Update matrix.cpp

grundman · alalek · commit cf4e9e5ce2d0 · 2017-05-24T13:55:18.000+03:00
Fix race condition in getDefaultAllocator and setDefaultAllocator interaction / not threadsafe currently
diff --git a/modules/core/src/matrix.cpp b/modules/core/src/matrix.cpp
@@ -222,15 +222,19 @@ class StdMatAllocator : public MatAllocator
 };
 namespace
 {
-    MatAllocator* g_matAllocator = NULL;
+    MatAllocator* volatile g_matAllocator = NULL;
 }
 
 
 MatAllocator* Mat::getDefaultAllocator()
 {
     if (g_matAllocator == NULL)
     {
-        g_matAllocator = getStdAllocator();
+        cv::AutoLock lock(cv::getInitializationMutex());
+        if (g_matAllocator == NULL)
+        {
+            g_matAllocator = getStdAllocator();
+        }
     }
     return g_matAllocator;
 }

Original file line number	Diff line number	Diff line change
`@@ -222,15 +222,19 @@ class StdMatAllocator : public MatAllocator`
`222`	`222`	`};`
`223`	`223`	`namespace`
`224`	`224`	`{`
`225`		`- MatAllocator* g_matAllocator = NULL;`
	`225`	`+ MatAllocator* volatile g_matAllocator = NULL;`
`226`	`226`	`}`
`227`	`227`
`228`	`228`
`229`	`229`	`MatAllocator* Mat::getDefaultAllocator()`
`230`	`230`	`{`
`231`	`231`	`if (g_matAllocator == NULL)`
`232`	`232`	`{`
`233`		`- g_matAllocator = getStdAllocator();`
	`233`	`+ cv::AutoLock lock(cv::getInitializationMutex());`
	`234`	`+ if (g_matAllocator == NULL)`
	`235`	`+ {`
	`236`	`+ g_matAllocator = getStdAllocator();`
	`237`	`+ }`
`234`	`238`	`}`
`235`	`239`	`return g_matAllocator;`
`236`	`240`	`}`