From 212815a10d1a8d9e14cd2a6372a2d4be0fd7769f Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.a.alekhin@gmail.com>
Date: Fri, 15 Jan 2021 17:58:57 +0000
Subject: [PATCH] core(ocl): fix lifetime handling of Image kernel args

---
 modules/core/src/ocl.cpp | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/modules/core/src/ocl.cpp b/modules/core/src/ocl.cpp
index bfdd3bba6d..54192efd3a 100644
--- a/modules/core/src/ocl.cpp
+++ b/modules/core/src/ocl.cpp
@@ -2802,16 +2802,24 @@ struct Kernel::Impl
             haveTempSrcUMats = true;  // UMat is created on RAW memory (without proper lifetime management, even from Mat)
     }
 
-    void addImage(const Image2D& image)
+    /// Preserve image lifetime (while it is specified as Kernel argument)
+    void registerImageArgument(int arg, const Image2D& image)
     {
-        images.push_back(image);
+        CV_CheckGE(arg, 0, "");
+        CV_CheckLT(arg, (int)MAX_ARRS, "");
+        if (arg < (int)shadow_images.size() && shadow_images[arg].ptr() != image.ptr())  // TODO future: replace ptr => impl (more strong check)
+        {
+            CV_Check(arg, !isInProgress, "ocl::Kernel: clearing of pending Image2D arguments is not allowed");
+        }
+        shadow_images.reserve(MAX_ARRS);
+        shadow_images.resize(std::max(shadow_images.size(), (size_t)arg + 1));
+        shadow_images[arg] = image;
     }
 
     void finit(cl_event e)
     {
         CV_UNUSED(e);
         cleanupUMats();
-        images.clear();
         isInProgress = false;
         release();
     }
@@ -2836,7 +2844,7 @@ struct Kernel::Impl
     bool isInProgress;
     bool isAsyncRun;  // true if kernel was scheduled in async mode
     int nu;
-    std::list<Image2D> images;
+    std::vector<Image2D> shadow_images;
     bool haveTempDstUMats;
     bool haveTempSrcUMats;
 };
@@ -2978,9 +2986,11 @@ int Kernel::set(int i, const void* value, size_t sz)
 
 int Kernel::set(int i, const Image2D& image2D)
 {
-    p->addImage(image2D);
     cl_mem h = (cl_mem)image2D.ptr();
-    return set(i, &h, sizeof(h));
+    int res = set(i, &h, sizeof(h));
+    if (res >= 0)
+        p->registerImageArgument(i, image2D);
+    return res;
 }
 
 int Kernel::set(int i, const UMat& m)