1 files changed, 26 insertions, 0 deletions
diff --git a/deps/npm/scripts/doc-build.sh b/deps/npm/scripts/doc-build.sh
index 98dfa82f60..18f4e6ca86 100755
--- a/deps/npm/scripts/doc-build.sh
+++ b/deps/npm/scripts/doc-build.sh
@@ -32,6 +32,32 @@ if ! [ -x node_modules/.bin/ronn ]; then
   fi
 fi
 
+if ! [ -x node_modules/.bin/marked ]; then
+  ps=0
+  if [ -f .building_marked ]; then
+    pid=$(cat .building_marked)
+    ps=$(ps -p $pid | grep $pid | wc -l) || true
+  fi
+
+  if [ -f .building_marked ] && [ $ps != 0 ]; then
+    while [ -f .building_marked ]; do
+      sleep 1
+    done
+  else
+    # a race to see which make process will be the one to install marked
+    echo $$ > .building_marked
+    sleep 1
+    if [ $(cat .building_marked) == $$ ]; then
+      make node_modules/.bin/marked
+      rm .building_marked
+    else
+      while [ -f .building_marked ]; do
+        sleep 1
+      done
+    fi
+  fi
+fi
+
 src=$1
 dest=$2
 name=$(basename ${src%.*})