wayne roberts / TimeoutAbs

Timeout driver for event at absolute time

Dependents:   demo_TimeoutAbs i2c_lora_slave

Timeout driver for generating event at absolute time, i.e. alarm at 12:00PM instead of alarm in 5 minutes.

This is the same concept as TIMER_ABSTIME in clock_nanosleep().

The purpose is to remove dependency on when attach() is called, so the event occurs at correct time regardless of any latency in calling attach().

This driver doesnt add any functionality over mbed-os library; it only skips the call to ticker_read_us() in Ticker::setup(), which just changes a relative time to absolute time.

example use here.

TimeoutAbs.cpp

Committer:
Wayne Roberts
Date:
2018-11-26
Revision:
0:900163d530ae

File content as of revision 0:900163d530ae:


#include "TimeoutAbs.h"
#include "drivers/TimerEvent.h"
#include "platform/FunctionPointer.h"
#include "hal/ticker_api.h"
#include "platform/mbed_critical.h"

namespace mbed {

void TimeoutAbs::detach()
{
    core_util_critical_section_enter();
    remove();
    // unlocked only if we were attached (we locked it) and this is not low power ticker
    if (_function && _lock_deepsleep) {
        sleep_manager_unlock_deep_sleep();
    }
    _function = 0;
    core_util_critical_section_exit();
}

void TimeoutAbs::abs_setup(us_timestamp_t t)
{
    core_util_critical_section_enter();
    remove();
    insert_absolute(t);
    core_util_critical_section_exit();
}

void TimeoutAbs::handler()
{
    Callback<void()> local = _function;
    detach();
    local.call();
}

} // namespace mbed