Files
micropython/ports/esp32/mphalport.c
Angus Gratton 05ac69329d esp32: Fix hang in taskYIELD() on riscv CPUs when IRQs disabled.
Regression introduced in 337742f.

The hang occurs because the esp32 port was calling "from ISR" port-layer
functions to set/clear the interrupt mask. FreeRTOS kernel therefore
doesn't know the CPU is in a critical section. In taskYIELD() the riscv
port layer blocks after yielding until it knows the yield has happened, and
would block indefinitely if IRQs are disabled (until INT WDT triggers).

Moving to the "public" portENTER_CRITICAL/portEXIT_CRITICAL API means that
FreeRTOS knows we're in a critical section and can react accordingly.

Adds a regression test for this case (should be safe to run on all ports).

On single core CPUs, this should result in almost exactly the same
behaviour apart from fixing this case.

On dual core CPUs, we now have cross-CPU mutual exclusion for atomic
sections. This also shouldn't change anything, mostly because all the code
which enters an atomic section runs on the same CPU. If it does change
something, it will be to fix a thread safety bug.

There is some risk that this change triggers a FreeRTOS crash where there
is a call to a blocking FreeRTOS API with interrupts disabled. Previously
this code might have worked, but was probably thread unsafe and would have
hung in some circumstances.

This work was funded through GitHub Sponsors.

Signed-off-by: Angus Gratton <angus@redyak.com.au>
2024-10-10 10:59:51 +11:00

268 lines
8.4 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 "esp_timer.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 "shared/tinyusb/mp_usbd.h"
#include "shared/tinyusb/mp_usbd_cdc.h"
#include "usb.h"
#include "usb_serial_jtag.h"
#include "uart.h"
#if MICROPY_PY_STRING_TX_GIL_THRESHOLD < 0
#error "MICROPY_PY_STRING_TX_GIL_THRESHOLD must be positive"
#endif
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};
portMUX_TYPE mp_atomic_mux = portMUX_INITIALIZER_UNLOCKED;
// Check the ESP-IDF error code and raise an OSError if it's not ESP_OK.
#if MICROPY_ERROR_REPORTING <= MICROPY_ERROR_REPORTING_NORMAL
void check_esp_err_(esp_err_t code)
#else
void check_esp_err_(esp_err_t code, const char *func, const int line, const char *file)
#endif
{
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;
#if MICROPY_ERROR_REPORTING > MICROPY_ERROR_REPORTING_NORMAL
char err_msg[64];
esp_err_to_name_r(code, err_msg, sizeof(err_msg));
vstr_t vstr;
vstr_init(&vstr, 80);
vstr_printf(&vstr, "0x%04X %s in function '%s' at line %d in file '%s'", code, err_msg, func, line, file);
o_str->data = (const byte *)vstr_null_terminated_str(&vstr);
#else
o_str->data = (const byte *)esp_err_to_name(code); // esp_err_to_name ret's ptr to const str
#endif
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 MICROPY_HW_ESP_USB_SERIAL_JTAG
usb_serial_jtag_poll_rx();
if ((poll_flags & MP_STREAM_POLL_RD) && ringbuf_peek(&stdin_ringbuf) != -1) {
ret |= MP_STREAM_POLL_RD;
}
if (poll_flags & MP_STREAM_POLL_WR) {
ret |= MP_STREAM_POLL_WR;
}
#endif
#if MICROPY_HW_USB_CDC
ret |= mp_usbd_cdc_poll_interfaces(poll_flags);
#endif
#if MICROPY_PY_OS_DUPTERM
ret |= mp_os_dupterm_poll(poll_flags);
#endif
return ret;
}
int mp_hal_stdin_rx_chr(void) {
for (;;) {
#if MICROPY_HW_ESP_USB_SERIAL_JTAG
usb_serial_jtag_poll_rx();
#endif
#if MICROPY_HW_USB_CDC
mp_usbd_cdc_poll_interfaces(0);
#endif
int c = ringbuf_get(&stdin_ringbuf);
if (c != -1) {
return c;
}
MICROPY_EVENT_POLL_HOOK
}
}
mp_uint_t mp_hal_stdout_tx_strn(const char *str, size_t len) {
// Only release the GIL if many characters are being sent
mp_uint_t ret = len;
bool did_write = false;
#if MICROPY_HW_ENABLE_UART_REPL || CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG_ENABLED
bool release_gil = len > MICROPY_PY_STRING_TX_GIL_THRESHOLD;
#if MICROPY_DEBUG_PRINTERS && MICROPY_DEBUG_VERBOSE && MICROPY_PY_THREAD_GIL
// If verbose debug output is enabled some strings are printed before the
// GIL mutex is set up. When that happens, no Python code is running and
// therefore the interpreter doesn't care about the GIL not being ready.
release_gil = release_gil && (MP_STATE_VM(gil_mutex).handle != NULL);
#endif
if (release_gil) {
MP_THREAD_GIL_EXIT();
}
#if MICROPY_HW_ESP_USB_SERIAL_JTAG
usb_serial_jtag_tx_strn(str, len);
did_write = true;
#endif
#if MICROPY_HW_ENABLE_UART_REPL
uart_stdout_tx_strn(str, len);
did_write = true;
#endif
if (release_gil) {
MP_THREAD_GIL_ENTER();
}
#endif // MICROPY_HW_ENABLE_UART_REPL || CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG_ENABLED
#if MICROPY_HW_USB_CDC
mp_uint_t cdc_res = mp_usbd_cdc_tx_strn(str, len);
if (cdc_res > 0) {
did_write = true;
ret = MIN(cdc_res, ret);
}
#endif
int dupterm_res = mp_os_dupterm_tx_strn(str, len);
if (dupterm_res >= 0) {
did_write = true;
ret = MIN((mp_uint_t)dupterm_res, ret);
}
return did_write ? ret : 0;
}
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 = (uint64_t)ms * 1000ULL;
uint64_t dt;
uint64_t t0 = esp_timer_get_time();
for (;;) {
mp_handle_pending(true);
MICROPY_PY_SOCKET_EVENTS_HANDLER
MP_THREAD_GIL_EXIT();
uint64_t t1 = esp_timer_get_time();
dt = t1 - t0;
if (dt + portTICK_PERIOD_MS * 1000ULL >= 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(void) {
xTaskNotifyGive(mp_main_task_handle);
}
// Wake up the main task if it is sleeping, to be called from an ISR.
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();
}
}