text: /*
   * This file is part of the Micro Python project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2014 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <stdint.h>
  #include <stdio.h>
  #include <errno.h>
  
  #include "stm32f4xx_hal.h"
  
  #include "mpconfig.h"
  #include "misc.h"
  #include "nlr.h"
  #include "qstr.h"
  #include "obj.h"
  #include "objlist.h"
  #include "pybioctl.h"
  
  /// \module select - Provides select function to wait for events on a stream
  ///
  /// This module provides the select function.
  
  typedef struct _poll_obj_t {
      mp_obj_t obj;
      mp_uint_t (*ioctl)(mp_obj_t obj, mp_uint_t request, int *errcode, ...);
      mp_uint_t flags;
      mp_uint_t flags_ret;
  } poll_obj_t;
  
  STATIC void poll_map_add(mp_map_t *poll_map, const mp_obj_t *obj, mp_uint_t obj_len, mp_uint_t flags, bool or_flags) {
      for (mp_uint_t i = 0; i < obj_len; i++) {
          mp_map_elem_t *elem = mp_map_lookup(poll_map, mp_obj_id(obj[i]), MP_MAP_LOOKUP_ADD_IF_NOT_FOUND);
          if (elem->value == NULL) {
              // object not found; get its ioctl and add it to the poll list
              mp_obj_type_t *type = mp_obj_get_type(obj[i]);
              if (type->stream_p == NULL || type->stream_p->ioctl == NULL) {
                  nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "object with stream.ioctl required"));
              }
              poll_obj_t *poll_obj = m_new_obj(poll_obj_t);
              poll_obj->obj = obj[i];
              poll_obj->ioctl = type->stream_p->ioctl;
              poll_obj->flags = flags;
              poll_obj->flags_ret = 0;
              elem->value = poll_obj;
          } else {
              // object exists; update its flags
              if (or_flags) {
                  ((poll_obj_t*)elem->value)->flags |= flags;
              } else {
                  ((poll_obj_t*)elem->value)->flags = flags;
              }
          }
      }
  }
  
  // poll each object in the map
  STATIC mp_uint_t poll_map_poll(mp_map_t *poll_map, mp_uint_t *rwx_num) {
      mp_uint_t n_ready = 0;
      for (mp_uint_t i = 0; i < poll_map->alloc; ++i) {
          if (!MP_MAP_SLOT_IS_FILLED(poll_map, i)) {
              continue;
          }
  
          poll_obj_t *poll_obj = (poll_obj_t*)poll_map->table[i].value;
          int errcode;
          mp_int_t ret = poll_obj->ioctl(poll_obj->obj, MP_IOCTL_POLL, &errcode, poll_obj->flags);
          poll_obj->flags_ret = ret;
  
          if (ret == -1) {
              // error doing ioctl
              nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(errcode)));
          }
  
          if (ret != 0) {
              // object is ready
              n_ready += 1;
              if (rwx_num != NULL) {
                  if (ret & MP_IOCTL_POLL_RD) {
                      rwx_num[0] += 1;
                  }
                  if (ret & MP_IOCTL_POLL_WR) {
                      rwx_num[1] += 1;
                  }
                  if ((ret & ~(MP_IOCTL_POLL_RD | MP_IOCTL_POLL_WR)) != 0) {
                      rwx_num[2] += 1;
                  }
              }
          }
      }
      return n_ready;
  }
  
  /// \function select(rlist, wlist, xlist[, timeout])
  STATIC mp_obj_t select_select(uint n_args, const mp_obj_t *args) {
      // get array data from tuple/list arguments
      mp_uint_t rwx_len[3];
      mp_obj_t *r_array, *w_array, *x_array;
      mp_obj_get_array(args[0], &rwx_len[0], &r_array);
      mp_obj_get_array(args[1], &rwx_len[1], &w_array);
      mp_obj_get_array(args[2], &rwx_len[2], &x_array);
  
      // get timeout
      mp_uint_t timeout = -1;
      if (n_args == 4) {
          if (args[3] != mp_const_none) {
              #if MICROPY_PY_BUILTINS_FLOAT
              float timeout_f = mp_obj_get_float(args[3]);
              if (timeout_f >= 0) {
                  timeout = (mp_uint_t)(timeout_f * 1000);
              }
              #else
              timeout = mp_obj_get_int(args[3]) * 1000;
              #endif
          }
      }
  
