Make setting preferences more convenient

LocalPreferences.toml

@@ -0,0 +1,9 @@
+[MPIPreferences]
+__clear__ = ["preloads_env_switch"]
+_format = "1.0"
+abi = "OpenMPI"
+binary = "system"
+cclibs = []
+libmpi = "libmpi"
+mpiexec = "mpiexec"
+preloads = []

Project.toml

@@ -5,6 +5,7 @@ version = "0.4.2"
 
 [deps]
 CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"
+Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
 MPI = "da04e1cc-30fd-572f-bb4f-1f8673147195"
 MPIPreferences = "3da0fdf6-3ccc-4f1b-acd9-58baa6c99267"
 Preferences = "21216c6a-2e73-6563-6e65-726566657250"

README.md

@@ -67,18 +67,7 @@ To enable this, you first need to obtain a local binary installation of
 implementation used to build your local installation of
 [`t8code`](https://github.com/DLR-AMR/t8code), see
 [the documentation of MPI.jl](https://juliaparallel.org/MPI.jl/stable/configuration/).
-At the time of writing, this can be done via
-
-```julia
-julia> using MPIPreferences
-
-julia> MPIPreferences.use_system_binary()
-```
-
-if you use the default system MPI binary installation to build
-[`t8code`](https://github.com/DLR-AMR/t8code).
-
-Next, you need to set up the
+At the time of writing, this can be done by first setting up the
 [Preferences.jl](https://github.com/JuliaPackaging/Preferences.jl)
 setting containing the path to your local build of the shared library of
 [`t8code`](https://github.com/DLR-AMR/t8code).
@@ -98,9 +87,51 @@ julia> set_preferences!(
            UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
            "libsc" => "/path/to/your/libsc.so", force = true)
 ```
+Alternatively, you can use the convenience functions `set_library_t8code!`,
+`set_library_p4est!` and `set_library_sc!` to set the paths:
+
+```julia
+julia> using T8code
+
+julia> T8code.set_library_t8code!("/path/to/your/libt8.so")
+[ Info: Please restart Julia and reload T8code.jl for the library changes to take effect
+
+julia> T8code.set_library_p4est!("/path/to/your/libp4est.so")
+[ Info: Please restart Julia and reload T8code.jl for the library changes to take effect
+
+julia> T8code.set_library_sc!("/path/to/your/libsc.so")
+[ Info: Please restart Julia and reload T8code.jl for the library changes to take effect
+
+```
+
+If all libraries are located in the same directory and have the default names (`libt8.so`,
+`libp4est.so` and `libsc.so` or other file endings according to your system), you can also
+set all three preferences by only specifying the directory:
+
+```julia
+julia> using T8code
+
+julia> T8code.set_libraries_path!("/path/to/your/lib/directory/")
+[ Info: Please restart Julia and reload T8code.jl for the library changes to take effect
+[ Info: Please restart Julia and reload T8code.jl for the library changes to take effect
+[ Info: Please restart Julia and reload T8code.jl for the library changes to take effect
+```
+To delete the preferences again, you can call `T8code.set_libraries_path!`() or for
+each library `T8code.set_library_t8code!()`, `T8code.set_library_p4est!()` and
+`T8code.set_library_sc!()`, respectively.
 
 Note that you should restart your Julia session after changing the preferences.
 
+Next, you need to set up the preferences for MPI, which can be done by
+```julia
+julia> using MPIPreferences
+
+julia> MPIPreferences.use_system_binary()
+```
+
+if you use the default system MPI binary installation to build
+[`p4est`](https://github.com/cburstedde/p4est).
+
 Currently, custom builds of [`t8code`](https://github.com/DLR-AMR/t8code)
 without MPI support are not supported.
 

dev/prologue.jl

@@ -2,20 +2,27 @@ using t8code_jll: t8code_jll
 export t8code_jll
 
 using ..T8code: _PREFERENCE_LIBT8, _PREFERENCE_LIBP4EST, _PREFERENCE_LIBSC
+using MPIPreferences: MPIPreferences
 
-@static if _PREFERENCE_LIBT8 == "t8code_jll"
+@static if _PREFERENCE_LIBT8 == "t8code_jll" && MPIPreferences.binary == "system"
+    @warn "System MPI version detected, but not a system t8code version. To make T8code.jl work, you need to set the preferences."
