Confused about wdtFeed, esp_yield and yield

[supersjimmie]

I have some trouble with the latest SoftwareSerial library:
#1426
and I am wondering if this could be fixed with either

    ESP.wdtFeed();
    esp_yield();
    yield();

But what is the difference and how could any of them help to avoid WDT Resets?

[supersjimmie]

Never mind, if I look closer to where the softwareserial crashes, I don't think a yield or wdtfeed will help.
Closing this.

[Defozo]

I'd like to know what is the difference between these functions?

[gunt2551]

I found the comment on line 502 in Arduino/libraries/ESP8266WiFiMesh/src/EspnowMeshBackend.cpp

ESP.wdtFeed(); // Prevents WDT reset in case we receive a lot of transmissions without break.

esp_yield(); and yield(); is decribed on line 139 in Arduino/cores/esp8266/core_esp8266_main.cpp

// Replacement for delay(0). In CONT, same as yield(). Whereas yield() panics
// in SYS, esp_yield() is safe to call and only schedules CONT. Use yield()
// whereever only called from CONT, use esp_yield() if code is called from SYS
// or both CONT and SYS.

From what i understand, CONT refers to the main function[void loop()] of Arduino IDE structure, which only yield() is used for, whereas esp_yield() is used inside interrupt function.