Error on invalid LAMMPS instance (#62)

* Error on invalid LAMMPS instance * fixup! * move NullPointer check to unsafe_convert * move argument checking to cconvert Co-authored-by: Valentin Churavy <[email protected]> * inline error handling in constructor --------- Co-authored-by: Valentin Churavy <[email protected]>
cesmix-mit · Aug 7, 2024 · c838e7e · c838e7e
1 parent e92fbc8
commit c838e7e
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Showing 2 changed files with 41 additions and 7 deletions.
diff --git a/src/LAMMPS.jl b/src/LAMMPS.jl
@@ -4,7 +4,7 @@ include("api.jl")
 
 export LMP, command, get_natoms, extract_atom, extract_compute, extract_global,
        extract_setting, gather, gather_bonds, gather_angles, gather_dihedrals, gather_impropers,
-       scatter!, group_to_atom_ids, get_category_ids, extract_variable,
+       scatter!, group_to_atom_ids, get_category_ids, extract_variable, LAMMPSError,
 
        # _LMP_DATATYPE
        LAMMPS_NONE,
@@ -140,11 +140,24 @@ mutable struct LMP
             end
         end
 
+        if API.lammps_has_error(handle) != 0
+            buf = zeros(UInt8, 100)
+            API.lammps_get_last_error_message(handle, buf, length(buf))
+            msg = replace(rstrip(String(buf), '\0'), "ERROR: " => "")
+            throw(LAMMPSError(msg))
+        end
+
         this = new(handle)
         finalizer(close!, this)
         return this
     end
 end
+
+function Base.cconvert(::Type{Ptr{Cvoid}}, lmp::LMP)    
+    lmp.handle == C_NULL && error("The LMP object doesn't point to a valid LAMMPS instance! "
+            * "This is usually caused by calling `LAMMPS.close!` or through serialization and deserialization.")
+    return lmp
+end
 Base.unsafe_convert(::Type{Ptr{Cvoid}}, lmp::LMP) = lmp.handle
 
 """
@@ -174,17 +187,29 @@ function version(lmp::LMP)
     API.lammps_version(lmp)
 end
 
+struct LAMMPSError <: Exception
+    msg::String
+end
+
+function LAMMPSError(lmp::LMP)
+    buf = zeros(UInt8, 100)
+    API.lammps_get_last_error_message(lmp, buf, length(buf))
+    msg = replace(rstrip(String(buf), '\0'), "ERROR: " => "")
+    LAMMPSError(msg)
+end
+
+function Base.showerror(io::IO, err::LAMMPSError)
+    print(io, "LAMMPSError: ", err.msg)
+end
+
 function check(lmp::LMP)
     err = API.lammps_has_error(lmp)
+    # TODO: Check err == 1 or err == 2 (MPI)
     if err != 0
-        # TODO: Check err == 1 or err == 2 (MPI)
-        buf = zeros(UInt8, 100)
-        API.lammps_get_last_error_message(lmp, buf, length(buf))
-        error(rstrip(String(buf), '\0'))
+        throw(LAMMPSError(lmp))
     end
 end
 
-
 """
     command(lmp::LMP, cmd::Union{String, Array{String}})
 

diff --git a/test/runtests.jl b/test/runtests.jl
@@ -12,9 +12,18 @@ LMP(["-screen", "none"]) do lmp
     @test LAMMPS.version(lmp) >= 0
     command(lmp, "clear")
 
-    @test_throws ErrorException command(lmp, "nonsense")
+    @test_throws LAMMPSError command(lmp, "nonsense")
+
+    LAMMPS.close!(lmp)
+
+    expected_error = ErrorException("The LMP object doesn't point to a valid LAMMPS instance! "
+        * "This is usually caused by calling `LAMMPS.close!` or through serialization and deserialization.")
+
+    @test_throws expected_error command(lmp, "")
 end
 
+@test_throws LAMMPSError LMP(["-nonesense"])
+
 @testset "Extract Setting/Global" begin
     LMP(["-screen", "none"]) do lmp
         command(lmp, """