      // merge separate lists and get the ioctl function for each object
      mp_map_t poll_map;
      mp_map_init(&poll_map, rwx_len[0] + rwx_len[1] + rwx_len[2]);
      poll_map_add(&poll_map, r_array, rwx_len[0], MP_IOCTL_POLL_RD, true);
      poll_map_add(&poll_map, w_array, rwx_len[1], MP_IOCTL_POLL_WR, true);
      poll_map_add(&poll_map, x_array, rwx_len[2], MP_IOCTL_POLL_ERR | MP_IOCTL_POLL_HUP, true);
  
      mp_uint_t start_tick = HAL_GetTick();
      rwx_len[0] = rwx_len[1] = rwx_len[2] = 0;
      for (;;) {
          // poll the objects
          mp_uint_t n_ready = poll_map_poll(&poll_map, rwx_len);
  
          if (n_ready > 0 || (timeout != -1 && HAL_GetTick() - start_tick >= timeout)) {
              // one or more objects are ready, or we had a timeout
              mp_obj_t list_array[3];
              list_array[0] = mp_obj_new_list(rwx_len[0], NULL);
              list_array[1] = mp_obj_new_list(rwx_len[1], NULL);
              list_array[2] = mp_obj_new_list(rwx_len[2], NULL);
              rwx_len[0] = rwx_len[1] = rwx_len[2] = 0;
              for (mp_uint_t i = 0; i < poll_map.alloc; ++i) {
                  if (!MP_MAP_SLOT_IS_FILLED(&poll_map, i)) {
                      continue;
                  }
                  poll_obj_t *poll_obj = (poll_obj_t*)poll_map.table[i].value;
                  if (poll_obj->flags_ret & MP_IOCTL_POLL_RD) {
                      ((mp_obj_list_t*)list_array[0])->items[rwx_len[0]++] = poll_obj->obj;
                  }
                  if (poll_obj->flags_ret & MP_IOCTL_POLL_WR) {
                      ((mp_obj_list_t*)list_array[1])->items[rwx_len[1]++] = poll_obj->obj;
                  }
                  if ((poll_obj->flags_ret & ~(MP_IOCTL_POLL_RD | MP_IOCTL_POLL_WR)) != 0) {
                      ((mp_obj_list_t*)list_array[2])->items[rwx_len[2]++] = poll_obj->obj;
                  }
              }
              mp_map_deinit(&poll_map);
              return mp_obj_new_tuple(3, list_array);
          }
          __WFI();
      }
  }
  MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_select_select_obj, 3, 4, select_select);
  
  /// \class Poll - poll class
  
  typedef struct _mp_obj_poll_t {
      mp_obj_base_t base;
      mp_map_t poll_map;
  } mp_obj_poll_t;
  
  /// \method register(obj[, eventmask])
  STATIC mp_obj_t poll_register(uint n_args, const mp_obj_t *args) {
      mp_obj_poll_t *self = args[0];
      mp_uint_t flags;
      if (n_args == 3) {
          flags = mp_obj_get_int(args[2]);
      } else {
          flags = MP_IOCTL_POLL_RD | MP_IOCTL_POLL_WR;
      }
      poll_map_add(&self->poll_map, &args[1], 1, flags, false);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(poll_register_obj, 2, 3, poll_register);
  
  /// \method unregister(obj)
  STATIC mp_obj_t poll_unregister(mp_obj_t self_in, mp_obj_t obj_in) {
      mp_obj_poll_t *self = self_in;
      mp_map_lookup(&self->poll_map, mp_obj_id(obj_in), MP_MAP_LOOKUP_REMOVE_IF_FOUND);
      // TODO raise KeyError if obj didn't exist in map
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_2(poll_unregister_obj, poll_unregister);
  
