Tracking All The Background Process in a shell script

Let's assume we have a scenario to write a shell script, where need to execute some statements  in parallel, after finishing those need to execute few more statements.

for example if i have a shell script,

cmd1 &
cmd2 &
cmd3 

i want to execute cmd3 after finishing cmd1 and cmd2.

This scenario may look simple, but it is not.

When i run statements in parallel using & operator, then that statement will be executed in background, so the other set of statements will be executed immediately, these will not wait for background processes.

i have solved this problem with the below script,

i am running one infinite loop, there i am tracking all the background processes, if all the background processes are done, then only i am running the final statements.

cmd1 &
cmd2 &
while true
do
if [ `jobs | grep Running | wc -l` -eq 0 ]; then
cmd 3
break;
fi;
done