int main(int argc, char *argv[])
{
int network_socket,client_socket;
struct sockaddr_in server_address;
int connection_status;
server_address.sin_family = AF_INET;
server_address.sin_port = htons(atoi(argv[1]));
server_address.sin_addr.s_addr = INADDR_ANY;
network_socket = socket(AF_INET,SOCK_STREAM,0);
bind(network_socket, (struct sockaddr*)&server_address,sizeof(server_address));
listen(network_socket,2);
printf("Waiting for Connection..\n");
client_socket = accept(network_socket,NULL,NULL);
char buf[50];
connection_status = recv(client_socket,buf,50,0);
checkConnectionStatus(connection_status);
buf[connection_status] = '\0';
printf("Recv: %s\n",buf);
char *received = "received";
connection_status = send(client_socket,received, sizeof(char)*strlen(received),0);
checkConnectionStatus(connection_status);
printf("Received Sent...\n");
connection_status = recv(client_socket,buf,50,0);
checkConnectionStatus(connection_status);
buf[connection_status] = '\0';
printf("Recv: %s\n",buf);
connection_status = send(client_socket,received, sizeof(char)*strlen(received),0);
checkConnectionStatus(connection_status);
printf("Received Sent...\n");
close(client_socket);
close(network_socket);
return 0;
}
/*
* Creates a new gang by logging on a session to each segDB involved.
*
* call this function in GangContext memory context.
* elog ERROR or return a non-NULL gang.
*/
static Gang *
createGang_thread(GangType type, int gang_id, int size, int content)
{
Gang *newGangDefinition = NULL;
SegmentDatabaseDescriptor *segdbDesc = NULL;
DoConnectParms *doConnectParmsAr = NULL;
DoConnectParms *pParms = NULL;
int parmIndex = 0;
int threadCount = 0;
int i = 0;
int create_gang_retry_counter = 0;
int in_recovery_mode_count = 0;
int successful_connections = 0;
PQExpBufferData create_gang_error;
ELOG_DISPATCHER_DEBUG("createGang type = %d, gang_id = %d, size = %d, content = %d",
type, gang_id, size, content);
/* check arguments */
Assert(size == 1 || size == getgpsegmentCount());
Assert(CurrentResourceOwner != NULL);
Assert(CurrentMemoryContext == GangContext);
Assert(gp_connections_per_thread > 0);
/* Writer gang is created before reader gangs. */
if (type == GANGTYPE_PRIMARY_WRITER)
Insist(!GangsExist());
initPQExpBuffer(&create_gang_error);
Assert(CurrentGangCreating == NULL);
create_gang_retry:
/*
* If we're in a retry, we may need to reset our initial state a bit. We
* also want to ensure that all resources have been released.
*/
Assert(newGangDefinition == NULL);
Assert(doConnectParmsAr == NULL);
successful_connections = 0;
in_recovery_mode_count = 0;
threadCount = 0;
/* allocate and initialize a gang structure */
newGangDefinition = buildGangDefinition(type, gang_id, size, content);
CurrentGangCreating = newGangDefinition;
Assert(newGangDefinition != NULL);
Assert(newGangDefinition->size == size);
Assert(newGangDefinition->perGangContext != NULL);
MemoryContextSwitchTo(newGangDefinition->perGangContext);
resetPQExpBuffer(&create_gang_error);
/*
* The most threads we could have is segdb_count /
* gp_connections_per_thread, rounded up. This is equivalent to 1 +
* (segdb_count-1) / gp_connections_per_thread. We allocate enough memory
* for this many DoConnectParms structures, even though we may not use
* them all.
