1/* Retrieve event.
2 Copyright (C) 1999-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <stddef.h>
20#include <string.h>
21
22#include "thread_dbP.h"
23
24
25td_err_e
26td_ta_event_getmsg (const td_thragent_t *ta_arg, td_event_msg_t *msg)
27{
28 td_thragent_t *const ta = (td_thragent_t *) ta_arg;
29 td_err_e err;
30 psaddr_t eventbuf, eventnum, eventdata;
31 psaddr_t thp, next;
32 void *copy;
33
34 /* XXX I cannot think of another way but using a static variable. */
35 /* XXX Use at least __thread once it is possible. */
36 static td_thrhandle_t th;
37
38 LOG ("td_thr_event_getmsg");
39
40 /* Test whether the TA parameter is ok. */
41 if (! ta_ok (ta))
42 return TD_BADTA;
43
44 /* Get the pointer to the thread descriptor with the last event. */
45 err = DB_GET_VALUE (thp, ta, __nptl_last_event, 0);
46 if (err != TD_OK)
47 return err;
48
49 if (thp == 0)
50 /* Nothing waiting. */
51 return TD_NOMSG;
52
53 /* Copy the event message buffer in from the inferior. */
54 err = DB_GET_FIELD_ADDRESS (eventbuf, ta, thp, pthread, eventbuf, 0);
55 if (err == TD_OK)
56 err = DB_GET_STRUCT (copy, ta, eventbuf, td_eventbuf_t);
57 if (err != TD_OK)
58 return err;
59
60 /* Read the event details from the target thread. */
61 err = DB_GET_FIELD_LOCAL (eventnum, ta, copy, td_eventbuf_t, eventnum, 0);
62 if (err != TD_OK)
63 return err;
64 /* If the structure is on the list there better be an event recorded. */
65 if ((int) (uintptr_t) eventnum == TD_EVENT_NONE)
66 return TD_DBERR;
67
68 /* Fill the user's data structure. */
69 err = DB_GET_FIELD_LOCAL (eventdata, ta, copy, td_eventbuf_t, eventdata, 0);
70 if (err != TD_OK)
71 return err;
72
73 /* Generate the thread descriptor. */
74 th.th_ta_p = (td_thragent_t *) ta;
75 th.th_unique = thp;
76
77 /* Fill the user's data structure. */
78 msg->msg.data = (uintptr_t) eventdata;
79 msg->event = (uintptr_t) eventnum;
80 msg->th_p = &th;
81
82 /* And clear the event message in the target. */
83 memset (copy, 0, ta->ta_sizeof_td_eventbuf_t);
84 err = DB_PUT_STRUCT (ta, eventbuf, td_eventbuf_t, copy);
85 if (err != TD_OK)
86 return err;
87
88 /* Get the pointer to the next descriptor with an event. */
89 err = DB_GET_FIELD (next, ta, thp, pthread, nextevent, 0);
90 if (err != TD_OK)
91 return err;
92
93 /* Store the pointer in the list head variable. */
94 err = DB_PUT_VALUE (ta, __nptl_last_event, 0, next);
95 if (err != TD_OK)
96 return err;
97
98 if (next != 0)
99 /* Clear the next pointer in the current descriptor. */
100 err = DB_PUT_FIELD (ta, thp, pthread, nextevent, 0, 0);
101
102 return err;
103}
104