From 835d21a2d0242601ce732eac3f2aee3e365ec663 Mon Sep 17 00:00:00 2001
From: Ben Walker <benjamin.walker@intel.com>
Date: Thu, 2 May 2019 12:44:32 -0700
Subject: [PATCH] thread: Allow thread schedule callback to fail

Change-Id: Id391c2c03804dda0ad354d98dfe0a75fb4d3d324
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/453012
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
---
 include/spdk/thread.h                     |  2 +-
 lib/event/reactor.c                       |  4 ++-
 lib/thread/thread.c                       | 18 ++++++++++-
 test/unit/lib/thread/thread.c/thread_ut.c | 37 ++++++++++++++++++++---
 4 files changed, 53 insertions(+), 8 deletions(-)

diff --git a/include/spdk/thread.h b/include/spdk/thread.h
index 3b1d7f738..35b5578fd 100644
--- a/include/spdk/thread.h
+++ b/include/spdk/thread.h
@@ -58,7 +58,7 @@ struct spdk_poller;
  *
  * \param thread The new spdk_thread.
  */
-typedef void (*spdk_new_thread_fn)(struct spdk_thread *thread);
+typedef int (*spdk_new_thread_fn)(struct spdk_thread *thread);
 
 /**
  * A function that will be called on the target thread.
diff --git a/lib/event/reactor.c b/lib/event/reactor.c
index 00213c159..712969a49 100644
--- a/lib/event/reactor.c
+++ b/lib/event/reactor.c
@@ -400,7 +400,7 @@ _schedule_thread(void *arg1, void *arg2)
 	TAILQ_INSERT_TAIL(&reactor->threads, lw_thread, link);
 }
 
-static void
+static int
 spdk_reactor_schedule_thread(struct spdk_thread *thread)
 {
 	uint32_t core;
@@ -421,6 +421,8 @@ spdk_reactor_schedule_thread(struct spdk_thread *thread)
 
 	evt = spdk_event_allocate(core, _schedule_thread, lw_thread, NULL);
 	spdk_event_call(evt);
+
+	return 0;
 }
 
 int
diff --git a/lib/thread/thread.c b/lib/thread/thread.c
index ba367cd65..492b6b01c 100644
--- a/lib/thread/thread.c
+++ b/lib/thread/thread.c
@@ -178,7 +178,11 @@ spdk_thread_lib_fini(void)
 
 	if (g_spdk_msg_mempool) {
 		spdk_mempool_free(g_spdk_msg_mempool);
+		g_spdk_msg_mempool = NULL;
 	}
+
+	g_new_thread_fn = NULL;
+	g_ctx_sz = 0;
 }
 
 struct spdk_thread *
@@ -248,7 +252,19 @@ spdk_thread_create(const char *name, struct spdk_cpuset *cpumask)
 	pthread_mutex_unlock(&g_devlist_mutex);
 
 	if (g_new_thread_fn) {
-		g_new_thread_fn(thread);
+		rc = g_new_thread_fn(thread);
+		if (rc != 0) {
+			spdk_cpuset_free(thread->cpumask);
+			spdk_ring_free(thread->messages);
+			spdk_mempool_put_bulk(g_spdk_msg_mempool, (void **)msgs, SPDK_MSG_MEMPOOL_CACHE_SIZE);
+			free(thread->name);
+			pthread_mutex_lock(&g_devlist_mutex);
+			TAILQ_REMOVE(&g_threads, thread, tailq);
+			g_thread_count--;
+			pthread_mutex_unlock(&g_devlist_mutex);
+			free(thread);
+			return NULL;
+		}
 	}
 
 	return thread;
diff --git a/test/unit/lib/thread/thread.c/thread_ut.c b/test/unit/lib/thread/thread.c/thread_ut.c
index bd74be263..3b8706d25 100644
--- a/test/unit/lib/thread/thread.c/thread_ut.c
+++ b/test/unit/lib/thread/thread.c/thread_ut.c
@@ -40,14 +40,41 @@
 #include "thread/thread.c"
 #include "common/lib/ut_multithread.c"
 
+static int g_sched_rc = 0;
+
+static int
+_thread_schedule(struct spdk_thread *thread)
+{
+	return g_sched_rc;
+}
+
 static void
 thread_alloc(void)
 {
-	CU_ASSERT(TAILQ_EMPTY(&g_threads));
-	allocate_threads(1);
-	CU_ASSERT(!TAILQ_EMPTY(&g_threads));
-	free_threads();
-	CU_ASSERT(TAILQ_EMPTY(&g_threads));
+	struct spdk_thread *thread;
+
+	/* No schedule callback */
+	spdk_thread_lib_init(NULL, 0);
+	thread = spdk_thread_create(NULL, NULL);
+	CU_ASSERT(thread != NULL);
+	spdk_thread_exit(thread);
+	spdk_thread_lib_fini();
+
+	/* Schedule callback exists */
+	spdk_thread_lib_init(_thread_schedule, 0);
+
+	/* Scheduling succeeds */
+	g_sched_rc = 0;
+	thread = spdk_thread_create(NULL, NULL);
+	CU_ASSERT(thread != NULL);
+	spdk_thread_exit(thread);
+
+	/* Scheduling fails */
+	g_sched_rc = -1;
+	thread = spdk_thread_create(NULL, NULL);
+	CU_ASSERT(thread == NULL);
+
+	spdk_thread_lib_fini();
 }
 
 static void