From: Matt Corallo <git@bluematt.me>
Date: Sun, 3 Oct 2021 21:41:18 +0000 (+0000)
Subject: [net] Ensure we don't spin loop by keeping the poll write bit set
X-Git-Tag: v0.0.102.0^2~6
X-Git-Url: http://git.bitcoin.ninja/index.cgi?p=ldk-c-bindings;a=commitdiff_plain;h=b1ea57acc81af14e8623deca4a8a352d0d2ff71e

[net] Ensure we don't spin loop by keeping the poll write bit set

Previously we'd not been unsetting POLLOUT, which will result in
us spin-loop'ing with ChannelManager_write_buffer_space_avail.

Further, we'd also not been unsetting the POLLIN bit, which would
result in us never pausing read as the SocketDescriptor API
requires us to.
---

diff --git a/ldk-net/ldk_net.c b/ldk-net/ldk_net.c
index dc19e8e..f404ddd 100644
--- a/ldk-net/ldk_net.c
+++ b/ldk-net/ldk_net.c
@@ -111,10 +111,9 @@ static uintptr_t sock_send_data(void* desc, struct LDKu8slice data, bool resume_
 		for (int i = 0; i < descriptor->handler->sockcount; i++) {
 			if (descriptor->handler->pollfds[i].fd == descriptor->fd) {
 				if (pause_read) {
-					descriptor->handler->pollfds[i].events &= POLLIN;
-					descriptor->handler->pollfds[i].events |= POLLOUT;
+					descriptor->handler->pollfds[i].events = POLLOUT;
 				} else {
-					descriptor->handler->pollfds[i].events |= POLLIN;
+					descriptor->handler->pollfds[i].events = POLLIN;
 				}
 				break;
 			}
@@ -243,8 +242,7 @@ static void *sock_thread_fn(void* arg) {
 									lockres = pthread_mutex_lock(&handler->sockets_mutex);
 									assert(lockres == 0);
 									assert(handler->pollfds[i - 1].fd == pollfds[i].fd); // Only we change fd order!
-									handler->pollfds[i - 1].events &= POLLIN;
-									handler->pollfds[i - 1].events |= POLLOUT;
+									handler->pollfds[i - 1].events = POLLOUT;
 									lockres = pthread_mutex_unlock(&handler->sockets_mutex);
 									assert(lockres == 0);
 								}