2022-06-16 04:15:34 -04:00
|
|
|
| Supported Targets | ESP32 | ESP32-S2 | ESP32-S3 | ESP32-C2 | ESP32-C3 |
|
|
|
|
| ----------------- | ----- | -------- | -------- | -------- | -------- |
|
2022-05-20 05:50:08 -04:00
|
|
|
|
2021-03-08 02:48:30 -05:00
|
|
|
# eventfd example
|
|
|
|
|
|
|
|
The example demonstrates the use of `eventfd()` to collect events from other tasks and ISRs in a
|
|
|
|
`select()` based main loop. The example starts two tasks and installs a timer interrupt handler:
|
|
|
|
1. The first task writes to the first `eventfd` periodically.
|
|
|
|
2. The timer interrupt handler writes to the second `eventfd`.
|
|
|
|
3. The second task collects the event from two fds with a `select()` loop.
|
|
|
|
|
2021-03-08 06:52:05 -05:00
|
|
|
## How to use example
|
|
|
|
|
|
|
|
### Hardware Required
|
|
|
|
|
|
|
|
This example should be able to run on any commonly available ESP32, ESP32S2, ESP32S3 or ESP32C3 development board.
|
|
|
|
|
|
|
|
### Configure the project
|
|
|
|
|
|
|
|
```
|
|
|
|
idf.py menuconfig
|
|
|
|
```
|
|
|
|
|
|
|
|
The default config will work.
|
|
|
|
|
|
|
|
### Build and Flash
|
|
|
|
|
|
|
|
Build the project and flash it to the board, then run monitor tool to view serial output:
|
|
|
|
|
|
|
|
```
|
|
|
|
idf.py -p PORT flash monitor
|
|
|
|
```
|
|
|
|
|
|
|
|
(Replace PORT with the name of the serial port to use.)
|
|
|
|
|
|
|
|
(To exit the serial monitor, type ``Ctrl-]``.)
|
|
|
|
|
|
|
|
See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
|
|
|
|
|
|
|
|
## Example Output
|
|
|
|
|
|
|
|
The following log output should appear when the example runs (note that the bootloader log has been omitted).
|
|
|
|
|
|
|
|
```
|
2021-11-03 07:31:33 -04:00
|
|
|
I (4340) eventfd_example: Elapsed since test start: 2003 ms
|
|
|
|
I (4340) eventfd_example: Select timeout
|
|
|
|
I (4830) eventfd_example: Elapsed since test start: 2499 ms
|
|
|
|
I (4830) eventfd_example: TimerEvent fd event triggered
|
|
|
|
I (5830) eventfd_example: Elapsed since test start: 3493 ms
|
|
|
|
I (5830) eventfd_example: Progress fd event triggered
|
|
|
|
I (7330) eventfd_example: Elapsed since test start: 4999 ms
|
|
|
|
I (7330) eventfd_example: TimerEvent fd event triggered
|
|
|
|
I (7330) eventfd_example: =================================
|
|
|
|
I (7340) eventfd_example: Select timeouted for 1 times
|
|
|
|
I (7340) eventfd_example: Timer triggerred for 2 times
|
|
|
|
I (7350) eventfd_example: Progress triggerred for 1 times
|
|
|
|
I (7360) eventfd_example: =================================
|
|
|
|
I (9330) eventfd_example: Elapsed since test start: 6993 ms
|
|
|
|
I (9330) eventfd_example: Progress fd event triggered
|
|
|
|
I (9830) eventfd_example: Elapsed since test start: 7499 ms
|
|
|
|
I (9830) eventfd_example: TimerEvent fd event triggered
|
|
|
|
I (11840) eventfd_example: Elapsed since test start: 9503 ms
|
|
|
|
I (11840) eventfd_example: Select timeout
|
|
|
|
I (12330) eventfd_example: Elapsed since test start: 9999 ms
|
|
|
|
I (12330) eventfd_example: TimerEvent fd event triggered
|
|
|
|
I (12330) eventfd_example: =================================
|
|
|
|
I (12340) eventfd_example: Select timeouted for 2 times
|
|
|
|
I (12340) eventfd_example: Timer triggerred for 4 times
|
|
|
|
I (12350) eventfd_example: Progress triggerred for 2 times
|
|
|
|
I (12360) eventfd_example: =================================
|
2021-03-08 06:52:05 -05:00
|
|
|
```
|
2021-11-03 07:31:33 -04:00
|
|
|
|
|
|
|
## Diagram
|
|
|
|
|
|
|
|
The following diagram shows, with a timeline, the order of the events:
|
|
|
|
|
|
|
|
![Timeline](timeline.svg)
|