nvdec: Do not access nvdec object from destroy function of qdata

The destroy callback can be called just before the fìnalization of
GstMiniObject. So the nvdec object might be destroyed already.
Instead, store the GstCudaContext with increased ref to safely
unregister the CUDA resource.

diff --git a/sys/nvcodec/gstnvdec.c b/sys/nvcodec/gstnvdec.c
index 6ad9277..2819fff 100644 (file)
--- a/sys/nvcodec/gstnvdec.c
+++ b/sys/nvcodec/gstnvdec.c
@@ -51,34 +51,50 @@ gst_nvdec_copy_device_to_system (GstNvDec * nvdec,
 typedef struct _GstNvDecCudaGraphicsResourceInfo
 {
   GstGLContext *gl_context;
-  GstNvDec *nvdec;
+  GstCudaContext *cuda_context;
   CUgraphicsResource resource;
 } GstNvDecCudaGraphicsResourceInfo;
 
+typedef struct _GstNvDecRegisterResourceData
+{
+  GstMemory *mem;
+  GstNvDecCudaGraphicsResourceInfo *info;
+  GstNvDec *nvdec;
+  gboolean ret;
+} GstNvDecRegisterResourceData;
+
 static void
-register_cuda_resource (GstGLContext * context, gpointer * args)
+register_cuda_resource (GstGLContext * context,
+    GstNvDecRegisterResourceData * data)
 {
-  GstMemory *mem = GST_MEMORY_CAST (args[0]);
-  GstNvDecCudaGraphicsResourceInfo *cgr_info =
-      (GstNvDecCudaGraphicsResourceInfo *) args[1];
+  GstMemory *mem = data->mem;
+  GstNvDecCudaGraphicsResourceInfo *cgr_info = data->info;
+  GstNvDec *nvdec = data->nvdec;
   GstMapInfo map_info = GST_MAP_INFO_INIT;
   guint texture_id;
-  GstNvDec *nvdec = cgr_info->nvdec;
 
-  if (!gst_cuda_context_push (nvdec->cuda_ctx))
-    GST_WARNING_OBJECT (nvdec, "failed to lock CUDA context");
+  data->ret = FALSE;
+
+  if (!gst_cuda_context_push (nvdec->cuda_ctx)) {
+    GST_WARNING_OBJECT (nvdec, "failed to push CUDA context");
+    return;
+  }
 
   if (gst_memory_map (mem, &map_info, GST_MAP_READ | GST_MAP_GL)) {
     texture_id = *(guint *) map_info.data;
 
     if (!gst_cuda_result (CuGraphicsGLRegisterImage (&cgr_info->resource,
                 texture_id, GL_TEXTURE_2D,
-                CU_GRAPHICS_REGISTER_FLAGS_WRITE_DISCARD)))
+                CU_GRAPHICS_REGISTER_FLAGS_WRITE_DISCARD))) {
       GST_WARNING_OBJECT (nvdec, "failed to register texture with CUDA");
+    } else {
+      data->ret = TRUE;
+    }
 
     gst_memory_unmap (mem, &map_info);
-  } else
+  } else {
     GST_WARNING_OBJECT (nvdec, "failed to map memory");
+  }
 
   if (!gst_cuda_context_pop (NULL))
     GST_WARNING_OBJECT (nvdec, "failed to unlock CUDA context");
@@ -88,17 +104,19 @@ static void
 unregister_cuda_resource (GstGLContext * context,
     GstNvDecCudaGraphicsResourceInfo * cgr_info)
 {
-  GstNvDec *nvdec = cgr_info->nvdec;
+  GstCudaContext *cuda_context = cgr_info->cuda_context;
 
-  if (!gst_cuda_context_push (nvdec->cuda_ctx))
-    GST_WARNING_OBJECT (nvdec, "failed to lock CUDA context");
+  if (!gst_cuda_context_push (cuda_context)) {
+    GST_WARNING_OBJECT (context, "failed to push CUDA context");
+    return;
+  }
 
