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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* 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 <stdio.h>
#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_data = NULL;
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 MICROPY_SCHEDULER_STATIC_NODES
// Run all pending C callbacks.
while (MP_STATE_VM(sched_head) != NULL) {
mp_sched_node_t *node = MP_STATE_VM(sched_head);
MP_STATE_VM(sched_head) = node->next;
if (MP_STATE_VM(sched_head) == NULL) {
MP_STATE_VM(sched_tail) = NULL;
}
mp_sched_callback_t callback = node->callback;
node->callback = NULL;
MICROPY_END_ATOMIC_SECTION(atomic_state);
callback(node);
atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
}
#endif
// Run at most one pending Python callback.
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
#if MICROPY_SCHEDULER_STATIC_NODES
|| MP_STATE_VM(sched_head) != NULL
#endif
|| 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;
}
#if MICROPY_SCHEDULER_STATIC_NODES
bool mp_sched_schedule_node(mp_sched_node_t *node, mp_sched_callback_t callback) {
mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
bool ret;
if (node->callback == NULL) {
if (MP_STATE_VM(sched_state) == MP_SCHED_IDLE) {
MP_STATE_VM(sched_state) = MP_SCHED_PENDING;
}
node->callback = callback;
node->next = NULL;
if (MP_STATE_VM(sched_tail) == NULL) {
MP_STATE_VM(sched_head) = node;
} else {
MP_STATE_VM(sched_tail)->next = node;
}
MP_STATE_VM(sched_tail) = node;
MICROPY_SCHED_HOOK_SCHEDULED;
ret = true;
} else {
// already scheduled
ret = false;
}
MICROPY_END_ATOMIC_SECTION(atomic_state);
return ret;
}
#endif
#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
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