folly::RequestContext Class Reference

#include <Request.h>

Classes
struct	State

Public Member Functions
void	setContextData (const RequestToken &val, std::unique_ptr< RequestData > data)
void	setContextData (const std::string &val, std::unique_ptr< RequestData > data)
bool	setContextDataIfAbsent (const RequestToken &val, std::unique_ptr< RequestData > data)
bool	setContextDataIfAbsent (const std::string &val, std::unique_ptr< RequestData > data)
void	clearContextData (const RequestToken &val)
void	clearContextData (const std::string &val)
bool	hasContextData (const RequestToken &val) const
bool	hasContextData (const std::string &val) const
RequestData *	getContextData (const RequestToken &val)
const RequestData *	getContextData (const RequestToken &val) const
RequestData *	getContextData (const std::string &val)
const RequestData *	getContextData (const std::string &val) const
void	onSet ()
void	onUnset ()

Static Public Member Functions
static void	create ()
static RequestContext *	get ()
static std::shared_ptr< RequestContext >	setContext (std::shared_ptr< RequestContext > ctx)
static std::shared_ptr< RequestContext >	saveContext ()

Private Types
enum	DoSetBehaviour { DoSetBehaviour::SET, DoSetBehaviour::SET_IF_ABSENT, DoSetBehaviour::OVERWRITE }

Private Member Functions
void	overwriteContextData (const RequestToken &val, std::unique_ptr< RequestData > data)
void	overwriteContextData (const std::string &val, std::unique_ptr< RequestData > data)
bool	doSetContextData (const RequestToken &val, std::unique_ptr< RequestData > &data, DoSetBehaviour behaviour)
bool	doSetContextData (const std::string &val, std::unique_ptr< RequestData > &data, DoSetBehaviour behaviour)

Static Private Member Functions
static std::shared_ptr< RequestContext > &	getStaticContext ()
static std::shared_ptr< RequestContext >	setShallowCopyContext ()

Private Attributes
folly::Synchronized< State >	state_

Friends
struct	ShallowCopyRequestContextScopeGuard

Detailed Description

Definition at line 113 of file Request.h.

Member Enumeration Documentation

enum folly::RequestContext::DoSetBehaviour

strongprivate

Enumerator
SET
SET_IF_ABSENT
OVERWRITE

Definition at line 223 of file Request.h.

                            {
    SET,
    SET_IF_ABSENT,
    OVERWRITE,
  };

Member Function Documentation

void folly::RequestContext::clearContextData

(

const RequestToken &

val

)

Definition at line 176 of file Request.cpp.

References folly::data(), folly::gen::move, folly::ulock(), and folly::wlock().

Referenced by TEST_F().

                                                             {
  RequestData::SharedPtr requestData;
  // Delete the RequestData after giving up the wlock just in case one of the
  // RequestData destructors will try to grab the lock again.
  {
    auto ulock = state_.ulock();
    auto it = ulock->requestData_.find(val);
    if (it == ulock->requestData_.end()) {
      return;
    }

    auto wlock = ulock.moveFromUpgradeToWrite();
    if (it->second && it->second->hasCallback()) {
      it->second->onUnset();
      wlock->callbackData_.erase(it->second.get());
    }

    requestData = std::move(it->second);
    wlock->requestData_.erase(it);
  }
}

void folly::RequestContext::clearContextData ( const std::string &  val )

inline

Definition at line 158 of file Request.h.

References folly::RequestToken::RequestToken().

                                              {
    clearContextData(RequestToken(val));
  }

static void folly::RequestContext::create ( )

inlinestatic

Definition at line 118 of file Request.h.

References folly::data(), and val.

Referenced by folly::RequestContextScopeGuard::RequestContextScopeGuard(), and TEST_F().

                       {
    setContext(std::make_shared<RequestContext>());
  }

bool folly::RequestContext::doSetContextData ( const RequestToken &  val, std::unique_ptr< RequestData > &  data, DoSetBehaviour  behaviour  )

private

Definition at line 87 of file Request.cpp.

References folly::RequestData::constructPtr(), folly::RequestToken::getDebugString(), folly::ulock(), val, folly::WARNING, and folly::wlock().

                              {
  auto ulock = state_.ulock();

  bool conflict = false;
  auto it = ulock->requestData_.find(val);
  if (it != ulock->requestData_.end()) {
    if (behaviour == DoSetBehaviour::SET_IF_ABSENT) {
      return false;
    } else if (behaviour == DoSetBehaviour::SET) {
      LOG_FIRST_N(WARNING, 1)
          << "Calling RequestContext::setContextData for "
          << val.getDebugString() << " but it is already set";
    }
    conflict = true;
  }

  auto wlock = ulock.moveFromUpgradeToWrite();
  if (conflict) {
    if (it->second) {
      if (it->second->hasCallback()) {
        it->second->onUnset();
        wlock->callbackData_.erase(it->second.get());
      }
      it->second.reset(nullptr);
    }
    if (behaviour == DoSetBehaviour::SET) {
      return true;
    }
  }

  if (data && data->hasCallback()) {
    wlock->callbackData_.insert(data.get());
    data->onSet();
  }
  wlock->requestData_[val] = RequestData::constructPtr(data.release());

  return true;
}

bool folly::RequestContext::doSetContextData ( const std::string &  val, std::unique_ptr< RequestData > &  data, DoSetBehaviour  behaviour  )

inlineprivate

Definition at line 233 of file Request.h.

