Condition Variable in pthread.h

Hello, I have a Spartan 3E and I have implemented a Xilkernel and
pthread for threading. Now I want to use "condition
variable" (pthread_cond_init, pthread_cond_wait,...) and I think that
this is not possible in EDK. Is this true??. How can I use condition
variable in FPGA??. Has anyone tried to do this??

Thanks for your help.