man/unmap, preventing getMat/getUMat from temp object, fix thread-unsafe code in `UMat::getMat()`

modules/core/include/opencv2/core/mat.hpp

@@ -496,6 +496,7 @@ struct CV_EXPORTS UMatData
     void* handle;
     void* userdata;
     int allocatorFlags_;
+    int mapcount;
 };
 
 

modules/core/src/ocl.cpp

@@ -4514,6 +4514,7 @@ public:
         CV_Assert(u->refcount >= 0);
 
         CV_Assert(u->handle != 0 && u->urefcount == 0);
+        CV_Assert(u->mapcount == 0);
         if(u->tempUMat())
         {
             CV_Assert(u->origdata);
@@ -4572,12 +4573,16 @@ public:
                     else
                     {
                         cl_int retval = 0;
-                        void* data = clEnqueueMapBuffer(q, (cl_mem)u->handle, CL_TRUE,
-                                                        (CL_MAP_READ | CL_MAP_WRITE),
-                                                        0, u->size, 0, 0, 0, &retval);
-                        CV_OclDbgAssert(retval == CL_SUCCESS);
-                        CV_OclDbgAssert(clEnqueueUnmapMemObject(q, (cl_mem)u->handle, data, 0, 0, 0) == CL_SUCCESS);
-                        CV_OclDbgAssert(clFinish(q) == CL_SUCCESS);
+                        if (u->tempUMat())
+                        {
+                            CV_Assert(u->mapcount == 0);
+                            void* data = clEnqueueMapBuffer(q, (cl_mem)u->handle, CL_TRUE,
+                                (CL_MAP_READ | CL_MAP_WRITE),
+                                0, u->size, 0, 0, 0, &retval);
+                            CV_OclDbgAssert(retval == CL_SUCCESS);
+                            CV_OclDbgAssert(clEnqueueUnmapMemObject(q, (cl_mem)u->handle, data, 0, 0, 0) == CL_SUCCESS);
+                            CV_OclDbgAssert(clFinish(q) == CL_SUCCESS);
+                        }
                     }
                 }
                 u->markHostCopyObsolete(false);
@@ -4715,11 +4720,16 @@ public:
                 }
 #endif
 
-                cl_int retval = 0;
-                u->data = (uchar*)clEnqueueMapBuffer(q, (cl_mem)u->handle, CL_TRUE,
-                                                     (CL_MAP_READ | CL_MAP_WRITE),
-                                                     0, u->size, 0, 0, 0, &retval);
-                if(u->data && retval == CL_SUCCESS)
+                cl_int retval = CL_SUCCESS;
+                if (!u->deviceMemMapped())
+                {
+                    CV_Assert(u->refcount == 1);
+                    CV_Assert(u->mapcount++ == 0);
+                    u->data = (uchar*)clEnqueueMapBuffer(q, (cl_mem)u->handle, CL_TRUE,
+                                                         (CL_MAP_READ | CL_MAP_WRITE),
+                                                         0, u->size, 0, 0, 0, &retval);
+                }
+                if (u->data && retval == CL_SUCCESS)
                 {
                     u->markHostCopyObsolete(false);
                     u->markDeviceMemMapped(true);
@@ -4765,7 +4775,6 @@ public:
         if( !u->copyOnMap() && u->deviceMemMapped() )
         {
             CV_Assert(u->data != NULL);
-            u->markDeviceMemMapped(false);
 #ifdef HAVE_OPENCL_SVM
             if ((u->allocatorFlags_ & svm::OPENCL_SVM_BUFFER_MASK) != 0)
             {
@@ -4792,16 +4801,21 @@ public:
                 return;
             }
 #endif
-            CV_Assert( (retval = clEnqueueUnmapMemObject(q,
-                                (cl_mem)u->handle, u->data, 0, 0, 0)) == CL_SUCCESS );
-            if (Device::getDefault().isAMD())
-            {
-                // required for multithreaded applications (see stitching test)
-                CV_OclDbgAssert(clFinish(q) == CL_SUCCESS);
-            }
-
             if (u->refcount == 0)
+            {
+                CV_Assert(u->mapcount-- == 1);
+                CV_Assert((retval = clEnqueueUnmapMemObject(q,
+                          (cl_mem)u->handle, u->data, 0, 0, 0)) == CL_SUCCESS);
+                if (Device::getDefault().isAMD())
+                {
+                    // required for multithreaded applications (see stitching test)
+                    CV_OclDbgAssert(clFinish(q) == CL_SUCCESS);
+                }
+                u->markDeviceMemMapped(false);
                 u->data = 0;
+                u->markDeviceCopyObsolete(false);
+                u->markHostCopyObsolete(true);
+            }
         }
         else if( u->copyOnMap() && u->deviceCopyObsolete() )
         {
@@ -4811,9 +4825,9 @@ public:
 #endif
             CV_Assert( (retval = clEnqueueWriteBuffer(q, (cl_mem)u->handle, CL_TRUE, 0,
                                 u->size, alignedPtr.getAlignedPtr(), 0, 0, 0)) == CL_SUCCESS );
+            u->markDeviceCopyObsolete(false);
+            u->markHostCopyObsolete(true);
         }
-        u->markDeviceCopyObsolete(false);
-        u->markHostCopyObsolete(true);
     }
 
