make v8-version-build job concurrent

.github/workflows/unit_tests.yml

@@ -143,6 +143,8 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
+      matrix:
+        job_split: [ 0/4, 1/4, 2/3, 3/4 ] # format index{0 .. index-1}/concurrency
     steps:
       - uses: actions/checkout@v2
       - uses: actions/cache@v2
@@ -153,6 +155,7 @@ jobs:
       - name: Test build v8 on supported versions
         env:
           SCRIPTX_TEST_FORCE_UPDATE_DEPS: ON
+          SCRIPTX_TEST_JOB_SPLIT_CONFIG: ${{ matrix.job_split }}
         run: |
           mkdir -p build && cd build
           ../test/cmake/test_v8_compiles.sh continue

test/cmake/test_v8_compiles.sh

@@ -62,9 +62,24 @@ function compile() {
 if [[ -n $TARGET_VERSION ]] ; then
   compile $TARGET_VERSION
 else
-  for version in "${SUPPORTED_VERSIONS[@]}"; do
-    compile $version
-  done
+  if echo $SCRIPTX_TEST_JOB_SPLIT_CONFIG | egrep -q -e '^\d+\/\d+$'; then
+    TOTAL=$(echo ${SCRIPTX_TEST_JOB_SPLIT_CONFIG} | cut -d/ -f 2)
+    INDEX=$(echo ${SCRIPTX_TEST_JOB_SPLIT_CONFIG} | cut -d/ -f 1)
+    COUNT=${#SUPPORTED_VERSIONS[@]}
+
+    START=$((($COUNT * $INDEX + $TOTAL - 1) / $TOTAL))  # upper COUNT * INDEX / TOTAL
+    END=$(($COUNT * ($INDEX + 1) / $TOTAL))  # upper COUNT * INDEX / TOTAL
+
+    echo "split job=[$START, $END] total=$COUNT"
+
+    for ((i = $START; i < $END; i++)); do
+      compile ${SUPPORTED_VERSIONS[$i]}
+    done
+  else
+    for version in "${SUPPORTED_VERSIONS[@]}"; do
+      compile $version
+    done
+  fi
 fi
 
 echo "passed versions: [${PASSED_VERSIONS[@]}]"