Fix data race in GenericPlatformManagerImpl_POSIX.ipp (project-chip#1588

) * Fix data race in GenericPlatformManagerImpl_POSIX.ipp The mShouldRunEventLoop member variable is used for cross thread communication without synchronization. This is a data race unless an atomic variable is used. Make it so. * Restyled by clang-format Co-authored-by: Restyled.io <[email protected]>
kedars · Jul 19, 2020 · a531b3e · a531b3e
1 parent b3a457a
commit a531b3e
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Showing 2 changed files with 5 additions and 4 deletions.
diff --git a/src/include/platform/internal/GenericPlatformManagerImpl_POSIX.h b/src/include/platform/internal/GenericPlatformManagerImpl_POSIX.h
@@ -33,6 +33,7 @@
 #include <sys/time.h>
 #include <unistd.h>
 
+#include <atomic>
 #include <pthread.h>
 #include <queue>
 
@@ -93,7 +94,7 @@ class GenericPlatformManagerImpl_POSIX : public GenericPlatformManagerImpl<ImplC
 
     void ProcessDeviceEvents();
 
-    bool mShouldRunEventLoop;
+    std::atomic<bool> mShouldRunEventLoop;
     static void * EventLoopTaskMain(void * arg);
 };
 

diff --git a/src/include/platform/internal/GenericPlatformManagerImpl_POSIX.ipp b/src/include/platform/internal/GenericPlatformManagerImpl_POSIX.ipp
@@ -73,7 +73,7 @@ CHIP_ERROR GenericPlatformManagerImpl_POSIX<ImplClass>::_InitChipStack(void)
     err = GenericPlatformManagerImpl<ImplClass>::_InitChipStack();
     SuccessOrExit(err);
 
-    mShouldRunEventLoop = true;
+    mShouldRunEventLoop.store(true, std::memory_order_relaxed);
 
 exit:
     return err;
@@ -196,7 +196,7 @@ void GenericPlatformManagerImpl_POSIX<ImplClass>::_RunEventLoop(void)
     {
         SysUpdate();
         SysProcess();
-    } while (mShouldRunEventLoop);
+    } while (mShouldRunEventLoop.load(std::memory_order_relaxed));
 
     Impl()->UnlockChipStack();
 
@@ -232,7 +232,7 @@ template <class ImplClass>
 CHIP_ERROR GenericPlatformManagerImpl_POSIX<ImplClass>::_Shutdown(void)
 {
     int err;
-    mShouldRunEventLoop = false;
+    mShouldRunEventLoop.store(false, std::memory_order_relaxed);;
     err                 = pthread_join(mChipTask, NULL);
     SuccessOrExit(err);