Serial readUntil locks if delimiter is not found and rx is full

[pelikhan]

codal-core/source/driver-models/Serial.cpp

Line 55 in 4aab097

Event(this->id, CODAL_SERIAL_EVT_RX_FULL);

If a fiber is waiting of readUntil and the RX is full, it never receives triggers and the serial is effectively locked.

[pelikhan]

@finneyj @jamesadevine not sure how to handle this case. What happens when RX gets full and a fiber is waiting on some delimiters?

[jamesadevine]

I think this is for the user to decide, I.e. wait forever or timeout

waitUntil(delimiters, timeout);

Default of 0?

[pelikhan]

Right now we have “readUntil” that waits forever. Get Outlook for iOS<https://aka.ms/o0ukef>

…

________________________________ From: James Devine <notifications@github.com> Sent: Tuesday, January 1, 2019 9:31 AM To: lancaster-university/codal-core Cc: Peli de Halleux; Author Subject: Re: [lancaster-university/codal-core] Serial readUntil locks if delimiter is not found and rx is full (#80) I think this is for the user to decide, I.e. wait forever or timeout waitUntil(delimiters, timeout); Default of 0? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Flancaster-university%2Fcodal-core%2Fissues%2F80%23issuecomment-450745108&data=02%7C01%7Cjhalleux%40microsoft.com%7Ccfeba1055fc748cc2cfe08d6700ef587%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636819606879798883&sdata=i3X3OS5o7XgOC%2FDPekclIGfr%2Bn3Vq5ov9ogz8ZrbIJI%3D&reserved=0>, or mute the thread<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fnotifications%2Funsubscribe-auth%2FAD-4KVAM57muRvhgkbU-36TG7Irkc2XUks5u-5tugaJpZM4Zl9u1&data=02%7C01%7Cjhalleux%40microsoft.com%7Ccfeba1055fc748cc2cfe08d6700ef587%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636819606879798883&sdata=LDGLI3fSSoixJeXol8O1PkVgI85WhrkHvrY6mqfFZHA%3D&reserved=0>.

[jamesadevine]

Sorry meant readUntil (mac is in the shop so I’m on my phone) James. On 1 Jan 2019, at 18:01, Peli de Halleux <notifications@github.com<mailto:notifications@github.com>> wrote: Right now we have “readUntil” that waits forever. Get Outlook for iOS<https://aka.ms/o0ukef>

…

________________________________ From: James Devine <notifications@github.com<mailto:notifications@github.com>> Sent: Tuesday, January 1, 2019 9:31 AM To: lancaster-university/codal-core Cc: Peli de Halleux; Author Subject: Re: [lancaster-university/codal-core] Serial readUntil locks if delimiter is not found and rx is full (#80) I think this is for the user to decide, I.e. wait forever or timeout waitUntil(delimiters, timeout); Default of 0? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Flancaster-university%2Fcodal-core%2Fissues%2F80%23issuecomment-450745108&data=02%7C01%7Cjhalleux%40microsoft.com%7Ccfeba1055fc748cc2cfe08d6700ef587%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636819606879798883&sdata=i3X3OS5o7XgOC%2FDPekclIGfr%2Bn3Vq5ov9ogz8ZrbIJI%3D&reserved=0>, or mute the thread<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fnotifications%2Funsubscribe-auth%2FAD-4KVAM57muRvhgkbU-36TG7Irkc2XUks5u-5tugaJpZM4Zl9u1&data=02%7C01%7Cjhalleux%40microsoft.com%7Ccfeba1055fc748cc2cfe08d6700ef587%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636819606879798883&sdata=LDGLI3fSSoixJeXol8O1PkVgI85WhrkHvrY6mqfFZHA%3D&reserved=0>. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<#80 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AEheKQHtYuDQ-zgoTpKBGJh53OS-j7EUks5u-6KGgaJpZM4Zl9u1>.

[pelikhan]

Since MakeCode moved to UF8 support, I ended not using this implementation in MakeCode at all.

[jamesadevine]

How does that work with serial now then?

[pelikhan]

Just doing the same logic on the TS side.

https://github.com/Microsoft/pxt-common-packages/blob/master/libs/serial/serial.ts#L53

[jamesadevine]

Same problem exists if you do a blocking read on read(), right? i.e. you will wait for a character forever...

[jamesadevine]

If you're going to implement this in ts, pass ASYNC and sleep in the loop.

[pelikhan]

ok will do. I am trying the new serial on SAMD21, which board did you test it on?

[jamesadevine]

Currently 0 boards, my SAMD's are at the office. It should work fine, I was going to test on CPX on A2.