Search found 265 matches

by PeterR
Mon Jan 20, 2020 7:17 pm
Forum: General Discussion
Topic: POSIX file operations implemented on ESP32
Replies: 3
Views: 388

Re: POSIX file operations implemented on ESP32

When would the filesystem release/set the mutex. On fopen()/fclose() or each fwrite()/fread()? What happens if you fseek() and then the file is renamed/deleted? Lots of documentation for the filesystem man. Guess he might just say that you should marshal access to the file system, (his) life is too ...
by PeterR
Sun Jan 19, 2020 11:05 am
Forum: General Discussion
Topic: IRAM cache hit/miss statistics
Replies: 0
Views: 115

IRAM cache hit/miss statistics

I collect task load statistics using uxTaskGetSystemState() and format in a 'top' style report. I am adding capability to the product one board at a time. Recently I noticed a large jump in CPU utilisation from one of my activities. However the activity using the extra CPU cycles seems to change acc...
by PeterR
Fri Jan 17, 2020 8:24 pm
Forum: General Discussion
Topic: POSIX file operations implemented on ESP32
Replies: 3
Views: 388

Re: POSIX file operations implemented on ESP32

e.g. https://stackoverflow.com/questions/42442387/is-write-safe-to-be-called-from-multiple-threads-simultaneously So no, not all concurrent file access are safe. Even if declared as safe then I would take a 'I don't want to debug a potential RT issue' and use a C++11 mutex and sleep at night. Simple...
by PeterR
Fri Jan 17, 2020 1:10 am
Forum: General Discussion
Topic: Sort files by date and delete oldest files
Replies: 7
Views: 387

Re: Sort files by date and delete oldest files

There are always better ways. Its great that you want to push forward. Delivery and improvement need to be held in balence though. IMHO the modern agile approaches are to get 'working' (test/functional) and then you may reflect on better structure (refactor etc). The solutions you read may not actua...
by PeterR
Fri Jan 17, 2020 12:34 am
Forum: General Discussion
Topic: Sort files by date and delete oldest files
Replies: 7
Views: 387

Re: Sort files by date and delete oldest files

PS Search first and show some attempt at solution with code else Stack will tend to roast you (or use a burner account!) But I think your's is a generic problem that (following an inteligent search) will have a well defined/accepted solution.
by PeterR
Fri Jan 17, 2020 12:13 am
Forum: General Discussion
Topic: regarding webserver
Replies: 2
Views: 436

Re: regarding webserver

Starting from basics: Webpages are static. Your browser requests a page, you serve and that page gets rendered and displayed. End of transaction. Still screen. So how do you get 'dynamic data' (time varying data) into your webpage? EDIT: In order to update your browser rendering you need code (Javas...
by PeterR
Thu Jan 16, 2020 11:51 pm
Forum: General Discussion
Topic: Sort files by date and delete oldest files
Replies: 7
Views: 387

Re: Sort files by date and delete oldest files

A POSIX question and so not ESP32 specific (I am sure that ESP comply with POSIX). You will therefore probably get better help on StackOverflow etc because of user volumes. I would be suprised if there is not a posted solution to your question. EDIT: Plus StackOverflow etc allow votes which simplifi...
by PeterR
Thu Jan 09, 2020 11:19 pm
Forum: General Discussion
Topic: std::thread not usuable in ESP-IDF 4.1 legacy build
Replies: 13
Views: 1001

Re: std::thread not usuable in ESP-IDF 4.1 legacy build

Hi, My appologies for not responding earlier. You are correct w.r.t. the new build system however the stable 3.3.1 tool, IDF 4.0 build allows menuconfig of exceptions but not rtti. I would love to know how to add project CPPFLAGS as then I could switch betweeen old/new emerging builds easily. I did ...
by PeterR
Tue Dec 31, 2019 1:50 pm
Forum: General Discussion
Topic: std::thread not usuable in ESP-IDF 4.1 legacy build
Replies: 13
Views: 1001

Re: std::thread not usuable in ESP-IDF 4.1 legacy build

Strange. The small worked example builds & links with or without -frtti in Makefile. I had previously looked at -frtti and also -fexceptions (I believe that also enables -frtti) & had made changes so I am not sure which build was the failing build last week Today: The example builds with a default M...
by PeterR
Mon Dec 30, 2019 10:59 am
Forum: General Discussion
Topic: std::thread not usuable in ESP-IDF 4.1 legacy build
Replies: 13
Views: 1001

Re: std::thread not usuable in ESP-IDF 4.1 legacy build

Thanks, that works.
I had missed the addition of -frtti in menuconfig.

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