1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
/*
* $Header$
*
* Copyright 2006, 2007 Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
#include "ccapi_context_change_time.h"
#include "cci_common.h"
#include "k5-thread.h"
static cci_identifier_t g_change_time_identifer = NULL;
static cc_time_t g_change_time = 0;
static cc_time_t g_change_time_offset = 0;
static k5_mutex_t g_change_time_mutex = K5_MUTEX_PARTIAL_INITIALIZER;
/* ------------------------------------------------------------------------ */
cc_int32 cci_context_change_time_thread_init (void)
{
return k5_mutex_finish_init(&g_change_time_mutex);
}
/* ------------------------------------------------------------------------ */
/* WARNING! Mutex must be locked when calling this! */
static cc_int32 cci_context_change_time_update_identifier (cci_identifier_t in_new_identifier,
cc_uint32 *out_server_ids_match,
cc_uint32 *out_old_server_running,
cc_uint32 *out_new_server_running)
{
cc_int32 err = ccNoError;
cc_uint32 server_ids_match = 0;
cc_uint32 old_server_running = 0;
cc_uint32 new_server_running = 0;
if (!in_new_identifier) { err = cci_check_error (err); }
if (!err && !g_change_time_identifer) {
g_change_time_identifer = cci_identifier_uninitialized;
}
if (!err) {
err = cci_identifier_compare_server_id (g_change_time_identifer,
in_new_identifier,
&server_ids_match);
}
if (!err && out_old_server_running) {
err = cci_identifier_is_initialized (g_change_time_identifer, &old_server_running);
}
if (!err && out_new_server_running) {
err = cci_identifier_is_initialized (in_new_identifier, &new_server_running);
}
if (!err && !server_ids_match) {
cci_identifier_t new_change_time_identifer = NULL;
err = cci_identifier_copy (&new_change_time_identifer, in_new_identifier);
if (!err) {
/* Save the new identifier */
if (g_change_time_identifer) {
cci_identifier_release (g_change_time_identifer);
}
g_change_time_identifer = new_change_time_identifer;
}
}
if (!err) {
if (out_server_ids_match ) { *out_server_ids_match = server_ids_match; }
if (out_old_server_running) { *out_old_server_running = old_server_running; }
if (out_new_server_running) { *out_new_server_running = new_server_running; }
}
return cci_check_error (err);
}
#ifdef TARGET_OS_MAC
#pragma mark -
#endif
/* ------------------------------------------------------------------------ */
cc_int32 cci_context_change_time_get (cc_time_t *out_change_time)
{
cc_int32 err = ccNoError;
err = k5_mutex_lock (&g_change_time_mutex);
if (!err) {
*out_change_time = g_change_time + g_change_time_offset;
k5_mutex_unlock (&g_change_time_mutex);
}
return err;
}
/* ------------------------------------------------------------------------ */
cc_int32 cci_context_change_time_update (cci_identifier_t in_identifier,
cc_time_t in_new_change_time)
{
cc_int32 err = ccNoError;
cc_int32 lock_err = err = k5_mutex_lock (&g_change_time_mutex);
if (!err) {
if (!in_identifier) { err = cci_check_error (err); }
}
if (!err) {
if (g_change_time < in_new_change_time) {
/* Only update if it increases the time. May be a different server. */
g_change_time = in_new_change_time;
cci_debug_printf ("%s: setting change time to %d",
__FUNCTION__, in_new_change_time);
}
}
if (!err) {
err = cci_context_change_time_update_identifier (in_identifier,
NULL, NULL, NULL);
}
if (!lock_err) {
k5_mutex_unlock (&g_change_time_mutex);
}
return err;
}
/* ------------------------------------------------------------------------ */
cc_int32 cci_context_change_time_sync (cci_identifier_t in_new_identifier)
{
cc_int32 err = ccNoError;
cc_int32 lock_err = err = k5_mutex_lock (&g_change_time_mutex);
cc_uint32 server_ids_match = 0;
cc_uint32 server_was_running = 0;
cc_uint32 server_is_running = 0;
if (!err) {
if (!in_new_identifier) { err = cci_check_error (err); }
}
if (!err) {
err = cci_context_change_time_update_identifier (in_new_identifier,
&server_ids_match,
&server_was_running,
&server_is_running);
}
if (!err && !server_ids_match) {
/* Increment the change time so callers re-read */
g_change_time_offset++;
/* If the server died, absorb the offset */
if (server_was_running && !server_is_running) {
cc_time_t now = time (NULL);
g_change_time += g_change_time_offset;
g_change_time_offset = 0;
/* Make sure the change time increases, ideally with the current time */
g_change_time = (g_change_time < now) ? now : g_change_time;
}
cci_debug_printf ("%s noticed server changed ("
"server_was_running = %d; server_is_running = %d; "
"g_change_time = %d; g_change_time_offset = %d",
__FUNCTION__, server_was_running, server_is_running,
g_change_time, g_change_time_offset);
}
if (!lock_err) {
k5_mutex_unlock (&g_change_time_mutex);
}
return err;
}
|