Merge pull request #6719

ec908d5 http: Force-exit event loop after predefined time (Wladimir J. van der Laan)
de9de2d http: Wait for worker threads to exit (Wladimir J. van der Laan)
5e0c221 Make HTTP server shutdown more graceful (Wladimir J. van der Laan)
This commit is contained in:
Wladimir J. van der Laan 2015-09-28 16:03:41 +02:00
commit 1a9f19a78d
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2 changed files with 67 additions and 10 deletions

View File

@ -72,13 +72,35 @@ private:
std::deque<WorkItem*> queue;
bool running;
size_t maxDepth;
int numThreads;
/** RAII object to keep track of number of running worker threads */
class ThreadCounter
{
public:
WorkQueue &wq;
ThreadCounter(WorkQueue &w): wq(w)
{
boost::lock_guard<boost::mutex> lock(wq.cs);
wq.numThreads += 1;
}
~ThreadCounter()
{
boost::lock_guard<boost::mutex> lock(wq.cs);
wq.numThreads -= 1;
wq.cond.notify_all();
}
};
public:
WorkQueue(size_t maxDepth) : running(true),
maxDepth(maxDepth)
maxDepth(maxDepth),
numThreads(0)
{
}
/* Precondition: worker threads have all stopped */
/*( Precondition: worker threads have all stopped
* (call WaitExit)
*/
~WorkQueue()
{
while (!queue.empty()) {
@ -100,6 +122,7 @@ public:
/** Thread function */
void Run()
{
ThreadCounter count(*this);
while (running) {
WorkItem* i = 0;
{
@ -122,6 +145,13 @@ public:
running = false;
cond.notify_all();
}
/** Wait for worker threads to exit */
void WaitExit()
{
boost::unique_lock<boost::mutex> lock(cs);
while (numThreads > 0)
cond.wait(lock);
}
/** Return current depth of queue */
size_t Depth()
@ -155,6 +185,8 @@ static std::vector<CSubNet> rpc_allow_subnets;
static WorkQueue<HTTPClosure>* workQueue = 0;
//! Handlers for (sub)paths
std::vector<HTTPPathHandler> pathHandlers;
//! Bound listening sockets
std::vector<evhttp_bound_socket *> boundSockets;
/** Check if a network address is allowed to access the HTTP server */
static bool ClientAllowed(const CNetAddr& netaddr)
@ -264,6 +296,13 @@ static void http_request_cb(struct evhttp_request* req, void* arg)
}
}
/** Callback to reject HTTP requests after shutdown. */
static void http_reject_request_cb(struct evhttp_request* req, void*)
{
LogPrint("http", "Rejecting request while shutting down\n");
evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
}
/** Event dispatcher thread */
static void ThreadHTTP(struct event_base* base, struct evhttp* http)
{
@ -278,7 +317,6 @@ static void ThreadHTTP(struct event_base* base, struct evhttp* http)
static bool HTTPBindAddresses(struct evhttp* http)
{
int defaultPort = GetArg("-rpcport", BaseParams().RPCPort());
int nBound = 0;
std::vector<std::pair<std::string, uint16_t> > endpoints;
// Determine what addresses to bind to
@ -304,13 +342,14 @@ static bool HTTPBindAddresses(struct evhttp* http)
// Bind addresses
for (std::vector<std::pair<std::string, uint16_t> >::iterator i = endpoints.begin(); i != endpoints.end(); ++i) {
LogPrint("http", "Binding RPC on address %s port %i\n", i->first, i->second);
if (evhttp_bind_socket(http, i->first.empty() ? NULL : i->first.c_str(), i->second) == 0) {
nBound += 1;
evhttp_bound_socket *bind_handle = evhttp_bind_socket_with_handle(http, i->first.empty() ? NULL : i->first.c_str(), i->second);
if (bind_handle) {
boundSockets.push_back(bind_handle);
} else {
LogPrintf("Binding RPC on address %s port %i failed.\n", i->first, i->second);
}
}
return nBound > 0;
return !boundSockets.empty();
}
/** Simple wrapper to set thread name and run work queue */
@ -410,8 +449,21 @@ bool StartHTTPServer(boost::thread_group& threadGroup)
void InterruptHTTPServer()
{
LogPrint("http", "Interrupting HTTP server\n");
if (eventBase)
event_base_loopbreak(eventBase);
if (eventHTTP) {
// Unlisten sockets
BOOST_FOREACH (evhttp_bound_socket *socket, boundSockets) {
evhttp_del_accept_socket(eventHTTP, socket);
}
// Reject requests on current connections
evhttp_set_gencb(eventHTTP, http_reject_request_cb, NULL);
}
if (eventBase) {
// Force-exit event loop after predefined time
struct timeval tv;
tv.tv_sec = 10;
tv.tv_usec = 0;
event_base_loopexit(eventBase, &tv);
}
if (workQueue)
workQueue->Interrupt();
}
@ -419,7 +471,11 @@ void InterruptHTTPServer()
void StopHTTPServer()
{
LogPrint("http", "Stopping HTTP server\n");
delete workQueue;
if (workQueue) {
LogPrint("http", "Waiting for HTTP worker threads to exit\n");
workQueue->WaitExit();
delete workQueue;
}
if (eventHTTP) {
evhttp_free(eventHTTP);
eventHTTP = 0;

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@ -243,7 +243,8 @@ UniValue stop(const UniValue& params, bool fHelp)
throw runtime_error(
"stop\n"
"\nStop Bitcoin server.");
// Shutdown will take long enough that the response should get back
// Event loop will exit after current HTTP requests have been handled, so
// this reply will get back to the client.
StartShutdown();
return "Bitcoin server stopping";
}