  /// \method modify(obj, eventmask)
  STATIC mp_obj_t poll_modify(mp_obj_t self_in, mp_obj_t obj_in, mp_obj_t eventmask_in) {
      mp_obj_poll_t *self = self_in;
      mp_map_elem_t *elem = mp_map_lookup(&self->poll_map, mp_obj_id(obj_in), MP_MAP_LOOKUP);
      if (elem == NULL) {
          nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(ENOENT)));
      }
      ((poll_obj_t*)elem->value)->flags = mp_obj_get_int(eventmask_in);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_3(poll_modify_obj, poll_modify);
  
  /// \method poll([timeout])
  /// Timeout is in milliseconds.
  STATIC mp_obj_t poll_poll(uint n_args, const mp_obj_t *args) {
      mp_obj_poll_t *self = args[0];
  
      // work out timeout (its given already in ms)
      mp_uint_t timeout = -1;
      if (n_args == 2) {
          if (args[1] != mp_const_none) {
              mp_int_t timeout_i = mp_obj_get_int(args[1]);
              if (timeout_i >= 0) {
                  timeout = timeout_i;
              }
          }
      }
  
      mp_uint_t start_tick = HAL_GetTick();
      for (;;) {
          // poll the objects
          mp_uint_t n_ready = poll_map_poll(&self->poll_map, NULL);
  
          if (n_ready > 0 || (timeout != -1 && HAL_GetTick() - start_tick >= timeout)) {
              // one or more objects are ready, or we had a timeout
              mp_obj_list_t *ret_list = mp_obj_new_list(n_ready, NULL);
              mp_uint_t n_ready = 0;
              for (mp_uint_t i = 0; i < self->poll_map.alloc; ++i) {
                  if (!MP_MAP_SLOT_IS_FILLED(&self->poll_map, i)) {
                      continue;
                  }
                  poll_obj_t *poll_obj = (poll_obj_t*)self->poll_map.table[i].value;
                  if (poll_obj->flags_ret != 0) {
                      mp_obj_t tuple[2] = {poll_obj->obj, MP_OBJ_NEW_SMALL_INT(poll_obj->flags_ret)};
                      ret_list->items[n_ready++] = mp_obj_new_tuple(2, tuple);
                  }
              }
              return ret_list;
          }
          __WFI();
      }
  }
  MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(poll_poll_obj, 1, 2, poll_poll);
  
  STATIC const mp_map_elem_t poll_locals_dict_table[] = {
      { MP_OBJ_NEW_QSTR(MP_QSTR_register), (mp_obj_t)&poll_register_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_unregister), (mp_obj_t)&poll_unregister_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_modify), (mp_obj_t)&poll_modify_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_poll), (mp_obj_t)&poll_poll_obj },
  };
  STATIC MP_DEFINE_CONST_DICT(poll_locals_dict, poll_locals_dict_table);
  
  STATIC const mp_obj_type_t mp_type_poll = {
      { &mp_type_type },
      .name = MP_QSTR_poll,
      .locals_dict = (mp_obj_t)&poll_locals_dict,
  };
  
  /// \function poll()
  STATIC mp_obj_t select_poll(void) {
      mp_obj_poll_t *poll = m_new_obj(mp_obj_poll_t);
      poll->base.type = &mp_type_poll;
      mp_map_init(&poll->poll_map, 0);
      return poll;
  }
  MP_DEFINE_CONST_FUN_OBJ_0(mp_select_poll_obj, select_poll);
  
  STATIC const mp_map_elem_t mp_module_select_globals_table[] = {
      { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_uselect) },
      { MP_OBJ_NEW_QSTR(MP_QSTR_select), (mp_obj_t)&mp_select_select_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_poll), (mp_obj_t)&mp_select_poll_obj },
  };
  
  STATIC const mp_obj_dict_t mp_module_select_globals = {
      .base = {&mp_type_dict},
      .map = {
          .all_keys_are_qstrs = 1,
          .table_is_fixed_array = 1,
          .used = MP_ARRAY_SIZE(mp_module_select_globals_table),
          .alloc = MP_ARRAY_SIZE(mp_module_select_globals_table),
          .table = (mp_map_elem_t*)mp_module_select_globals_table,
      },
  };
  
  const mp_obj_module_t mp_module_uselect = {
      .base = { &mp_type_module },
      .name = MP_QSTR_uselect,
      .globals = (mp_obj_dict_t*)&mp_module_select_globals,
  };
  