os-evflags.cpp

Go to the documentation of this file.

/*
 * This file is part of the µOS++ project (https://micro-os-plus.github.io/).
 * Copyright (c) 2016-2025 Liviu Ionescu. All rights reserved.
 *
 * Permission to use, copy, modify, and/or distribute this software
 * for any purpose is hereby granted, under the terms of the MIT license.
 *
 * If a copy of the license was not distributed with this file, it can
 * be obtained from https://opensource.org/licenses/mit.
 */
 
#if defined(OS_USE_OS_APP_CONFIG_H)
#include <cmsis-plus/os-app-config.h>
#endif
 
#include <cmsis-plus/rtos/os.h>
 
// ----------------------------------------------------------------------------
 
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wc++98-compat"
#endif
 
// ----------------------------------------------------------------------------
 
namespace os
{
  namespace rtos
  {
    // ------------------------------------------------------------------------
 
    const event_flags::attributes event_flags::initializer;
 
    // ------------------------------------------------------------------------
 
    event_flags::event_flags (const attributes& attr)
        : event_flags{ nullptr, attr }
    {
    }
 
#pragma GCC diagnostic push
#if defined(__clang__)
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif
 
    event_flags::event_flags (const char* name, const attributes& attr)
        : object_named_system{ name }
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s() @%p %s\n", __func__, this, this->name ());
#endif
 
      // Don't call this from interrupt handlers.
      os_assert_throw (!interrupts::in_handler_mode (), EPERM);
 
#if !defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
      clock_ = attr.clock != nullptr ? attr.clock : &sysclock;
#endif
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      port::event_flags::create (this);
 
#else
 
#endif
    }
 
#pragma GCC diagnostic pop
 
    event_flags::~event_flags ()
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s() @%p %s\n", __func__, this, name ());
#endif
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      port::event_flags::destroy (this);
 
#else
 
      // There must be no threads waiting for these flags.
      assert (list_.empty ());
 
#endif
    }
 
    result_t
    event_flags::wait (flags::mask_t mask, flags::mask_t* oflags,
                       flags::mode_t mode)
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X,%u) @%p %s <0x%X\n", __func__, mask, mode, this,
                     name (), event_flags_.mask ());
#endif
 
      // Don't call this from interrupt handlers.
      os_assert_throw (!interrupts::in_handler_mode (), EPERM);
      // Don't call this from critical regions.
      os_assert_throw (!scheduler::locked (), EPERM);
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      return port::event_flags::wait (this, mask, oflags, mode);
 
#else
 
      {
        // ----- Enter critical section ---------------------------------------
        interrupts::critical_section ics;
 
        if (event_flags_.check_raised (mask, oflags, mode))
          {
#if defined(OS_TRACE_RTOS_EVFLAGS)
            trace::printf ("%s(0x%X,%u) @%p %s >0x%X\n", __func__, mask, mode,
                           this, name (), event_flags_.mask ());
#endif
            return result::ok;
          }
        // ----- Exit critical section ----------------------------------------
      }
 
      thread& crt_thread = this_thread::thread ();
 
      // Prepare a list node pointing to the current thread.
      // Do not worry for being on stack, it is temporarily linked to the
      // list and guaranteed to be removed before this function returns.
      internal::waiting_thread_node node{ crt_thread };
 
      for (;;)
        {
          {
            // ----- Enter critical section -----------------------------------
            interrupts::critical_section ics;
 
            if (event_flags_.check_raised (mask, oflags, mode))
              {
#if defined(OS_TRACE_RTOS_EVFLAGS)
                trace::printf ("%s(0x%X,%u) @%p %s >0x%X\n", __func__, mask,
                               mode, this, name (), event_flags_.mask ());
#endif
                return result::ok;
              }
 
            // Add this thread to the event flags waiting list.
            scheduler::internal_link_node (list_, node);
            // state::suspended set in above link().
            // ----- Exit critical section ------------------------------------
          }
 
          port::scheduler::reschedule ();
 
          {
            // ----- Enter critical section -----------------------------------
            interrupts::critical_section ics;
 
