1. A computer-implemented method of performing exception-less system calls on a computer system executing an operating system having a user mode and a kernel mode, the operating system executing at least one user application, the method comprising the steps of: creating a shared memory space between the user application and the operating system for each at least one user application; in the shared memory space of each at least one user application, creating a system call entry for each of at least one exception-less system call; instantiating a system call thread in the operating system kernel for each system call entry in each shared memory space; allowing the at least one user application to set the contents of the at least one system call entry to request the performance of a system call by the operating system and to set the status of that system call entry appropriately; causing a system call thread executing in the kernel space of the operating system to check the status of at least one system call entry in the shared memory space to identify a requested exception-less system call waiting to be performed and to execute the system call requested by that system call entry and to update the corresponding status of that system call entry; and causing the at least one user application to check the status of the system call entries in the shared memory space to determine when a corresponding exception-less system call has been completed.