Make it clear the finalizers shouldn't be called directly.

src/array.jl

@@ -35,7 +35,7 @@ CuArray
  devptr = Mem.alloc(T, len)
 
  obj = new{T,N}(devptr, shape)
- finalizer(obj, free!)
+ finalizer(obj, _free!)
  return obj
  end
  function (::Type{CuArray{T,N}}){T,N}(shape::NTuple{N,Int}, devptr::DevicePtr{T})
@@ -52,7 +52,8 @@ end
 (::Type{CuArray{T,N}}){T,N,I<:Integer}(dims::NTuple{N,I}) = CuArray{T,N}(Int.(dims))
 (::Type{CuArray{T,N}}){T,N,I<:Integer}(dims::Vararg{I,N}) = CuArray{T,N}(Int.(dims))
 
-function free!(a::CuArray)
+"""Don't call this method directly, use `finalize(obj)` instead."""
+function _free!(a::CuArray)
  if isvalid(a.devptr.ctx)
  @trace("Finalizing CuArray at $(Base.pointer_from_objref(a))")
  Mem.free(a.devptr)

src/context.jl

@@ -46,7 +46,7 @@ type CuContext
  # this prevents contexts from getting collected, requiring the user to destroy it.
  ctx = get!(context_instances, handle) do
  obj = new(handle, owned, true)
- finalizer(obj, destroy!)
+ finalizer(obj, _destroy!)
  return obj
  end
 
@@ -71,7 +71,8 @@ function invalidate!(ctx::CuContext)
  nothing
 end
 
-function destroy!(ctx::CuContext)
+"""Don't call this method directly, use `finalize(obj)` instead."""
+function _destroy!(ctx::CuContext)
  @trace("Finalizing CuContext at $(Base.pointer_from_objref(ctx))")
  if !ctx.owned
  @trace("Not destroying context $ctx because we don't own it")

src/events.jl

@@ -15,12 +15,13 @@ type CuEvent
 
  ctx = CuCurrentContext()
  obj = new(handle_ref[], ctx)
- finalizer(obj, destroy!)
+ finalizer(obj, _destroy!)
  return obj
  end 
 end
 
-function destroy!(e::CuEvent)
+"""Don't call this method directly, use `finalize(obj)` instead."""
+function _destroy!(e::CuEvent)
  if isvalid(e.ctx)
  @trace("Finalizing CuEvent at $(Base.pointer_from_objref(e))")
  @apicall(:cuEventDestroy, (CuEvent_t,), e)

src/module.jl

@@ -49,12 +49,13 @@ type CuModule
 
  ctx = CuCurrentContext()
  obj = new(handle_ref[], ctx)
- finalizer(obj, unload!)
+ finalizer(obj, _unload!)
  return obj
  end
 end
 
-function unload!(mod::CuModule)
+"""Don't call this method directly, use `finalize(obj)` instead."""
+function _unload!(mod::CuModule)
  if isvalid(mod.ctx)
  @trace("Finalizing CuModule at $(Base.pointer_from_objref(mod)))")
  @apicall(:cuModuleUnload, (CuModule_t,), mod)

src/module/linker.jl

@@ -34,12 +34,13 @@ type CuLink
 
  ctx = CuCurrentContext()
  obj = new(handle_ref[], ctx, options, optionKeys, optionVals)
- finalizer(obj, destroy!)
+ finalizer(obj, _destroy!)
  return obj
  end
 end
 
-function destroy!(link::CuLink)
+"""Don't call this method directly, use `finalize(obj)` instead."""
+function _destroy!(link::CuLink)
  if isvalid(link.ctx)
  @trace("Finalizing CuLink at $(Base.pointer_from_objref(link))")
  @apicall(:cuLinkDestroy, (CuLinkState_t,), link)

src/stream.jl

@@ -23,11 +23,12 @@ function CuStream(flags::Integer=0)
 
  ctx = CuCurrentContext()
  obj = CuStream(handle_ref[], ctx)
- finalizer(obj, destroy!)
+ finalizer(obj, _destroy!)
  return obj
 end
 
-function destroy!(s::CuStream)
+"""Don't call this method directly, use `finalize(obj)` instead."""
+function _destroy!(s::CuStream)
  if isvalid(s.ctx)
  @trace("Finalizing CuStream at $(Base.pointer_from_objref(s))")
  @apicall(:cuStreamDestroy, (CuModule_t,), s)