            // Remove the thread from the event flags waiting list,
            // if not already removed by raise().
            scheduler::internal_unlink_node (node);
            // ----- Exit critical section ------------------------------------
          }
 
          if (crt_thread.interrupted ())
            {
#if defined(OS_TRACE_RTOS_EVFLAGS)
              trace::printf ("%s(0x%X,%u) EINTR @%p %s\n", __func__, mask,
                             mode, this, name ());
#endif
              return EINTR;
            }
        }
 
      /* NOTREACHED */
      return ENOTRECOVERABLE;
 
#endif
    }
 
    result_t
    event_flags::try_wait (flags::mask_t mask, flags::mask_t* oflags,
                           flags::mode_t mode)
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X,%u) @%p %s <0x%X\n", __func__, mask, mode, this,
                     name (), event_flags_.mask ());
#endif
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      return port::event_flags::try_wait (this, mask, oflags, mode);
 
#else
 
      // Don't call this from high priority interrupts.
      assert (port::interrupts::is_priority_valid ());
 
      {
        // ----- Enter critical section ---------------------------------------
        interrupts::critical_section ics;
 
        if (event_flags_.check_raised (mask, oflags, mode))
          {
#if defined(OS_TRACE_RTOS_EVFLAGS)
            trace::printf ("%s(0x%X,%u) @%p %s >0x%X\n", __func__, mask, mode,
                           this, name (), event_flags_.mask ());
#endif
            return result::ok;
          }
        else
          {
#if defined(OS_TRACE_RTOS_EVFLAGS)
            trace::printf ("%s(0x%X,%u) EWOULDBLOCK @%p %s \n", __func__, mask,
                           mode, this, name ());
#endif
            return EWOULDBLOCK;
          }
        // ----- Exit critical section ----------------------------------------
      }
 
#endif
    }
 
    result_t
    event_flags::timed_wait (flags::mask_t mask, clock::duration_t timeout,
                             flags::mask_t* oflags, flags::mode_t mode)
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X,%u,%u) @%p %s <0x%X\n", __func__, mask, timeout,
                     mode, this, name (), event_flags_.mask ());
#endif
 
      // Don't call this from interrupt handlers.
      os_assert_throw (!interrupts::in_handler_mode (), EPERM);
      // Don't call this from critical regions.
      os_assert_throw (!scheduler::locked (), EPERM);
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      return port::event_flags::timed_wait (this, mask, timeout, oflags, mode);
 
#else
 
      // Extra test before entering the loop, with its inherent weight.
      // Trade size for speed.
      {
        // ----- Enter critical section ---------------------------------------
        interrupts::critical_section ics;
 
        if (event_flags_.check_raised (mask, oflags, mode))
          {
#if defined(OS_TRACE_RTOS_EVFLAGS)
            trace::printf ("%s(0x%X,%u,%u) @%p %s >0x%X\n", __func__, mask,
                           timeout, mode, this, name (), event_flags_.mask ());
#endif
            return result::ok;
          }
        // ----- Exit critical section ----------------------------------------
      }
 
      thread& crt_thread = this_thread::thread ();
 
      // Prepare a list node pointing to the current thread.
      // Do not worry for being on stack, it is temporarily linked to the
      // list and guaranteed to be removed before this function returns.
      internal::waiting_thread_node node{ crt_thread };
 
      internal::clock_timestamps_list& clock_list = clock_->steady_list ();
      clock::timestamp_t timeout_timestamp = clock_->steady_now () + timeout;
 
      // Prepare a timeout node pointing to the current thread.
      internal::timeout_thread_node timeout_node{ timeout_timestamp,
                                                  crt_thread };
 
      for (;;)
        {
          {
            // ----- Enter critical section -----------------------------------
            interrupts::critical_section ics;
 
            if (event_flags_.check_raised (mask, oflags, mode))
              {
#if defined(OS_TRACE_RTOS_EVFLAGS)
                trace::printf ("%s(0x%X,%u,%u) @%p %s >0x%X\n", __func__, mask,
                               timeout, mode, this, name (),
                               event_flags_.mask ());
#endif
                return result::ok;
              }
 