References folly::RequestToken::RequestToken().

                                {
    return doSetContextData(RequestToken(val), data, behaviour);
  }

RequestContext * folly::RequestContext::get ( )

static

Definition at line 290 of file Request.cpp.

References context.

Referenced by folly::RequestEventBase::get(), RequestContextTest::getContext(), folly::RequestEventBase::set(), folly::ShallowCopyRequestContextScopeGuard::ShallowCopyRequestContextScopeGuard(), TEST(), and TEST_F().

                                    {
  auto& context = getStaticContext();
  if (!context) {
    static RequestContext defaultContext;
    return std::addressof(defaultContext);
  }
  return context.get();
}

RequestData * folly::RequestContext::getContextData

(

const RequestToken &

val

)

Definition at line 151 of file Request.cpp.

References folly::get_ref_default(), and val.

Referenced by folly::RequestEventBase::get(), TEST(), and TEST_F().

                                                                   {
  const RequestData::SharedPtr dflt{nullptr};
  return get_ref_default(state_.rlock()->requestData_, val, dflt).get();
}

const RequestData * folly::RequestContext::getContextData

(

const RequestToken &

val

)

const

Definition at line 156 of file Request.cpp.

References folly::get_ref_default(), and val.

                                   {
  const RequestData::SharedPtr dflt{nullptr};
  return get_ref_default(state_.rlock()->requestData_, val, dflt).get();
}

RequestData* folly::RequestContext::getContextData ( const std::string &  val )

inline

Definition at line 173 of file Request.h.

References folly::RequestToken::RequestToken().

                                                    {
    return getContextData(RequestToken(val));
  }

const RequestData* folly::RequestContext::getContextData ( const std::string &  val ) const

inline

Definition at line 176 of file Request.h.

References folly::RequestToken::RequestToken().

                                                                {
    return getContextData(RequestToken(val));
  }

std::shared_ptr< RequestContext > & folly::RequestContext::getStaticContext ( )

staticprivate

Definition at line 263 of file Request.cpp.

References folly::pushmi::operators::get.

                                                                {
  using SingletonT = SingletonThreadLocal<std::shared_ptr<RequestContext>>;
  return SingletonT::get();
}

bool folly::RequestContext::hasContextData

(

const RequestToken &

val

)

const

Definition at line 147 of file Request.cpp.

                                                                 {
  return state_.rlock()->requestData_.count(val);
}

bool folly::RequestContext::hasContextData ( const std::string &  val ) const

inline

Definition at line 165 of file Request.h.

References folly::RequestToken::RequestToken().

                                                  {
    return hasContextData(RequestToken(val));
  }

void folly::RequestContext::onSet

(

)

Definition at line 162 of file Request.cpp.

References folly::data(), and folly::rlock().

                           {
  auto rlock = state_.rlock();
  for (const auto& data : rlock->callbackData_) {
    data->onSet();
  }
}

void folly::RequestContext::onUnset

(

)

Definition at line 169 of file Request.cpp.

References folly::data(), and folly::rlock().

                             {
  auto rlock = state_.rlock();
  for (const auto& data : rlock->callbackData_) {
    data->onUnset();
  }
}

void folly::RequestContext::overwriteContextData ( const RequestToken &  val, std::unique_ptr< RequestData >  data  )

private

Definition at line 141 of file Request.cpp.

Referenced by folly::ShallowCopyRequestContextScopeGuard::ShallowCopyRequestContextScopeGuard().

                                     {
  doSetContextData(val, data, DoSetBehaviour::OVERWRITE);
}

void folly::RequestContext::overwriteContextData ( const std::string &  val, std::unique_ptr< RequestData >  data  )

inlineprivate

Definition at line 216 of file Request.h.

References folly::gen::move, and folly::RequestToken::RequestToken().

                                       {
    overwriteContextData(RequestToken(val), std::move(data));
  }

static std::shared_ptr<RequestContext> folly::RequestContext::saveContext ( )

inlinestatic

Definition at line 196 of file Request.h.

Referenced by folly::fibers::FiberManager::initLocalData(), folly::fibers::FiberManager::loopUntilNoReadyImpl(), folly::NotificationQueue< folly::AsyncServerSocket::QueueMessage >::putMessageImpl(), folly::NotificationQueue< folly::AsyncServerSocket::QueueMessage >::putMessagesImpl(), folly::EventBase::runInLoop(), folly::fibers::FiberManager::runReadyFiber(), folly::AsyncTimeout::scheduleTimeout(), proxygen::AsyncTimeoutSet::scheduleTimeout(), folly::HHWheelTimer::scheduleTimeout(), folly::futures::detail::FutureBase< T >::setCallback_(), folly::TEST(), TEST(), and TEST_F().

