freeRTOS UART Implementation on LPC1769

Dear Sir i am new with FreeRTOS and iam work on LPC1769 mbed board. i am write driver for is work normally but if i use semaphore or mutex for interrupt handling then it stuck on UART3IRQHandler function.i have attached my code with it please find it. when i run this code it stuck on UART3IRQHandler function and not running any thread. please guide to resolve it. remarks:- without semaphore or mutex it receive and send data on UART is ok.but in fast data on UART it is miss data so i think to used semaphore and mutex. please guide me to resolve this problem. thanks in advance.