commit 564eb4fa9de27fb9c26213fd94eef703fbe6f2f9
author Willy Tu <wltu@google.com> Thu Sep 07 16:02:46 2023 -0700
committer Willy Tu <wltu@google.com> Fri Sep 08 08:32:34 2023 -0700
tree 0f703e331e0b6d658ad2da2877f7bb611cabb0be
parent 7a7c38dba2460e6365311ff9ebd71a9ffc27792d

Set lastRebootTime once at startup only

The lastRebootTime doesn't change once the daemon starts, so we only
need to fetch the info once and save the time instead of calculating it
everytime.

Change-Id: I5e665d637f122727be9bb8f0e7b731d75a567f02
Signed-off-by: Willy Tu <wltu@google.com>

bmc_state_manager.cpp

diff --git a/bmc_state_manager.cpp b/bmc_state_manager.cpp
index 5071d89..9f67a31 100644
--- a/bmc_state_manager.cpp
+++ b/bmc_state_manager.cpp
@@ -4,13 +4,11 @@
 #include "xyz/openbmc_project/Common/error.hpp"
 
 #include <gpiod.h>
-#include <sys/sysinfo.h>
 
 #include <phosphor-logging/elog-errors.hpp>
 #include <phosphor-logging/lg2.hpp>
 #include <sdbusplus/exception.hpp>
 
-#include <cassert>
 #include <filesystem>
 #include <fstream>
 #include <iostream>
@@ -246,17 +244,7 @@
 
 uint64_t BMC::lastRebootTime() const
 {
-    using namespace std::chrono;
-    struct sysinfo info;
-
-    auto rc = sysinfo(&info);
-    assert(rc == 0);
-
-    // Since uptime is in seconds, also get the current time in seconds.
-    auto now = time_point_cast<seconds>(system_clock::now());
-    auto rebootTime = now - seconds(info.uptime);
-
-    return duration_cast<milliseconds>(rebootTime.time_since_epoch()).count();
+    return rebootTime;
 }
 
 void BMC::discoverLastRebootCause()

bmc_state_manager.hpp

diff --git a/bmc_state_manager.hpp b/bmc_state_manager.hpp
index e832451..d50d4f3 100644
--- a/bmc_state_manager.hpp
+++ b/bmc_state_manager.hpp
@@ -4,9 +4,13 @@
 #include "xyz/openbmc_project/State/BMC/server.hpp"
 
 #include <linux/watchdog.h>
+#include <sys/sysinfo.h>
 
 #include <sdbusplus/bus.hpp>
 
+#include <cassert>
+#include <chrono>
+
 namespace phosphor
 {
 namespace state
@@ -44,6 +48,19 @@
         utils::subscribeToSystemdSignals(bus);
         discoverInitialState();
         discoverLastRebootCause();
+
+        using namespace std::chrono;
+        struct sysinfo info;
+
+        auto rc = sysinfo(&info);
+        assert(rc == 0);
+        // Since uptime is in seconds, also get the current time in seconds.
+        auto now = time_point_cast<seconds>(system_clock::now());
+        auto rebootTimeTs = now - seconds(info.uptime);
+        rebootTime =
+            duration_cast<milliseconds>(rebootTimeTs.time_since_epoch())
+                .count();
+
         this->emit_object_added();
     };
 
@@ -102,6 +119,11 @@
      * @brief discover the last reboot cause of the bmc
      **/
     void discoverLastRebootCause();
+
+    /**
+     * @brief the lastRebootTime calcuated at startup.
+     **/
+    uint64_t rebootTime;
 };
 
 } // namespace manager