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/*
* Phusion Passenger - https://www.phusionpassenger.com/
* Copyright (c) 2014-2018 Phusion Holding B.V.
*
* "Passenger", "Phusion Passenger" and "Union Station" are registered
* trademarks of Phusion Holding B.V.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef _PASSENGER_SERVER_KIT_SERVER_H_
#define _PASSENGER_SERVER_KIT_SERVER_H_
#include <psg_sysqueue.h>
#include <boost/cstdint.hpp>
#include <boost/config.hpp>
#include <boost/scoped_ptr.hpp>
#include <oxt/system_calls.hpp>
#include <oxt/backtrace.hpp>
#include <oxt/macros.hpp>
#include <vector>
#include <new>
#include <ev++.h>
// for std::swap()
#if __cplusplus >= 201103L
#include <utility>
#else
#include <algorithm>
#endif
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <pthread.h>
#include <cstdio>
#include <jsoncpp/json.h>
#include <LoggingKit/LoggingKit.h>
#include <SafeLibev.h>
#include <Constants.h>
#include <ServerKit/Context.h>
#include <ServerKit/Errors.h>
#include <ServerKit/Hooks.h>
#include <ServerKit/Client.h>
#include <ServerKit/ClientRef.h>
#include <ConfigKit/ConfigKit.h>
#include <Algorithms/MovingAverage.h>
#include <Utils.h>
#include <Utils/ScopeGuard.h>
#include <StrIntTools/StrIntUtils.h>
#include <IOTools/IOUtils.h>
#include <SystemTools/SystemTime.h>
namespace Passenger {
namespace ServerKit {
using namespace std;
using namespace boost;
using namespace oxt;
// We use 'this' so that the macros work in derived template classes like HttpServer<>.
#define SKS_LOG(level, file, line, expr) P_LOG(Passenger::LoggingKit::context, level, file, line, "[" << this->getServerName() << "] " << expr)
#define SKS_ERROR(expr) P_ERROR("[" << this->getServerName() << "] " << expr)
#define SKS_WARN(expr) P_WARN("[" << this->getServerName() << "] " << expr)
#define SKS_INFO(expr) P_INFO("[" << this->getServerName() << "] " << expr)
#define SKS_NOTICE(expr) P_NOTICE("[" << this->getServerName() << "] " << expr)
#define SKS_DEBUG(expr) P_DEBUG("[" << this->getServerName() << "] " << expr)
#define SKS_TRACE(level, expr) P_TRACE(level, "[" << this->getServerName() << "] " << expr)
#define SKS_NOTICE_FROM_STATIC(server, expr) P_NOTICE("[" << server->getServerName() << "] " << expr)
#define SKC_LOG(client, level, expr) SKC_LOG_FROM_STATIC(this, client, level, expr)
#define SKC_ERROR(client, expr) SKC_ERROR_FROM_STATIC(this, client, expr)
#define SKC_WARN(client, expr) SKC_WARN_FROM_STATIC(this, client, expr)
#define SKC_NOTICE(client, expr) SKC_NOTICE_FROM_STATIC(this, client, expr)
#define SKC_INFO(client, expr) SKC_INFO_FROM_STATIC(this, client, expr)
#define SKC_DEBUG(client, expr) SKC_DEBUG_FROM_STATIC(this, client, expr)
#define SKC_DEBUG_WITH_POS(client, file, line, expr) \
SKC_DEBUG_FROM_STATIC_WITH_POS(this, client, file, line, expr)
#define SKC_TRACE(client, level, expr) SKC_TRACE_FROM_STATIC(this, client, level, expr)
#define SKC_TRACE_WITH_POS(client, level, file, line, expr) \
SKC_TRACE_FROM_STATIC_WITH_POS(this, client, level, file, line, expr)
#define SKC_LOG_FROM_STATIC(server, client, level, expr) \
do { \
if (Passenger::LoggingKit::getLevel() >= level) { \
char _clientName[16]; \
int _clientNameSize = server->getClientName((client), _clientName, sizeof(_clientName)); \
P_LOG(LoggingKit::context, level, __FILE__, __LINE__, \
"[Client " << StaticString(_clientName, _clientNameSize) << "] " << expr); \
} \
} while (0)
#define SKC_ERROR_FROM_STATIC(server, client, expr) \
SKC_LOG_FROM_STATIC(server, client, Passenger::LoggingKit::ERROR, expr)
#define SKC_WARN_FROM_STATIC(server, client, expr) \
SKC_LOG_FROM_STATIC(server, client, Passenger::LoggingKit::WARN, expr)
#define SKC_NOTICE_FROM_STATIC(server, client, expr) \
SKC_LOG_FROM_STATIC(server, client, Passenger::LoggingKit::NOTICE, expr)
#define SKC_INFO_FROM_STATIC(server, client, expr) \
SKC_LOG_FROM_STATIC(server, client, Passenger::LoggingKit::INFO, expr)
#define SKC_DEBUG_FROM_STATIC(server, client, expr) \
SKC_LOG_FROM_STATIC(server, client, Passenger::LoggingKit::DEBUG, expr)
#define SKC_DEBUG_FROM_STATIC_WITH_POS(server, client, file, line, expr) \
do { \
if (OXT_UNLIKELY(Passenger::LoggingKit::getLevel() >= Passenger::LoggingKit::DEBUG)) { \
char _clientName[16]; \
int _clientNameSize = server->getClientName((client), _clientName, sizeof(_clientName)); \
