micropython/ports/esp32/mphalport.c
Daniël van de Giessen 665f0e2a68 esp32: Sleep one tick in MICROPY_EVENT_POLL_HOOK.
If MicroPython threads are enabled, loops waiting for an incoming event
should release the GIL and suspend, allowing other tasks to run while they
wait.

Prior to this commit, the problem can easily be observed by running a
thread that is both busy and regularly releases the GIL (for example a loop
doing something then sleeping a few ms after each iteration).  When the
main task is at the REPL, the thread is significantly stalled.  If the main
task is manually made to release the GIL (for example, by calling
utime.sleep_ms(500)) the other thread can be seen immediately working at
the expected speed again.

Additionally, there are various instances in where blocking functions run
MICROPY_EVENT_POLL_HOOK in a loop while they wait for a certain event/
condition.  For example the uselect methods poll objects to determine
whether data is available, but uses 100% of CPU while it does, constantly
calling MICROPY_EVENT_POLL_HOOK in the process.

The MICROPY_EVENT_POLL_HOOK macro is only ever used in waiting loops, where
(if threads are enabled) it makes sense to yield for a single tick so that
these loops do not consume all CPU cycles but instead other threads may
execute.  (In fact, the thing these loops wait for may even indirectly or
directly depend on another task being able to run.)

This change moves the sleep that was inside the REPL input function to
inside the MICROPY_EVENT_POLL_HOOK macro, where the GIL is already being
released, solving both the blocking REPL issue and the 100% CPU use issue
at the same time.

Signed-off-by: Daniël van de Giessen <daniel@dvdgiessen.nl>
2022-03-02 12:57:43 +11:00

200 lines
6.0 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* Development of the code in this file was sponsored by Microbric Pty Ltd
*
* 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 <stdio.h>
#include <string.h>
#include <sys/time.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "py/obj.h"
#include "py/objstr.h"
#include "py/stream.h"
#include "py/mpstate.h"
#include "py/mphal.h"
#include "extmod/misc.h"
#include "shared/timeutils/timeutils.h"
#include "shared/runtime/pyexec.h"
#include "mphalport.h"
#include "usb.h"
#include "usb_serial_jtag.h"
#include "uart.h"
TaskHandle_t mp_main_task_handle;
STATIC uint8_t stdin_ringbuf_array[260];
ringbuf_t stdin_ringbuf = {stdin_ringbuf_array, sizeof(stdin_ringbuf_array), 0, 0};
// Check the ESP-IDF error code and raise an OSError if it's not ESP_OK.
void check_esp_err(esp_err_t code) {
if (code != ESP_OK) {
// map esp-idf error code to posix error code
uint32_t pcode = -code;
switch (code) {
case ESP_ERR_NO_MEM:
pcode = MP_ENOMEM;
break;
case ESP_ERR_TIMEOUT:
pcode = MP_ETIMEDOUT;
break;
case ESP_ERR_NOT_SUPPORTED:
pcode = MP_EOPNOTSUPP;
break;
}
// construct string object
mp_obj_str_t *o_str = m_new_obj_maybe(mp_obj_str_t);
if (o_str == NULL) {
mp_raise_OSError(pcode);
return;
}
o_str->base.type = &mp_type_str;
o_str->data = (const byte *)esp_err_to_name(code); // esp_err_to_name ret's ptr to const str
o_str->len = strlen((char *)o_str->data);
o_str->hash = qstr_compute_hash(o_str->data, o_str->len);
// raise
mp_obj_t args[2] = { MP_OBJ_NEW_SMALL_INT(pcode), MP_OBJ_FROM_PTR(o_str)};
nlr_raise(mp_obj_exception_make_new(&mp_type_OSError, 2, 0, args));
}
}
uintptr_t mp_hal_stdio_poll(uintptr_t poll_flags) {
uintptr_t ret = 0;
if ((poll_flags & MP_STREAM_POLL_RD) && stdin_ringbuf.iget != stdin_ringbuf.iput) {
ret |= MP_STREAM_POLL_RD;
}
return ret;
}
int mp_hal_stdin_rx_chr(void) {
for (;;) {
int c = ringbuf_get(&stdin_ringbuf);
if (c != -1) {
return c;
}
MICROPY_EVENT_POLL_HOOK
}
}
void mp_hal_stdout_tx_strn(const char *str, size_t len) {
// Only release the GIL if many characters are being sent
bool release_gil = len > 20;
if (release_gil) {
MP_THREAD_GIL_EXIT();
}
#if CONFIG_USB_ENABLED
usb_tx_strn(str, len);
#elif CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG
usb_serial_jtag_tx_strn(str, len);
#else
uart_stdout_tx_strn(str, len);
#endif
if (release_gil) {
MP_THREAD_GIL_ENTER();
}
mp_uos_dupterm_tx_strn(str, len);
}
uint32_t mp_hal_ticks_ms(void) {
return esp_timer_get_time() / 1000;
}
uint32_t mp_hal_ticks_us(void) {
return esp_timer_get_time();
}
void mp_hal_delay_ms(uint32_t ms) {
uint64_t us = ms * 1000;
uint64_t dt;
uint64_t t0 = esp_timer_get_time();
for (;;) {
mp_handle_pending(true);
MICROPY_PY_USOCKET_EVENTS_HANDLER
MP_THREAD_GIL_EXIT();
uint64_t t1 = esp_timer_get_time();
dt = t1 - t0;
if (dt + portTICK_PERIOD_MS * 1000 >= us) {
// doing a vTaskDelay would take us beyond requested delay time
taskYIELD();
MP_THREAD_GIL_ENTER();
t1 = esp_timer_get_time();
dt = t1 - t0;
break;
} else {
ulTaskNotifyTake(pdFALSE, 1);
MP_THREAD_GIL_ENTER();
}
}
if (dt < us) {
// do the remaining delay accurately
mp_hal_delay_us(us - dt);
}
}
void mp_hal_delay_us(uint32_t us) {
// these constants are tested for a 240MHz clock
const uint32_t this_overhead = 5;
const uint32_t pend_overhead = 150;
// return if requested delay is less than calling overhead
if (us < this_overhead) {
return;
}
us -= this_overhead;
uint64_t t0 = esp_timer_get_time();
for (;;) {
uint64_t dt = esp_timer_get_time() - t0;
if (dt >= us) {
return;
}
if (dt + pend_overhead < us) {
// we have enough time to service pending events
// (don't use MICROPY_EVENT_POLL_HOOK because it also yields)
mp_handle_pending(true);
}
}
}
uint64_t mp_hal_time_ns(void) {
struct timeval tv;
gettimeofday(&tv, NULL);
uint64_t ns = tv.tv_sec * 1000000000ULL;
ns += (uint64_t)tv.tv_usec * 1000ULL;
return ns;
}
// Wake up the main task if it is sleeping
void mp_hal_wake_main_task_from_isr(void) {
BaseType_t xHigherPriorityTaskWoken = pdFALSE;
vTaskNotifyGiveFromISR(mp_main_task_handle, &xHigherPriorityTaskWoken);
if (xHigherPriorityTaskWoken == pdTRUE) {
portYIELD_FROM_ISR();
}
}