add a warning if objects are finalized without being destroyed

src/AMGX.jl

@@ -116,12 +116,8 @@ end
 inc_refcount!(x::AMGXObject) = x.ref_count[] += 1
 dec_refcount!(x::AMGXObject) = x.ref_count[] -= 1
 
-function with(f, object::AMGXObject)
-    try
-        f(object)
-    finally
-        close(object)
-    end
+function warn_not_destroyed_on_finalize(x::AMGXObject)
+    !(x.handle == C_NULL) && @async @warn("AMGX: likely memory leak: a `$(typeof(x))` was finalized without having been `close`d")
 end
 
 

src/Config.jl

@@ -1,6 +1,11 @@
 Base.@kwdef mutable struct Config <: AMGXObject
-    handle::API.AMGX_config_handle = C_NULL
+    handle::API.AMGX_config_handle = API.AMGX_config_handle(C_NULL)
     ref_count::Threads.Atomic{Int} = Threads.Atomic{Int}(0)
+    function Config(handle::API.AMGX_config_handle, ref_count::Threads.Atomic{Int})
+        config = new(handle, ref_count)
+        finalizer(warn_not_destroyed_on_finalize, config)
+        return config
+    end
 end
 get_api_destroy_call(::Type{Config}) = API.AMGX_config_destroy
 dec_refcount_parents(config::Config) = nothing

src/Matrix.jl

@@ -1,9 +1,15 @@
 # TODO: Add support for uploading a CuSparseMatrixBSR
 
 Base.@kwdef mutable struct AMGXMatrix <: AMGXObject
-    handle::API.AMGX_matrix_handle = C_NULL
+    handle::API.AMGX_matrix_handle = API.AMGX_matrix_handle(C_NULL)
     mode::Union{Mode, Nothing} = nothing
     resources::Union{Resources, Nothing} = nothing
+    function AMGXMatrix(handle::API.AMGX_matrix_handle, mode::Union{Mode, Nothing},
+                       resources::Union{Resources, Nothing})
+        m = new(handle, mode, resources)
+        finalizer(warn_not_destroyed_on_finalize, m)
+        return m
+    end
 end
 get_api_destroy_call(::Type{AMGXMatrix}) = API.AMGX_matrix_destroy
 function dec_refcount_parents(m::AMGXMatrix)

src/Resources.jl

@@ -1,7 +1,13 @@
 Base.@kwdef mutable struct Resources <: AMGXObject
-    handle::API.AMGX_resources_handle = C_NULL
+    handle::API.AMGX_resources_handle = API.AMGX_resources_handle(C_NULL)
     ref_count::Threads.Atomic{Int} = Threads.Atomic{Int}(0)
     cfg::Union{Config, Nothing} = nothing
+    function Resources(handle::API.AMGX_resources_handle, ref_count::Threads.Atomic{Int},
+                       cfg::Union{Config, Nothing})
+        resources = new(handle, ref_count, cfg)
+        finalizer(warn_not_destroyed_on_finalize, resources)
+        return resources
+    end
 end
 get_api_destroy_call(::Type{Resources}) = API.AMGX_resources_destroy
 function dec_refcount_parents(resources::Resources)

src/Solver.jl

@@ -1,8 +1,14 @@
 Base.@kwdef mutable struct Solver <: AMGXObject
-    handle::API.AMGX_solver_handle = C_NULL
+    handle::API.AMGX_solver_handle = API.AMGX_solver_handle(C_NULL)
     resources::Union{Resources, Nothing} = nothing
     config::Union{Config, Nothing} = nothing
     bound_matrix::Union{AMGXMatrix, Nothing} = nothing
+    function Solver(handle::API.AMGX_solver_handle, resources::Union{Resources, Nothing},
+                    config::Union{Config, Nothing}, bound_matrix::Union{AMGXMatrix, Nothing})
+        solver = new(handle, resources, config, bound_matrix)
+        finalizer(warn_not_destroyed_on_finalize, solver)
+        return solver
+    end
 end
 function dec_refcount_parents(solver::Solver)
     dec_refcount!(solver.resources)

src/Vector.jl

@@ -1,7 +1,13 @@
 Base.@kwdef mutable struct AMGXVector <: AMGXObject
-    handle::API.AMGX_vector_handle = C_NULL
+    handle::API.AMGX_vector_handle = API.AMGX_vector_handle(C_NULL)
     mode::Union{Mode, Nothing} = nothing
     resources::Union{Resources, Nothing} = nothing
+    function AMGXVector(handle::API.AMGX_vector_handle, mode::Union{Mode, Nothing},
+                       resources::Union{Resources, Nothing})
+        v = new(handle, mode, resources)
+        finalizer(warn_not_destroyed_on_finalize, v)
+        return v
+    end
 end
 get_api_destroy_call(::Type{AMGXVector}) = API.AMGX_vector_destroy
 function dec_refcount_parents(v::AMGXVector)