Version 10.0.1
ex_thread.c

Shows how to access a database with multiple threads.

/*-
* Public Domain 2014-present MongoDB, Inc.
* Public Domain 2008-2014 WiredTiger, Inc.
*
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* ex_thread.c
* This is an example demonstrating how to create and access a simple
* table from multiple threads.
*/
#include "test_util.h"
static const char *home;
#define NUM_THREADS 10
static WT_THREAD_RET
scan_thread(void *conn_arg)
{
WT_CURSOR *cursor;
WT_SESSION *session;
int ret;
const char *key, *value;
conn = conn_arg;
error_check(conn->open_session(conn, NULL, NULL, &session));
error_check(session->open_cursor(session, "table:access", NULL, NULL, &cursor));
/* Show all records. */
while ((ret = cursor->next(cursor)) == 0) {
error_check(cursor->get_key(cursor, &key));
error_check(cursor->get_value(cursor, &value));
printf("Got record: %s : %s\n", key, value);
}
if (ret != WT_NOTFOUND)
fprintf(stderr, "WT_CURSOR.next: %s\n", session->strerror(session, ret));
return (WT_THREAD_RET_VALUE);
}
int
main(int argc, char *argv[])
{
WT_SESSION *session;
WT_CURSOR *cursor;
wt_thread_t threads[NUM_THREADS];
int i;
home = example_setup(argc, argv);
error_check(wiredtiger_open(home, NULL, "create", &conn));
error_check(conn->open_session(conn, NULL, NULL, &session));
error_check(session->create(session, "table:access", "key_format=S,value_format=S"));
error_check(session->open_cursor(session, "table:access", NULL, "overwrite", &cursor));
cursor->set_key(cursor, "key1");
cursor->set_value(cursor, "value1");
error_check(cursor->insert(cursor));
error_check(session->close(session, NULL));
for (i = 0; i < NUM_THREADS; i++)
error_check(__wt_thread_create(NULL, &threads[i], scan_thread, conn));
for (i = 0; i < NUM_THREADS; i++)
error_check(__wt_thread_join(NULL, &threads[i]));
error_check(conn->close(conn, NULL));
return (EXIT_SUCCESS);
}
WT_SESSION::create
int create(WT_SESSION *session, const char *name, const char *config)
Create a table, column group, index or file.
WT_SESSION::open_cursor
int open_cursor(WT_SESSION *session, const char *uri, WT_HANDLE_NULLABLE(WT_CURSOR) *to_dup, const char *config, WT_CURSOR **cursorp)
Open a new cursor on a data source or duplicate an existing cursor.
WT_CURSOR::get_key
int get_key(WT_CURSOR *cursor,...)
Get the key for the current record.
WT_CURSOR
A WT_CURSOR handle is the interface to a cursor.
Definition: wiredtiger.in:211
WT_CONNECTION::open_session
int open_session(WT_CONNECTION *connection, WT_EVENT_HANDLER *event_handler, const char *config, WT_SESSION **sessionp)
Open a session.
WT_CURSOR::next
int next(WT_CURSOR *cursor)
Return the next record.
WT_CURSOR::get_value
int get_value(WT_CURSOR *cursor,...)
Get the value for the current record.
WT_CONNECTION
A connection to a WiredTiger database.
Definition: wiredtiger.in:1968
WT_CONNECTION::close
int close(WT_HANDLE_CLOSED(WT_CONNECTION) *connection, const char *config)
Close a connection.
WT_CURSOR::set_value
void set_value(WT_CURSOR *cursor,...)
Set the value for the next operation.
wiredtiger_open
int wiredtiger_open(const char *home, WT_EVENT_HANDLER *event_handler, const char *config, WT_CONNECTION **connectionp)
Open a connection to a database.
WT_CURSOR::set_key
void set_key(WT_CURSOR *cursor,...)
Set the key for the next operation.
WT_NOTFOUND
#define WT_NOTFOUND
Item not found.
Definition: wiredtiger.in:3758
WT_SESSION
All data operations are performed in the context of a WT_SESSION.
Definition: wiredtiger.in:753
WT_SESSION::close
int close(WT_HANDLE_CLOSED(WT_SESSION) *session, const char *config)
Close the session handle.
WT_SESSION::strerror
const char * strerror(WT_SESSION *session, int error)
Return information about an error as a string.
WT_CURSOR::insert
int insert(WT_CURSOR *cursor)
Insert a record and optionally update an existing record.