P_DEBUG_WITH_POS(file, line, \
"[Client " << StaticString(_clientName, _clientNameSize) << "] " << expr); \
} \
} while (0)
#define SKC_TRACE_FROM_STATIC(server, client, level, expr) \
SKC_TRACE_FROM_STATIC_WITH_POS(server, client, level, __FILE__, __LINE__, expr)
#define SKC_TRACE_FROM_STATIC_WITH_POS(server, client, level, file, line, expr) \
do { \
if (OXT_UNLIKELY(Passenger::LoggingKit::getLevel() >= Passenger::LoggingKit::INFO + level)) { \
char _clientName[16]; \
int _clientNameSize = server->getClientName((client), _clientName, sizeof(_clientName)); \
P_TRACE_WITH_POS(level, file, line, \
"[Client " << StaticString(_clientName, _clientNameSize) << "] " << expr); \
} \
} while (0)
#define SKC_LOG_EVENT(klass, client, eventName) SKC_LOG_EVENT_FROM_STATIC(this, klass, client, eventName)
#define SKC_LOG_EVENT_FROM_STATIC(server, klass, client, eventName) \
TRACE_POINT_WITH_DATA_FUNCTION(klass::_getClientNameFromTracePoint, client); \
SKC_TRACE_FROM_STATIC(server, client, 3, "Event: " eventName)
/*
* BEGIN ConfigKit schema: Passenger::ServerKit::BaseServerSchema
* (do not edit: following text is automatically generated
* by 'rake configkit_schemas_inline_comments')
*
* accept_burst_count unsigned integer - default(32)
* client_freelist_limit unsigned integer - default(0)
* min_spare_clients unsigned integer - default(0)
* start_reading_after_accept boolean - default(true)
*
* END
*/
class BaseServerSchema: public ConfigKit::Schema {
private:
void initialize() {
using namespace ConfigKit;
add("accept_burst_count", UINT_TYPE, OPTIONAL, 32);
add("start_reading_after_accept", BOOL_TYPE, OPTIONAL, true);
add("min_spare_clients", UINT_TYPE, OPTIONAL, 0);
add("client_freelist_limit", UINT_TYPE, OPTIONAL, 0);
}
public:
BaseServerSchema() {
initialize();
finalize();
}
BaseServerSchema(bool _subclassing) {
initialize();
}
};
struct BaseServerConfigRealization {
unsigned int acceptBurstCount: 7;
bool startReadingAfterAccept: 1;
unsigned int minSpareClients: 12;
unsigned int clientFreelistLimit: 12;
BaseServerConfigRealization(const ConfigKit::Store &config)
: acceptBurstCount(config["accept_burst_count"].asUInt()),
startReadingAfterAccept(config["start_reading_after_accept"].asBool()),
minSpareClients(config["min_spare_clients"].asUInt()),
clientFreelistLimit(config["client_freelist_limit"].asUInt())
{ }
void swap(BaseServerConfigRealization &other) BOOST_NOEXCEPT_OR_NOTHROW {
#define SWAP_BITFIELD(Type, name) \
do { \
Type tmp = name; \
name = other.name; \
other.name = tmp; \
} while (false)
SWAP_BITFIELD(unsigned int, acceptBurstCount);
SWAP_BITFIELD(bool, startReadingAfterAccept);
SWAP_BITFIELD(unsigned int, minSpareClients);
SWAP_BITFIELD(unsigned int, clientFreelistLimit);
#undef SWAP_BITFIELD
}
};
struct BaseServerConfigChangeRequest {
boost::scoped_ptr<ConfigKit::Store> config;
boost::scoped_ptr<BaseServerConfigRealization> configRlz;
};
/**
* A highly optimized generic base class for evented socket servers, implementing basic,
* low-level connection management.
*
* ## Features
*
* ### Client objects
*
* Every connected client is represented by a client object, which inherits from
* ServerKit::BaseClient. The client object provides input and output, and you can
* extend with your own fields.
*
* Client objects are reference counted, for easy memory management.
*
* Creation and destruction is very efficient, because client objects are put on a
* freelist upon destruction, so that no malloc calls are necessary next time.
*
* ### Zero-copy buffers
*
* All input is handled in a zero-copy manner, by using the mbuf system.
*
* ### Channel I/O abstraction
*
* All input is handled through the Channel abstraction, and all output is
* handled through the FileBufferedFdSinkChannel abstraction.. This makes writing
* evented servers very easy.
*
* ### Multiple listen endpoints
*
* The server can listen on multiple server endpoints at the same time (e.g. TCP and
* Unix domain sockets), up to SERVER_KIT_MAX_SERVER_ENDPOINTS.
*
* ### Automatic backoff when too many file descriptors are active
*
* If ENFILES or EMFILES is encountered when accepting new clients, Server will stop
* accepting new clients for a few seconds so that doesn't keep triggering the error
* in a busy loop.
*
* ### Logging
*
* Provides basic logging macros that also log the client name.
