Precomp: Halve the default number of precompilation tasks in windows to avoid ReadOnlyMemoryError (#2366)

* halve the default number of precompilation tasks in windows to avoid #2323

Co-authored-by: Fredrik Ekre <[email protected]>
(cherry picked from commit 320ec76)

Author: 2 people

src/API.jl

@@ -914,7 +914,12 @@ function precompile(ctx::Context; internal_call::Bool=false, kwargs...)
     Context!(ctx; kwargs...)
     instantiate(ctx; allow_autoprecomp=false, kwargs...)
     time_start = time_ns()
-    num_tasks = parse(Int, get(ENV, "JULIA_NUM_PRECOMPILE_TASKS", string(Sys.CPU_THREADS::Int + 1)))
+
+    # Windows sometimes hits a ReadOnlyMemoryError, so we halve the default number of tasks. Issue #2323
+    # TODO: Investigate why this happens in windows and restore the full task limit
+    default_num_tasks = Sys.iswindows() ? div(Sys.CPU_THREADS::Int, 2) + 1 : Sys.CPU_THREADS::Int + 1
+
+    num_tasks = parse(Int, get(ENV, "JULIA_NUM_PRECOMPILE_TASKS", string(default_num_tasks)))
     parallel_limiter = Base.Semaphore(num_tasks)
     io = ctx.io
     fancyprint = can_fancyprint(io)