os-main.cpp

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/*
 * 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>
#include <cmsis-plus/estd/memory_resource>
 
// ----------------------------------------------------------------------------
 
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wc++98-compat"
#endif
 
// ----------------------------------------------------------------------------
 
using namespace os;
 
// ----------------------------------------------------------------------------
 
extern "C" void
os_goodbye (void);
 
namespace
{
  // --------------------------------------------------------------------------
 
  // Since the native threads have a single argument, and it is better to
  // avoid C++11 tuples and function objects, there is no other simple
  // way than to pack the args in a structure and use it by the
  // trampoline to invoke the os_main().
 
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wpadded"
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wpadded"
#endif
 
  using main_args_t = struct
  {
    int argc;
    char** argv;
  };
 
#pragma GCC diagnostic pop
 
  static main_args_t main_args;
 
  // --------------------------------------------------------------------------
 
  [[noreturn]] static void
  _main_trampoline (void)
  {
    trace::puts ("");
    trace::dump_args (main_args.argc, main_args.argv);
 
    int code = os_main (main_args.argc, main_args.argv);
    trace::printf ("%s() exit = %d\n", __func__, code);
 
    // Exit will run the atexit() and destructors, then
    // terminate gracefully.
    std::exit (code);
  }
 
  // --------------------------------------------------------------------------
 
} /* namespace  */
 
// ----------------------------------------------------------------------------
extern rtos::thread* os_main_thread;
 
// Intentionally a raw pointer, to prevent destruction.
rtos::thread* os_main_thread;
 
#if defined(OS_EXCLUDE_DYNAMIC_MEMORY_ALLOCATIONS)
 
// Necessarily static, on Cortex-M the reset stack will be used
// as MSP for the interrupts, so the current stack must be freed
// and os_main() shall run on its own stack.
using main_thread
    = rtos::thread_inclusive<OS_INTEGER_RTOS_MAIN_STACK_SIZE_BYTES>;
static std::aligned_storage<sizeof (main_thread), alignof (main_thread)>::type
    os_main_thread_;
 
#endif /* defined(OS_EXCLUDE_DYNAMIC_MEMORY_ALLOCATIONS) */
 
int
#if !defined(__APPLE__)
    __attribute__ ((weak))
#endif
    main (int argc, char* argv[])
{
  using namespace os::rtos;
 
  trace::printf ("\nµOS++ IIIe version " OS_STRING_RTOS_IMPL_VERSION "\n");
  trace::printf ("Copyright (c) 2007-" OS_STRING_RTOS_IMPL_YEAR
                 " Liviu Ionescu\n");
 
  port::scheduler::greeting ();
 
  trace::printf ("Scheduler frequency: %u ticks/sec\n",
                 rtos::clock_systick::frequency_hz);
  trace::printf ("Default stack size: %u bytes\n",
                 thread::stack::default_size ());
#if defined(OS_HAS_INTERRUPTS_STACK)
  trace::printf ("Interrupts stack size: %u bytes\n",
                 interrupts::stack ()->size ());
#endif /* defined(OS_HAS_INTERRUPTS_STACK) */
 
#if defined(__clang__)
  trace::printf ("Built with clang " __VERSION__);
#else
  trace::printf ("Built with GCC " __VERSION__);
#endif
 
#if defined(__EXCEPTIONS)
  trace::printf (", with exceptions");
#else
  trace::printf (", no exceptions");
#endif
  trace::puts ("\n");
 
  scheduler::initialize ();
 
  // Store the parameters in the static structure, to be used by os_main().
  main_args.argc = argc;
  main_args.argv = argv;
 
#if defined(OS_EXCLUDE_DYNAMIC_MEMORY_ALLOCATIONS)
 
  // Running the constructor manually has the additional advantage of
  // not registering any destructor, and for main this is important,
  // since the destructors are executed on its context, and it cannot
  // destruct itself.
  new (&os_main_thread_)
      main_thread{ "main", reinterpret_cast<thread::func_t> (_main_trampoline),
                   nullptr };
 
  os_main_thread = reinterpret_cast<rtos::thread*> (&os_main_thread_);
 
#else
 
  thread::attributes attr = thread::initializer;
  attr.th_stack_size_bytes = OS_INTEGER_RTOS_MAIN_STACK_SIZE_BYTES;
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wcast-function-type-strict"
#endif
  os_main_thread = new thread (
      "main", reinterpret_cast<thread::func_t> (_main_trampoline), nullptr,
      attr);
#pragma GCC diagnostic pop
 
#endif /* defined(OS_EXCLUDE_DYNAMIC_MEMORY_ALLOCATIONS) */
 
#if !defined(OS_USE_RTOS_PORT_SCHEDULER)
  os_startup_create_thread_idle ();
#endif /* !defined(OS_USE_RTOS_PORT_SCHEDULER) */
 
  // Execution will proceed to first registered thread, possibly
  // "idle", which will immediately lower its priority,
  // and at a certain moment will reach os_main().
  scheduler::start ();
 
  /* NOTREACHED */
}
 
void
#if !defined(__APPLE__)
    __attribute__ ((weak))
#endif
    os_terminate_goodbye (void)
{
#if defined(TRACE)
 
  trace::printf ("\n");
 
#if !defined(OS_EXCLUDE_DYNAMIC_MEMORY_ALLOCATIONS)
 
  // Application memory.
  estd::pmr::get_default_resource ()->trace_print_statistics ();
 
#if defined(OS_INTEGER_RTOS_DYNAMIC_MEMORY_SIZE_BYTES)
  rtos::memory::get_default_resource ()->trace_print_statistics ();
#endif /* defined(OS_INTEGER_RTOS_DYNAMIC_MEMORY_SIZE_BYTES) */
 
#endif /* !defined(OS_EXCLUDE_DYNAMIC_MEMORY_ALLOCATIONS) */
 
  class rtos::thread::stack& st = os_main_thread->stack ();
 
  trace::printf ("Main thread stack: %u/%u bytes used\n",
                 st.size () - st.available (), st.size ());
 
#if defined(OS_HAS_INTERRUPTS_STACK)
  trace::printf ("Interrupts stack: %u/%u bytes used\n",
                 rtos::interrupts::stack ()->size ()
                     - rtos::interrupts::stack ()->available (),
                 rtos::interrupts::stack ()->size ());
#endif /* defined(OS_HAS_INTERRUPTS_STACK) */
 
  trace::printf ("\nHasta la Vista!\n");
 
#endif /* defined(TRACE) */
}
 
// ----------------------------------------------------------------------------