init: add pidlock for polymake initialization

Project.toml

@@ -1,7 +1,7 @@
 name = "Polymake"
 uuid = "d720cf60-89b5-51f5-aff5-213f193123e7"
 repo = "https://github.com/oscar-system/Polymake.jl.git"
-version = "0.11.16"
+version = "0.11.17"
 
 [deps]
 AbstractAlgebra = "c3fe647b-3220-5bb0-a1ea-a7954cac585d"
@@ -14,6 +14,7 @@ Mongoc = "4fe8b98c-fc19-5c23-8ec2-168ff83495f2"
 NetworkOptions = "ca575930-c2e3-43a9-ace4-1e988b2c1908"
 Ninja_jll = "76642167-d241-5cee-8c94-7a494e8cb7b7"
 Perl_jll = "83958c19-0796-5285-893e-a1267f8ec499"
+Pidfile = "fa939f87-e72e-5be4-a000-7fc836dbe307"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
 Scratch = "6c6a2e73-6563-6170-7368-637461726353"
@@ -35,6 +36,7 @@ Mongoc = "~0.6.0, ~0.7.0, ~0.8.0, ~0.9.0"
 NetworkOptions = "1.2"
 Ninja_jll = "^1.11.1"
 Perl_jll = "^5.34.0"
+Pidfile = "^1.3"
 Pkg = "^1.6"
 REPL = "^1.6"
 Scratch = "^1.1"

src/Polymake.jl

@@ -32,6 +32,7 @@ using CxxWrap
 
 using BinaryWrappers
 using Scratch
+import Pidfile
 
 import Perl_jll
 import Ninja_jll
@@ -188,6 +189,7 @@ function __init__()
       Downloads.default_downloader!(Downloads.Downloader(grace=0.01))
     end
     # we run this on every init to make sure all artifacts still exist
+    # (this code should be race condition free even with multiple processes)
     prepare_deps_tree(polymake_deps_tree)
     @static if isdefined(Downloads, :default_downloader!)
       # restore default
@@ -243,8 +245,11 @@ function __init__()
        try
            show_banner = should_show_banner() &&
                           !any(x->x.name in ["Oscar"], keys(Base.package_locks))
-
-           initialize_polymake_with_dir("$(polymake_extension_config);user=$(polymake_user_dir)", installtop, installarch, show_banner)
+           mkpath(polymake_user_dir)
+           # lock to avoid race-conditions when recompiling wrappers in multiple processes
+           Pidfile.mkpidlock("$(polymake_user_dir)/userdir.lock") do
+               initialize_polymake_with_dir("$(polymake_extension_config);user=$(polymake_user_dir)", installtop, installarch, show_banner)
+           end
            if !show_banner
                shell_execute(raw"$Verbose::credits=\"0\";")
            end