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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=4 et :
*/
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef ipc_glue_MessageChannel_h
#define ipc_glue_MessageChannel_h 1
#include "ipc/EnumSerializer.h"
#include "mozilla/Atomics.h"
#include "mozilla/BaseProfilerMarkers.h"
#include "mozilla/LinkedList.h"
#include "mozilla/Monitor.h"
#include "mozilla/Vector.h"
#if defined(OS_WIN)
# include "mozilla/ipc/Neutering.h"
#endif // defined(OS_WIN)
#include <functional>
#include <map>
#include <stack>
#include <vector>
#include "MessageLink.h" // for HasResultCodes
#include "mozilla/ipc/Transport.h"
#include "mozilla/ipc/ScopedPort.h"
class MessageLoop;
namespace IPC {
template <typename T>
struct ParamTraits;
}
namespace mozilla {
namespace ipc {
class IToplevelProtocol;
class ActorLifecycleProxy;
class RefCountedMonitor : public Monitor {
public:
RefCountedMonitor() : Monitor("mozilla.ipc.MessageChannel.mMonitor") {}
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(RefCountedMonitor)
private:
~RefCountedMonitor() = default;
};
enum class MessageDirection {
eSending,
eReceiving,
};
enum class MessagePhase {
Endpoint,
TransferStart,
TransferEnd,
};
enum class SyncSendError {
SendSuccess,
PreviousTimeout,
SendingCPOWWhileDispatchingSync,
SendingCPOWWhileDispatchingUrgent,
NotConnectedBeforeSend,
DisconnectedDuringSend,
CancelledBeforeSend,
CancelledAfterSend,
TimedOut,
ReplyError,
};
enum class ResponseRejectReason {
SendError,
ChannelClosed,
HandlerRejected,
ActorDestroyed,
ResolverDestroyed,
EndGuard_,
};
template <typename T>
using ResolveCallback = std::function<void(T&&)>;
using RejectCallback = std::function<void(ResponseRejectReason)>;
enum ChannelState {
ChannelClosed,
ChannelConnected,
ChannelTimeout,
ChannelClosing,
ChannelError
};
class AutoEnterTransaction;
class MessageChannel : HasResultCodes {
friend class PortLink;
#ifdef FUZZING
friend class ProtocolFuzzerHelper;
#endif
class CxxStackFrame;
class InterruptFrame;
typedef mozilla::Monitor Monitor;
// We could templatize the actor type but it would unnecessarily
// expand the code size. Using the actor address as the
// identifier is already good enough.
typedef void* ActorIdType;
public:
struct UntypedCallbackHolder {
UntypedCallbackHolder(ActorIdType aActorId, RejectCallback&& aReject)
: mActorId(aActorId), mReject(std::move(aReject)) {}
virtual ~UntypedCallbackHolder() = default;
void Reject(ResponseRejectReason&& aReason) { mReject(std::move(aReason)); }
ActorIdType mActorId;
RejectCallback mReject;
};
template <typename Value>
struct CallbackHolder : public UntypedCallbackHolder {
CallbackHolder(ActorIdType aActorId, ResolveCallback<Value>&& aResolve,
RejectCallback&& aReject)
: UntypedCallbackHolder(aActorId, std::move(aReject)),
mResolve(std::move(aResolve)) {}
void Resolve(Value&& aReason) { mResolve(std::move(aReason)); }
ResolveCallback<Value> mResolve;
};
private:
static Atomic<size_t> gUnresolvedResponses;
friend class PendingResponseReporter;
public:
static constexpr int32_t kNoTimeout = INT32_MIN;
typedef IPC::Message Message;
typedef IPC::MessageInfo MessageInfo;
typedef mozilla::ipc::Transport Transport;
using ScopedPort = mozilla::ipc::ScopedPort;
explicit MessageChannel(const char* aName, IToplevelProtocol* aListener);
~MessageChannel();
IToplevelProtocol* Listener() const { return mListener; }
// "Open" a connection using an existing ScopedPort. The ScopedPort must be
// valid and connected to a remote.
//
// The `aEventTarget` parameter must be on the current thread.
bool Open(ScopedPort aPort, Side aSide,
nsISerialEventTarget* aEventTarget = nullptr);
// "Open" a connection to another thread in the same process.
//
// Returns true if the transport layer was successfully connected,
// i.e., mChannelState == ChannelConnected.