-  if (!gst_cuda_result (CuGraphicsUnregisterResource ((const CUgraphicsResource)
-              cgr_info->resource)))
-    GST_WARNING_OBJECT (nvdec, "failed to unregister resource");
+  if (!gst_cuda_result (CuGraphicsUnregisterResource (cgr_info->resource)))
+    GST_WARNING_OBJECT (cuda_context, "failed to unregister resource");
 
-  if (!gst_cuda_context_pop (NULL))
-    GST_WARNING_OBJECT (nvdec, "failed to unlock CUDA context");
+  if (!gst_cuda_context_pop (NULL)) {
+    GST_WARNING_OBJECT (cuda_context, "failed to pop CUDA context");
+  }
 }
 
 static void
@@ -107,7 +125,8 @@ free_cgr_info (GstNvDecCudaGraphicsResourceInfo * cgr_info)
   gst_gl_context_thread_add (cgr_info->gl_context,
       (GstGLContextThreadFunc) unregister_cuda_resource, cgr_info);
   gst_object_unref (cgr_info->gl_context);
-  g_slice_free (GstNvDecCudaGraphicsResourceInfo, cgr_info);
+  gst_object_unref (cgr_info->cuda_context);
+  g_free (cgr_info);
 }
 
 static CUgraphicsResource
@@ -115,10 +134,10 @@ ensure_cuda_graphics_resource (GstMemory * mem, GstNvDec * nvdec)
 {
   static GQuark quark = 0;
   GstNvDecCudaGraphicsResourceInfo *cgr_info;
-  gpointer args[2];
+  GstNvDecRegisterResourceData data;
 
   if (!gst_is_gl_base_memory (mem)) {
-    GST_WARNING ("memory is not GL base memory");
+    GST_WARNING_OBJECT (nvdec, "memory is not GL base memory");
     return NULL;
   }
 
@@ -127,14 +146,24 @@ ensure_cuda_graphics_resource (GstMemory * mem, GstNvDec * nvdec)
 
   cgr_info = gst_mini_object_get_qdata (GST_MINI_OBJECT (mem), quark);
   if (!cgr_info) {
-    cgr_info = g_slice_new (GstNvDecCudaGraphicsResourceInfo);
+    cgr_info = g_new0 (GstNvDecCudaGraphicsResourceInfo, 1);
     cgr_info->gl_context =
         gst_object_ref (GST_GL_BASE_MEMORY_CAST (mem)->context);
-    cgr_info->nvdec = nvdec;
-    args[0] = mem;
-    args[1] = cgr_info;
+    cgr_info->cuda_context = gst_object_ref (nvdec->cuda_ctx);
+    data.mem = mem;
+    data.info = cgr_info;
+    data.nvdec = nvdec;
     gst_gl_context_thread_add (cgr_info->gl_context,
-        (GstGLContextThreadFunc) register_cuda_resource, args);
+        (GstGLContextThreadFunc) register_cuda_resource, &data);
+    if (!data.ret) {
+      GST_WARNING_OBJECT (nvdec, "could not register resource");
+      gst_object_unref (cgr_info->gl_context);
+      gst_object_unref (cgr_info->cuda_context);
+      g_free (cgr_info);
+
+      return NULL;
+    }
+
     gst_mini_object_set_qdata (GST_MINI_OBJECT (mem), quark, cgr_info,
         (GDestroyNotify) free_cgr_info);
   }
@@ -847,10 +876,14 @@ gst_nvdec_copy_device_to_gl (GstNvDec * nvdec,
   data.resources = g_newa (CUgraphicsResource, data.num_resources);
 
   for (i = 0; i < data.num_resources; i++) {
-    mem = gst_buffer_get_memory (output_buffer, i);
+    mem = gst_buffer_peek_memory (output_buffer, i);
     data.resources[i] = ensure_cuda_graphics_resource (mem, nvdec);
+    if (!data.resources[i]) {
+      GST_WARNING_OBJECT (nvdec, "could not register %dth memory", i);
+      return FALSE;
+    }
+
     GST_MINI_OBJECT_FLAG_SET (mem, GST_GL_BASE_MEMORY_TRANSFER_NEED_DOWNLOAD);
-    gst_memory_unref (mem);
   }
 
   gst_gl_context_thread_add (nvdec->gl_context,