fix finalizer problems

Author: SimonDanisch

src/array.jl

@@ -42,11 +42,14 @@ similar(::Type{<: CLArray}, ::Type{T}, size::Base.Dims{N}) where {T, N} = CLArra
 function unsafe_free!(a::CLArray)
     ptr = pointer(a)
     ctxid = context(ptr).id
-    if cl.is_ctx_id_alive(ctxid) && ctxid != C_NULL
-        Mem.free(ptr)
+    err = Mem.free(ptr)
+    if err == cl.CL_SUCCESS
         Mem.current_allocated_mem[] -= sizeof(eltype(a)) * length(a)
+    elseif err == cl.CL_INVALID_CONTEXT
+        # ignore (log it!)
+    else
+        cl.@check err
     end
-    #TODO logging that we don't free since context is not alive
 end
 
 function unsafe_reinterpret(::Type{T}, A::CLArray{ET}, size::NTuple{N, Integer}) where {T, ET, N}

src/memory.jl

@@ -24,17 +24,16 @@ function convert{T}(::Type{OwnedPtr{T}}, p::OwnedPtr)
 end
 
 function retain(p::OwnedPtr)
-    cl.@check cl.api.clRetainMemObject(p)
-    return
+    err = cl.api.clRetainMemObject(p)
+    return err
 end
 
 
 
 
 const current_allocated_mem = Ref(0)
 function free(p::OwnedPtr)
-    cl.@check_release cl.api.clReleaseMemObject(p)
-    return
+    cl.api.clReleaseMemObject(p)
 end
 
 function pressure_gc!(device, bytes)