//
// For more details on the process of opening a channel between
// threads, see the extended comment on this function
// in MessageChannel.cpp.
bool Open(MessageChannel* aTargetChan, nsISerialEventTarget* aEventTarget,
Side aSide);
// "Open" a connection to an actor on the current thread.
//
// Returns true if the transport layer was successfully connected,
// i.e., mChannelState == ChannelConnected.
//
// Same-thread channels may not perform synchronous or blocking message
// sends, to avoid deadlocks.
bool OpenOnSameThread(MessageChannel* aTargetChan, Side aSide);
/**
* This sends a special message that is processed on the IO thread, so that
* other actors can know that the process will soon shutdown.
*/
void NotifyImpendingShutdown();
// Close the underlying transport channel.
void Close();
// Force the channel to behave as if a channel error occurred. Valid
// for process links only, not thread links.
void CloseWithError();
void CloseWithTimeout();
void SetAbortOnError(bool abort) { mAbortOnError = abort; }
// Call aInvoke for each pending message until it returns false.
// XXX: You must get permission from an IPC peer to use this function
// since it requires custom deserialization and re-orders events.
void PeekMessages(const std::function<bool(const Message& aMsg)>& aInvoke);
// Misc. behavioral traits consumers can request for this channel
enum ChannelFlags {
REQUIRE_DEFAULT = 0,
// Windows: if this channel operates on the UI thread, indicates
// WindowsMessageLoop code should enable deferred native message
// handling to prevent deadlocks. Should only be used for protocols
// that manage child processes which might create native UI, like
// plugins.
REQUIRE_DEFERRED_MESSAGE_PROTECTION = 1 << 0,
// Windows: When this flag is specified, any wait that occurs during
// synchronous IPC will be alertable, thus allowing a11y code in the
// chrome process to reenter content while content is waiting on a
// synchronous call.
REQUIRE_A11Y_REENTRY = 1 << 1,
};
void SetChannelFlags(ChannelFlags aFlags) { mFlags = aFlags; }
ChannelFlags GetChannelFlags() { return mFlags; }
// Asynchronously send a message to the other side of the channel
bool Send(UniquePtr<Message> aMsg);
// Asynchronously send a message to the other side of the channel
// and wait for asynchronous reply.
template <typename Value>
void Send(UniquePtr<Message> aMsg, ActorIdType aActorId,
ResolveCallback<Value>&& aResolve, RejectCallback&& aReject) {
int32_t seqno = NextSeqno();
aMsg->set_seqno(seqno);
if (!Send(std::move(aMsg))) {
aReject(ResponseRejectReason::SendError);
return;
}
UniquePtr<UntypedCallbackHolder> callback =
MakeUnique<CallbackHolder<Value>>(aActorId, std::move(aResolve),
std::move(aReject));
mPendingResponses.insert(std::make_pair(seqno, std::move(callback)));
gUnresolvedResponses++;
}
bool SendBuildIDsMatchMessage(const char* aParentBuildI);
bool DoBuildIDsMatch() { return mBuildIDsConfirmedMatch; }
// Synchronously send |msg| (i.e., wait for |reply|)
bool Send(UniquePtr<Message> aMsg, Message* aReply);
// Make an Interrupt call to the other side of the channel
bool Call(UniquePtr<Message> aMsg, Message* aReply);
bool CanSend() const;
// Remove and return a callback that needs reply
UniquePtr<UntypedCallbackHolder> PopCallback(const Message& aMsg);
// Used to reject and remove pending responses owned by the given
// actor when it's about to be destroyed.
void RejectPendingResponsesForActor(ActorIdType aActorId);
// If sending a sync message returns an error, this function gives a more
// descriptive error message.
SyncSendError LastSendError() const {
AssertWorkerThread();
return mLastSendError;
}
void SetReplyTimeoutMs(int32_t aTimeoutMs);
bool IsOnCxxStack() const { return !mCxxStackFrames.empty(); }
void CancelCurrentTransaction();
// Force all calls to Send to defer actually sending messages. This will
// cause sync messages to block until another thread calls
// StopPostponingSends.
//
// This must be called from the worker thread.
void BeginPostponingSends();
// Stop postponing sent messages, and immediately flush all postponed
// messages to the link. This may be called from any thread.
