void _read(unsigned int *task, unsigned int **tasks, size_t task_count, struct pipe_ringbuffer *pipes) {
task[-1] = TASK_READY;
/* If the fd is invalid, or trying to read too much */
if(task[2+0] > PIPE_LIMIT || task[2+2] > PIPE_BUF) {
task[2+0] = -1;
} else {
struct pipe_ringbuffer *pipe = &pipes[task[2+0]];
if((size_t)PIPE_LEN(*pipe) < task[2+2]) {
/* Trying to read more than there is: block */
task[-1] = TASK_WAIT_READ;
} else {
size_t i;
char *buf = (char*)task[2+1];
/* Copy data into buf */
for(i = 0; i < task[2+2]; i++) {
PIPE_POP(*pipe,buf[i]);
}
/* Unblock any waiting writes
XXX: nondeterministic unblock order
*/
for(i = 0; i < task_count; i++) {
if(tasks[i][-1] == TASK_WAIT_WRITE) {
_write(tasks[i], tasks, task_count, pipes);
}
}
}
}
}
int
mq_read (struct pipe_ringbuffer *pipe,
struct task_control_block *task)
{
size_t msg_len;
size_t i;
char *buf = (char*)task->stack->r1;
/* Get length */
for (i = 0; i < 4; i++) {
PIPE_POP(*pipe, *(((char*)&msg_len)+i));
}
/* Copy data into buf */
for (i = 0; i < msg_len; i++) {
PIPE_POP(*pipe, buf[i]);
}
return msg_len;
}
int
fifo_read (struct pipe_ringbuffer *pipe,
struct task_control_block *task)
{
size_t i;
char *buf = (char*)task->stack->r1;
/* Copy data into buf */
for (i = 0; i < task->stack->r2; i++) {
PIPE_POP(*pipe, buf[i]);
}
return task->stack->r2;
}