xref: /spdk/lib/notify/notify.c (revision a6dbe3721eb3b5990707fc3e378c95e505dd8ab5)
1  /*   SPDX-License-Identifier: BSD-3-Clause
2   *   Copyright (C) 2018 Intel Corporation.
3   *   All rights reserved.
4   */
5  
6  #include <sys/queue.h>
7  
8  #include "spdk/stdinc.h"
9  #include "spdk/util.h"
10  #include "spdk/queue.h"
11  #include "spdk/string.h"
12  #include "spdk/log.h"
13  
14  #include "spdk/notify.h"
15  
16  #define SPDK_NOTIFY_MAX_EVENTS	1024
17  
18  struct spdk_notify_type {
19  	char name[SPDK_NOTIFY_MAX_NAME_SIZE];
20  	TAILQ_ENTRY(spdk_notify_type) tailq;
21  };
22  
23  pthread_mutex_t g_events_lock = PTHREAD_MUTEX_INITIALIZER;
24  static struct spdk_notify_event g_events[SPDK_NOTIFY_MAX_EVENTS];
25  static uint64_t g_events_head;
26  
27  static TAILQ_HEAD(, spdk_notify_type) g_notify_types = TAILQ_HEAD_INITIALIZER(g_notify_types);
28  
29  struct spdk_notify_type *
30  spdk_notify_type_register(const char *type)
31  {
32  	struct spdk_notify_type *it = NULL;
33  
34  	if (!type) {
35  		SPDK_ERRLOG("Invalid notification type %p\n", type);
36  		return NULL;
37  	} else if (!type[0] || strlen(type) >= SPDK_NOTIFY_MAX_NAME_SIZE) {
38  		SPDK_ERRLOG("Notification type '%s' too short or too long\n", type);
39  		return NULL;
40  	}
41  
42  	pthread_mutex_lock(&g_events_lock);
43  	TAILQ_FOREACH(it, &g_notify_types, tailq) {
44  		if (strcmp(type, it->name) == 0) {
45  			SPDK_NOTICELOG("Notification type '%s' already registered.\n", type);
46  			goto out;
47  		}
48  	}
49  
50  	it = calloc(1, sizeof(*it));
51  	if (it == NULL) {
52  		goto out;
53  	}
54  
55  	snprintf(it->name, sizeof(it->name), "%s", type);
56  	TAILQ_INSERT_TAIL(&g_notify_types, it, tailq);
57  
58  out:
59  	pthread_mutex_unlock(&g_events_lock);
60  	return it;
61  }
62  
63  const char *
64  spdk_notify_type_get_name(const struct spdk_notify_type *type)
65  {
66  	return type->name;
67  }
68  
69  
70  void
71  spdk_notify_foreach_type(spdk_notify_foreach_type_cb cb, void *ctx)
72  {
73  	struct spdk_notify_type *it;
74  
75  	pthread_mutex_lock(&g_events_lock);
76  	TAILQ_FOREACH(it, &g_notify_types, tailq) {
77  		if (cb(it, ctx)) {
78  			break;
79  		}
80  	}
81  	pthread_mutex_unlock(&g_events_lock);
82  }
83  
84  uint64_t
85  spdk_notify_send(const char *type, const char *ctx)
86  {
87  	uint64_t head;
88  	struct spdk_notify_event *ev;
89  
90  	pthread_mutex_lock(&g_events_lock);
91  	head = g_events_head;
92  	g_events_head++;
93  
94  	ev = &g_events[head % SPDK_NOTIFY_MAX_EVENTS];
95  	spdk_strcpy_pad(ev->type, type, sizeof(ev->type), '\0');
96  	spdk_strcpy_pad(ev->ctx, ctx, sizeof(ev->ctx), '\0');
97  	pthread_mutex_unlock(&g_events_lock);
98  
99  	return head;
100  }
101  
102  uint64_t
103  spdk_notify_foreach_event(uint64_t start_idx, uint64_t max,
104  			  spdk_notify_foreach_event_cb cb_fn, void *ctx)
105  {
106  	uint64_t i;
107  
108  	pthread_mutex_lock(&g_events_lock);
109  
110  	if (g_events_head > SPDK_NOTIFY_MAX_EVENTS && start_idx < g_events_head - SPDK_NOTIFY_MAX_EVENTS) {
111  		start_idx = g_events_head - SPDK_NOTIFY_MAX_EVENTS;
112  	}
113  
114  	for (i = 0; start_idx < g_events_head && i < max; start_idx++, i++) {
115  		if (cb_fn(start_idx, &g_events[start_idx % SPDK_NOTIFY_MAX_EVENTS], ctx)) {
116  			break;
117  		}
118  	}
119  	pthread_mutex_unlock(&g_events_lock);
120  
121  	return i;
122  }
123