//
// Note that there are no ordering guarantees between two different
// MessageChannels. If channel B sends a message, then stops postponing
// channel A, messages from A may arrive before B. The easiest way to order
// this, if needed, is to make B send a sync message.
void StopPostponingSends();
// Unsound_IsClosed and Unsound_NumQueuedMessages are safe to call from any
// thread, but they make no guarantees about whether you'll get an
// up-to-date value; the values are written on one thread and read without
// locking, on potentially different threads. Thus you should only use
// them when you don't particularly care about getting a recent value (e.g.
// in a memory report).
bool Unsound_IsClosed() const {
return mLink ? mLink->Unsound_IsClosed() : true;
}
uint32_t Unsound_NumQueuedMessages() const {
return mLink ? mLink->Unsound_NumQueuedMessages() : 0;
}
static bool IsPumpingMessages() { return sIsPumpingMessages; }
static void SetIsPumpingMessages(bool aIsPumping) {
sIsPumpingMessages = aIsPumping;
}
/**
* Does this MessageChannel currently cross process boundaries?
*/
bool IsCrossProcess() const;
void SetIsCrossProcess(bool aIsCrossProcess);
#ifdef OS_WIN
struct MOZ_STACK_CLASS SyncStackFrame {
SyncStackFrame(MessageChannel* channel, bool interrupt);
~SyncStackFrame();
bool mInterrupt;
bool mSpinNestedEvents;
bool mListenerNotified;
MessageChannel* mChannel;
// The previous stack frame for this channel.
SyncStackFrame* mPrev;
// The previous stack frame on any channel.
SyncStackFrame* mStaticPrev;
};
friend struct MessageChannel::SyncStackFrame;
static bool IsSpinLoopActive() {
for (SyncStackFrame* frame = sStaticTopFrame; frame; frame = frame->mPrev) {
if (frame->mSpinNestedEvents) return true;
}
return false;
}
protected:
// The deepest sync stack frame for this channel.
SyncStackFrame* mTopFrame = nullptr;
bool mIsSyncWaitingOnNonMainThread = false;
// The deepest sync stack frame on any channel.
static SyncStackFrame* sStaticTopFrame;
public:
void ProcessNativeEventsInInterruptCall();
static void NotifyGeckoEventDispatch();
private:
void SpinInternalEventLoop();
# if defined(ACCESSIBILITY)
bool WaitForSyncNotifyWithA11yReentry();
# endif // defined(ACCESSIBILITY)
#endif // defined(OS_WIN)
private:
void PostErrorNotifyTask();
void OnNotifyMaybeChannelError();
void ReportConnectionError(const char* aChannelName,
Message* aMsg = nullptr) const;
void ReportMessageRouteError(const char* channelName) const;
bool MaybeHandleError(Result code, const Message& aMsg,
const char* channelName);
void Clear();
bool InterruptEventOccurred();
bool HasPendingEvents();
void ProcessPendingRequests(AutoEnterTransaction& aTransaction);
bool ProcessPendingRequest(Message&& aUrgent);
void MaybeUndeferIncall();
void EnqueuePendingMessages();
// Dispatches an incoming message to its appropriate handler.
void DispatchMessage(Message&& aMsg);
// DispatchMessage will route to one of these functions depending on the
// protocol type of the message.
void DispatchSyncMessage(ActorLifecycleProxy* aProxy, const Message& aMsg,
Message*& aReply);
void DispatchAsyncMessage(ActorLifecycleProxy* aProxy, const Message& aMsg);
void DispatchInterruptMessage(ActorLifecycleProxy* aProxy, Message&& aMsg,
size_t aStackDepth);
// Return true if the wait ended because a notification was received.
//
// Return false if the time elapsed from when we started the process of
// waiting until afterwards exceeded the currently allotted timeout.
// That *DOES NOT* mean false => "no event" (== timeout); there are many
// circumstances that could cause the measured elapsed time to exceed the
// timeout EVEN WHEN we were notified.
//
// So in sum: true is a meaningful return value; false isn't,
// necessarily.
bool WaitForSyncNotify(bool aHandleWindowsMessages);
bool WaitForInterruptNotify();
bool WaitResponse(bool aWaitTimedOut);
bool ShouldContinueFromTimeout();
void EndTimeout();
void CancelTransaction(int transaction);
void RepostAllMessages();
// The "remote view of stack depth" can be different than the
// actual stack depth when there are out-of-turn replies. When we
// receive one, our actual Interrupt stack depth doesn't decrease, but
// the other side (that sent the reply) thinks it has. So, the
// "view" returned here is |stackDepth| minus the number of
// out-of-turn replies.
