From: Adam C. Emerson <aemerson@redhat.com>
Date: Tue, 22 Oct 2019 15:39:20 +0000 (-0400)
Subject: common/thread: Fix race condition in make_named_thread
X-Git-Tag: v15.1.0~1181^2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=2bd106ec0da52e7fcf616d7b3cb20d570c1a5c50;p=ceph-ci.git

common/thread: Fix race condition in make_named_thread

The thread may well no longer exist by the time we try to set the
name, so have the thread set its own name first thing.

Thanks to Ilya Dryomov <idryomov@gmail.com> for pointing it out.

Signed-off-by: Adam C. Emerson <aemerson@redhat.com>
---

diff --git a/src/common/Thread.h b/src/common/Thread.h
index bc32755c30e..0ab65fca52f 100644
--- a/src/common/Thread.h
+++ b/src/common/Thread.h
@@ -16,6 +16,8 @@
 #ifndef CEPH_THREAD_H
 #define CEPH_THREAD_H
 
+#include <functional>
+#include <string_view>
 #include <system_error>
 #include <thread>
 
@@ -68,13 +70,14 @@ std::string get_thread_name(const std::thread& t);
 void kill(std::thread& t, int signal);
 
 template<typename Fun, typename... Args>
-std::thread make_named_thread(const std::string& s,
+std::thread make_named_thread(std::string_view n,
 			      Fun&& fun,
 			      Args&& ...args) {
-  auto t = std::thread(std::forward<Fun>(fun),
-		       std::forward<Args>(args)...);
-  set_thread_name(t, s);
-  return t;
-}
 
+  return std::thread([n = std::string(n)](auto&& fun, auto&& ...args) {
+		       ceph_pthread_setname(pthread_self(), n.data());
+		       std::invoke(std::forward<Fun>(fun),
+				   std::forward<Args>(args)...);
+		     }, std::forward<Fun>(fun), std::forward<Args>(args)...);
+}
 #endif