     bool checkContinuous(int dims, const size_t sz[],

modules/core/src/umatrix.cpp

@@ -60,7 +60,7 @@ static Mutex umatLocks[UMAT_NLOCKS];
 UMatData::UMatData(const MatAllocator* allocator)
 {
     prevAllocator = currAllocator = allocator;
-    urefcount = refcount = 0;
+    urefcount = refcount = mapcount = 0;
     data = origdata = 0;
     size = 0;
     flags = 0;
@@ -73,6 +73,7 @@ UMatData::~UMatData()
 {
     prevAllocator = currAllocator = 0;
     urefcount = refcount = 0;
+    CV_Assert(mapcount == 0);
     data = origdata = 0;
     size = 0;
     flags = 0;
@@ -221,6 +222,7 @@ UMat Mat::getUMat(int accessFlags, UMatUsageFlags usageFlags) const
     UMat hdr;
     if(!data)
         return hdr;
+    CV_Assert((!u || u->mapcount==0) && "Don't get UMat from temp-Mat!");
     accessFlags |= ACCESS_RW;
     UMatData* temp_u = u;
     if(!temp_u)
@@ -637,18 +639,28 @@ Mat UMat::getMat(int accessFlags) const
 {
     if(!u)
         return Mat();
+    CV_Assert(!u->tempUMat() && "Don't get Mat from temp UMat! Use copyTo().");
     // TODO Support ACCESS_READ (ACCESS_WRITE) without unnecessary data transfers
     accessFlags |= ACCESS_RW;
-    u->currAllocator->map(u, accessFlags);
-    CV_Assert(u->data != 0);
-    Mat hdr(dims, size.p, type(), u->data + offset, step.p);
-    hdr.flags = flags;
-    hdr.u = u;
-    hdr.datastart = u->data;
-    hdr.data = u->data + offset;
-    hdr.datalimit = hdr.dataend = u->data + u->size;
-    CV_XADD(&hdr.u->refcount, 1);
-    return hdr;
+    UMatDataAutoLock autolock(u);
+    if(CV_XADD(&u->refcount, 1) == 0)
+        u->currAllocator->map(u, accessFlags);
+    if (u->data != 0)
+    {
+        Mat hdr(dims, size.p, type(), u->data + offset, step.p);
+        hdr.flags = flags;
+        hdr.u = u;
+        hdr.datastart = u->data;
+        hdr.data = u->data + offset;
+        hdr.datalimit = hdr.dataend = u->data + u->size;
+        return hdr;
+    }
+    else
+    {
+        CV_XADD(&u->refcount, -1);
+        CV_Assert(u->data != 0 && "Error mapping of UMat to host memory.");
+        return Mat();
+    }
 }
 
 void* UMat::handle(int accessFlags) const

modules/core/test/test_umat.cpp

@@ -243,9 +243,11 @@ TEST_P(UMatBasicTests, GetUMat)
         EXPECT_MAT_NEAR(ub, ua, 0);
     }
     {
-        Mat b;
-        b = a.getUMat(ACCESS_RW).getMat(ACCESS_RW);
-        EXPECT_MAT_NEAR(b, a, 0);
+        UMat u = a.getUMat(ACCESS_RW);
+        {
+            Mat b = u.getMat(ACCESS_RW);
+            EXPECT_MAT_NEAR(b, a, 0);
+        }
     }
     {
         Mat b;
@@ -253,9 +255,11 @@ TEST_P(UMatBasicTests, GetUMat)
         EXPECT_MAT_NEAR(b, a, 0);
     }
     {
-        UMat ub;
-        ub = ua.getMat(ACCESS_RW).getUMat(ACCESS_RW);
-        EXPECT_MAT_NEAR(ub, ua, 0);
+        Mat m = ua.getMat(ACCESS_RW);
+        {
+            UMat ub = m.getUMat(ACCESS_RW);
+            EXPECT_MAT_NEAR(ub, ua, 0);
+        }
     }
 }
 
@@ -1268,5 +1272,17 @@ TEST(UMat, DISABLED_Test_same_behaviour_write_and_write)
     ASSERT_TRUE(exceptionDetected); // data race
 }
 
+TEST(UMat, mat_umat_sync)
+{
+    UMat u(10, 10, CV_8UC1, Scalar(1));
+    {
+        Mat m = u.getMat(ACCESS_RW).reshape(1);
+        m.setTo(Scalar(255));
+    }
+
+    UMat uDiff;
+    compare(u, 255, uDiff, CMP_NE);
+    ASSERT_EQ(0, countNonZero(uDiff));
+}
 
 } } // namespace cvtest::ocl