blob: 671f0cd7ca9583e667807b04cf50086cdd64778a [file] [log] [blame]
// Copyright 2022 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <cstdint>
#include "ipcz/ipcz.h"
#include "third_party/abseil-cpp/absl/container/inlined_vector.h"
namespace ipcz {
class TrapEventDispatcher;
// A set of traps installed on a portal.
class TrapSet {
// The reason for each status update when something happens that might
// interest a trap. This is particularly useful for observing edge-triggered
// conditions.
enum class UpdateReason {
// A new trap is being installed and this is an initial state query.
// A new inbound parcel has arrived for retrieval.
// We just discovered that the remote portal is gone.
// A previously queued inbound parcel has been fully or partially retrieved
// by the application.
// A remote peer has changed state in a way that may be interesting to a
// trap in the set; for example, parcels may have been consumed from the
// remote queue.
TrapSet(const TrapSet&) = delete;
TrapSet& operator=(const TrapSet&) = delete;
// NOTE: A TrapSet must be empty before it can be destroyed.
bool empty() const { return traps_.empty(); }
// Indicates whether any installed traps in this set require monitoring of
// remote queue state.
bool need_remote_state() const {
return num_traps_monitoring_remote_state_ > 0;
// Attempts to install a new trap in the set. This effectively implements
// the ipcz Trap() API. If `conditions` are already met, returns
// IPCZ_RESULT_FAILED_PRECONDITION and populates `satisfied_condition_flags`
// and/or `status` if non-null.
IpczResult Add(const IpczTrapConditions& conditions,
IpczTrapEventHandler handler,
uintptr_t context,
const IpczPortalStatus& current_status,
IpczTrapConditionFlags* satisfied_condition_flags,
IpczPortalStatus* status);
// Notifies this TrapSet of a state change on the portal it's interested in.
// If the state change is interesting to any trap in the set, an appropriate
// event may be appended to `dispatcher` for imminent dispatch and the trap is
// removed from the set before returning.
void UpdatePortalStatus(const IpczPortalStatus& status,
UpdateReason reason,
TrapEventDispatcher& dispatcher);
// Immediately removes all traps from the set. Every trap present appends an
// IPCZ_TRAP_REMOVED event to `dispatcher` before removal.
void RemoveAll(TrapEventDispatcher& dispatcher);
struct Trap {
Trap(IpczTrapConditions conditions,
IpczTrapEventHandler handler,
uintptr_t context);
IpczTrapConditions conditions;
IpczTrapEventHandler handler;
uintptr_t context;
using TrapList = absl::InlinedVector<Trap, 4>;
TrapList traps_;
size_t num_traps_monitoring_remote_state_ = 0;
IpczPortalStatus last_known_status_ = {.size = sizeof(last_known_status_)};
} // namespace ipcz