From 4fd287655a72b9aea14cdac715ad5b90ed082ed2 Mon Sep 17 00:00:00 2001 From: Raghuram Subramani Date: Sun, 19 Jun 2022 19:47:51 +0530 Subject: add circuitpython code --- circuitpython/py/scheduler.c | 162 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 circuitpython/py/scheduler.c (limited to 'circuitpython/py/scheduler.c') diff --git a/circuitpython/py/scheduler.c b/circuitpython/py/scheduler.c new file mode 100644 index 0000000..1fd5dae --- /dev/null +++ b/circuitpython/py/scheduler.c @@ -0,0 +1,162 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * SPDX-FileCopyrightText: Copyright (c) 2017 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 + +#include "py/runtime.h" + +// Schedules an exception on the main thread (for exceptions "thrown" by async +// sources such as interrupts and UNIX signal handlers). +void MICROPY_WRAP_MP_SCHED_EXCEPTION(mp_sched_exception)(mp_obj_t exc) { + MP_STATE_MAIN_THREAD(mp_pending_exception) = exc; + #if MICROPY_ENABLE_SCHEDULER + if (MP_STATE_VM(sched_state) == MP_SCHED_IDLE) { + MP_STATE_VM(sched_state) = MP_SCHED_PENDING; + } + #endif +} + +#if MICROPY_KBD_EXCEPTION +// This function may be called asynchronously at any time so only do the bare minimum. +void MICROPY_WRAP_MP_SCHED_KEYBOARD_INTERRUPT(mp_sched_keyboard_interrupt)(void) { + MP_STATE_VM(mp_kbd_exception).traceback = (mp_obj_traceback_t *)&mp_const_empty_traceback_obj; + mp_sched_exception(MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception))); +} +#endif + +#if MICROPY_ENABLE_SCHEDULER + +#define IDX_MASK(i) ((i) & (MICROPY_SCHEDULER_DEPTH - 1)) + +// This is a macro so it is guaranteed to be inlined in functions like +// mp_sched_schedule that may be located in a special memory region. +#define mp_sched_full() (mp_sched_num_pending() == MICROPY_SCHEDULER_DEPTH) + +static inline bool mp_sched_empty(void) { + MP_STATIC_ASSERT(MICROPY_SCHEDULER_DEPTH <= 255); // MICROPY_SCHEDULER_DEPTH must fit in 8 bits + MP_STATIC_ASSERT((IDX_MASK(MICROPY_SCHEDULER_DEPTH) == 0)); // MICROPY_SCHEDULER_DEPTH must be a power of 2 + + return mp_sched_num_pending() == 0; +} + +// A variant of this is inlined in the VM at the pending exception check +void mp_handle_pending(bool raise_exc) { + if (MP_STATE_VM(sched_state) == MP_SCHED_PENDING) { + mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION(); + // Re-check state is still pending now that we're in the atomic section. + if (MP_STATE_VM(sched_state) == MP_SCHED_PENDING) { + mp_obj_t obj = MP_STATE_THREAD(mp_pending_exception); + if (obj != MP_OBJ_NULL) { + MP_STATE_THREAD(mp_pending_exception) = MP_OBJ_NULL; + if (!mp_sched_num_pending()) { + MP_STATE_VM(sched_state) = MP_SCHED_IDLE; + } + if (raise_exc) { + MICROPY_END_ATOMIC_SECTION(atomic_state); + nlr_raise(obj); + } + } + mp_handle_pending_tail(atomic_state); + } else { + MICROPY_END_ATOMIC_SECTION(atomic_state); + } + } +} + +// This function should only be called by mp_handle_pending, +// or by the VM's inlined version of that function. +void mp_handle_pending_tail(mp_uint_t atomic_state) { + MP_STATE_VM(sched_state) = MP_SCHED_LOCKED; + if (!mp_sched_empty()) { + mp_sched_item_t item = MP_STATE_VM(sched_queue)[MP_STATE_VM(sched_idx)]; + MP_STATE_VM(sched_idx) = IDX_MASK(MP_STATE_VM(sched_idx) + 1); + --MP_STATE_VM(sched_len); + MICROPY_END_ATOMIC_SECTION(atomic_state); + mp_call_function_1_protected(item.func, item.arg); + } else { + MICROPY_END_ATOMIC_SECTION(atomic_state); + } + mp_sched_unlock(); +} + +void mp_sched_lock(void) { + mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION(); + if (MP_STATE_VM(sched_state) < 0) { + --MP_STATE_VM(sched_state); + } else { + MP_STATE_VM(sched_state) = MP_SCHED_LOCKED; + } + MICROPY_END_ATOMIC_SECTION(atomic_state); +} + +void mp_sched_unlock(void) { + mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION(); + assert(MP_STATE_VM(sched_state) < 0); + if (++MP_STATE_VM(sched_state) == 0) { + // vm became unlocked + if (MP_STATE_THREAD(mp_pending_exception) != MP_OBJ_NULL || mp_sched_num_pending()) { + MP_STATE_VM(sched_state) = MP_SCHED_PENDING; + } else { + MP_STATE_VM(sched_state) = MP_SCHED_IDLE; + } + } + MICROPY_END_ATOMIC_SECTION(atomic_state); +} + +bool MICROPY_WRAP_MP_SCHED_SCHEDULE(mp_sched_schedule)(mp_obj_t function, mp_obj_t arg) { + mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION(); + bool ret; + if (!mp_sched_full()) { + if (MP_STATE_VM(sched_state) == MP_SCHED_IDLE) { + MP_STATE_VM(sched_state) = MP_SCHED_PENDING; + } + uint8_t iput = IDX_MASK(MP_STATE_VM(sched_idx) + MP_STATE_VM(sched_len)++); + MP_STATE_VM(sched_queue)[iput].func = function; + MP_STATE_VM(sched_queue)[iput].arg = arg; + MICROPY_SCHED_HOOK_SCHEDULED; + ret = true; + } else { + // schedule queue is full + ret = false; + } + MICROPY_END_ATOMIC_SECTION(atomic_state); + return ret; +} + +#else // MICROPY_ENABLE_SCHEDULER + +// A variant of this is inlined in the VM at the pending exception check +void mp_handle_pending(bool raise_exc) { + if (MP_STATE_THREAD(mp_pending_exception) != MP_OBJ_NULL) { + mp_obj_t obj = MP_STATE_THREAD(mp_pending_exception); + MP_STATE_THREAD(mp_pending_exception) = MP_OBJ_NULL; + if (raise_exc) { + nlr_raise(obj); + } + } +} + +#endif // MICROPY_ENABLE_SCHEDULER -- cgit v1.2.3