//
// Only called from the worker thread.
size_t RemoteViewOfStackDepth(size_t stackDepth) const {
AssertWorkerThread();
return stackDepth - mOutOfTurnReplies.size();
}
int32_t NextSeqno() {
AssertWorkerThread();
return (mSide == ChildSide) ? --mNextSeqno : ++mNextSeqno;
}
// This helper class manages mCxxStackDepth on behalf of MessageChannel.
// When the stack depth is incremented from zero to non-zero, it invokes
// a callback, and similarly for when the depth goes from non-zero to zero.
void EnteredCxxStack();
void ExitedCxxStack();
void EnteredCall();
void ExitedCall();
void EnteredSyncSend();
void ExitedSyncSend();
void DebugAbort(const char* file, int line, const char* cond, const char* why,
bool reply = false);
// This method is only safe to call on the worker thread, or in a
// debugger with all threads paused.
void DumpInterruptStack(const char* const pfx = "") const;
void AddProfilerMarker(const IPC::Message& aMessage,
MessageDirection aDirection);
private:
// Called from both threads
size_t InterruptStackDepth() const {
mMonitor->AssertCurrentThreadOwns();
return mInterruptStack.size();
}
bool AwaitingInterruptReply() const {
mMonitor->AssertCurrentThreadOwns();
return !mInterruptStack.empty();
}
// Returns true if we're dispatching an async message's callback.
bool DispatchingAsyncMessage() const {
AssertWorkerThread();
return mDispatchingAsyncMessage;
}
int DispatchingAsyncMessageNestedLevel() const {
AssertWorkerThread();
return mDispatchingAsyncMessageNestedLevel;
}
bool Connected() const;
private:
// Executed on the IO thread.
void NotifyWorkerThread();
// Return true if |aMsg| is a special message targeted at the IO
// thread, in which case it shouldn't be delivered to the worker.
bool MaybeInterceptSpecialIOMessage(const Message& aMsg);
// Tell the IO thread to close the channel and wait for it to ACK.
void SynchronouslyClose();
// Returns true if ShouldDeferMessage(aMsg) is guaranteed to return true.
// Otherwise, the result of ShouldDeferMessage(aMsg) may be true or false,
// depending on context.
static bool IsAlwaysDeferred(const Message& aMsg);
// Helper for sending a message via the link. This should only be used for
// non-special messages that might have to be postponed.
void SendMessageToLink(UniquePtr<Message> aMsg);
bool WasTransactionCanceled(int transaction);
bool ShouldDeferMessage(const Message& aMsg);
bool ShouldDeferInterruptMessage(const Message& aMsg, size_t aStackDepth);
void OnMessageReceivedFromLink(Message&& aMsg);
void OnChannelErrorFromLink();
private:
// Clear this channel, and notify the listener that the channel has either
// closed or errored.
//
// These methods must be called on the worker thread, passing in a
// `Maybe<MonitorAutoLock>`. This lock guard will be reset before the listener
// is called, allowing for the mutex to be unlocked before the MessageChannel
// is potentially destroyed.
void NotifyChannelClosed(Maybe<MonitorAutoLock>& aLock);
void NotifyMaybeChannelError(Maybe<MonitorAutoLock>& aLock);
private:
void AssertWorkerThread() const {
MOZ_ASSERT(mWorkerThread, "Channel hasn't been opened yet");
MOZ_RELEASE_ASSERT(mWorkerThread && mWorkerThread->IsOnCurrentThread(),
"not on worker thread!");
}
private:
class MessageTask : public CancelableRunnable,
public LinkedListElement<RefPtr<MessageTask>>,
public nsIRunnablePriority,
public nsIRunnableIPCMessageType {
public:
explicit MessageTask(MessageChannel* aChannel, Message&& aMessage);
MessageTask() = delete;
MessageTask(const MessageTask&) = delete;
NS_DECL_ISUPPORTS_INHERITED
NS_IMETHOD Run() override;
nsresult Cancel() override;
NS_IMETHOD GetPriority(uint32_t* aPriority) override;
NS_DECL_NSIRUNNABLEIPCMESSAGETYPE
void Post();
bool IsScheduled() const {
mMonitor->AssertCurrentThreadOwns();
return mScheduled;
}
Message& Msg() { return mMessage; }
const Message& Msg() const { return mMessage; }
private:
~MessageTask() = default;
MessageChannel* Channel() {
mMonitor->AssertCurrentThreadOwns();
MOZ_RELEASE_ASSERT(isInList());
return mChannel;
}
// The connected MessageChannel's monitor. Guards `mChannel` and
// `mScheduled`.
