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From:   Doug Nazar <nazard@nazar.ca>
To:     libtirpc-devel@lists.sourceforge.net
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH 4/5] Add ability to detect if we're on the main thread.
Date:   Wed, 22 Jul 2020 01:34:44 -0400
Message-Id: <20200722053445.27987-5-nazard@nazar.ca>
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Signed-off-by: Doug Nazar <nazard@nazar.ca>
---
 src/mt_misc.c     | 17 +++++++++++++++++
 tirpc/reentrant.h |  1 +
 2 files changed, 18 insertions(+)

diff --git a/src/mt_misc.c b/src/mt_misc.c
index 5a49b78..020b55d 100644
--- a/src/mt_misc.c
+++ b/src/mt_misc.c
@@ -151,3 +151,20 @@ void tsd_key_delete(void)
 	return;
 }
 
+static pthread_t main_thread_id;
+
+__attribute__((constructor))
+static void
+get_thread_id(void)
+{
+	/* This will only work if we're opened by the main thread.
+	 * Shouldn't be a problem in practice since we expect to be
+	 * linked against, not dlopen() from a random thread.
+	 */
+	main_thread_id = pthread_self();
+}
+
+int thr_main(void)
+{
+	return pthread_equal(main_thread_id, pthread_self());
+}
diff --git a/tirpc/reentrant.h b/tirpc/reentrant.h
index 5bb581a..ee65454 100644
--- a/tirpc/reentrant.h
+++ b/tirpc/reentrant.h
@@ -76,4 +76,5 @@
 #define thr_self()		pthread_self()
 #define thr_exit(x)		pthread_exit(x)
 
+extern int thr_main(void);
 #endif
-- 
2.26.2