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14a00470 | 1 | /* Notification to GDB. |
3666a048 | 2 | Copyright (C) 1989-2021 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 | ||
d41f6d8e | 50 | #include "server.h" |
14a00470 YQ |
51 | #include "notif.h" |
52 | ||
53 | static struct notif_server *notifs[] = | |
54 | { | |
55 | ¬if_stop, | |
56 | }; | |
57 | ||
58 | /* Write another event or an OK, if there are no more left, to | |
59 | OWN_BUF. */ | |
60 | ||
61 | void | |
62 | notif_write_event (struct notif_server *notif, char *own_buf) | |
63 | { | |
b494cdff | 64 | if (!notif->queue.empty ()) |
14a00470 | 65 | { |
b494cdff | 66 | struct notif_event *event = notif->queue.front (); |
14a00470 YQ |
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 | { | |
e7f0d979 YQ |
81 | size_t i; |
82 | struct notif_server *np; | |
14a00470 YQ |
83 | |
84 | for (i = 0; i < ARRAY_SIZE (notifs); i++) | |
85 | { | |
e7f0d979 YQ |
86 | const char *ack_name = notifs[i]->ack_name; |
87 | ||
61012eef | 88 | if (startswith (own_buf, ack_name) |
e7f0d979 | 89 | && packet_len == strlen (ack_name)) |
14a00470 YQ |
90 | break; |
91 | } | |
92 | ||
e7f0d979 | 93 | if (i == ARRAY_SIZE (notifs)) |
14a00470 YQ |
94 | return 0; |
95 | ||
e7f0d979 YQ |
96 | np = notifs[i]; |
97 | ||
14a00470 YQ |
98 | /* If we're waiting for GDB to acknowledge a pending event, |
99 | consider that done. */ | |
b494cdff | 100 | if (!np->queue.empty ()) |
14a00470 | 101 | { |
b494cdff TT |
102 | struct notif_event *head = np->queue.front (); |
103 | np->queue.pop_front (); | |
14a00470 YQ |
104 | |
105 | if (remote_debug) | |
4eefa7bc | 106 | debug_printf ("%s: acking %d\n", np->ack_name, |
b494cdff | 107 | (int) np->queue.size ()); |
14a00470 | 108 | |
b494cdff | 109 | delete head; |
14a00470 YQ |
110 | } |
111 | ||
112 | notif_write_event (np, own_buf); | |
113 | ||
114 | return 1; | |
115 | } | |
116 | ||
117 | /* Put EVENT to the queue of NOTIF. */ | |
118 | ||
119 | void | |
120 | notif_event_enque (struct notif_server *notif, | |
121 | struct notif_event *event) | |
122 | { | |
b494cdff | 123 | notif->queue.push_back (event); |
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124 | |
125 | if (remote_debug) | |
4eefa7bc | 126 | debug_printf ("pending events: %s %d\n", notif->notif_name, |
b494cdff | 127 | (int) notif->queue.size ()); |
14a00470 YQ |
128 | |
129 | } | |
130 | ||
131 | /* Push one event NEW_EVENT of notification NP into NP->queue. */ | |
132 | ||
133 | void | |
134 | notif_push (struct notif_server *np, struct notif_event *new_event) | |
135 | { | |
b494cdff | 136 | bool is_first_event = np->queue.empty (); |
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137 | |
138 | /* Something interesting. Tell GDB about it. */ | |
139 | notif_event_enque (np, new_event); | |
140 | ||
141 | /* If this is the first stop reply in the queue, then inform GDB | |
142 | about it, by sending a corresponding notification. */ | |
143 | if (is_first_event) | |
144 | { | |
145 | char buf[PBUFSIZ]; | |
146 | char *p = buf; | |
147 | ||
148 | xsnprintf (p, PBUFSIZ, "%s:", np->notif_name); | |
149 | p += strlen (p); | |
150 | ||
151 | np->write (new_event, p); | |
152 | putpkt_notif (buf); | |
153 | } | |
154 | } |