RefPtr<RefCountedMonitor> const mMonitor;
// The channel which this MessageTask is associated with. Only valid while
// `mMonitor` is held, and this MessageTask `isInList()`.
MessageChannel* const mChannel;
Message mMessage;
bool mScheduled : 1;
};
bool ShouldRunMessage(const Message& aMsg);
void RunMessage(MessageTask& aTask);
typedef LinkedList<RefPtr<MessageTask>> MessageQueue;
typedef std::map<size_t, Message> MessageMap;
typedef std::map<size_t, UniquePtr<UntypedCallbackHolder>> CallbackMap;
typedef IPC::Message::msgid_t msgid_t;
private:
// This will be a string literal, so lifetime is not an issue.
const char* const mName;
// Based on presumption the listener owns and overlives the channel,
// this is never nullified.
IToplevelProtocol* const mListener;
// This monitor guards all state in this MessageChannel, except where
// otherwise noted. It is refcounted so a reference to it can be shared with
// IPC listener objects which need to access weak references to this
// `MessageChannel`.
RefPtr<RefCountedMonitor> const mMonitor;
ChannelState mChannelState = ChannelClosed;
Side mSide = UnknownSide;
bool mIsCrossProcess = false;
UniquePtr<MessageLink> mLink;
// NotifyMaybeChannelError runnable
RefPtr<CancelableRunnable> mChannelErrorTask;
// Thread we are allowed to send and receive on.
nsCOMPtr<nsISerialEventTarget> mWorkerThread;
// Timeout periods are broken up in two to prevent system suspension from
// triggering an abort. This method (called by WaitForEvent with a 'did
// timeout' flag) decides if we should wait again for half of mTimeoutMs
// or give up.
int32_t mTimeoutMs = kNoTimeout;
bool mInTimeoutSecondHalf = false;
// Worker-thread only; sequence numbers for messages that require
// replies.
int32_t mNextSeqno = 0;
static bool sIsPumpingMessages;
// If ::Send returns false, this gives a more descriptive error.
SyncSendError mLastSendError = SyncSendError::SendSuccess;
template <class T>
class AutoSetValue {
public:
explicit AutoSetValue(T& var, const T& newValue)
: mVar(var), mPrev(var), mNew(newValue) {
mVar = newValue;
}
~AutoSetValue() {
// The value may have been zeroed if the transaction was
// canceled. In that case we shouldn't return it to its previous
// value.
if (mVar == mNew) {
mVar = mPrev;
}
}
private:
T& mVar;
T mPrev;
T mNew;
};
bool mDispatchingAsyncMessage = false;
int mDispatchingAsyncMessageNestedLevel = 0;
// When we send an urgent request from the parent process, we could race
// with an RPC message that was issued by the child beforehand. In this
// case, if the parent were to wake up while waiting for the urgent reply,
// and process the RPC, it could send an additional urgent message. The
// child would wake up to process the urgent message (as it always will),
// then send a reply, which could be received by the parent out-of-order
// with respect to the first urgent reply.
//
// To address this problem, urgent or RPC requests are associated with a
// "transaction". Whenever one side of the channel wishes to start a
// chain of RPC/urgent messages, it allocates a new transaction ID. Any
// messages the parent receives, not apart of this transaction, are
// deferred. When issuing RPC/urgent requests on top of a started
// transaction, the initiating transaction ID is used.
//
// To ensure IDs are unique, we use sequence numbers for transaction IDs,
// which grow in opposite directions from child to parent.
friend class AutoEnterTransaction;
AutoEnterTransaction* mTransactionStack = nullptr;
int32_t CurrentNestedInsideSyncTransaction() const;
bool AwaitingSyncReply() const;
int AwaitingSyncReplyNestedLevel() const;
bool DispatchingSyncMessage() const;
int DispatchingSyncMessageNestedLevel() const;
#ifdef DEBUG
void AssertMaybeDeferredCountCorrect();
#else
void AssertMaybeDeferredCountCorrect() {}
#endif
// If a sync message times out, we store its sequence number here. Any
// future sync messages will fail immediately. Once the reply for original
// sync message is received, we allow sync messages again.
