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extmod/modlwip: Use mp_sched_schedule to schedule socket callbacks.

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The helper function exec_user_callback executes within the context of an
lwIP C callback, and the user (Python) callback to be scheduled may want to
perform further TCP/IP actions, so the latter should be scheduled to run
outside the lwIP context (otherwise it's effectively a "hard IRQ" and such
callbacks have lots of restrictions).
This commit is contained in:
Damien George 2019-07-03 16:22:48 +10:00
parent 1d6cb6357a
commit c60caf1995
1 changed files with 5 additions and 19 deletions
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24
extmod/modlwip.c
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@ -356,7 +356,8 @@ STATIC void lwip_socket_free_incoming(lwip_socket_obj_t *socket) {
static inline void exec_user_callback(lwip_socket_obj_t *socket) {
if (socket->callback != MP_OBJ_NULL) {
mp_call_function_1_protected(socket->callback, MP_OBJ_FROM_PTR(socket));
// Schedule the user callback to execute outside the lwIP context
mp_sched_schedule(socket->callback, MP_OBJ_FROM_PTR(socket));
}
}
@ -446,18 +447,6 @@ STATIC err_t _lwip_tcp_recv_unaccepted(void *arg, struct tcp_pcb *pcb, struct pb
return ERR_BUF;
}
// "Poll" (idle) callback to be called ASAP after accept callback
// to execute Python callback function, as it can't be executed
// from accept callback itself.
STATIC err_t _lwip_tcp_accept_finished(void *arg, struct tcp_pcb *pcb)
{
// The ->connected entry of the pcb holds the listening socket of the accept
lwip_socket_obj_t *socket = (lwip_socket_obj_t*)pcb->connected;
tcp_poll(pcb, NULL, 0);
exec_user_callback(socket);
return ERR_OK;
}
// Callback for incoming tcp connections.
STATIC err_t _lwip_tcp_accept(void *arg, struct tcp_pcb *newpcb, err_t err) {
// err can be ERR_MEM to notify us that there was no memory for an incoming connection
@ -476,12 +465,9 @@ STATIC err_t _lwip_tcp_accept(void *arg, struct tcp_pcb *newpcb, err_t err) {
if (++socket->incoming.connection.iput >= socket->incoming.connection.alloc) {
socket->incoming.connection.iput = 0;
}
if (socket->callback != MP_OBJ_NULL) {
// Schedule accept callback to be called when lwIP is done
// with processing this incoming connection on its side and
// is idle.
tcp_poll(newpcb, _lwip_tcp_accept_finished, 1);
}
// Schedule user accept callback
exec_user_callback(socket);
// Set the error callback to handle the case of a dropped connection before we
// have a chance to take it off the accept queue.