*/
template<typename DerivedServer, typename Client = Client>
class BaseServer: public HooksImpl {
public:
/***** Types *****/
typedef BaseServer BaseClass;
typedef Client ClientType;
typedef ClientRef<DerivedServer, Client> ClientRefType;
STAILQ_HEAD(FreeClientList, Client);
TAILQ_HEAD(ClientList, Client);
enum State {
ACTIVE,
TOO_MANY_FDS,
SHUTTING_DOWN,
FINISHED_SHUTDOWN
};
static const unsigned int MAX_ACCEPT_BURST_COUNT = 127;
typedef void (*Callback)(DerivedServer *server);
typedef BaseServerConfigChangeRequest ConfigChangeRequest;
/***** Configuration *****/
ConfigKit::Store config;
BaseServerConfigRealization configRlz;
Callback shutdownFinishCallback;
/***** Working state and statistics (do not modify) *****/
State serverState;
FreeClientList freeClients;
ClientList activeClients, disconnectedClients;
unsigned int freeClientCount, activeClientCount, disconnectedClientCount;
unsigned int peakActiveClientCount;
unsigned long totalClientsAccepted, lastTotalClientsAccepted;
unsigned long long totalBytesConsumed;
ev_tstamp lastStatisticsUpdateTime;
double clientAcceptSpeed1m, clientAcceptSpeed1h;
private:
Context *ctx;
unsigned int nextClientNumber: 28;
uint8_t nEndpoints: 3;
bool accept4Available: 1;
ev::timer acceptResumptionWatcher;
ev::timer statisticsUpdateWatcher;
ev::io endpoints[SERVER_KIT_MAX_SERVER_ENDPOINTS];
/***** Private methods *****/
void preinitialize(Context *context) {
STAILQ_INIT(&freeClients);
TAILQ_INIT(&activeClients);
TAILQ_INIT(&disconnectedClients);
acceptResumptionWatcher.set(context->libev->getLoop());
acceptResumptionWatcher.set<
BaseServer<DerivedServer, Client>,
&BaseServer<DerivedServer, Client>::onAcceptResumeTimeout>(this);
statisticsUpdateWatcher.set(context->libev->getLoop());
statisticsUpdateWatcher.set<
BaseServer<DerivedServer, Client>,
&BaseServer<DerivedServer, Client>::onStatisticsUpdateTimeout>(this);
}
static void _onAcceptable(EV_P_ ev_io *io, int revents) {
static_cast<BaseServer *>(io->data)->onAcceptable(io, revents);
}
void onAcceptable(ev_io *io, int revents) {
TRACE_POINT();
unsigned int acceptCount = 0;
bool error = false;
int fd, errcode = 0;
Client *client;
Client *acceptedClients[MAX_ACCEPT_BURST_COUNT];
P_ASSERT_EQ(serverState, ACTIVE);
SKS_DEBUG("New clients can be accepted on a server socket");
for (unsigned int i = 0; i < configRlz.acceptBurstCount; i++) {
fd = acceptNonBlockingSocket(io->fd);
if (fd == -1) {
error = true;
errcode = errno;
break;
}
FdGuard guard(fd, NULL, 0);
client = checkoutClientObject();
TAILQ_INSERT_HEAD(&activeClients, client, nextClient.activeOrDisconnectedClient);
acceptedClients[acceptCount] = client;
activeClientCount++;
acceptCount++;
totalClientsAccepted++;
client->number = getNextClientNumber();
reinitializeClient(client, fd);
P_LOG_FILE_DESCRIPTOR_PURPOSE(fd, "Server " << getServerName()
<< ", client " << getClientName(client));
guard.clear();
}
if (acceptCount > 0) {
SKS_DEBUG(acceptCount << " new client(s) accepted; there are now " <<
activeClientCount << " active client(s)");
}
if (error && errcode != EAGAIN && errcode != EWOULDBLOCK) {
SKS_ERROR("Cannot accept client: " << getErrorDesc(errcode) <<
" (errno=" << errcode << "). " <<
"Stop accepting clients for 3 seconds. " <<
"Current client count: " << activeClientCount);
serverState = TOO_MANY_FDS;
acceptResumptionWatcher.set(3, 0);
acceptResumptionWatcher.start();
for (uint8_t i = 0; i < nEndpoints; i++) {
ev_io_stop(ctx->libev->getLoop(), &endpoints[i]);
}
}
onClientsAccepted(acceptedClients, acceptCount);
}
void onAcceptResumeTimeout(ev::timer &timer, int revents) {
TRACE_POINT();
P_ASSERT_EQ(serverState, TOO_MANY_FDS);
SKS_NOTICE("Resuming accepting new clients");
serverState = ACTIVE;
for (uint8_t i = 0; i < nEndpoints; i++) {
ev_io_start(ctx->libev->getLoop(), &endpoints[i]);
}
}
int acceptNonBlockingSocket(int serverFd) {
union {
struct sockaddr_in inaddr;
struct sockaddr_in6 inaddr6;
struct sockaddr_un unaddr;
} u;
socklen_t addrlen = sizeof(u);
if (accept4Available) {
int fd = callAccept4(serverFd,
(struct sockaddr *) &u,
&addrlen,
O_NONBLOCK);
// FreeBSD returns EINVAL if accept4() is called with invalid flags.