//
// When a message times out, nothing is done to inform the other side. The
// other side will eventually dispatch the message and send a reply. Our
// side is responsible for replying to all sync messages sent by the other
// side when it dispatches the timed out message. The response is always an
// error.
//
// A message is only timed out if it initiated a transaction. This avoids
// hitting a lot of corner cases with message nesting that we don't really
// care about.
int32_t mTimedOutMessageSeqno = 0;
int mTimedOutMessageNestedLevel = 0;
// Queue of all incoming messages.
//
// If both this side and the other side are functioning correctly, the queue
// can only be in certain configurations. Let
//
// |A<| be an async in-message,
// |S<| be a sync in-message,
// |C<| be an Interrupt in-call,
// |R<| be an Interrupt reply.
//
// The queue can only match this configuration
//
// A<* (S< | C< | R< (?{mInterruptStack.size() == 1} A<* (S< | C<)))
//
// The other side can send as many async messages |A<*| as it wants before
// sending us a blocking message.
//
// The first case is |S<|, a sync in-msg. The other side must be blocked,
// and thus can't send us any more messages until we process the sync
// in-msg.
//
// The second case is |C<|, an Interrupt in-call; the other side must be
// blocked. (There's a subtlety here: this in-call might have raced with an
// out-call, but we detect that with the mechanism below,
// |mRemoteStackDepth|, and races don't matter to the queue.)
//
// Final case, the other side replied to our most recent out-call |R<|.
// If that was the *only* out-call on our stack,
// |?{mInterruptStack.size() == 1}|, then other side "finished with us,"
// and went back to its own business. That business might have included
// sending any number of async message |A<*| until sending a blocking
// message |(S< | C<)|. If we had more than one Interrupt call on our
// stack, the other side *better* not have sent us another blocking
// message, because it's blocked on a reply from us.
//
MessageQueue mPending;
// The number of messages in mPending for which IsAlwaysDeferred is false
// (i.e., the number of messages that might not be deferred, depending on
// context).
size_t mMaybeDeferredPendingCount = 0;
// Stack of all the out-calls on which this channel is awaiting responses.
// Each stack refers to a different protocol and the stacks are mutually
// exclusive: multiple outcalls of the same kind cannot be initiated while
// another is active.
std::stack<MessageInfo> mInterruptStack;
// This is what we think the Interrupt stack depth is on the "other side" of
// this Interrupt channel. We maintain this variable so that we can detect
// racy Interrupt calls. With each Interrupt out-call sent, we send along
// what *we* think the stack depth of the remote side is *before* it will
// receive the Interrupt call.
//
// After sending the out-call, our stack depth is "incremented" by pushing
// that pending message onto mPending.
//
// Then when processing an in-call |c|, it must be true that
//
// mInterruptStack.size() == c.remoteDepth
//
// I.e., my depth is actually the same as what the other side thought it
// was when it sent in-call |c|. If this fails to hold, we have detected
// racy Interrupt calls.
//
// We then increment mRemoteStackDepth *just before* processing the
// in-call, since we know the other side is waiting on it, and decrement
// it *just after* finishing processing that in-call, since our response
// will pop the top of the other side's |mPending|.
//
// One nice aspect of this race detection is that it is symmetric; if one
// side detects a race, then the other side must also detect the same race.
size_t mRemoteStackDepthGuess = 0;
// Approximation of code frames on the C++ stack. It can only be
// interpreted as the implication:
//
// !mCxxStackFrames.empty() => MessageChannel code on C++ stack
//
// This member is only accessed on the worker thread, and so is not
// protected by mMonitor. It is managed exclusively by the helper
// |class CxxStackFrame|.
mozilla::Vector<InterruptFrame> mCxxStackFrames;
// Did we process an Interrupt out-call during this stack? Only meaningful in
// ExitedCxxStack(), from which this variable is reset.
bool mSawInterruptOutMsg = false;
// Map of replies received "out of turn", because of Interrupt
// in-calls racing with replies to outstanding in-calls. See
MessageMap mOutOfTurnReplies;
// Map of async Callbacks that are still waiting replies.
