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/*
*
* Copyright (c) 2020-2021 Project CHIP Authors
* Copyright (c) 2014-2017 Nest Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
* This file implements LayerImplFreeRTOS. Used by LwIP implementation and OpenThread
*/
#include <lib/support/CodeUtils.h>
#include <platform/LockTracker.h>
#include <system/PlatformEventSupport.h>
#include <system/SystemFaultInjection.h>
#include <system/SystemLayer.h>
#include <system/SystemLayerImplFreeRTOS.h>
namespace chip {
namespace System {
LayerImplFreeRTOS::LayerImplFreeRTOS() : mHandlingTimerComplete(false) {}
CHIP_ERROR LayerImplFreeRTOS::Init()
{
VerifyOrReturnError(mLayerState.SetInitializing(), CHIP_ERROR_INCORRECT_STATE);
#if CHIP_SYSTEM_CONFIG_USE_LWIP
RegisterLwIPErrorFormatter();
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP
VerifyOrReturnError(mLayerState.SetInitialized(), CHIP_ERROR_INCORRECT_STATE);
return CHIP_NO_ERROR;
}
void LayerImplFreeRTOS::Shutdown()
{
mLayerState.ResetFromInitialized();
}
CHIP_ERROR LayerImplFreeRTOS::StartTimer(Clock::Timeout delay, TimerCompleteCallback onComplete, void * appState)
{
assertChipStackLockedByCurrentThread();
VerifyOrReturnError(mLayerState.IsInitialized(), CHIP_ERROR_INCORRECT_STATE);
CHIP_SYSTEM_FAULT_INJECT(FaultInjection::kFault_TimeoutImmediate, delay = Clock::kZero);
CancelTimer(onComplete, appState);
TimerList::Node * timer = mTimerPool.Create(*this, SystemClock().GetMonotonicTimestamp() + delay, onComplete, appState);
VerifyOrReturnError(timer != nullptr, CHIP_ERROR_NO_MEMORY);
if (mTimerList.Add(timer) == timer)
{
// this is the new earliest timer and so the timer needs (re-)starting provided that
// the system is not currently processing expired timers, in which case it is left to
// HandleExpiredTimers() to re-start the timer.
if (!mHandlingTimerComplete)
{
StartPlatformTimer(delay);
}
}
return CHIP_NO_ERROR;
}
CHIP_ERROR LayerImplFreeRTOS::ExtendTimerTo(Clock::Timeout delay, TimerCompleteCallback onComplete, void * appState)
{
VerifyOrReturnError(delay.count() > 0, CHIP_ERROR_INVALID_ARGUMENT);
assertChipStackLockedByCurrentThread();
Clock::Timeout remainingTime = mTimerList.GetRemainingTime(onComplete, appState);
if (remainingTime.count() < delay.count())
{
return StartTimer(delay, onComplete, appState);
}
return CHIP_NO_ERROR;
}
bool LayerImplFreeRTOS::IsTimerActive(TimerCompleteCallback onComplete, void * appState)
{
return (mTimerList.GetRemainingTime(onComplete, appState) > Clock::kZero);
}
Clock::Timeout LayerImplFreeRTOS::GetRemainingTime(TimerCompleteCallback onComplete, void * appState)
{
return mTimerList.GetRemainingTime(onComplete, appState);
}
void LayerImplFreeRTOS::CancelTimer(TimerCompleteCallback onComplete, void * appState)
{
assertChipStackLockedByCurrentThread();
VerifyOrReturn(mLayerState.IsInitialized());
TimerList::Node * timer = mTimerList.Remove(onComplete, appState);
if (timer != nullptr)
{
mTimerPool.Release(timer);
}
}
CHIP_ERROR LayerImplFreeRTOS::ScheduleWork(TimerCompleteCallback onComplete, void * appState)
{
assertChipStackLockedByCurrentThread();
VerifyOrReturnError(mLayerState.IsInitialized(), CHIP_ERROR_INCORRECT_STATE);
// Ideally we would not use a timer here at all, but if we try to just
// ScheduleLambda the lambda needs to capture the following:
// 1) onComplete
// 2) appState
// 3) The `this` pointer, because onComplete needs to be passed a pointer to
// the System::Layer.
