General :: Signal Communication Between The Processes?

I am writing a code which communicates between 2 processes created by fork() statement. Parent reads a file and write the data into a shared memory and sends a signal to the child. The child then receives a signal from the parent to start reading. After finishing the read operation the child sends a signal to the parent asking it to resume its action. Some things are going wrong in my code.

1. segmentation error in memcpy() statement.
2. terminal hangs after running the code.
3. Synchronization problem between processes..

Code: #include <stdio.h>
#include <sys/types.h>
#include <wait.h>
#include <unistd.h>

[code].....