882ec01e42
This patch brings the _thread module to stmhal/pyboard. There is a very simple round-robin thread scheduler, which is disabled if there is only one thread (for efficiency when threading is not used). The scheduler currently switches threads at a rate of 250Hz using the systick timer and the pend-SV interrupt. The GIL is disabled so one must be careful to use lock objects to prevent concurrent access of objects. The threading is disabled by default, one can enabled it with the config option MICROPY_PY_THREAD to test it out.
98 lines
3.6 KiB
C
98 lines
3.6 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2017 Damien P. George
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <string.h>
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#include <stdio.h>
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#include "py/obj.h"
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#include "gccollect.h"
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#include "irq.h"
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#include "pybthread.h"
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#if MICROPY_PY_THREAD
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int pyb_thread_enabled;
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pyb_thread_t *pyb_thread_cur;
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void pyb_thread_init(pyb_thread_t *thread) {
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pyb_thread_cur = thread;
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pyb_thread_cur->sp = NULL; // will be set when this thread switches out
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pyb_thread_cur->local_state = 0; // will be set by mp_thread_init
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pyb_thread_cur->arg = NULL;
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pyb_thread_cur->stack = &_heap_end;
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pyb_thread_cur->stack_len = ((uint32_t)&_estack - (uint32_t)&_heap_end) / sizeof(uint32_t);
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pyb_thread_cur->prev = thread;
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pyb_thread_cur->next = thread;
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}
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STATIC void pyb_thread_terminate(void) {
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uint32_t irq_state = raise_irq_pri(IRQ_PRI_PENDSV);
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pyb_thread_cur->prev->next = pyb_thread_cur->next;
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pyb_thread_cur->next->prev = pyb_thread_cur->prev;
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if (pyb_thread_cur->next == pyb_thread_cur->prev) {
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pyb_thread_enabled = 0;
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}
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restore_irq_pri(irq_state);
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pyb_thread_yield(); // should not return
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}
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uint32_t pyb_thread_new(pyb_thread_t *thread, void *stack, size_t stack_len, void *entry, void *arg) {
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uint32_t *stack_top = (uint32_t*)stack + stack_len; // stack is full descending
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*--stack_top = 0x01000000; // xPSR (thumb bit set)
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*--stack_top = (uint32_t)entry & 0xfffffffe; // pc (must have bit 0 cleared, even for thumb code)
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*--stack_top = (uint32_t)pyb_thread_terminate; // lr
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*--stack_top = 0; // r12
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*--stack_top = 0; // r3
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*--stack_top = 0; // r2
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*--stack_top = 0; // r1
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*--stack_top = (uint32_t)arg; // r0
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*--stack_top = 0xfffffff9; // lr (return to thread mode, non-FP, use MSP)
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stack_top -= 8; // r4-r11
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stack_top -= 16; // s16-s31 (we assume all threads use FP registers)
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thread->sp = stack_top;
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thread->local_state = 0;
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thread->arg = arg;
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thread->stack = stack;
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thread->stack_len = stack_len;
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uint32_t irq_state = raise_irq_pri(IRQ_PRI_PENDSV);
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pyb_thread_enabled = 1;
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thread->next = pyb_thread_cur->next;
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thread->prev = pyb_thread_cur;
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pyb_thread_cur->next->prev = thread;
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pyb_thread_cur->next = thread;
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restore_irq_pri(irq_state);
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return (uint32_t)thread; // success
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}
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// should only be called from pendsv_isr_handler
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void *pyb_thread_next(void *sp) {
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pyb_thread_cur->sp = sp;
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pyb_thread_cur = pyb_thread_cur->next;
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return pyb_thread_cur->sp;
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}
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#endif // MICROPY_PY_THREAD
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