init: Declare a formal public API

The functions to initialize the SPDK subsystems or tear them down
was previously an internal-only API. Make it public for use by
applications that aren't leverage SPDK's application framework.

Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Change-Id: I2ebfd020e6fa4c1947fa1c1a2ac509ce9b0242f8
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/6643
Reviewed-by: Tom Nabarro <tom.nabarro@outlook.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot

examples/bdev/fio_plugin/fio_plugin.c

@@ -37,13 +37,13 @@
 #include "spdk/bdev_zone.h"
 #include "spdk/accel_engine.h"
 #include "spdk/env.h"
+#include "spdk/init.h"
 #include "spdk/thread.h"
 #include "spdk/log.h"
 #include "spdk/string.h"
 #include "spdk/queue.h"
 #include "spdk/util.h"
 
-#include "spdk_internal/init.h"
 #include "spdk_internal/event.h"
 
 #include "config-host.h"

examples/nvmf/nvmf/nvmf.c

@@ -32,8 +32,10 @@
  */
 
 #include "spdk/stdinc.h"
+
 #include "spdk/env.h"
 #include "spdk/event.h"
+#include "spdk/init.h"
 #include "spdk/string.h"
 #include "spdk/thread.h"
 #include "spdk/bdev.h"
@@ -42,7 +44,6 @@
 #include "spdk/likely.h"
 
 #include "spdk_internal/event.h"
-#include "spdk_internal/init.h"
 
 #define NVMF_DEFAULT_SUBSYSTEMS		32
 #define ACCEPT_TIMEOUT_US		10000 /* 10ms */

include/spdk/init.h

@@ -0,0 +1,76 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.  All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * \file
+ * SPDK Initialization Helper
+ */
+
+#ifndef SPDK_INIT_H
+#define SPDK_INIT_H
+
+#include "spdk/stdinc.h"
+#include "spdk/queue.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void (*spdk_subsystem_init_fn)(int rc, void *ctx);
+
+/**
+ * Begin the initialization process for all SPDK subsystems. SPDK is divided into subsystems at a macro-level
+ * and each subsystem automatically registers itself with this library at start up using a C
+ * constructor. Further, each subsystem can declare other subsystems that it depends on.
+ * Calling this function will correctly initialize all subsystems that are present, in the
+ * required order.
+ *
+ * \param cb_fn Function called when the process is complete.
+ * \param cb_arg User context passed to cb_fn.
+ */
+void spdk_subsystem_init(spdk_subsystem_init_fn cb_fn, void *cb_arg);
+
+typedef void (*spdk_subsystem_fini_fn)(void *ctx);
+
+/**
+ * Tear down all of the subsystems in the correct order.
+ *
+ * \param cb_fn Function called when the process is complete.
+ * \param cb_arg User context passed to cb_fn
+ */
+void spdk_subsystem_fini(spdk_subsystem_fini_fn cb_fn, void *cb_arg);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

include/spdk_internal/init.h

@@ -30,13 +30,8 @@
  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/**
- * \file
- * SPDK Initialization Helper
- */
-
-#ifndef SPDK_INIT_H
-#define SPDK_INIT_H
+#ifndef SPDK_INIT_INTERNAL_H
+#define SPDK_INIT_INTERNAL_H
 
 #include "spdk/stdinc.h"
 #include "spdk/queue.h"
@@ -67,11 +62,6 @@ struct spdk_subsystem_depend {
 void spdk_add_subsystem(struct spdk_subsystem *subsystem);
 void spdk_add_subsystem_depend(struct spdk_subsystem_depend *depend);
 
-typedef void (*spdk_subsystem_init_fn)(int rc, void *ctx);
-void spdk_subsystem_init(spdk_subsystem_init_fn cb_fn, void *cb_arg);
-
-typedef void (*spdk_subsystem_fini_fn)(void *ctx);
-void spdk_subsystem_fini(spdk_subsystem_fini_fn cb_fn, void *cb_arg);
 void spdk_subsystem_init_next(int rc);
 void spdk_subsystem_fini_next(void);
 

lib/event/app.c

@@ -35,10 +35,10 @@
 #include "spdk/version.h"
 
 #include "spdk_internal/event.h"
-#include "spdk_internal/init.h"
 
 #include "spdk/assert.h"
 #include "spdk/env.h"
+#include "spdk/init.h"
 #include "spdk/log.h"
 #include "spdk/thread.h"
 #include "spdk/trace.h"

lib/event/json_config.c

@@ -33,6 +33,7 @@
 
 #include "spdk/stdinc.h"
 
+#include "spdk/init.h"
 #include "spdk/util.h"
 #include "spdk/file.h"
 #include "spdk/log.h"
@@ -42,7 +43,6 @@
 #include "spdk/rpc.h"
 
 #include "spdk_internal/event.h"
-#include "spdk_internal/init.h"
 
 #define SPDK_DEBUG_APP_CFG(...) SPDK_DEBUGLOG(app_config, __VA_ARGS__)
 

lib/init/subsystem.c

@@ -33,7 +33,9 @@
 
 #include "spdk/stdinc.h"
 
+#include "spdk/init.h"
 #include "spdk/log.h"
+#include "spdk/queue.h"
 #include "spdk/thread.h"
 
 #include "spdk_internal/init.h"

test/event/event_perf/event_perf.c

@@ -35,7 +35,6 @@
 
 #include "spdk/env.h"
 #include "spdk/event.h"
-#include "spdk_internal/init.h"
 #include "spdk/log.h"
 #include "spdk/string.h"