if (fd == -1 && (errno == ENOSYS || errno == EINVAL)) {
accept4Available = false;
return acceptNonBlockingSocket(serverFd);
} else {
return fd;
}
} else {
int fd = syscalls::accept(serverFd,
(struct sockaddr *) &u,
&addrlen);
FdGuard guard(fd, __FILE__, __LINE__);
if (fd == -1) {
return -1;
} else {
try {
setNonBlocking(fd);
} catch (const SystemException &e) {
SKS_DEBUG("Unable to set non-blocking flag on accepted client socket: " <<
e.what() << " (errno=" << e.code() << ")");
errno = e.code();
return -1;
}
guard.clear();
return fd;
}
}
}
void onStatisticsUpdateTimeout(ev::timer &timer, int revents) {
TRACE_POINT();
this->onUpdateStatistics();
this->onFinalizeStatisticsUpdate();
timer.repeat = timeToNextMultipleD(5, ev_now(this->getLoop()));
timer.again();
}
unsigned int getNextClientNumber() {
return nextClientNumber++;
}
Client *checkoutClientObject() {
// Try to obtain client object from freelist.
if (!STAILQ_EMPTY(&freeClients)) {
return checkoutClientObjectFromFreelist();
} else {
return createNewClientObject();
}
}
Client *checkoutClientObjectFromFreelist() {
assert(freeClientCount > 0);
SKS_TRACE(3, "Checking out client object from freelist (" <<
freeClientCount << " -> " << (freeClientCount - 1) << ")");
Client *client = STAILQ_FIRST(&freeClients);
P_ASSERT_EQ(client->getConnState(), Client::IN_FREELIST);
client->refcount.store(2, boost::memory_order_relaxed);
freeClientCount--;
STAILQ_REMOVE_HEAD(&freeClients, nextClient.freeClient);
return client;
}
Client *createNewClientObject() {
Client *client;
SKS_TRACE(3, "Creating new client object");
try {
client = new Client(this);
} catch (const std::bad_alloc &) {
return NULL;
}
onClientObjectCreated(client);
return client;
}
void clientReachedZeroRefcount(Client *client) {
TRACE_POINT();
assert(disconnectedClientCount > 0);
assert(!TAILQ_EMPTY(&disconnectedClients));
SKC_TRACE(client, 3, "Client object reached a reference count of 0");
TAILQ_REMOVE(&disconnectedClients, client, nextClient.activeOrDisconnectedClient);
disconnectedClientCount--;
if (addClientToFreelist(client)) {
SKC_TRACE(client, 3, "Client object added to freelist (" <<
(freeClientCount - 1) << " -> " << freeClientCount << ")");
} else {
SKC_TRACE(client, 3, "Client object destroyed; not added to freelist " <<
"because it's full (" << freeClientCount << ")");
delete client;
}
if (serverState == SHUTTING_DOWN
&& activeClientCount == 0
&& disconnectedClientCount == 0)
{
finishShutdown();
}
}
bool addClientToFreelist(Client *client) {
if (freeClientCount < configRlz.clientFreelistLimit) {
STAILQ_INSERT_HEAD(&freeClients, client, nextClient.freeClient);
freeClientCount++;
client->refcount.store(2, boost::memory_order_relaxed);
client->setConnState(Client::IN_FREELIST);
return true;
} else {
return false;
}
}
void passClientToEventLoopThread(Client *client) {
// The shutdown procedure waits until all ACTIVE and DISCONNECTED
// clients are gone before destroying a Server, so we know for sure
// that this async callback outlives the Server.
ctx->libev->runLater(boost::bind(&BaseServer::passClientToEventLoopThreadCallback,
this, ClientRefType(client, __FILE__, __LINE__)));
}
void passClientToEventLoopThreadCallback(ClientRefType clientRef) {
// Do nothing. Once this method returns, the reference count of the
// client drops to 0, and clientReachedZeroRefcount() is called.
}
const char *getServerStateString() const {
switch (serverState) {
case ACTIVE:
return "ACTIVE";
case TOO_MANY_FDS:
return "TOO_MANY_FDS";
case SHUTTING_DOWN:
return "SHUTTING_DOWN";
case FINISHED_SHUTDOWN:
return "FINISHED_SHUTDOWN";
default:
return "UNKNOWN";
}
}
void finishShutdown() {
TRACE_POINT();
compact(LoggingKit::INFO);
acceptResumptionWatcher.stop();
statisticsUpdateWatcher.stop();
SKS_NOTICE("Shutdown finished");
serverState = FINISHED_SHUTDOWN;
if (shutdownFinishCallback) {
shutdownFinishCallback(static_cast<DerivedServer *>(this));
}
}
void logClientDataReceived(Client *client, const MemoryKit::mbuf &buffer, int errcode) {
if (buffer.size() > 0) {
SKC_TRACE(client, 3, "Processing " << buffer.size() << " bytes of client data");
} else if (errcode == 0) {
SKC_TRACE(client, 2, "Client sent EOF");
} else {
SKC_TRACE(client, 2, "Error reading from client socket: " <<
getErrorDesc(errcode) << " (errno=" << errcode << ")");
}
}
static Channel::Result _onClientDataReceived(Channel *_channel,
const MemoryKit::mbuf &buffer, int errcode)
{
FdSourceChannel *channel = reinterpret_cast<FdSourceChannel *>(_channel);
Client *client = static_cast<Client *>(static_cast<BaseClient *>(
channel->getHooks()->userData));
BaseServer *server = getServerFromClient(client);
const size_t bufferSize = buffer.size();
server->logClientDataReceived(client, buffer, errcode);
Channel::Result result = server->onClientDataReceived(client, buffer, errcode);
// This counter is mostly useful for unit tests, so it's too much hassle to
// support cases where result.consumed < 1.