CallbackMap mPendingResponses;
// Stack of Interrupt in-calls that were deferred because of race
// conditions.
std::stack<Message> mDeferred;
#ifdef OS_WIN
HANDLE mEvent;
#endif
// Should the channel abort the process from the I/O thread when
// a channel error occurs?
bool mAbortOnError = false;
// True if the listener has already been notified of a channel close or
// error.
bool mNotifiedChannelDone = false;
// See SetChannelFlags
ChannelFlags mFlags = REQUIRE_DEFAULT;
// Channels can enter messages are not sent immediately; instead, they are
// held in a queue until another thread deems it is safe to send them.
bool mIsPostponingSends = false;
std::vector<UniquePtr<Message>> mPostponedSends;
bool mBuildIDsConfirmedMatch = false;
// If this is true, both ends of this message channel have event targets
// on the same thread.
bool mIsSameThreadChannel = false;
};
void CancelCPOWs();
} // namespace ipc
} // namespace mozilla
namespace IPC {
template <>
struct ParamTraits<mozilla::ipc::ResponseRejectReason>
: public ContiguousEnumSerializer<
mozilla::ipc::ResponseRejectReason,
mozilla::ipc::ResponseRejectReason::SendError,
mozilla::ipc::ResponseRejectReason::EndGuard_> {};
} // namespace IPC
namespace geckoprofiler::markers {
struct IPCMarker {
static constexpr mozilla::Span<const char> MarkerTypeName() {
return mozilla::MakeStringSpan("IPC");
}
static void StreamJSONMarkerData(
mozilla::baseprofiler::SpliceableJSONWriter& aWriter,
mozilla::TimeStamp aStart, mozilla::TimeStamp aEnd, int32_t aOtherPid,
int32_t aMessageSeqno, IPC::Message::msgid_t aMessageType,
mozilla::ipc::Side aSide, mozilla::ipc::MessageDirection aDirection,
mozilla::ipc::MessagePhase aPhase, bool aSync) {
using namespace mozilla::ipc;
// This payload still streams a startTime and endTime property because it
// made the migration to MarkerTiming on the front-end easier.
aWriter.TimeProperty("startTime", aStart);
aWriter.TimeProperty("endTime", aEnd);
aWriter.IntProperty("otherPid", aOtherPid);
aWriter.IntProperty("messageSeqno", aMessageSeqno);
aWriter.StringProperty(
"messageType",
mozilla::MakeStringSpan(IPC::StringFromIPCMessageType(aMessageType)));
aWriter.StringProperty("side", IPCSideToString(aSide));
aWriter.StringProperty("direction",
aDirection == MessageDirection::eSending
? mozilla::MakeStringSpan("sending")
: mozilla::MakeStringSpan("receiving"));
aWriter.StringProperty("phase", IPCPhaseToString(aPhase));
aWriter.BoolProperty("sync", aSync);
}
static mozilla::MarkerSchema MarkerTypeDisplay() {
return mozilla::MarkerSchema::SpecialFrontendLocation{};
}
private:
static mozilla::Span<const char> IPCSideToString(mozilla::ipc::Side aSide) {
switch (aSide) {
case mozilla::ipc::ParentSide:
return mozilla::MakeStringSpan("parent");
case mozilla::ipc::ChildSide:
return mozilla::MakeStringSpan("child");
case mozilla::ipc::UnknownSide:
return mozilla::MakeStringSpan("unknown");
default:
MOZ_ASSERT_UNREACHABLE("Invalid IPC side");
return mozilla::MakeStringSpan("<invalid IPC side>");
}
}
static mozilla::Span<const char> IPCPhaseToString(
mozilla::ipc::MessagePhase aPhase) {
switch (aPhase) {
case mozilla::ipc::MessagePhase::Endpoint:
return mozilla::MakeStringSpan("endpoint");
case mozilla::ipc::MessagePhase::TransferStart:
return mozilla::MakeStringSpan("transferStart");
case mozilla::ipc::MessagePhase::TransferEnd:
return mozilla::MakeStringSpan("transferEnd");
default:
MOZ_ASSERT_UNREACHABLE("Invalid IPC phase");
return mozilla::MakeStringSpan("<invalid IPC phase>");
}
}
};
} // namespace geckoprofiler::markers
#endif // ifndef ipc_glue_MessageChannel_h