hcq/MaxScale
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

dcb.c

Browse Source 
: dcb_alloc switched malloc to calloc, dcb->fd is initialized to -1. 
: dcb_process_zombies return value of close(fd) is checked. Closed fds are stored to conn_open array. 
: dcb_connect assigns new fd only if backend connection succeeds. Dcb is added to poll set in the same way, only if connect succeed.
gateway.c : conn_open array is initialized in main. For each created socket, a true is set to corresponding slot. Max. number of slots is 1024.
mysql_client_server_protocol.h : gw_do_connect_to declaration 
mysql_backend.c : gw_create_backend_connection returns rv >= 0 and a protocol which is assigned to backend_dcb. In error, -1 is returned and fd is not set.
mysql_client.c : conn_open array is kept up-to-date and protocol pointer is assigned also to dcb outside mysql_protocol_init.
mysql_common.c : gw_do_connect_to_backend 3rd argument is pointer to fd, not protocol. dcb is added to poll set later in dcb_connect.
skygw_debug.h : define conn_open[1024] array where open connections can be marked in debug build.
This commit is contained in:
vraatikka
2013-09-13 22:10:40 +03:00
parent c3fba63b45
commit 710fc5cfa6
7 changed files with 135 additions and 73 deletions
Download Patch File Download Diff File Expand all files Collapse all files

50
server/modules/protocol/mysql_backend.c
View File

@ -486,10 +486,13 @@ static int gw_error_backend_event(DCB *dcb) {
* This routine will connect to a backend server and it is called by dbc_connect
* in router->newSession
*
* @param backend The Backend DCB allocated from dcb_connect
* @param server The selected server to connect to
* @param session The current session from Client DCB
* @return 0 on Success or 1 on Failure.
* @param backend_dcb, in, out, use - backend DCB allocated from dcb_connect
* @param server, in, use - server to connect to
* @param session, in use - current session from client DCB
* @return 0/1 on Success and -1 on Failure.
* If succesful, returns positive fd to socket which is connected to
* backend server. Positive fd is copied to protocol and to dcb.
* If fails, fd == -1 and socket is closed.
*/
static int gw_create_backend_connection(
DCB *backend_dcb,
@ -507,66 +510,65 @@ static int gw_create_backend_connection(
skygw_log_write_flush(
LOGFILE_ERROR,
"%lu [gw_create_backend_connection] Failed to create "
"protocol object for back-end connection.",
"protocol object for backend connection.",
pthread_self());
goto return_fd;
}
rv = gw_do_connect_to_backend(server->name, server->port, protocol);
/**
* We could also move later, this in to the gw_do_connect_to_backend
* using protocol->descriptor
* NOTE that protocol->fd can be -1 too. Not sure if it is necessary.
*/
backend_dcb->fd = protocol->fd;
fd = backend_dcb->fd;
/** if succeed, fd > 0, -1 otherwise */
rv = gw_do_connect_to_backend(server->name, server->port, &fd);
/** Assign fd with protocol */
protocol->fd = fd;
/** Assign protocol with backend_dcb */
backend_dcb->protocol = protocol;
/** Set protocol state */
switch (rv) {
case 0:
ss_dassert(backend_dcb->fd > 0);
ss_dassert(fd > 0);
protocol->state = MYSQL_CONNECTED;
skygw_log_write(
LOGFILE_TRACE,
"%lu [gw_create_backend_connection] Established "
"connection to %s:%i, backend fd %d client "
"connection to %s:%i, protocol fd %d client "
"fd %d.",
pthread_self(),
server->name,
server->port,
backend_dcb->fd,
protocol->fd,
session->client->fd);
break;
case 1:
ss_dassert(backend_dcb->fd > 0);
ss_dassert(fd > 0);
protocol->state = MYSQL_PENDING_CONNECT;
skygw_log_write(
LOGFILE_TRACE,
"%lu [gw_create_backend_connection] Connection "
"pending to %s:%i, backend fd %d client fd %d.",
"pending to %s:%i, protocol fd %d client fd %d.",
pthread_self(),
server->name,
server->port,
backend_dcb->fd,
protocol->fd,
session->client->fd);
break;
default:
ss_dassert(backend_dcb->fd == -1);
ss_dassert(fd == -1);
ss_dassert(protocol->state == MYSQL_ALLOC);
skygw_log_write(
LOGFILE_ERROR,
"%lu [gw_create_backend_connection] Connection "
"failed to %s:%i, backend fd %d client fd %d.",
"failed to %s:%i, protocol fd %d client fd %d.",
pthread_self(),
server->name,
server->port,
backend_dcb->fd,
protocol->fd,
session->client->fd);
break;
} /**< switch */
return_fd:
ss_dassert(backend_dcb->fd == fd);
ss_dassert(backend_dcb->fd == protocol->fd);
return fd;
}