void TrapTtyRecieve(UserContext *user_context) {
TracePrintf(TRACE_LEVEL_FUNCTION_INFO, ">>> TrapTtyRecieve(%p)\n", user_context);
int tty_id = user_context->code;
// Find the proper terminal struct
Tty term = ttys[tty_id];
if (ListEmpty(term.waiting_to_receive)) {
// no waiting procs, so create line buffer and
// add to list
LineBuffer *lb = calloc(1, sizeof(LineBuffer));
lb->buffer = calloc(TERMINAL_MAX_LINE, sizeof(char));
lb->length = TtyReceive(tty_id, lb->buffer, TERMINAL_MAX_LINE);
ListEnqueue(term.line_buffers, lb, 0);
} else {
// at least one proc waiting
// create heap in kernel to use
char *input = calloc(TERMINAL_MAX_LINE, sizeof(char));
char *input_ptr = input; // point how far into the buffer we've read
int input_length = TtyReceive(tty_id, input, TERMINAL_MAX_LINE);
int input_remaining = input_length;
// Continue so long as procs are waiting and there is unconsumed input
while (!ListEmpty(term.waiting_to_receive) && input_remaining > 0) {
PCB *waiting_proc = (PCB *) ListDequeue(term.waiting_to_receive);
assert(waiting_proc->tty_receive_buffer);
// put proc back into ready queue
ListAppend(ready_queue, waiting_proc, waiting_proc->pid);
if (input_remaining <= waiting_proc->tty_receive_len) {
// Consuming all the input
memcpy(waiting_proc->tty_receive_buffer, input_ptr, input_remaining);
waiting_proc->tty_receive_len = input_remaining;
input_remaining = 0;
} else {
// Only consuming some of the input
memcpy(waiting_proc->tty_receive_buffer, input_ptr, waiting_proc->tty_receive_len);
input_remaining -= waiting_proc->tty_receive_len;
input_ptr += waiting_proc->tty_receive_len;
}
}
// Check if there is still input left after all the procs have been filled
if (input_remaining > 0) {
// Create new line buffer and store
char *remaining_buff = calloc(input_remaining, sizeof(char));
memcpy(remaining_buff, input_ptr, input_remaining);
LineBuffer *lb = calloc(1, sizeof(LineBuffer));
lb->buffer = remaining_buff;
lb->length = input_remaining;
ListEnqueue(term.line_buffers, lb, 0);
}
free(input);
}
TracePrintf(TRACE_LEVEL_FUNCTION_INFO, "<<< TrapTtyRecieve(%p)\n", user_context);
}
/* Reading process read buf
*/
void tty_reading_wake_up(unsigned int tty_id)
{
pcb_t *pcb;
int chars_get;
pcb = tty_reading_procs[tty_id];
chars_get = TtyReceive(tty_id, pcb -> tty_buf, pcb -> exit_code);
pcb -> exit_code = chars_get;
//pcb_wake_up(pcb);
return;
}