1 files changed, 288 insertions, 0 deletions
diff --git a/src/spdk/lib/event/subsystem.c b/src/spdk/lib/event/subsystem.c
new file mode 100644
index 000000000..2cff890b2
--- /dev/null
+++ b/src/spdk/lib/event/subsystem.c
@@ -0,0 +1,288 @@
+/*-
+ *   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.
+ */
+
+#include "spdk/stdinc.h"
+
+#include "spdk/log.h"
+#include "spdk/thread.h"
+
+#include "spdk_internal/event.h"
+#include "spdk/env.h"
+
+TAILQ_HEAD(spdk_subsystem_list, spdk_subsystem);
+struct spdk_subsystem_list g_subsystems = TAILQ_HEAD_INITIALIZER(g_subsystems);
+
+TAILQ_HEAD(spdk_subsystem_depend_list, spdk_subsystem_depend);
+struct spdk_subsystem_depend_list g_subsystems_deps = TAILQ_HEAD_INITIALIZER(g_subsystems_deps);
+static struct spdk_subsystem *g_next_subsystem;
+static bool g_subsystems_initialized = false;
+static bool g_subsystems_init_interrupted = false;
+static spdk_subsystem_init_fn g_subsystem_start_fn = NULL;
+static void *g_subsystem_start_arg = NULL;
+static spdk_msg_fn g_subsystem_stop_fn = NULL;
+static void *g_subsystem_stop_arg = NULL;
+static struct spdk_thread *g_fini_thread = NULL;
+
+void
+spdk_add_subsystem(struct spdk_subsystem *subsystem)
+{
+	TAILQ_INSERT_TAIL(&g_subsystems, subsystem, tailq);
+}
+
+void
+spdk_add_subsystem_depend(struct spdk_subsystem_depend *depend)
+{
+	TAILQ_INSERT_TAIL(&g_subsystems_deps, depend, tailq);
+}
+
+static struct spdk_subsystem *
+_subsystem_find(struct spdk_subsystem_list *list, const char *name)
+{
+	struct spdk_subsystem *iter;
+
+	TAILQ_FOREACH(iter, list, tailq) {
+		if (strcmp(name, iter->name) == 0) {
+			return iter;
+		}
+	}
+
+	return NULL;
+}
+
+struct spdk_subsystem *
+spdk_subsystem_find(const char *name)
+{
+	return _subsystem_find(&g_subsystems, name);
+}
+
+struct spdk_subsystem *
+spdk_subsystem_get_first(void)
+{
+	return TAILQ_FIRST(&g_subsystems);
+}
+
+struct spdk_subsystem *
+spdk_subsystem_get_next(struct spdk_subsystem *cur_subsystem)
+{
+	return TAILQ_NEXT(cur_subsystem, tailq);
+}
+
+
+struct spdk_subsystem_depend *
+spdk_subsystem_get_first_depend(void)
+{
+	return TAILQ_FIRST(&g_subsystems_deps);
+}
+
+struct spdk_subsystem_depend *
+spdk_subsystem_get_next_depend(struct spdk_subsystem_depend *cur_depend)
+{
+	return TAILQ_NEXT(cur_depend, tailq);
+}
+
+static void
+subsystem_sort(void)
+{
+	bool depends_on, depends_on_sorted;
+	struct spdk_subsystem *subsystem, *subsystem_tmp;
+	struct spdk_subsystem_depend *subsystem_dep;
+
+	struct spdk_subsystem_list subsystems_list = TAILQ_HEAD_INITIALIZER(subsystems_list);
+
+	while (!TAILQ_EMPTY(&g_subsystems)) {
+		TAILQ_FOREACH_SAFE(subsystem, &g_subsystems, tailq, subsystem_tmp) {
+			depends_on = false;
+			TAILQ_FOREACH(subsystem_dep, &g_subsystems_deps, tailq) {
+				if (strcmp(subsystem->name, subsystem_dep->name) == 0) {
+					depends_on = true;
+					depends_on_sorted = !!_subsystem_find(&subsystems_list, subsystem_dep->depends_on);
+					if (depends_on_sorted) {
+						continue;
+					}
+					break;
+				}
+			}
+
+			if (depends_on == false) {
+				TAILQ_REMOVE(&g_subsystems, subsystem, tailq);
+				TAILQ_INSERT_TAIL(&subsystems_list, subsystem, tailq);
+			} else {
+				if (depends_on_sorted == true) {
+					TAILQ_REMOVE(&g_subsystems, subsystem, tailq);
+					TAILQ_INSERT_TAIL(&subsystems_list, subsystem, tailq);
+				}
+			}
+		}
+	}
+