size_t consumed = std::max<size_t>(0,
std::min<size_t>(result.consumed, bufferSize));
server->totalBytesConsumed += consumed;
SKC_TRACE_FROM_STATIC(server, client, 2,
consumed << " bytes of client data consumed in this callback");
return result;
}
static void _onClientOutputError(FileBufferedFdSinkChannel *_channel, int errcode) {
FileBufferedFdSinkChannel *channel =
reinterpret_cast<FileBufferedFdSinkChannel *>(_channel);
Client *client = static_cast<Client *>(static_cast<BaseClient *>(
channel->getHooks()->userData));
BaseServer *server = getServerFromClient(client);
server->onClientOutputError(client, errcode);
}
protected:
/***** Hooks *****/
virtual void onClientObjectCreated(Client *client) {
TRACE_POINT();
client->hooks.impl = this;
client->hooks.userData = static_cast<BaseClient *>(client);
client->input.setContext(ctx);
client->input.setHooks(&client->hooks);
client->input.setDataCallback(_onClientDataReceived);
client->output.setContext(ctx);
client->output.setHooks(&client->hooks);
client->output.errorCallback = _onClientOutputError;
}
virtual void onClientsAccepted(Client **clients, unsigned int size) {
unsigned int i;
peakActiveClientCount = std::max(peakActiveClientCount, activeClientCount);
for (i = 0; i < size; i++) {
Client *client = clients[i];
onClientAccepted(client);
if (client->connected()) {
if (configRlz.startReadingAfterAccept) {
client->input.startReading();
} else {
client->input.startReadingInNextTick();
}
}
// A Client object starts with a refcount of 2 so that we can
// be sure it won't be destroyted while we're looping inside this
// function. But we also need an extra unref here.
unrefClient(client, __FILE__, __LINE__);
}
}
virtual void onClientAccepted(Client *client) {
// Do nothing.
}
virtual void onClientDisconnecting(Client *client) {
// Do nothing.
}
virtual void onClientDisconnected(Client *client) {
// Do nothing.
}
virtual bool shouldDisconnectClientOnShutdown(Client *client) {
return false;
}
virtual Channel::Result onClientDataReceived(Client *client, const MemoryKit::mbuf &buffer,
int errcode)
{
if (buffer.empty()) {
disconnect(&client);
}
return Channel::Result(0, true);
}
virtual void onClientOutputError(Client *client, int errcode) {
SKC_LOG_EVENT(DerivedServer, client, "onClientOutputError");
char message[1024];
int ret = snprintf(message, sizeof(message),
"client socket write error: %s (errno=%d)",
getErrorDesc(errcode), errcode);
disconnectWithError(&client, StaticString(message, ret),
getClientOutputErrorDisconnectionLogLevel(client, errcode));
}
virtual LoggingKit::Level getClientOutputErrorDisconnectionLogLevel(
Client *client, int errcode) const
{
return LoggingKit::WARN;
}
virtual void onUpdateStatistics() {
SKS_DEBUG("Updating statistics");
ev_tstamp now = ev_now(this->getLoop());
ev_tstamp duration = now - lastStatisticsUpdateTime;
// Statistics are updated about every 5 seconds, so about 12 updates
// per minute. We want the old average to decay to 5% after 1 minute
// and 1 hour, respectively, so:
// 1 minute: 1 - exp(ln(0.05) / 12) = 0.22092219194555585
// 1 hour : 1 - exp(ln(0.05) / (60 * 12)) = 0.0041520953856636345
clientAcceptSpeed1m = expMovingAverage(clientAcceptSpeed1m,
(totalClientsAccepted - lastTotalClientsAccepted) / duration,
0.22092219194555585);
clientAcceptSpeed1h = expMovingAverage(clientAcceptSpeed1h,
(totalClientsAccepted - lastTotalClientsAccepted) / duration,
0.0041520953856636345);
}
virtual void onFinalizeStatisticsUpdate() {
lastTotalClientsAccepted = totalClientsAccepted;
lastStatisticsUpdateTime = ev_now(this->getLoop());
}
virtual void reinitializeClient(Client *client, int fd) {
client->setConnState(Client::ACTIVE);
SKC_TRACE(client, 2, "Client associated with file descriptor: " << fd);
client->input.reinitialize(fd);
client->output.reinitialize(fd);
}
virtual void deinitializeClient(Client *client) {
client->input.deinitialize();
client->output.deinitialize();
}
virtual void onShutdown(bool forceDisconnect) {
// Do nothing.
}
public:
/***** Public methods *****/
BaseServer(Context *context, const BaseServerSchema &schema,
const Json::Value &initialConfig = Json::Value(),
const ConfigKit::Translator &translator = ConfigKit::DummyTranslator())
: config(schema, initialConfig, translator),
configRlz(config),
shutdownFinishCallback(NULL),
serverState(ACTIVE),
freeClientCount(0),
activeClientCount(0),
disconnectedClientCount(0),
peakActiveClientCount(0),
totalClientsAccepted(0),
lastTotalClientsAccepted(0),
totalBytesConsumed(0),
lastStatisticsUpdateTime(ev_time()),
clientAcceptSpeed1m(-1),
clientAcceptSpeed1h(-1),
ctx(context),
nextClientNumber(1),
nEndpoints(0),
accept4Available(true)
{
preinitialize(context);
}
virtual ~BaseServer() {
P_ASSERT_EQ(serverState, FINISHED_SHUTDOWN);
}
/***** Initialization, listening and shutdown *****/
virtual void initialize() {
statisticsUpdateWatcher.set(5, 5);
statisticsUpdateWatcher.start();
}
// Pre-create multiple client objects so that they get allocated
// near each other in memory. Hopefully increases CPU cache locality.
