From 0b9bb84c39a25b0361d8fe30eddf47c8c4c441d4 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Wed, 15 Jul 2020 13:05:08 +0200
Subject: [PATCH] Run tests in parallel.

---
 .circleci/config.yml     |  1 +
 .circleci/soltest_all.sh | 47 ++++++++++++++++++++++++++++++++++++----
 2 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 826c04785..df0eba03d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -139,6 +139,7 @@ defaults:
   - test_ubuntu2004: &test_ubuntu2004
       docker:
         - image: ethereum/solidity-buildpack-deps:ubuntu2004-<< pipeline.parameters.ubuntu-2004-docker-image-rev >>
+      parallelism: 6
       steps:
         - checkout
         - attach_workspace:
diff --git a/.circleci/soltest_all.sh b/.circleci/soltest_all.sh
index 86f172a04..7b1fb053b 100755
--- a/.circleci/soltest_all.sh
+++ b/.circleci/soltest_all.sh
@@ -28,10 +28,49 @@ set -e
 
 REPODIR="$(realpath $(dirname $0)/..)"
 
-EVM=istanbul OPTIMIZE=1 ABI_ENCODER_V2=1 ${REPODIR}/.circleci/soltest.sh
+EVM_VALUES=(homestead byzantium constantinople petersburg istanbul)
+OPTIMIZE_VALUES=(0 1)
+STEPS=$(( 1 + ${#EVM_VALUES[@]} * ${#OPTIMIZE_VALUES[@]} ))
 
-for OPTIMIZE in 0 1; do
-    for EVM in homestead byzantium constantinople petersburg istanbul; do
-        EVM=$EVM OPTIMIZE=$OPTIMIZE BOOST_TEST_ARGS="-t !@nooptions" ${REPODIR}/.circleci/soltest.sh
+if (( $CIRCLE_NODE_TOTAL )) && (( $CIRCLE_NODE_TOTAL > 1 ))
+then
+    # Run step 1 as the only step on the first executor
+    # and evenly distribute the other steps among
+    # the other executors.
+    # The first step takes much longer than the other steps.
+    if (( $CIRCLE_NODE_INDEX == 0 ))
+    then
+        RUN_STEPS="1"
+    else
+        export CIRCLE_NODE_INDEX=$(($CIRCLE_NODE_INDEX - 1))
+        export CIRCLE_NODE_TOTAL=$(($CIRCLE_NODE_TOTAL - 1))
+        RUN_STEPS=$(seq 2 "$STEPS" | circleci tests split)
+    fi
+else
+    RUN_STEPS=$(seq "$STEPS")
+fi
+
+# turn newlines into spaces
+RUN_STEPS=$(echo $RUN_STEPS)
+
+echo "Running steps $RUN_STEPS..."
+
+STEP=1
+
+[[ " $RUN_STEPS " =~ " $STEP " ]] && EVM=istanbul OPTIMIZE=1 ABI_ENCODER_V2=1 "${REPODIR}/.circleci/soltest.sh"
+STEP=$(($STEP + 1))
+
+for OPTIMIZE in ${OPTIMIZE_VALUES[@]}
+do
+    for EVM in ${EVM_VALUES[@]}
+    do
+        [[ " $RUN_STEPS " =~ " $STEP " ]] && EVM="$EVM" OPTIMIZE="$OPTIMIZE" BOOST_TEST_ARGS="-t !@nooptions" "${REPODIR}/.circleci/soltest.sh"
+        STEP=$(($STEP + 1))
     done
 done
+
+if (($STEP != $STEPS + 1))
+then
+    echo "Step counter not properly adjusted!" >2
+    exit 1
+fi