Each GAP.jl session uses fresh dir for mutable GAP root

Project.toml

@@ -8,6 +8,7 @@ AbstractAlgebra = "c3fe647b-3220-5bb0-a1ea-a7954cac585d"
 Artifacts = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
 BinaryWrappers = "f01c122e-0ea1-4f85-ad8f-907073ad7a9f"
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
+Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 Downloads = "f43a241f-c20a-4ad4-852c-f6b1247861c6"
 GAP_jll = "5cd7a574-2c56-5be2-91dc-c8bc375b9ddf"
 GAP_lib_jll = "de1ad85e-c930-5cd4-919d-ccd3fcafd1a3"
@@ -41,6 +42,7 @@ Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 Ncurses_jll = "68e3532b-a499-55ff-9963-d1c0c0748b3a"
 Pidfile = "fa939f87-e72e-5be4-a000-7fc836dbe307"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Scratch = "6c6a2e73-6563-6170-7368-637461726353"
@@ -52,6 +54,7 @@ AbstractAlgebra = "0.41.11, 0.42.1, 0.43"
 Artifacts = "1.6"
 BinaryWrappers = "0.1.3"
 Compat = "4.4.0"
+Dates = "1.6"
 Downloads = "1.4.3"
 GAP_jll = "~400.1400.000"
 GAP_lib_jll = "~400.1400.000"
@@ -85,6 +88,7 @@ Markdown = "1.6"
 Ncurses_jll = "6.4.1"
 Pidfile = "1.3"
 Pkg = "1.6"
+PrecompileTools = "1.2.1"
 REPL = "1.6"
 Random = "1.6"
 Scratch = "1.1"

src/GAP.jl

@@ -55,10 +55,7 @@ import Libdl
 import Random
 
 # setup the initial sysinfo dictionary; we'll update this later in __init__
-# this also ensures that Setup.regenerate_gaproot gets precompiled, reducing
-# the startup time a little bit
-const sysinfo = Setup.regenerate_gaproot()
-
+const sysinfo = Dict{String, String}()
 
 include("types.jl")
 
@@ -336,4 +333,19 @@ include("doctestfilters.jl")
 
 include("GAP_pkg.jl")
 
+################################################################################
+#
+#  Precompilation
+#
+################################################################################
+
+using PrecompileTools: @setup_workload, @compile_workload
+
+@setup_workload begin
+  @compile_workload begin
+    sysinfo = Setup.regenerate_gaproot()
+    Setup.locate_JuliaInterface_so(sysinfo)
+  end
+end
+
 end

src/setup.jl

@@ -6,14 +6,40 @@ import GAP_jll
 import GAP_lib_jll
 import GAP_pkg_juliainterface_jll
 import Scratch: @get_scratch!
-import Pidfile
 import TOML
+import Dates
+
+# We use a scratch space to store subdirectories created via mktempdir
+# that are then set up to contain a mutable gap root directory. A fresh
+# one of these is created each time GAP.jl is loaded.
+# This has the advantage that multiple GAP.jl sessions don't interfere
+# with each other. Their mutable temp directories are usually cleaned up
+# when Julia exits.
+#
+# The reason we don't just put these into `/tmp` is that files in there
+# are cleaned out by the operating system at regular intervals, which
+# could mess up long-running computations. Hence we use a Julia scratch space
+# instead.
+#
+# We put the year & month into the scratch space name to ensure each is
+# only used for about a month. Then after a time, `Pkg.gc()` will reap it
+# (and using the Julia package manager will also automatically perform a gc
+# from time to time).
+const scratch_key = "gap_$(Dates.format(Dates.today(), "yyyy-mm"))"
+const _gaproot = Ref("")
+
+function __init__()
+    _gaproot[] = ""
+end
 
-# to separate the scratchspaces of different GAP.jl copies and Julia versions
-# put the Julia version and the hash of the path to this file into the key
-const scratch_key = "gap_$(hash(@__FILE__))-$(VERSION.major).$(VERSION.minor)"
-
-gaproot() = @get_scratch!(scratch_key)
+function gaproot()
+    if isempty(_gaproot[])
+        parent = @get_scratch!(scratch_key)
+        _gaproot[] = mktempdir(parent; prefix="gap_$(Dates.today())_", cleanup=true)
+        println("#I Setting gaproot to $(_gaproot[])")
+    end
+    return _gaproot[]
+end
 
 #############################################################################
 #
@@ -160,50 +186,48 @@ function regenerate_gaproot()
 