*/
threadCount = 1 + (size - 1) / gp_connections_per_thread;
Assert(threadCount > 0);
/* initialize connect parameters */
doConnectParmsAr = makeConnectParms(threadCount, type, gang_id);
for (i = 0; i < size; i++)
{
parmIndex = i / gp_connections_per_thread;
pParms = &doConnectParmsAr[parmIndex];
segdbDesc = &newGangDefinition->db_descriptors[i];
pParms->segdbDescPtrArray[pParms->db_count++] = segdbDesc;
}
/* start threads and doing the connect */
for (i = 0; i < threadCount; i++)
{
int pthread_err;
pParms = &doConnectParmsAr[i];
ELOG_DISPATCHER_DEBUG("createGang creating thread %d of %d for libpq connections",
i + 1, threadCount);
pthread_err = gp_pthread_create(&pParms->thread, thread_DoConnect, pParms, "createGang");
if (pthread_err != 0)
{
int j;
/*
* Error during thread create (this should be caused by resource
* constraints). If we leave the threads running, they'll
* immediately have some problems -- so we need to join them, and
* *then* we can issue our FATAL error
*/
for (j = 0; j < i; j++)
{
pthread_join(doConnectParmsAr[j].thread, NULL);
}
ereport(FATAL, (errcode(ERRCODE_INTERNAL_ERROR),
errmsg("failed to create thread %d of %d", i + 1, threadCount),
errdetail("pthread_create() failed with err %d", pthread_err)));
}
}
/*
* wait for all of the DoConnect threads to complete.
*/
for (i = 0; i < threadCount; i++)
{
ELOG_DISPATCHER_DEBUG("joining to thread %d of %d for libpq connections",
i + 1, threadCount);
if (0 != pthread_join(doConnectParmsAr[i].thread, NULL))
{
elog(FATAL, "could not create segworker group");
}
}
/*
* Free the memory allocated for the threadParms array
*/
destroyConnectParms(doConnectParmsAr, threadCount);
doConnectParmsAr = NULL;
SIMPLE_FAULT_INJECTOR(GangCreated);
/* find out the successful connections and the failed ones */
checkConnectionStatus(newGangDefinition, &in_recovery_mode_count,
&successful_connections, &create_gang_error);
ELOG_DISPATCHER_DEBUG("createGang: %d processes requested; %d successful connections %d in recovery",
size, successful_connections, in_recovery_mode_count);
MemoryContextSwitchTo(GangContext);
if (size == successful_connections)
{
setLargestGangsize(size);
termPQExpBuffer(&create_gang_error);
CurrentGangCreating = NULL;
return newGangDefinition;
}
/* there'er failed connections */
/* FTS shows some segment DBs are down, destroy all gangs. */
if (isFTSEnabled() &&
FtsTestSegmentDBIsDown(newGangDefinition->db_descriptors, size))
{
appendPQExpBuffer(&create_gang_error, "FTS detected one or more segments are down\n");
goto exit;
}
/* failure due to recovery */
if (successful_connections + in_recovery_mode_count == size)
{
if (gp_gang_creation_retry_count &&
create_gang_retry_counter++ < gp_gang_creation_retry_count &&
type == GANGTYPE_PRIMARY_WRITER)
{
/*
* Retry for non-writer gangs is meaningless because writer gang
* must be gone when QE is in recovery mode
*/
DisconnectAndDestroyGang(newGangDefinition);
newGangDefinition = NULL;
CurrentGangCreating = NULL;
ELOG_DISPATCHER_DEBUG("createGang: gang creation failed, but retryable.");
CHECK_FOR_INTERRUPTS();
pg_usleep(gp_gang_creation_retry_timer * 1000);
CHECK_FOR_INTERRUPTS();
goto create_gang_retry;
}
appendPQExpBuffer(&create_gang_error, "segment(s) are in recovery mode\n");
}
exit:
if (newGangDefinition != NULL)
DisconnectAndDestroyGang(newGangDefinition);
if (type == GANGTYPE_PRIMARY_WRITER)
{
DisconnectAndDestroyAllGangs(true);
CheckForResetSession();
}
CurrentGangCreating = NULL;
ereport(ERROR,
(errcode(ERRCODE_GP_INTERCONNECTION_ERROR),
errmsg("failed to acquire resources on one or more segments"),
errdetail("%s", create_gang_error.data)));
return NULL;
}