void createSpareClients() {
for (unsigned int i = 0; i < configRlz.minSpareClients; i++) {
Client *client = createNewClientObject();
client->setConnState(Client::IN_FREELIST);
STAILQ_INSERT_HEAD(&freeClients, client, nextClient.freeClient);
freeClientCount++;
}
}
void listen(int fd) {
#ifdef EOPNOTSUPP
#define EXTENSION_EOPNOTSUPP EOPNOTSUPP
#else
#define EXTENSION_EOPNOTSUPP ENOTSUP
#endif
TRACE_POINT();
assert(nEndpoints < SERVER_KIT_MAX_SERVER_ENDPOINTS);
int flag = 1;
setNonBlocking(fd);
if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &flag, sizeof(int)) == -1
&& errno != ENOPROTOOPT
&& errno != ENOTSUP
&& errno != EXTENSION_EOPNOTSUPP)
{
int e = errno;
SKS_WARN("Cannot disable Nagle's algorithm on a TCP socket: " <<
strerror(e) << " (errno=" << e << ")");
}
ev_io_init(&endpoints[nEndpoints], _onAcceptable, fd, EV_READ);
endpoints[nEndpoints].data = this;
ev_io_start(ctx->libev->getLoop(), &endpoints[nEndpoints]);
nEndpoints++;
#undef EXTENSION_EOPNOTSUPP
}
void shutdown(bool forceDisconnect = false) {
if (serverState != ACTIVE) {
return;
}
vector<Client *> clients;
Client *client;
typename vector<Client *>::iterator v_it, v_end;
SKS_DEBUG("Shutting down");
serverState = SHUTTING_DOWN;
onShutdown(forceDisconnect);
// Stop listening on all endpoints.
acceptResumptionWatcher.stop();
for (uint8_t i = 0; i < nEndpoints; i++) {
ev_io_stop(ctx->libev->getLoop(), &endpoints[i]);
}
if (activeClientCount == 0 && disconnectedClientCount == 0) {
finishShutdown();
return;
}
// Once we've set serverState to SHUTTING_DOWN, `activeClientCount` will no
// longer grow, but may change due to hooks and callbacks.
// So we make a copy of the client list here and operate on that.
clients.reserve(activeClientCount);
TAILQ_FOREACH (client, &activeClients, nextClient.activeOrDisconnectedClient) {
P_ASSERT_EQ(client->getConnState(), Client::ACTIVE);
refClient(client, __FILE__, __LINE__);
clients.push_back(client);
}
// Disconnect each active client.
v_end = clients.end();
for (v_it = clients.begin(); v_it != v_end; v_it++) {
client = (Client *) *v_it;
Client *c = client;
if (forceDisconnect || shouldDisconnectClientOnShutdown(client)) {
disconnectWithError(&client, "server is shutting down");
}
unrefClient(c, __FILE__, __LINE__);
}
// When all active and disconnected clients are gone,
// finishShutdown() will be called to set state to FINISHED_SHUTDOWN.
}
void feedNewClients(const int *fds, unsigned int size) {
Client *client;
Client *acceptedClients[MAX_ACCEPT_BURST_COUNT];
assert(size > 0);
assert(size <= MAX_ACCEPT_BURST_COUNT);
P_ASSERT_EQ(serverState, ACTIVE);
activeClientCount += size;
totalClientsAccepted += size;
for (unsigned int i = 0; i < size; i++) {
client = checkoutClientObject();
TAILQ_INSERT_HEAD(&activeClients, client, nextClient.activeOrDisconnectedClient);
acceptedClients[i] = client;
client->number = getNextClientNumber();
reinitializeClient(client, fds[i]);
P_LOG_FILE_DESCRIPTOR_PURPOSE(fds[i], "Server " << getServerName()
<< ", client " << getClientName(client));
}
SKS_DEBUG(size << " new client(s) accepted; there are now " <<
activeClientCount << " active client(s)");
onClientsAccepted(acceptedClients, size);
}
/***** Server management *****/
virtual void compact(LoggingKit::Level logLevel = LoggingKit::NOTICE) {
unsigned int count = freeClientCount;
while (!STAILQ_EMPTY(&freeClients)) {
Client *client = STAILQ_FIRST(&freeClients);
P_ASSERT_EQ(client->getConnState(), Client::IN_FREELIST);
client->refcount.store(2, boost::memory_order_relaxed);
freeClientCount--;
STAILQ_REMOVE_HEAD(&freeClients, nextClient.freeClient);
delete client;
}
assert(freeClientCount == 0);
SKS_LOG(logLevel, __FILE__, __LINE__,
"Freed " << count << " spare client objects");
}
/***** Client management *****/
// Ensures that the buffer is NULL-terminated.