                                                     {
    return getStaticContext();
  }

std::shared_ptr< RequestContext > folly::RequestContext::setContext ( std::shared_ptr< RequestContext >  ctx )

static

Definition at line 227 of file Request.cpp.

References folly::acquireLocked(), folly::as_const(), folly::data(), FOLLY_SDT, folly::RequestData::onSet(), and folly::RequestData::onUnset().

Referenced by folly::fibers::FiberManager::loopUntilNoReadyImpl(), folly::fibers::FiberManager::runReadyFiber(), RequestContextTest::SetUp(), TEST(), TEST_F(), proxygen::AsyncTimeoutSet::timeoutExpired(), folly::NotificationQueue< folly::AsyncServerSocket::QueueMessage >::tryConsume(), folly::RequestContextScopeGuard::~RequestContextScopeGuard(), and folly::ShallowCopyRequestContextScopeGuard::~ShallowCopyRequestContextScopeGuard().

                                          {
  auto& staticCtx = getStaticContext();
  if (newCtx == staticCtx) {
    return newCtx;
  }

  FOLLY_SDT(
      folly, request_context_switch_before, staticCtx.get(), newCtx.get());

  auto curCtx = staticCtx;
  if (newCtx && curCtx) {
    // Only call set/unset for all request data that differs
    auto ret = folly::acquireLocked(
        as_const(newCtx->state_), as_const(curCtx->state_));
    auto& newLock = std::get<0>(ret);
    auto& curLock = std::get<1>(ret);
    auto& newData = newLock->callbackData_;
    auto& curData = curLock->callbackData_;
    exec_set_difference(
        curData, newData, [](RequestData* data) { data->onUnset(); });
    staticCtx = newCtx;
    exec_set_difference(
        newData, curData, [](RequestData* data) { data->onSet(); });
  } else {
    if (curCtx) {
      curCtx->onUnset();
    }
    staticCtx = newCtx;
    if (newCtx) {
      newCtx->onSet();
    }
  }
  return curCtx;
}

void folly::RequestContext::setContextData	(	const RequestToken &	val,
		std::unique_ptr< RequestData >	data
	)

Definition at line 129 of file Request.cpp.

Referenced by folly::RequestEventBase::set(), TEST(), and TEST_F().

                                     {
  doSetContextData(val, data, DoSetBehaviour::SET);
}

void folly::RequestContext::setContextData ( const std::string &  val, std::unique_ptr< RequestData >  data  )

inline

Definition at line 138 of file Request.h.

References folly::gen::move, and folly::RequestToken::RequestToken().

                                       {
    setContextData(RequestToken(val), std::move(data));
  }

bool folly::RequestContext::setContextDataIfAbsent	(	const RequestToken &	val,
		std::unique_ptr< RequestData >	data
	)

Definition at line 135 of file Request.cpp.

                                     {
  return doSetContextData(val, data, DoSetBehaviour::SET_IF_ABSENT);
}

bool folly::RequestContext::setContextDataIfAbsent ( const std::string &  val, std::unique_ptr< RequestData >  data  )

inline

Definition at line 150 of file Request.h.

References folly::gen::move, and folly::RequestToken::RequestToken().

                                       {
    return setContextDataIfAbsent(RequestToken(val), std::move(data));
  }

std::shared_ptr< RequestContext > folly::RequestContext::setShallowCopyContext ( )

staticprivate

Definition at line 269 of file Request.cpp.

References folly::acquireLocked(), folly::as_const(), child, folly::RequestData::constructPtr(), parent, and folly::f14::swap().

                                      {
  auto& parent = getStaticContext();
  auto child = std::make_shared<RequestContext>();

  if (parent) {
    auto ret = folly::acquireLocked(as_const(parent->state_), child->state_);
    auto& parentLock = std::get<0>(ret);
    auto& childLock = std::get<1>(ret);
    childLock->callbackData_ = parentLock->callbackData_;
    childLock->requestData_.reserve(parentLock->requestData_.size());
    for (const auto& entry : parentLock->requestData_) {
      childLock->requestData_.insert(std::make_pair(
          entry.first, RequestData::constructPtr(entry.second.get())));
    }
  }

  // Do not use setContext to avoid global set/unset
  std::swap(child, parent);
  return child;
}

Friends And Related Function Documentation

friend struct ShallowCopyRequestContextScopeGuard

friend

Definition at line 205 of file Request.h.

Member Data Documentation

folly::Synchronized<State> folly::RequestContext::state_

private

Definition at line 249 of file Request.h.

---

The documentation for this class was generated from the following files:

• proxygen/folly/folly/io/async/Request.h
• proxygen/folly/folly/io/async/Request.cpp