Switch to parrallel execution of SDK commands

Use subshell execution of the `run-all-sdk-command` make target.

build/includes/sdk.mk

@@ -55,17 +55,22 @@ gen-all-sdk-grpc: run-all-sdk-command
 gen-sdk-grpc: COMMAND := gen
 gen-sdk-grpc: run-sdk-command
 
-# Runs a command on all supported languages, use COMMAND variable to select which command.
+# Runs a command on all supported languages in parallel, use COMMAND variable to select which command.
 run-all-sdk-command:
 	cd $(sdk_build_folder); \
+	FAIL=0; \
 	for d in */ ; do \
 		if [ "$${d%?}" != "tool" ] &&  [ -f $$d/$(COMMAND).sh ]; then  \
-			( cd .. && $(MAKE) run-sdk-command COMMAND=$(COMMAND) SDK_FOLDER=$${d%?} ) \
-			|| { failed=1; break; }; \
+			(cd .. && $(MAKE) run-sdk-command COMMAND=$(COMMAND) SDK_FOLDER=$${d%?}) & \
 		fi \
 	done; \
-	if (( failed )); then \
-   		echo "Failed to run SDK command"; exit -1; \
+	for job in `jobs -p` ; \
+	do \
+		wait $$job || let "FAIL+=1"; \
+	done ; \
+	if [ "$$FAIL" != "0" ]; \
+	then \
+		echo "Failed to run SDK command"; exit -1; \
 	fi
 
 # Runs a command for a specific SDK.