diff options
Diffstat (limited to 'src/ccapi/lib/ccapi_context_change_time.c')
| -rw-r--r-- | src/ccapi/lib/ccapi_context_change_time.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/src/ccapi/lib/ccapi_context_change_time.c b/src/ccapi/lib/ccapi_context_change_time.c new file mode 100644 index 000000000000..ec6b955e9f7d --- /dev/null +++ b/src/ccapi/lib/ccapi_context_change_time.c @@ -0,0 +1,199 @@ +/* ccapi/lib/ccapi_context_change_time.c */ +/* + * 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); +} + +/* ------------------------------------------------------------------------ */ + +void cci_context_change_time_thread_fini (void) +{ + k5_mutex_destroy(&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; + + k5_mutex_lock (&g_change_time_mutex); + + *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; + k5_mutex_lock (&g_change_time_mutex); + + 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); + } + + 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_uint32 server_ids_match = 0; + cc_uint32 server_was_running = 0; + cc_uint32 server_is_running = 0; + + k5_mutex_lock (&g_change_time_mutex); + + 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); + } + + k5_mutex_unlock (&g_change_time_mutex); + + return err; +} |