void *fetch_thread(void * arg) {
struct request_queue * queue = (struct request_queue *)arg;
struct item * item;
enum protoCmd res;
for (int i = 0; i < NO_QUEUE_REQUESTS; i++) {
item = request_queue_fetch_request(queue);
}
}
/**
* This function is used as a the start function for the slave renderer thread.
* It pulls a request from the central queue of requests and dispatches it to
* the slave renderer. It then blocks and waits for the response with no timeout.
* As it only sends one request at a time (there are as many slave_thread threads as there
* are rendering threads on the slaves) nothing gets queued on the slave and should get
* rendererd immediately. Thus overall, requests should be nicely load balanced between
* all the rendering threads available both locally and in the slaves.
*/
void *slave_thread(void * arg) {
renderd_config * sConfig = (renderd_config *) arg;
int pfd = FD_INVALID;
int retry;
size_t ret_size;
struct protocol * resp;
struct protocol * req_slave;
req_slave = (struct protocol *)malloc(sizeof(struct protocol));
resp = (struct protocol *)malloc(sizeof(struct protocol));
bzero(req_slave, sizeof(struct protocol));
bzero(resp, sizeof(struct protocol));
while (1) {
if (pfd == FD_INVALID) {
pfd = client_socket_init(sConfig);
if (pfd == FD_INVALID) {
if (sConfig->ipport > 0) {
syslog(LOG_ERR,
"Failed to connect to render slave %s:%i, trying again in 30 seconds",
sConfig->iphostname, sConfig->ipport);
} else {
syslog( LOG_ERR,
"Failed to connect to render slave %s, trying again in 30 seconds",
sConfig->socketname);
}
sleep(30);
continue;
}
}
enum protoCmd ret;
struct item *item = request_queue_fetch_request(render_request_queue);
if (item) {
struct protocol *req = &item->req;
req_slave->ver = PROTO_VER;
req_slave->cmd = cmdRender;
strcpy(req_slave->xmlname, req->xmlname);
strcpy(req_slave->mimetype, req->mimetype);
strcpy(req_slave->options, req->options);
req_slave->x = req->x;
req_slave->y = req->y;
req_slave->z = req->z;
/*Dispatch request to slave renderd*/
retry = 2;
syslog(LOG_INFO,
"Dispatching request to slave thread on fd %i", pfd);
do {
ret_size = send_cmd(req_slave, pfd);
if (ret_size == sizeof(struct protocol)) {
//correctly sent command to slave
break;
}
if (errno != EPIPE) {
syslog(LOG_ERR,
"Failed to send cmd to render slave, shutting down thread");
free(resp);
free(req_slave);
close(pfd);
return NULL;
}
syslog(LOG_WARNING, "Failed to send cmd to render slave, retrying");
close(pfd);
pfd = client_socket_init(sConfig);
if (pfd == FD_INVALID) {
syslog(LOG_ERR,
"Failed to re-connect to render slave, dropping request");
ret = cmdNotDone;
send_response(item, ret, -1);
break;
}
} while (retry--);
if (pfd == FD_INVALID || ret_size != sizeof(struct protocol)) {
continue;
}
ret_size = 0;
retry = 10;
while ((ret_size < sizeof(struct protocol)) && (retry > 0)) {
ret_size = recv(pfd, resp + ret_size, (sizeof(struct protocol)
- ret_size), 0);
if ((errno == EPIPE) || ret_size == 0) {
close(pfd);
pfd = FD_INVALID;
ret_size = 0;
syslog(LOG_ERR, "Pipe to render slave closed");
break;
}
retry--;
}
if (ret_size < sizeof(struct protocol)) {
if (sConfig->ipport > 0) {
syslog( LOG_ERR,
"Invalid reply from render slave %s:%i, trying again in 30 seconds",
sConfig->iphostname, sConfig->ipport);
} else {
syslog( LOG_ERR,
"Invalid reply render slave %s, trying again in 30 seconds",
sConfig->socketname);
}
ret = cmdNotDone;
send_response(item, ret, -1);
sleep(30);
} else {
ret = resp->cmd;
send_response(item, ret, -1);
if (resp->cmd != cmdDone) {
if (sConfig->ipport > 0) {
syslog( LOG_ERR,
"Request from render slave %s:%i did not complete correctly",
sConfig->iphostname, sConfig->ipport);
} else {
syslog( LOG_ERR,
"Request from render slave %s did not complete correctly",
sConfig->socketname);
}
//Sleep for a while to make sure we don't overload the renderer
//This only happens if it didn't correctly block on the rendering
//request
sleep(30);
}
}
} else {
sleep(1); // TODO: Use an event to indicate there are new requests
}
}
free(resp);
free(req_slave);
return NULL;
}