virtual unsigned int getClientName(const Client *client, char *buf, size_t size) const {
unsigned int ret = uintToString(client->number, buf, size - 1);
buf[ret] = '\0';
return ret;
}
string getClientName(const Client *client) {
char buf[128];
unsigned int size = getClientName(client, buf, sizeof(buf));
return string(buf, size);
}
vector<ClientRefType> getActiveClients() {
vector<ClientRefType> result;
Client *client;
TAILQ_FOREACH (client, &activeClients, nextClient.activeOrDisconnectedClient) {
P_ASSERT_EQ(client->getConnState(), Client::ACTIVE);
result.push_back(ClientRefType(client, __FILE__, __LINE__));
}
return result;
}
Client *lookupClient(int fd) {
Client *client;
TAILQ_FOREACH (client, &activeClients, nextClient.activeOrDisconnectedClient) {
P_ASSERT_EQ(client->getConnState(), Client::ACTIVE);
if (client->fd == fd) {
return client;
}
}
return NULL;
}
Client *lookupClient(const StaticString &clientName) {
Client *client;
TAILQ_FOREACH (client, &activeClients, nextClient.activeOrDisconnectedClient) {
P_ASSERT_EQ(client->getConnState(), Client::ACTIVE);
char buf[512];
unsigned int size;
size = getClientName(client, buf, sizeof(buf));
if (StaticString(buf, size) == clientName) {
return client;
}
}
return NULL;
}
bool clientOnUnixDomainSocket(Client *client) {
union {
struct sockaddr genericAddress;
struct sockaddr_un unixAddress;
struct sockaddr_in inetAddress;
} addr;
socklen_t len = sizeof(addr);
int ret;
do {
ret = getsockname(client->getFd(), &addr.genericAddress, &len);
} while (ret == -1 && errno == EINTR);
if (ret == -1) {
int e = errno;
throw SystemException("Unable to autodetect socket type (getsockname() failed)", e);
} else {
#ifdef AF_UNIX
return addr.genericAddress.sa_family == AF_UNIX;
#else
return addr.genericAddress.sa_family == AF_LOCAL;
#endif
}
}
/** Increase client reference count. */
void refClient(Client *client, const char *file, unsigned int line) {
int oldRefcount = client->refcount.fetch_add(1, boost::memory_order_relaxed);
SKC_TRACE_WITH_POS(client, 3, file, line,
"Refcount increased; it is now " << (oldRefcount + 1));
}
/** Decrease client reference count. Adds client to the
* freelist if reference count drops to 0.
*/
void unrefClient(Client *client, const char *file, unsigned int line) {
int oldRefcount = client->refcount.fetch_sub(1, boost::memory_order_release);
assert(oldRefcount >= 1);
SKC_TRACE_WITH_POS(client, 3, file, line,
"Refcount decreased; it is now " << (oldRefcount - 1));
if (oldRefcount == 1) {
boost::atomic_thread_fence(boost::memory_order_acquire);
if (ctx->libev->onEventLoopThread()) {
assert(client->getConnState() != Client::IN_FREELIST);
/* As long as the client is still in the ACTIVE state, it has at least
* one reference, namely from the Server itself. Therefore it's impossible
* to get to a zero reference count without having disconnected a client. */
P_ASSERT_EQ(client->getConnState(), Client::DISCONNECTED);
clientReachedZeroRefcount(client);
} else {
// Let the event loop handle the client reaching the 0 refcount.
SKC_TRACE(client, 3, "Passing client object to event loop thread");
passClientToEventLoopThread(client);
}
}
}
bool disconnect(int fd) {
assert(serverState != FINISHED_SHUTDOWN);
Client *client = lookupClient(fd);
if (client != NULL) {
return disconnect(&client);
} else {
return false;
}
}
bool disconnect(const StaticString &clientName) {
assert(serverState != FINISHED_SHUTDOWN);
Client *client = lookupClient(clientName);
if (client != NULL) {
return disconnect(&client);
} else {
return false;
}
}
bool disconnect(Client **client) {
Client *c = *client;
if (c->getConnState() != Client::ACTIVE) {
return false;
}
int fdnum = c->getFd();
SKC_TRACE(c, 2, "Disconnecting; there are now " << (activeClientCount - 1) <<
" active clients");
onClientDisconnecting(c);
c->setConnState(ClientType::DISCONNECTED);
TAILQ_REMOVE(&activeClients, c, nextClient.activeOrDisconnectedClient);
activeClientCount--;
TAILQ_INSERT_HEAD(&disconnectedClients, c, nextClient.activeOrDisconnectedClient);
disconnectedClientCount++;
deinitializeClient(c);
SKC_TRACE(c, 2, "Closing client file descriptor: " << fdnum);
try {
safelyClose(fdnum);
P_LOG_FILE_DESCRIPTOR_CLOSE(fdnum);
} catch (const SystemException &e) {
SKC_WARN(c, "An error occurred while closing the client file descriptor: " <<
e.what() << " (errno=" << e.code() << ")");
}
*client = NULL;
onClientDisconnected(c);
unrefClient(c, __FILE__, __LINE__);
return true;
}
void disconnectWithWarning(Client **client, const StaticString &message) {
SKC_WARN(*client, "Disconnecting client with warning: " << message);
disconnect(client);
}
void disconnectWithError(Client **client, const StaticString &message,
LoggingKit::Level logLevel = LoggingKit::WARN)
{
SKC_LOG(*client, logLevel, "Disconnecting client with error: " << message);
disconnect(client);
}
/***** Introspection *****/
OXT_FORCE_INLINE
Context *getContext() {
return ctx;
}
OXT_FORCE_INLINE
const Context *getContext() const {
return ctx;
}
OXT_FORCE_INLINE
struct ev_loop *getLoop() const {
return ctx->libev->getLoop();
