From 6613c1ec801ebf79eb0de76e9d29e75fa4b1f482 Mon Sep 17 00:00:00 2001
From: Glauber Costa <glommer@cloudius-systems.com>
Date: Mon, 28 Apr 2014 17:59:47 +0200
Subject: [PATCH] sched: provide thread exit notifiers
Functions to be run when a thread finishes.
Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
---
core/sched.cc | 12 ++++++++++++
include/osv/sched.hh | 12 ++++++++++++
2 files changed, 24 insertions(+)
diff --git a/core/sched.cc b/core/sched.cc
index a301591ee..35b4174cb 100644
--- a/core/sched.cc
+++ b/core/sched.cc
@@ -652,6 +652,14 @@ thread::thread(std::function<void ()> func, attr attr, bool main)
}
}
+static std::list<std::function<void (thread *)>> exit_notifiers;
+void thread::register_exit_notifier(std::function<void (thread *)> &&n)
+{
+ WITH_LOCK(thread_map_mutex) {
+ exit_notifiers.push_front(std::move(n));
+ }
+}
+
thread::~thread()
{
cancel_this_thread_alarm();
@@ -662,6 +670,10 @@ thread::~thread()
WITH_LOCK(thread_map_mutex) {
thread_map.erase(_id);
total_app_time_exited += _total_cpu_time;
+
+ for (auto& notifier : exit_notifiers) {
+ notifier(this);
+ }
}
if (_attr._stack.deleter) {
_attr._stack.deleter(_attr._stack);
diff --git a/include/osv/sched.hh b/include/osv/sched.hh
index c51981aaf..d8079f128 100644
--- a/include/osv/sched.hh
+++ b/include/osv/sched.hh
@@ -585,6 +585,18 @@ public:
static thread *find_by_id(unsigned int id);
static int numthreads();
+ /**
+ * Registers an std::function that will be called when a thread is torn
+ * down. This is useful, for example, to run code that needs to cleanup
+ * resources acquired by a given thread, about which the thread has no
+ * knowledge about
+ *
+ * In general, this will not run in the same context as the dying thread,
+ * but rather from special scheduler methods. Therefore, one needs to be
+ * careful about stack usage in here. Do not register notifiers that use a
+ * lot of stack
+ */
+ static void register_exit_notifier(std::function<void (thread *)> &&n);
private:
class reaper;
friend class reaper;
--
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