     # create the mutable gaproot
     mkpath(gaproot_mutable)
-    Pidfile.mkpidlock("$gaproot_mutable.lock"; stale_age=10) do
-        # create fake sysinfo.gap
-        unquoted = Set(["GAParch", "GAP_ABI", "GAP_HPCGAP", "GAP_KERNEL_MAJOR_VERSION", "GAP_KERNEL_MINOR_VERSION", "GAP_OBJEXT"])
-        open("$gaproot_mutable/sysinfo.gap", "w") do file
-            write(file, """
-            # This file has been generated by the GAP build system,
-            # do not edit manually!
-            """)
-            for key in sort(collect(keys(sysinfo)))
-                if key in unquoted
-                    str = "$(key)=$(sysinfo[key])"
-                else
-                    str = "$(key)=\"$(sysinfo[key])\""
-                end
-                write(file, str, "\n")
+
+    # create fake sysinfo.gap
+    unquoted = Set(["GAParch", "GAP_ABI", "GAP_HPCGAP", "GAP_KERNEL_MAJOR_VERSION", "GAP_KERNEL_MINOR_VERSION", "GAP_OBJEXT"])
+    open("$gaproot_mutable/sysinfo.gap", "w") do file
+        write(file, """
+        # This file has been generated by the GAP build system,
+        # do not edit manually!
+        """)
+        for key in sort(collect(keys(sysinfo)))
+            if key in unquoted
+                str = "$(key)=$(sysinfo[key])"
+            else
+                str = "$(key)=\"$(sysinfo[key])\""
             end
+            write(file, str, "\n")
         end
+    end
 
-        # patch gac to load correct sysinfo.gap
-        gac = read(joinpath(gap_prefix, "bin", "gac"), String)
-        gac = replace(gac, r"^\. \"[^\"]+\"$"m => ". \"$(gaproot_mutable)/sysinfo.gap\"")
-        write("$gaproot_mutable/gac", gac)
-        chmod("$gaproot_mutable/gac", 0o755)
-
-        # 
-        mkpath(joinpath(gaproot_mutable, "bin"))
-        for d in (("include/gap", "src"), ("lib", "lib"), ("bin/gap", "gap"))
-            force_symlink(joinpath(gap_prefix, d[1]), joinpath(gaproot_mutable, d[2]))
-        end
+    # patch gac to load correct sysinfo.gap
+    gac = read(joinpath(gap_prefix, "bin", "gac"), String)
+    gac = replace(gac, r"^\. \"[^\"]+\"$"m => ". \"$(gaproot_mutable)/sysinfo.gap\"")
+    write("$gaproot_mutable/gac", gac)
+    chmod("$gaproot_mutable/gac", 0o755)
 
-        # emulate the "compat mode" of the GAP build system, to help certain
-        # packages like Browse with an outdated build system
-        mkpath(joinpath(gaproot_mutable, "bin", sysinfo["GAParch"]))
-        force_symlink("../../gac",
-                      joinpath(gaproot_mutable, "bin", sysinfo["GAParch"], "gac"))
-
-        # create a `pkg` directory with symlinks to all the GAP packages artifacts
-        mkpath(joinpath(gaproot_mutable, "pkg"))
-        pkg_artifacts = filter(startswith("GAP_pkg_"), keys(TOML.parsefile(find_artifacts_toml(@__FILE__))))
-        for name in pkg_artifacts
-            force_symlink(@artifact_str(name), joinpath(gaproot_mutable, "pkg", name))
-        end
+    # 
+    mkpath(joinpath(gaproot_mutable, "bin"))
+    for d in (("include/gap", "src"), ("lib", "lib"), ("bin/gap", "gap"))
+        force_symlink(joinpath(gap_prefix, d[1]), joinpath(gaproot_mutable, d[2]))
+    end
 
-    end # mkpidlock
+    # emulate the "compat mode" of the GAP build system, to help certain
+    # packages like Browse with an outdated build system
+    mkpath(joinpath(gaproot_mutable, "bin", sysinfo["GAParch"]))
+    force_symlink("../../gac",
+                  joinpath(gaproot_mutable, "bin", sysinfo["GAParch"], "gac"))
+
+    # create a `pkg` directory with symlinks to all the GAP packages artifacts
+    mkpath(joinpath(gaproot_mutable, "pkg"))
+    pkg_artifacts = filter(startswith("GAP_pkg_"), keys(TOML.parsefile(find_artifacts_toml(@__FILE__))))
+    for name in pkg_artifacts
+        force_symlink(@artifact_str(name), joinpath(gaproot_mutable, "pkg", name))
+    end
 
     return sysinfo
 end