void virNetServerServiceToggle(virNetServerServicePtr svc,
bool enabled)
{
int i;
for (i = 0 ; i < svc->nsocks ; i++)
virNetSocketUpdateIOCallback(svc->socks[i],
enabled ?
VIR_EVENT_HANDLE_READABLE :
0);
}
/*
* @client: a locked client object
*/
static void virNetServerClientUpdateEvent(virNetServerClientPtr client)
{
int mode;
if (!client->sock)
return;
mode = virNetServerClientCalculateHandleMode(client);
virNetSocketUpdateIOCallback(client->sock, mode);
if (client->rx && virNetSocketHasCachedData(client->sock))
virEventUpdateTimeout(client->sockTimer, 0);
}
static void
libxlDoMigrateReceive(virNetSocketPtr sock,
int events ATTRIBUTE_UNUSED,
void *opaque)
{
libxlMigrationDstArgs *args = opaque;
virConnectPtr conn = args->conn;
virDomainObjPtr vm = args->vm;
virNetSocketPtr *socks = args->socks;
size_t nsocks = args->nsocks;
bool paused = args->flags & VIR_MIGRATE_PAUSED;
libxlDriverPrivatePtr driver = conn->privateData;
virNetSocketPtr client_sock;
int recvfd = -1;
size_t i;
int ret;
if (virNetSocketAccept(sock, &client_sock) < 0) {
virReportError(VIR_ERR_OPERATION_INVALID, "%s",
_("Fail to accept migration connection"));
goto cleanup;
}
VIR_DEBUG("Accepted migration connection\n");
recvfd = virNetSocketDupFD(client_sock, true);
virObjectUnref(client_sock);
virObjectLock(vm);
ret = libxlDomainStart(driver, vm, paused, recvfd);
virObjectUnlock(vm);
if (ret < 0 && !vm->persistent)
virDomainObjListRemove(driver->domains, vm);
cleanup:
/* Remove all listen socks from event handler, and close them. */
for (i = 0; i < nsocks; i++) {
virNetSocketUpdateIOCallback(socks[i], 0);
virNetSocketRemoveIOCallback(socks[i]);
virNetSocketClose(socks[i]);
virObjectUnref(socks[i]);
socks[i] = NULL;
}
args->nsocks = 0;
VIR_FORCE_CLOSE(recvfd);
}
/*
* Handles read/write of monitor data on the monitor server side
*/
static void qemuMonitorTestIO(virNetSocketPtr sock,
int events,
void *opaque)
{
qemuMonitorTestPtr test = opaque;
bool err = false;
virMutexLock(&test->lock);
if (events & VIR_EVENT_HANDLE_WRITABLE) {
ssize_t ret;
if ((ret = virNetSocketWrite(sock,
test->outgoing,
test->outgoingLength)) < 0) {
err = true;
goto cleanup;
}
memmove(test->outgoing,
test->outgoing + ret,
test->outgoingLength - ret);
test->outgoingLength -= ret;
if ((test->outgoingCapacity - test->outgoingLength) > 1024)
VIR_SHRINK_N(test->outgoing, test->outgoingCapacity, 1024);
}
if (events & VIR_EVENT_HANDLE_READABLE) {
ssize_t ret, used;
char *t1, *t2;
if ((test->incomingCapacity - test->incomingLength) < 1024) {
if (VIR_EXPAND_N(test->incoming, test->incomingCapacity, 1024) < 0) {
err = true;
goto cleanup;
}
}
if ((ret = virNetSocketRead(sock,
test->incoming + test->incomingLength,
(test->incomingCapacity - test->incomingLength) - 1)) < 0) {
err = true;
goto cleanup;
}
test->incomingLength += ret;
test->incoming[test->incomingLength] = '\0';
/* Look to see if we've got a complete line, and
* if so, handle that command
*/
t1 = test->incoming;
while ((t2 = strstr(t1, "\r\n"))) {
*t2 = '\0';
if (qemuMonitorTestProcessCommand(test, t1) < 0) {
err = true;
goto cleanup;
}
t1 = t2 + 2;
}
used = t1 - test->incoming;
memmove(test->incoming, t1, test->incomingLength - used);
test->incomingLength -= used;
if ((test->incomingCapacity - test->incomingLength) > 1024) {
VIR_SHRINK_N(test->incoming,
test->incomingCapacity,
1024);
}
}
if (events & (VIR_EVENT_HANDLE_HANGUP |
VIR_EVENT_HANDLE_ERROR))
err = true;
cleanup:
if (err) {
virNetSocketRemoveIOCallback(sock);
virNetSocketClose(sock);
virObjectUnref(test->client);
test->client = NULL;
} else {
events = VIR_EVENT_HANDLE_READABLE;
if (test->outgoingLength)
events |= VIR_EVENT_HANDLE_WRITABLE;
virNetSocketUpdateIOCallback(sock, events);
}
virMutexUnlock(&test->lock);
}
/*
* This function sends a message to remote server and awaits a reply
*
* NB. This does not free the args structure (not desirable, since you
* often want this allocated on the stack or else it contains strings
* which come from the user). It does however free any intermediate
* results, eg. the error structure if there is one.
