Commit | Line | Data |
---|---|---|
14a00470 | 1 | /* Notification to GDB. |
28e7fd62 | 2 | Copyright (C) 1989-2013 Free Software Foundation, Inc. |
14a00470 YQ |
3 | |
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 3 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | /* Async notifications to GDB. When the state of remote target is | |
20 | changed or something interesting to GDB happened, async | |
21 | notifications are used to tell GDB. | |
22 | ||
23 | Each type of notification is represented by an object | |
24 | 'struct notif_server', in which there is a queue for events to GDB | |
25 | represented by 'struct notif_event'. GDBserver writes (by means of | |
26 | 'write' field) each event in the queue into the buffer and send the | |
27 | contents in buffer to GDB. The contents in buffer is specified in | |
28 | RSP. See more in the comments to field 'queue' of | |
29 | 'struct notif_server'. | |
30 | ||
31 | Here is the workflow of sending events and managing queue: | |
32 | 1. At any time, when something interesting FOO happens, a object | |
33 | of 'struct notif_event' or its sub-class EVENT is created for FOO. | |
34 | ||
35 | 2. Enque EVENT to the 'queue' field of 'struct notif_server' for | |
36 | FOO and send corresponding notification packet to GDB if EVENT is | |
37 | the first one. | |
38 | #1 and #2 are done by function 'notif_push'. | |
39 | ||
40 | 3. EVENT is not deque'ed until the ack of FOO from GDB arrives. | |
41 | Before ack of FOO arrives, FOO happens again, a new object of | |
42 | EVENT is created and enque EVENT silently. | |
43 | Once GDB has a chance to ack to FOO, it sends an ack to GDBserver, | |
44 | and GDBserver repeatedly sends events to GDB and gets ack of FOO, | |
45 | until queue is empty. Then, GDBserver sends 'OK' to GDB that all | |
46 | queued notification events are done. | |
47 | ||
48 | # 3 is done by function 'handle_notif_ack'. */ | |
49 | ||
50 | #include "notif.h" | |
51 | ||
52 | static struct notif_server *notifs[] = | |
53 | { | |
54 | ¬if_stop, | |
55 | }; | |
56 | ||
57 | /* Write another event or an OK, if there are no more left, to | |
58 | OWN_BUF. */ | |
59 | ||
60 | void | |
61 | notif_write_event (struct notif_server *notif, char *own_buf) | |
62 | { | |
63 | if (!QUEUE_is_empty (notif_event_p, notif->queue)) | |
64 | { | |
65 | struct notif_event *event | |
66 | = QUEUE_peek (notif_event_p, notif->queue); | |
67 | ||
68 | notif->write (event, own_buf); | |
69 | } | |
70 | else | |
71 | write_ok (own_buf); | |
72 | } | |
73 | ||
74 | /* Handle the ack in buffer OWN_BUF,and packet length is PACKET_LEN. | |
75 | Return 1 if the ack is handled, and return 0 if the contents | |
76 | in OWN_BUF is not a ack. */ | |
77 | ||
78 | int | |
79 | handle_notif_ack (char *own_buf, int packet_len) | |
80 | { | |
81 | int i = 0; | |
82 | struct notif_server *np = NULL; | |
83 | ||
84 | for (i = 0; i < ARRAY_SIZE (notifs); i++) | |
85 | { | |
86 | np = notifs[i]; | |
87 | if (strncmp (own_buf, np->ack_name, strlen (np->ack_name)) == 0 | |
88 | && packet_len == strlen (np->ack_name)) | |
89 | break; | |
90 | } | |
91 | ||
92 | if (np == NULL) | |
93 | return 0; | |
94 | ||
95 | /* If we're waiting for GDB to acknowledge a pending event, | |
96 | consider that done. */ | |
97 | if (!QUEUE_is_empty (notif_event_p, np->queue)) | |
98 | { | |
99 | struct notif_event *head | |
100 | = QUEUE_deque (notif_event_p, np->queue); | |
101 | ||
102 | if (remote_debug) | |
103 | fprintf (stderr, "%s: acking %d\n", np->ack_name, | |
104 | QUEUE_length (notif_event_p, np->queue)); | |
105 | ||
106 | xfree (head); | |
107 | } | |
108 | ||
109 | notif_write_event (np, own_buf); | |
110 | ||
111 | return 1; | |
112 | } | |
113 | ||
114 | /* Put EVENT to the queue of NOTIF. */ | |
115 | ||
116 | void | |
117 | notif_event_enque (struct notif_server *notif, | |
118 | struct notif_event *event) | |
119 | { | |
120 | QUEUE_enque (notif_event_p, notif->queue, event); | |
121 | ||
122 | if (remote_debug) | |
123 | fprintf (stderr, "pending events: %s %d\n", notif->notif_name, | |
124 | QUEUE_length (notif_event_p, notif->queue)); | |
125 | ||
126 | } | |
127 | ||
128 | /* Push one event NEW_EVENT of notification NP into NP->queue. */ | |
129 | ||
130 | void | |
131 | notif_push (struct notif_server *np, struct notif_event *new_event) | |
132 | { | |
133 | int is_first_event = QUEUE_is_empty (notif_event_p, np->queue); | |
134 | ||
135 | /* Something interesting. Tell GDB about it. */ | |
136 | notif_event_enque (np, new_event); | |
137 | ||
138 | /* If this is the first stop reply in the queue, then inform GDB | |
139 | about it, by sending a corresponding notification. */ | |
140 | if (is_first_event) | |
141 | { | |
142 | char buf[PBUFSIZ]; | |
143 | char *p = buf; | |
144 | ||
145 | xsnprintf (p, PBUFSIZ, "%s:", np->notif_name); | |
146 | p += strlen (p); | |
147 | ||
148 | np->write (new_event, p); | |
149 | putpkt_notif (buf); | |
150 | } | |
151 | } | |
152 | ||
153 | static void | |
154 | notif_event_xfree (struct notif_event *event) | |
155 | { | |
156 | xfree (event); | |
157 | } | |
158 | ||
159 | void | |
160 | initialize_notif (void) | |
161 | { | |
162 | int i = 0; | |
163 | ||
164 | for (i = 0; i < ARRAY_SIZE (notifs); i++) | |
165 | notifs[i]->queue | |
166 | = QUEUE_alloc (notif_event_p, notif_event_xfree); | |
167 | } |