//
// On a 64-bit system that's 24 bytes, but lambdas passed to ScheduleLambda
// are capped at CHIP_CONFIG_LAMBDA_EVENT_SIZE which is 16 bytes.
//
// So for now use a timer as a poor-man's closure that captures `this` and
// onComplete and appState in a single pointer, so we fit inside the size
// limit.
//
// TODO: We could do something here where we compile-time condition on the
// sizes of things and use a direct ScheduleLambda if it would fit and this
// setup otherwise.
TimerList::Node * timer = mTimerPool.Create(*this, SystemClock().GetMonotonicTimestamp(), onComplete, appState);
VerifyOrReturnError(timer != nullptr, CHIP_ERROR_NO_MEMORY);
CHIP_ERROR err = ScheduleLambda([this, timer] { this->mTimerPool.Invoke(timer); });
if (err != CHIP_NO_ERROR)
{
mTimerPool.Release(timer);
}
return err;
}
/**
* Start the platform timer with specified millsecond duration.
*/
CHIP_ERROR LayerImplFreeRTOS::StartPlatformTimer(System::Clock::Timeout aDelay)
{
VerifyOrReturnError(IsInitialized(), CHIP_ERROR_INCORRECT_STATE);
CHIP_ERROR status = PlatformEventing::StartTimer(*this, aDelay);
return status;
}
/**
* Handle the platform timer expiration event. Completes any timers that have expired.
*
* A static API that gets called when the platform timer expires. Any expired timers are completed and removed from the list
* of active timers in the layer object. If unexpired timers remain on completion, StartPlatformTimer will be called to
* restart the platform timer.
*
* It is assumed that this API is called only while on the thread which owns the CHIP System Layer object.
*
* @note
* It's harmless if this API gets called and there are no expired timers.
*
* @return CHIP_NO_ERROR on success, error code otherwise.
*
*/
CHIP_ERROR LayerImplFreeRTOS::HandlePlatformTimer()
{
VerifyOrReturnError(IsInitialized(), CHIP_ERROR_INCORRECT_STATE);
// Expire each timer in turn until an unexpired timer is reached or the timerlist is emptied. We set the current expiration
// time outside the loop; that way timers set after the current tick will not be executed within this expiration window
// regardless how long the processing of the currently expired timers took.
// The platform timer API has MSEC resolution so expire any timer with less than 1 msec remaining.
Clock::Timestamp expirationTime = SystemClock().GetMonotonicTimestamp() + Clock::Timeout(1);
// limit the number of timers handled before the control is returned to the event queue. The bound is similar to
// (though not exactly same) as that on the sockets-based systems.
size_t timersHandled = 0;
TimerList::Node * timer = nullptr;
while ((timersHandled < CHIP_SYSTEM_CONFIG_NUM_TIMERS) && ((timer = mTimerList.PopIfEarlier(expirationTime)) != nullptr))
{
mHandlingTimerComplete = true;
mTimerPool.Invoke(timer);
mHandlingTimerComplete = false;
timersHandled++;
}
if (!mTimerList.Empty())
{
// timers still exist so restart the platform timer.
Clock::Timeout delay = System::Clock::kZero;
Clock::Timestamp currentTime = SystemClock().GetMonotonicTimestamp();
if (currentTime < mTimerList.Earliest()->AwakenTime())
{
// the next timer expires in the future, so set the delay to a non-zero value
delay = mTimerList.Earliest()->AwakenTime() - currentTime;
}
StartPlatformTimer(delay);
}
return CHIP_NO_ERROR;
}
} // namespace System
} // namespace chip