, boost::asio::steady_timer& timer);
 } // namespace dbus_configuration