*
* NB(2). Make sure to memset (&ret, 0, sizeof ret) before calling,
* else Bad Things will happen in the XDR code.
*
* NB(3) You must have the client lock before calling this
*
* NB(4) This is very complicated. Multiple threads are allowed to
* use the client for RPC at the same time. Obviously only one of
* them can. So if someone's using the socket, other threads are put
* to sleep on condition variables. The existing thread may completely
* send & receive their RPC call/reply while they're asleep. Or it
* may only get around to dealing with sending the call. Or it may
* get around to neither. So upon waking up from slumber, the other
* thread may or may not have more work todo.
*
* We call this dance 'passing the buck'
*
* http://en.wikipedia.org/wiki/Passing_the_buck
*
* "Buck passing or passing the buck is the action of transferring
* responsibility or blame unto another person. It is also used as
* a strategy in power politics when the actions of one country/
* nation are blamed on another, providing an opportunity for war."
*
* NB(5) Don't Panic!
*/
static int virNetClientIO(virNetClientPtr client,
virNetClientCallPtr thiscall)
{
int rv = -1;
VIR_DEBUG("Outgoing message prog=%u version=%u serial=%u proc=%d type=%d length=%zu dispatch=%p",
thiscall->msg->header.prog,
thiscall->msg->header.vers,
thiscall->msg->header.serial,
thiscall->msg->header.proc,
thiscall->msg->header.type,
thiscall->msg->bufferLength,
client->waitDispatch);
/* Check to see if another thread is dispatching */
if (client->waitDispatch) {
/* Stick ourselves on the end of the wait queue */
virNetClientCallPtr tmp = client->waitDispatch;
char ignore = 1;
while (tmp && tmp->next)
tmp = tmp->next;
if (tmp)
tmp->next = thiscall;
else
client->waitDispatch = thiscall;
/* Force other thread to wakeup from poll */
if (safewrite(client->wakeupSendFD, &ignore, sizeof(ignore)) != sizeof(ignore)) {
if (tmp)
tmp->next = NULL;
else
client->waitDispatch = NULL;
virReportSystemError(errno, "%s",
_("failed to wake up polling thread"));
return -1;
}
VIR_DEBUG("Going to sleep %p %p", client->waitDispatch, thiscall);
/* Go to sleep while other thread is working... */
if (virCondWait(&thiscall->cond, &client->lock) < 0) {
if (client->waitDispatch == thiscall) {
client->waitDispatch = thiscall->next;
} else {
tmp = client->waitDispatch;
while (tmp && tmp->next &&
tmp->next != thiscall) {
tmp = tmp->next;
}
if (tmp && tmp->next == thiscall)
tmp->next = thiscall->next;
}
virNetError(VIR_ERR_INTERNAL_ERROR, "%s",
_("failed to wait on condition"));
return -1;
}
VIR_DEBUG("Wokeup from sleep %p %p", client->waitDispatch, thiscall);
/* Two reasons we can be woken up
* 1. Other thread has got our reply ready for us
* 2. Other thread is all done, and it is our turn to
* be the dispatcher to finish waiting for
* our reply
*/
if (thiscall->mode == VIR_NET_CLIENT_MODE_COMPLETE) {
rv = 0;
/*
* We avoided catching the buck and our reply is ready !
* We've already had 'thiscall' removed from the list
* so just need to (maybe) handle errors & free it
*/
goto cleanup;
}
/* Grr, someone passed the buck onto us ... */
} else {
/* We're first to catch the buck */
client->waitDispatch = thiscall;
}
VIR_DEBUG("We have the buck %p %p", client->waitDispatch, thiscall);
/*
* The buck stops here!
*
* At this point we're about to own the dispatch
* process...
*/
/*
* Avoid needless wake-ups of the event loop in the
* case where this call is being made from a different
* thread than the event loop. These wake-ups would
* cause the event loop thread to be blocked on the
* mutex for the duration of the call
*/
virNetSocketUpdateIOCallback(client->sock, 0);
virResetLastError();
rv = virNetClientIOEventLoop(client, thiscall);
virNetSocketUpdateIOCallback(client->sock, VIR_EVENT_HANDLE_READABLE);
if (rv == 0 &&
virGetLastError())
rv = -1;
cleanup:
VIR_DEBUG("All done with our call %p %p %d", client->waitDispatch, thiscall, rv);
return rv;
}
