commit 1afda6bbb6db0e266795af3229b962c32775b928
author Yong Li <yong.b.li@linux.intel.com> Thu Apr 09 19:24:13 2020 +0800
committer Yong Li <yong.b.li@intel.com> Tue Apr 21 01:13:55 2020 +0000
tree f6a378c0f087111813900c4435f00a489c492a9f
parent bf8b1dadc117e93c1c9e328c8f3f7236483ee7f7

adcsensor: Check if the object is still valid in the async callback functions

Sometimes adcsesnor will crash during stress test.
The root cause is that the object is destroyed already
when the async callback functions are executed.
The timer cancel() cannot cancel the expired callback
handlers. When the callback handler is executed,
the object is deleted already.
The buffer used by async_read_util must guarantee
that they remain valid until the handler is called.

Using the weak_ptr to check if the object is still valid
before using these member variables/functions.

Tested:
No adcsensor crash with stress test,
Change the threshold of ADC sensor 0x51 P3VBAT:
while [ true ]; do; \
ipmitool raw 4 0x26 0x51 0x1b 0x20 0x1b 0 0x2a 0x2a 0;\
 ipmitool raw 4 0x26 0x51 0x1b 0x20 0x1b 0 0x2a 0x2b 0;\
 sleep 1; done

Signed-off-by: Yong Li <yong.b.li@linux.intel.com>
Change-Id: I2ddb934199e2d0f52a1a6df25c46eadfe06cfda3

src/ADCSensorMain.cpp

diff --git a/src/ADCSensorMain.cpp b/src/ADCSensorMain.cpp
index 1b56d93..df35722 100644
--- a/src/ADCSensorMain.cpp
+++ b/src/ADCSensorMain.cpp
@@ -65,7 +65,7 @@
 
 void createSensors(
     boost::asio::io_service& io, sdbusplus::asio::object_server& objectServer,
-    boost::container::flat_map<std::string, std::unique_ptr<ADCSensor>>&
+    boost::container::flat_map<std::string, std::shared_ptr<ADCSensor>>&
         sensors,
     std::shared_ptr<sdbusplus::asio::connection>& dbusConnection,
     const std::unique_ptr<boost::container::flat_set<std::string>>&
@@ -269,10 +269,11 @@
                     }
                 }
 
-                sensor = std::make_unique<ADCSensor>(
+                sensor = std::make_shared<ADCSensor>(
                     path.string(), objectServer, dbusConnection, io, sensorName,
                     std::move(sensorThresholds), scaleFactor, readState,
                     *interfacePath, std::move(bridgeGpio));
+                sensor->setupRead();
             }
         }));
 
@@ -286,7 +287,7 @@
     auto systemBus = std::make_shared<sdbusplus::asio::connection>(io);
     systemBus->request_name("xyz.openbmc_project.ADCSensor");
     sdbusplus::asio::object_server objectServer(systemBus);
-    boost::container::flat_map<std::string, std::unique_ptr<ADCSensor>> sensors;
+    boost::container::flat_map<std::string, std::shared_ptr<ADCSensor>> sensors;
     std::vector<std::unique_ptr<sdbusplus::bus::match::match>> matches;
     std::unique_ptr<boost::container::flat_set<std::string>> sensorsChanged =
         std::make_unique<boost::container::flat_set<std::string>>();