+	TAILQ_FOREACH_SAFE(subsystem, &subsystems_list, tailq, subsystem_tmp) {
+		TAILQ_REMOVE(&subsystems_list, subsystem, tailq);
+		TAILQ_INSERT_TAIL(&g_subsystems, subsystem, tailq);
+	}
+}
+
+void
+spdk_subsystem_init_next(int rc)
+{
+	/* The initialization is interrupted by the spdk_subsystem_fini, so just return */
+	if (g_subsystems_init_interrupted) {
+		return;
+	}
+
+	if (rc) {
+		SPDK_ERRLOG("Init subsystem %s failed\n", g_next_subsystem->name);
+		g_subsystem_start_fn(rc, g_subsystem_start_arg);
+		return;
+	}
+
+	if (!g_next_subsystem) {
+		g_next_subsystem = TAILQ_FIRST(&g_subsystems);
+	} else {
+		g_next_subsystem = TAILQ_NEXT(g_next_subsystem, tailq);
+	}
+
+	if (!g_next_subsystem) {
+		g_subsystems_initialized = true;
+		g_subsystem_start_fn(0, g_subsystem_start_arg);
+		return;
+	}
+
+	if (g_next_subsystem->init) {
+		g_next_subsystem->init();
+	} else {
+		spdk_subsystem_init_next(0);
+	}
+}
+
+void
+spdk_subsystem_init(spdk_subsystem_init_fn cb_fn, void *cb_arg)
+{
+	struct spdk_subsystem_depend *dep;
+
+	g_subsystem_start_fn = cb_fn;
+	g_subsystem_start_arg = cb_arg;
+
+	/* Verify that all dependency name and depends_on subsystems are registered */
+	TAILQ_FOREACH(dep, &g_subsystems_deps, tailq) {
+		if (!spdk_subsystem_find(dep->name)) {
+			SPDK_ERRLOG("subsystem %s is missing\n", dep->name);
+			g_subsystem_start_fn(-1, g_subsystem_start_arg);
+			return;
+		}
+		if (!spdk_subsystem_find(dep->depends_on)) {
+			SPDK_ERRLOG("subsystem %s dependency %s is missing\n",
+				    dep->name, dep->depends_on);
+			g_subsystem_start_fn(-1, g_subsystem_start_arg);
+			return;
+		}
+	}
+
+	subsystem_sort();
+
+	spdk_subsystem_init_next(0);
+}
+
+static void
+subsystem_fini_next(void *arg1)
+{
+	assert(g_fini_thread == spdk_get_thread());
+
+	if (!g_next_subsystem) {
+		/* If the initialized flag is false, then we've failed to initialize
+		 * the very first subsystem and no de-init is needed
+		 */
+		if (g_subsystems_initialized) {
+			g_next_subsystem = TAILQ_LAST(&g_subsystems, spdk_subsystem_list);
+		}
+	} else {
+		if (g_subsystems_initialized || g_subsystems_init_interrupted) {
+			g_next_subsystem = TAILQ_PREV(g_next_subsystem, spdk_subsystem_list, tailq);
+		} else {
+			g_subsystems_init_interrupted = true;
+		}
+	}
+
+	while (g_next_subsystem) {
+		if (g_next_subsystem->fini) {
+			g_next_subsystem->fini();
+			return;
+		}
+		g_next_subsystem = TAILQ_PREV(g_next_subsystem, spdk_subsystem_list, tailq);
+	}
+
+	g_subsystem_stop_fn(g_subsystem_stop_arg);
+	return;
+}
+
+void
+spdk_subsystem_fini_next(void)
+{
+	if (g_fini_thread != spdk_get_thread()) {
+		spdk_thread_send_msg(g_fini_thread, subsystem_fini_next, NULL);
+	} else {
+		subsystem_fini_next(NULL);
+	}
+}
+
+void
+spdk_subsystem_fini(spdk_msg_fn cb_fn, void *cb_arg)
+{
+	g_subsystem_stop_fn = cb_fn;
+	g_subsystem_stop_arg = cb_arg;
+
+	g_fini_thread = spdk_get_thread();
+
+	spdk_subsystem_fini_next();
+}
+
+void
+spdk_subsystem_config(FILE *fp)
+{
+	struct spdk_subsystem *subsystem;
+
+	TAILQ_FOREACH(subsystem, &g_subsystems, tailq) {
+		if (subsystem->config) {
+			subsystem->config(fp);
+		}
+	}
+}
+
+void
+spdk_subsystem_config_json(struct spdk_json_write_ctx *w, struct spdk_subsystem *subsystem)
+{
+	if (subsystem && subsystem->write_config_json) {
+		subsystem->write_config_json(w);
+	} else {
+		spdk_json_write_null(w);
+	}
+}