}
virtual StaticString getServerName() const {
return P_STATIC_STRING("Server");
}
bool prepareConfigChange(const Json::Value &updates,
vector<ConfigKit::Error> &errors, BaseServerConfigChangeRequest &req)
{
req.config.reset(new ConfigKit::Store(config, updates, errors));
if (errors.empty()) {
req.configRlz.reset(new BaseServerConfigRealization(*req.config));
}
return errors.empty();
}
void commitConfigChange(BaseServerConfigChangeRequest &req)
BOOST_NOEXCEPT_OR_NOTHROW
{
config.swap(*req.config);
configRlz.swap(*req.configRlz);
}
virtual Json::Value inspectConfig() const {
return config.inspect();
}
virtual Json::Value inspectStateAsJson() const {
Json::Value doc = ctx->inspectStateAsJson();
const Client *client;
doc["pid"] = (unsigned int) getpid();
doc["server_state"] = getServerStateString();
doc["free_client_count"] = freeClientCount;
Json::Value &activeClientsDoc = doc["active_clients"] = Json::Value(Json::objectValue);
doc["active_client_count"] = activeClientCount;
Json::Value &disconnectedClientsDoc = doc["disconnected_clients"] = Json::Value(Json::objectValue);
doc["disconnected_client_count"] = disconnectedClientCount;
doc["peak_active_client_count"] = peakActiveClientCount;
doc["client_accept_speed"]["1m"] = averageSpeedToJson(
capFloatPrecision(clientAcceptSpeed1m * 60),
"minute", "1 minute", -1);
doc["client_accept_speed"]["1h"] = averageSpeedToJson(
capFloatPrecision(clientAcceptSpeed1h * 60),
"minute", "1 hour", -1);
doc["total_clients_accepted"] = (Json::UInt64) totalClientsAccepted;
doc["total_bytes_consumed"] = (Json::UInt64) totalBytesConsumed;
TAILQ_FOREACH (client, &activeClients, nextClient.activeOrDisconnectedClient) {
Json::Value subdoc;
char clientName[16];
getClientName(client, clientName, sizeof(clientName));
activeClientsDoc[clientName] = inspectClientStateAsJson(client);
}
TAILQ_FOREACH (client, &disconnectedClients, nextClient.activeOrDisconnectedClient) {
Json::Value subdoc;
char clientName[16];
getClientName(client, clientName, sizeof(clientName));
disconnectedClientsDoc[clientName] = inspectClientStateAsJson(client);
}
return doc;
}
virtual Json::Value inspectClientStateAsJson(const Client *client) const {
Json::Value doc;
char clientName[16];
assert(client->getConnState() != Client::IN_FREELIST);
getClientName(client, clientName, sizeof(clientName));
doc["connection_state"] = client->getConnStateString();
doc["name"] = clientName;
doc["number"] = client->number;
doc["refcount"] = client->refcount.load(boost::memory_order_relaxed);
doc["output_channel_state"] = client->output.inspectAsJson();
return doc;
}
/***** Miscellaneous *****/
/** Get a thread-safe reference to the client. As long as the client
* has a reference, it will never be added to the freelist.
*/
ClientRefType getClientRef(Client *client, const char *file, unsigned int line) {
return ClientRefType(client, file, line);
}
/**
* Returns a pointer to the BaseServer that created the given Client object.
* Unlike the void pointer that Client::getServerBaseClassPointer() returns,
* this method's typed return value allows safe recasting of the result pointer.
*/
static const BaseServer *getConstServerFromClient(const Client *client) {
return static_cast<BaseServer *>(client->getServerBaseClassPointer());
}
static BaseServer *getServerFromClient(Client *client) {
return static_cast<BaseServer *>(client->getServerBaseClassPointer());
}
/***** Friend-public methods and hook implementations *****/
void _refClient(Client *client, const char *file, unsigned int line) {
refClient(client, file, line);
}
void _unrefClient(Client *client, const char *file, unsigned int line) {
unrefClient(client, __FILE__, __LINE__);
}
static bool _getClientNameFromTracePoint(char *output, unsigned int size, void *userData) {
Client *client = static_cast<Client *>(userData);
BaseServer *server = getServerFromClient(client);
char *pos = output;
const char *end = output + size;
pos = appendData(pos, end, "Client ");
server->getClientName(client, pos, end - pos);
return true;
}
virtual bool hook_isConnected(Hooks *hooks, void *source) {
Client *client = static_cast<Client *>(static_cast<BaseClient *>(hooks->userData));
return client->connected();
}
virtual void hook_ref(Hooks *hooks, void *source, const char *file, unsigned int line) {
Client *client = static_cast<Client *>(static_cast<BaseClient *>(hooks->userData));
refClient(client, file, line);
}
virtual void hook_unref(Hooks *hooks, void *source, const char *file, unsigned int line) {
Client *client = static_cast<Client *>(static_cast<BaseClient *>(hooks->userData));
unrefClient(client, file, line);
}
};
template <typename Client = Client>
class Server: public BaseServer<Server<Client>, Client> {
public:
Server(Context *context, const BaseServerSchema &schema,
const Json::Value &initialConfig = Json::Value())
: BaseServer<Server, Client>(context, schema, initialConfig)
{ }
};
} // namespace ServerKit
} // namespace Passenger
#endif /* _PASSENGER_SERVER_KIT_SERVER_H_ */
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