From 56e5322b452ada676ca03884d7e813f42e007013 Mon Sep 17 00:00:00 2001
From: Maxime Coste <mawww@kakoune.org>
Date: Sun, 3 Jun 2018 12:04:55 +1000
Subject: [PATCH] EventManager: Never block if a forced file descriptor is
 present

---
 src/event_manager.cc | 5 +++++
 src/event_manager.hh | 1 +
 2 files changed, 6 insertions(+)

diff --git a/src/event_manager.cc b/src/event_manager.cc
index eed7614f..0767473a 100644
--- a/src/event_manager.cc
+++ b/src/event_manager.cc
@@ -91,6 +91,9 @@ bool EventManager::handle_next_events(EventMode mode, sigset_t* sigmask, bool bl
     }
 
     bool with_timeout = false;
+    if (m_has_forced_fd)
+        block = false;
+
     timespec ts{};
     if (block and not m_timers.empty())
     {
@@ -113,6 +116,7 @@ bool EventManager::handle_next_events(EventMode mode, sigset_t* sigmask, bool bl
 
     // copy forced fds *after* select, so that signal handlers can write to
     // m_forced_fd, interupt select, and directly be serviced.
+    m_has_forced_fd = false;
     fd_set forced = m_forced_fd;
     FD_ZERO(&m_forced_fd);
 
@@ -147,6 +151,7 @@ bool EventManager::handle_next_events(EventMode mode, sigset_t* sigmask, bool bl
 void EventManager::force_signal(int fd)
 {
     FD_SET(fd, &m_forced_fd);
+    m_has_forced_fd = true;
 }
 
 SignalHandler set_signal_handler(int signum, SignalHandler handler)
diff --git a/src/event_manager.hh b/src/event_manager.hh
index 91a8d41c..f4bece31 100644
--- a/src/event_manager.hh
+++ b/src/event_manager.hh
@@ -98,6 +98,7 @@ private:
     Vector<FDWatcher*, MemoryDomain::Events> m_fd_watchers;
     Vector<Timer*, MemoryDomain::Events>     m_timers;
     fd_set m_forced_fd;
+    bool   m_has_forced_fd = false;
 
     TimePoint m_last;
 };