From 27ef04f95320d2205a9b6b3aa30fa206fb1ef438 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BD=99=E5=B0=89=E6=81=92?=
 <174832469+hengweiyv@users.noreply.github.com>
Date: Sat, 3 Oct 2026 22:02:05 +0800
Subject: [PATCH] Schedule shared Unicode data downloads before recursive makes

---
 Makefile              | 17 ++++++++++++-----
 test/parallel_make.sh | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 5 deletions(-)
 create mode 100644 test/parallel_make.sh

diff --git a/Makefile b/Makefile
index 76a11e4..9bb2085 100644
--- a/Makefile
+++ b/Makefile
@@ -49,7 +49,7 @@ pkgincludedir=$(includedir:$(prefix)/%=%)
 
 # meta targets
 
-.PHONY: all clean data update manifest install test_install_uninstall
+.PHONY: all clean data update manifest install test_install_uninstall test_parallel_make
 
 all: libutf8proc.a libutf8proc.$(SHLIB_EXT)
 
@@ -73,7 +73,7 @@ manifest: MANIFEST.new
 
 # real targets
 
-data/utf8proc_data.c.new: libutf8proc.$(SHLIB_EXT) data/data_generator.jl
+data/utf8proc_data.c.new: libutf8proc.$(SHLIB_EXT) data/data_generator.jl data/DerivedCoreProperties.txt
 	$(MAKE) -C data utf8proc_data.c.new
 
 utf8proc.o: utf8proc.h utf8proc.c utf8proc_data.c
@@ -141,10 +141,14 @@ data/NormalizationTest.txt:
 data/GraphemeBreakTest.txt:
 	$(MAKE) -C data GraphemeBreakTest.txt
 
-data/Lowercase.txt:
+# These recursive makes share a download; schedule it only once at this level.
+data/DerivedCoreProperties.txt:
+	$(MAKE) -C data DerivedCoreProperties.txt
+
+data/Lowercase.txt: data/DerivedCoreProperties.txt
 	$(MAKE) -C data Lowercase.txt
 
-data/Uppercase.txt:
+data/Uppercase.txt: data/DerivedCoreProperties.txt
 	$(MAKE) -C data Uppercase.txt
 
 test/tests.o: test/tests.c test/tests.h utf8proc.h
@@ -186,6 +190,9 @@ test/maxdecomposition: test/maxdecomposition.c test/tests.o utf8proc.o utf8proc.
 test_install_uninstall: manifest
 	./test/install_uninstall.sh
 
+test_parallel_make:
+	$(SHELL) test/parallel_make.sh
+
 # make release tarball from master branch
 dist:
 	git archive master --prefix=utf8proc-$(VERSION)/ -o utf8proc-$(VERSION).tar.gz
@@ -201,7 +208,7 @@ distcheck: dist
 	make -C utf8proc-$(VERSION) check
 	rm -rf utf8proc-$(VERSION)
 
-check: test/normtest data/NormalizationTest.txt data/Lowercase.txt data/Uppercase.txt test/graphemetest data/GraphemeBreakTest.txt test/printproperty test/case test/iscase test/custom test/charwidth test/misc test/maxdecomposition test/valid test/iterate bench/bench.c bench/util.c bench/util.h utf8proc.o test_install_uninstall
+check: test/normtest data/NormalizationTest.txt data/Lowercase.txt data/Uppercase.txt test/graphemetest data/GraphemeBreakTest.txt test/printproperty test/case test/iscase test/custom test/charwidth test/misc test/maxdecomposition test/valid test/iterate bench/bench.c bench/util.c bench/util.h utf8proc.o test_install_uninstall test_parallel_make
 	$(MAKE) -C bench
 	test/normtest data/NormalizationTest.txt
 	test/graphemetest data/GraphemeBreakTest.txt
diff --git a/test/parallel_make.sh b/test/parallel_make.sh
new file mode 100644
index 0000000..5c224c5
--- /dev/null
+++ b/test/parallel_make.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+# The casing test data share a downloaded prerequisite. Recursive makes must
+# not download it twice when these targets are requested in parallel.
+set -eu
+
+scratch=$(mktemp -d)
+trap 'rm -rf "$scratch"' EXIT HUP INT TERM
+mkdir "$scratch/data"
+cp Makefile "$scratch/Makefile"
+cp data/Makefile "$scratch/data/Makefile"
+
+cat > "$scratch/curl" <<'EOF'
+#!/bin/sh
+set -eu
+while [ "$1" != '-o' ]; do shift; done
+shift
+printf '%s\n' "$1" >> ../downloads.log
+sleep 0.1
+printf 'complete\n' > "$1"
+EOF
+
+cat > "$scratch/julia" <<'EOF'
+#!/bin/sh
+set -eu
+test "$(cat DerivedCoreProperties.txt)" = complete
+printf 'generated\n'
+EOF
+chmod +x "$scratch/curl" "$scratch/julia"
+
+MAKEFLAGS= MFLAGS= ${MAKE:-make} -C "$scratch" -j8 data/Lowercase.txt data/Uppercase.txt \
+    CURL="$scratch/curl" JULIA="$scratch/julia"
+
+downloads=$(wc -l < "$scratch/downloads.log")
+test "$downloads" -eq 1 || {
+    echo "Expected one shared data download, got $downloads" >&2
+    exit 1
+}
+test "$(cat "$scratch/data/Lowercase.txt")" = generated
+test "$(cat "$scratch/data/Uppercase.txt")" = generated