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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-13 12:24:36 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-13 12:24:36 +0000
commit06eaf7232e9a920468c0f8d74dcf2fe8b555501c (patch)
treee2c7b5777f728320e5b5542b6213fd3591ba51e2 /client/async_example.c
parentInitial commit. (diff)
downloadmariadb-06eaf7232e9a920468c0f8d74dcf2fe8b555501c.tar.xz
mariadb-06eaf7232e9a920468c0f8d74dcf2fe8b555501c.zip
Adding upstream version 1:10.11.6.upstream/1%10.11.6
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'client/async_example.c')
-rw-r--r--client/async_example.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/client/async_example.c b/client/async_example.c
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+/*
+ Copyright 2011 Kristian Nielsen and Monty Program Ab.
+
+ This file is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+#ifndef _WIN32
+#include <poll.h>
+#else
+#include <WinSock2.h>
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <mysql.h>
+
+#define SL(s) (s), sizeof(s)
+
+static const char *my_groups[]= { "client", NULL };
+
+static int
+wait_for_mysql(MYSQL *mysql, int status)
+{
+#ifdef _WIN32
+ fd_set rs, ws, es;
+ int res;
+ struct timeval tv, *timeout;
+ my_socket s= mysql_get_socket(mysql);
+ FD_ZERO(&rs);
+ FD_ZERO(&ws);
+ FD_ZERO(&es);
+ if (status & MYSQL_WAIT_READ)
+ FD_SET(s, &rs);
+ if (status & MYSQL_WAIT_WRITE)
+ FD_SET(s, &ws);
+ if (status & MYSQL_WAIT_EXCEPT)
+ FD_SET(s, &es);
+ if (status & MYSQL_WAIT_TIMEOUT)
+ {
+ tv.tv_sec= mysql_get_timeout_value(mysql);
+ tv.tv_usec= 0;
+ timeout= &tv;
+ }
+ else
+ timeout= NULL;
+ res= select(1, &rs, &ws, &es, timeout);
+ if (res == 0)
+ return MYSQL_WAIT_TIMEOUT;
+ else if (res == SOCKET_ERROR)
+ {
+ /*
+ In a real event framework, we should handle errors and re-try the select.
+ */
+ return MYSQL_WAIT_TIMEOUT;
+ }
+ else
+ {
+ int status= 0;
+ if (FD_ISSET(s, &rs))
+ status|= MYSQL_WAIT_READ;
+ if (FD_ISSET(s, &ws))
+ status|= MYSQL_WAIT_WRITE;
+ if (FD_ISSET(s, &es))
+ status|= MYSQL_WAIT_EXCEPT;
+ return status;
+ }
+#else
+ struct pollfd pfd;
+ int timeout;
+ int res;
+
+ pfd.fd= mysql_get_socket(mysql);
+ pfd.events=
+ (status & MYSQL_WAIT_READ ? POLLIN : 0) |
+ (status & MYSQL_WAIT_WRITE ? POLLOUT : 0) |
+ (status & MYSQL_WAIT_EXCEPT ? POLLPRI : 0);
+ if (status & MYSQL_WAIT_TIMEOUT)
+ timeout= 1000*mysql_get_timeout_value(mysql);
+ else
+ timeout= -1;
+ res= poll(&pfd, 1, timeout);
+ if (res == 0)
+ return MYSQL_WAIT_TIMEOUT;
+ else if (res < 0)
+ {
+ /*
+ In a real event framework, we should handle EINTR and re-try the poll.
+ */
+ return MYSQL_WAIT_TIMEOUT;
+ }
+ else
+ {
+ int status= 0;
+ if (pfd.revents & POLLIN)
+ status|= MYSQL_WAIT_READ;
+ if (pfd.revents & POLLOUT)
+ status|= MYSQL_WAIT_WRITE;
+ if (pfd.revents & POLLPRI)
+ status|= MYSQL_WAIT_EXCEPT;
+ return status;
+ }
+#endif
+}
+
+static void
+fatal(MYSQL *mysql, const char *msg)
+{
+ fprintf(stderr, "%s: %s\n", msg, mysql_error(mysql));
+ exit(1);
+}
+
+static void
+doit(const char *host, const char *user, const char *password)
+{
+ int err;
+ MYSQL mysql, *ret;
+ MYSQL_RES *res;
+ MYSQL_ROW row;
+ int status;
+
+ mysql_init(&mysql);
+ mysql_options(&mysql, MYSQL_OPT_NONBLOCK, 0);
+ mysql_options(&mysql, MYSQL_READ_DEFAULT_GROUP, "myapp");
+
+ /* Returns 0 when done, else flag for what to wait for when need to block. */
+ status= mysql_real_connect_start(&ret, &mysql, host, user, password, NULL,
+ 0, NULL, 0);
+ while (status)
+ {
+ status= wait_for_mysql(&mysql, status);
+ status= mysql_real_connect_cont(&ret, &mysql, status);
+ }
+
+ if (!ret)
+ fatal(&mysql, "Failed to mysql_real_connect()");
+
+ status= mysql_real_query_start(&err, &mysql, SL("SHOW STATUS"));
+ while (status)
+ {
+ status= wait_for_mysql(&mysql, status);
+ status= mysql_real_query_cont(&err, &mysql, status);
+ }
+ if (err)
+ fatal(&mysql, "mysql_real_query() returns error");
+
+ /* This method cannot block. */
+ res= mysql_use_result(&mysql);
+ if (!res)
+ fatal(&mysql, "mysql_use_result() returns error");
+
+ for (;;)
+ {
+ status= mysql_fetch_row_start(&row, res);
+ while (status)
+ {
+ status= wait_for_mysql(&mysql, status);
+ status= mysql_fetch_row_cont(&row, res, status);
+ }
+ if (!row)
+ break;
+ printf("%s: %s\n", row[0], row[1]);
+ }
+ if (mysql_errno(&mysql))
+ fatal(&mysql, "Got error while retrieving rows");
+ mysql_free_result(res);
+
+ /*
+ mysql_close() sends a COM_QUIT packet, and so in principle could block
+ waiting for the socket to accept the data.
+ In practise, for many applications it will probably be fine to use the
+ blocking mysql_close().
+ */
+ status= mysql_close_start(&mysql);
+ while (status)
+ {
+ status= wait_for_mysql(&mysql, status);
+ status= mysql_close_cont(&mysql, status);
+ }
+}
+
+int
+main(int argc, char *argv[])
+{
+ int err;
+
+ if (argc != 4)
+ {
+ fprintf(stderr, "Usage: %s <host> <user> <password>\n", argv[0]);
+ exit(1);
+ }
+
+ err= mysql_library_init(argc, argv, (char **)my_groups);
+ if (err)
+ {
+ fprintf(stderr, "Fatal: mysql_library_init() returns error: %d\n", err);
+ exit(1);
+ }
+
+ doit(argv[1], argv[2], argv[3]);
+
+ mysql_library_end();
+
+ return 0;
+}