unionize mutually exclusive wsi members
Large chunks of struct libwebsocket members actually have a mutually
exclusive lifecycle, eg, once the http headers are finished they sit
there unused until the instance is destroyed.
This makes a big improvement in memory efficiency by making four
categories of member: always needed, needed for header processing,
needed for http processing, and needed for ws processing. The last
three are mutually exclusive and bound into a union inside the wsi.
Care needs taking now at "union transitions", although we zeroed down
the struct at init, the other union siblings have been writing the
same memory by the time later member siblings start to use it. So
it must be cleared down appropriately when we cross from one
mutually-exclusive use to another.
Signed-off-by: Andy Green <andy.green@linaro.org>
diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index 1d97782..7de976f 100644
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -156,7 +156,7 @@
if (old_state == WSI_STATE_DEAD_SOCKET)
return;
- wsi->close_reason = reason;
+ wsi->u.ws.close_reason = reason;
#ifndef LWS_NO_EXTENSIONS
/*
@@ -337,8 +337,8 @@
if (wsi->c_address)
free(wsi->c_address);
#endif
- if (wsi->rxflow_buffer)
- free(wsi->rxflow_buffer);
+ if (wsi->u.ws.rxflow_buffer)
+ free(wsi->u.ws.rxflow_buffer);
/* lwsl_info("closing fd=%d\n", wsi->sock); */
@@ -1209,15 +1209,15 @@
struct libwebsocket_context *context = wsi->protocol->owning_server;
int n;
- if (!(wsi->rxflow_change_to & 2))
+ if (!(wsi->u.ws.rxflow_change_to & 2))
return 0;
- wsi->rxflow_change_to &= ~2;
+ wsi->u.ws.rxflow_change_to &= ~2;
- lwsl_info("rxflow: wsi %p change_to %d\n", wsi, wsi->rxflow_change_to);
+ lwsl_info("rxflow: wsi %p change_to %d\n", wsi, wsi->u.ws.rxflow_change_to);
/* if we're letting it come again, did we interrupt anything? */
- if ((wsi->rxflow_change_to & 1) && wsi->rxflow_buffer) {
+ if ((wsi->u.ws.rxflow_change_to & 1) && wsi->u.ws.rxflow_buffer) {
n = libwebsocket_interpret_incoming_packet(wsi, NULL, 0);
if (n < 0) {
libwebsocket_close_and_free_session(context, wsi, LWS_CLOSE_STATUS_NOSTATUS);
@@ -1228,12 +1228,12 @@
return 0;
}
- if (wsi->rxflow_change_to & 1)
+ if (wsi->u.ws.rxflow_change_to & 1)
context->fds[wsi->position_in_fds_table].events |= POLLIN;
else
context->fds[wsi->position_in_fds_table].events &= ~POLLIN;
- if (wsi->rxflow_change_to & 1)
+ if (wsi->u.ws.rxflow_change_to & 1)
/* external POLL support via protocol 0 */
context->protocols[0].callback(context, wsi,
LWS_CALLBACK_SET_MODE_POLL_FD,
@@ -1262,7 +1262,7 @@
int
libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
{
- wsi->rxflow_change_to = 2 | !!enable;
+ wsi->u.ws.rxflow_change_to = 2 | !!enable;
return 0;
}
@@ -2152,13 +2152,13 @@
int
libwebsocket_is_final_fragment(struct libwebsocket *wsi)
{
- return wsi->final;
+ return wsi->u.ws.final;
}
unsigned char
libwebsocket_get_reserved_bits(struct libwebsocket *wsi)
{
- return wsi->rsv;
+ return wsi->u.ws.rsv;
}
void *