+elseif _PREFERENCE_LIBP4EST == "t8code_jll"
     const libt8 = t8code_jll.libt8
 else
     const libt8 = _PREFERENCE_LIBT8
 end
 
-@static if _PREFERENCE_LIBP4EST == "t8code_jll"
+@static if _PREFERENCE_LIBP4EST == "t8code_jll" && MPIPreferences.binary == "system"
+    @warn "System MPI version detected, but not a system t8code version. To make T8code.jl work, you need to set the preferences."
+elseif _PREFERENCE_LIBP4EST == "t8code_jll"
     const libp4est = t8code_jll.libp4est
 else
     const libp4est = _PREFERENCE_LIBP4EST
 end
 
-@static if _PREFERENCE_LIBSC == "t8code_jll"
+@static if _PREFERENCE_LIBSC == "t8code_jll" && MPIPreferences.binary == "system"
+    @warn "System MPI version detected, but not a system t8code version. To make T8code.jl work, you need to set the preferences."
+elseif _PREFERENCE_LIBP4EST == "t8code_jll"
     const libsc = t8code_jll.libsc
 else
     const libsc = _PREFERENCE_LIBSC

src/Libt8.jl

@@ -11,20 +11,27 @@ using t8code_jll: t8code_jll
 export t8code_jll
 
 using ..T8code: _PREFERENCE_LIBT8, _PREFERENCE_LIBP4EST, _PREFERENCE_LIBSC
+using MPIPreferences: MPIPreferences
 
-@static if _PREFERENCE_LIBT8 == "t8code_jll"
+@static if _PREFERENCE_LIBT8 == "t8code_jll" && MPIPreferences.binary == "system"
+    @warn "System MPI version detected, but not a system t8code version. To make T8code.jl work, you need to set the preferences."
+elseif _PREFERENCE_LIBP4EST == "t8code_jll"
     const libt8 = t8code_jll.libt8
 else
     const libt8 = _PREFERENCE_LIBT8
 end
 
-@static if _PREFERENCE_LIBP4EST == "t8code_jll"
+@static if _PREFERENCE_LIBP4EST == "t8code_jll" && MPIPreferences.binary == "system"
+    @warn "System MPI version detected, but not a system t8code version. To make T8code.jl work, you need to set the preferences."
+elseif _PREFERENCE_LIBP4EST == "t8code_jll"
     const libp4est = t8code_jll.libp4est
 else
     const libp4est = _PREFERENCE_LIBP4EST
 end
 
-@static if _PREFERENCE_LIBSC == "t8code_jll"
+@static if _PREFERENCE_LIBSC == "t8code_jll" && MPIPreferences.binary == "system"
+    @warn "System MPI version detected, but not a system t8code version. To make T8code.jl work, you need to set the preferences."
+elseif _PREFERENCE_LIBP4EST == "t8code_jll"
     const libsc = t8code_jll.libsc
 else
     const libsc = _PREFERENCE_LIBSC

src/T8code.jl

@@ -1,11 +1,14 @@
 module T8code
 
 using Reexport: @reexport
+using Libdl
 
+using MPIPreferences: MPIPreferences
 # We need to load the preference setting from here and not from `Libt8.jl`
 # since `@load_preference` looks into the module it is running from. Thus, we
 # load all preferences here and access them from the `module Libt8`.
-using Preferences: @load_preference
+using Preferences: @load_preference, set_preferences!, delete_preferences!
+using UUIDs: UUID
 const _PREFERENCE_LIBT8 = @load_preference("libt8", "t8code_jll")
 const _PREFERENCE_LIBP4EST = @load_preference("libp4est", "t8code_jll")
 const _PREFERENCE_LIBSC = @load_preference("libsc", "t8code_jll")
@@ -40,6 +43,118 @@ Returns the version of the underlying `t8code` library (*not* of T8code.jl).
 """
 version() = VersionNumber(T8_VERSION_MAJOR, T8_VERSION_MINOR)
 
+
+const T8CODE_UUID = UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1")
+
+"""
+    T8Code.set_libraries_path!(path = nothing; force = true)
+
+Set the paths of all three libraries `libt8`, `libp4est` and `libsc` by
+specifying the directory `path`, where all of these libraries are located.
+It is assumed that the libraries are called `libt8.so`, `libp4est.so` and
+`libsc.so` (or with the file endings `.dll`, `.dylib` depending on the system).
+"""
+function set_libraries_path!(path = nothing; force = true)
+    if isnothing(path)
+        set_library_t8code!(force = force)
+        set_library_p4est!(force = force)
+        set_library_sc!(force = force)
+    else
+        set_library_t8code!(joinpath(path, "libt8." * Libdl.dlext), force = force)
+        set_library_p4est!(joinpath(path, "libp4est." * Libdl.dlext), force = force)
