[PATCH] Fix a pthreadpool race

[Volker Lendecke]

On Tue, Dec 12, 2017 at 01:02:46PM -0700, Christof Schmitt wrote:
> The assumption here is that no call to pthread_create is done and hence no call
> to will_return is required. What likely happened is that the worker thread
> exited, then test_create_do triggered the creation of a new pthread, which in
> turn caused a call to mock_type. As there is no entry in the global list,
> cmocka tried to abort through a jump while still holding the mutex.

The helper thread did not exit, it was *not yet* idle.

The attached patch fixes the problem for me.

Volker

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-------------- next part --------------
From ae056538b473d94e720af93092dec13f5386c38f Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl at samba.org>
Date: Tue, 12 Dec 2017 23:07:39 +0100
Subject: [PATCH] pthreadpool: Fix deadlock

Christof's idea from was that the thread already exited. It could also be that
the thread is not yet idle when the new pthreadpool_add_jobs comes around the
corner.

Signed-off-by: Volker Lendecke <vl at samba.org>
---
 lib/pthreadpool/tests_cmocka.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/pthreadpool/tests_cmocka.c b/lib/pthreadpool/tests_cmocka.c
index 75a935fa42c..9753d212e1c 100644
--- a/lib/pthreadpool/tests_cmocka.c
+++ b/lib/pthreadpool/tests_cmocka.c
@@ -28,6 +28,7 @@
 #include <pthreadpool_tevent.h>
 
 #include <cmocka.h>
+#include <poll.h>
 
 struct pthreadpool_tevent_test {
 	struct tevent_context *ev;
@@ -152,6 +153,8 @@ static void test_create(void **state)
 	assert_return_code(ret, 0);
 	assert_false(in_main_thread);
 
+	poll(NULL, 0, 10);
+
 	/*
 	 * Workerthread will still be active for a second; immediately
 	 * running another job will also use the worker thread, even
-- 
2.11.0