            // Add this thread to the event flags waiting list,
            // and the clock timeout list.
            scheduler::internal_link_node (list_, node, clock_list,
                                           timeout_node);
            // state::suspended set in above link().
            // ----- Exit critical section ------------------------------------
          }
 
          port::scheduler::reschedule ();
 
          // Remove the thread from the event flags waiting list,
          // if not already removed by raise() and from the clock
          // timeout list, if not already removed by the timer.
          scheduler::internal_unlink_node (node, timeout_node);
 
          if (crt_thread.interrupted ())
            {
#if defined(OS_TRACE_RTOS_EVFLAGS)
              trace::printf ("%s(0x%X,%u,%u) EINTR @%p %s 0x%X \n", __func__,
                             mask, timeout, mode, this, name ());
#endif
              return EINTR;
            }
 
          if (clock_->steady_now () >= timeout_timestamp)
            {
#if defined(OS_TRACE_RTOS_EVFLAGS)
              trace::printf ("%s(0x%X,%u,%u) ETIMEDOUT @%p %s 0x%X \n",
                             __func__, mask, timeout, mode, this, name ());
#endif
              return ETIMEDOUT;
            }
        }
 
      /* NOTREACHED */
      return ENOTRECOVERABLE;
 
#endif
    }
 
    result_t
    event_flags::raise (flags::mask_t mask, flags::mask_t* oflags)
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X) @%p %s <0x%X \n", __func__, mask, this, name (),
                     event_flags_.mask ());
#endif
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      os_assert_err (mask != 0, EINVAL);
 
      return port::event_flags::raise (this, mask, oflags);
 
#else
 
      result_t res = event_flags_.raise (mask, oflags);
 
      // Wake-up all threads, if any.
      // Need not be inside the critical section,
      // the list is protected by inner `resume_one()`.
      list_.resume_all ();
 
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X) @%p %s >0x%X\n", __func__, mask, this, name (),
                     event_flags_.mask ());
#endif
      return res;
 
#endif
    }
 
    result_t
    event_flags::clear (flags::mask_t mask, flags::mask_t* oflags)
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X) @%p %s <0x%X \n", __func__, mask, this, name (),
                     event_flags_.mask ());
#endif
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      os_assert_err (mask != 0, EINVAL);
 
      return port::event_flags::clear (this, mask, oflags);
 
#else
 
      result_t res = event_flags_.clear (mask, oflags);
 
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X) @%p %s >0x%X\n", __func__, mask, this, name (),
                     event_flags_.mask ());
#endif
 
      return res;
 
#endif
    }
 
    flags::mask_t
    event_flags::get (flags::mask_t mask, flags::mode_t mode)
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X) @%p %s  \n", __func__, mask, this, name ());
#endif
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      return port::event_flags::get (this, mask, mode);
 
#else
 
      flags::mask_t ret = event_flags_.get (mask, mode);
 
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s(0x%X)=0x%X @%p %s \n", __func__, mask,
                     event_flags_.mask (), this, name ());
#endif
      // Return the selected flags.
      return ret;
 
#endif
    }
 
    bool
    event_flags::waiting (void)
    {
#if defined(OS_TRACE_RTOS_EVFLAGS)
      trace::printf ("%s() @%p %s\n", __func__, this, name ());
#endif
 
#if defined(OS_USE_RTOS_PORT_EVENT_FLAGS)
 
      return port::event_flags::waiting (this);
 
#else
 
      // Don't call this from high priority interrupts.
      assert (port::interrupts::is_priority_valid ());
 
      {
        // ----- Enter critical section ---------------------------------------
        interrupts::critical_section ics;
 
        return !list_.empty ();
        // ----- Exit critical section ----------------------------------------
      }
 
#endif
    }
 
    // ------------------------------------------------------------------------
 
  } /* namespace rtos */
} /* namespace os */
 
// ----------------------------------------------------------------------------