+        set_library_sc!(joinpath(path, "libsc." * Libdl.dlext), force = force)
+    end
+end
+
+"""
+    T8code.set_library_t8code!(path; force = true)
+
+Set the `path` to a system-provided `t8code` installation. Restart the Julia session
+after executing this function so that the changes take effect. Calling this
+function is necessary when you want to use a system-provided `t8code`
+installation.
+"""
+function set_library_t8code!(path = nothing; force = true)
+    if isnothing(path)
+        delete_preferences!(T8CODE_UUID, "libt8"; force = force)
+    else
+        isfile(path) || throw(ArgumentError("$path is not a file that exists."))
+        set_preferences!(T8CODE_UUID, "libt8" => path, force = force)
+    end
+    @info "Please restart Julia and reload T8code.jl for the library changes to take effect"
+end
+
+"""
+    T8code.path_t8code_library()
+
+Return the path of the `t8code` library that is used, when a system-provided library
+is configured via the preferences. Otherwise `t8code_jll` is returned, which means
+that the default p4est version from t8code_jll.jl is used.
+"""
+path_t8code_library() = _PREFERENCE_LIBT8
+
+"""
+    T8code.set_library_p4est!(path; force = true)
+
+Set the `path` to a system-provided `p4est` installation. Restart the Julia session
+after executing this function so that the changes take effect. Calling this
+function is necessary when you want to use a system-provided `t8code`
+installation.
+"""
+function set_library_p4est!(path = nothing; force = true)
+    if isnothing(path)
+        delete_preferences!(T8CODE_UUID, "libp4est"; force = force)
+    else
+        isfile(path) || throw(ArgumentError("$path is not a file that exists."))
+        set_preferences!(T8CODE_UUID, "libp4est" => path, force = force)
+    end
+    @info "Please restart Julia and reload T8code.jl for the library changes to take effect"
+end
+
+"""
+    T8code.path_p4est_library()
+
+Return the path of the `p4est` library that is used, when a system-provided library
+is configured via the preferences. Otherwise `t8code_jll` is returned, which means
+that the default p4est version from t8code_jll.jl is used.
+"""
+path_p4est_library() = _PREFERENCE_LIBP4EST
+
+"""
+    T8code.set_library_sc!(path; force = true)
+
+Set the `path` to a system-provided `sc` installation. Restart the Julia session
+after executing this function so that the changes take effect. Calling this
+function is necessary, when you want to use a system-provided `t8code`
+installation.
+"""
+function set_library_sc!(path = nothing; force = true)
+    if isnothing(path)
+        delete_preferences!(T8CODE_UUID, "libsc"; force = force)
+    else
+        isfile(path) || throw(ArgumentError("$path is not a file that exists."))
+        set_preferences!(T8CODE_UUID, "libsc" => path, force = force)
+    end
+    @info "Please restart Julia and reload T8code.jl for the library changes to take effect"
+end
+
+"""
+    T8code.path_sc_library()
+
+Return the path of the `sc` library that is used, when a system-provided library
+is configured via the preferences. Otherwise `t8code_jll` is returned, which means
+that the default sc version from t8code_jll.jl is used.
+"""
+path_sc_library() = _PREFERENCE_LIBSC
+
+"""
+    T8code.preferences_set_correctly()
+
+Returns `false` if a system-provided MPI installation is set via the MPIPreferences, but
+not a system-provided `t8code` installation. In this case, T8code.jl is not usable.
+"""
+preferences_set_correctly() = !(_PREFERENCE_LIBT8 == "t8code_jll" && MPIPreferences.binary == "system")
+
 const T8_QUAD_MAXLEVEL = 30
 const T8_HEX_MAXLEVEL = 19
 
@@ -81,4 +196,10 @@ macro t8_replace_callback(callback)
   :( @cfunction($callback, Cvoid, (Ptr{Cvoid}, Ptr{Cvoid}, t8_locidx_t, Ptr{Cvoid}, Cint, Cint, t8_locidx_t, Cint, t8_locidx_t)) )
 end
 
+function __init__()
+    if !preferences_set_correctly()
+       @warn "System MPI version detected, but not a system t8code version. To make T8code.jl work, you need to set the preferences."
+    end
+end
+
 end