Why does our FR10 diagnostic display wait for the log writer?

MayaAllen0301 · 16 Mar 2026, 10:20 UTC

Reply to discussion
MA
MayaAllen0301
Detailed logging makes our separate read-only FR10 display stall when the folder is busy; I suspect file writes, but I want to measure that before blaming the connection or buying another laptop.

20 replies

BR
BrunoChen1148
Replying to MayaAllen0301

Time the read, write and display update separately, then try controlled delays in each offline. The busy folder gives you somewhere to look. It doesn't yet tell you which operation the display is waiting for.

19 points
MA
MayaAllen0301
Replying to BrunoChen1148

Developer found reads returning normally during a stall. The display waits for a shared lock held by the log writer. Still checking why the screen needs that lock

16 points
CA
CallumAllen0273
Replying to MayaAllen0301

Does the display read back from the file, or use the latest value already in memory?

13 points
VI
VictorChen1142
Replying to MayaAllen0301

Also check what happens when no new reading arrives. A responsive display can still show an old value without making its age clear.

3 points
BE
BethBrooks0846
Replying to VictorChen1142

Victor's point caught us. Our screen stopped freezing after a change, and everyone called it fixed. It was then very smoothly drawing the same old value when communication stopped. Much nicer animation, same wrong impression.

17 points
MA
MayaAllen0301
Replying to CallumAllen0273

Callum, it uses an in-memory value but shares the writer's lock while taking its snapshot. Developer is separating the display snapshot from file access. Victor, reading age is also being added

9 points
BR
BrunoChen1148
Replying to MayaAllen0301

Keep the handoff to the writer bounded. Removing the shared wait shouldn't mean accumulating an unlimited backlog whenever the destination is slow. Decide how recording gaps will be reported when it cannot keep up.

14 points
CA
CallumAllen0273
Replying to MayaAllen0301

Which records are essential, and which are the new verbose diagnostic detail?

6 points
BE
BethBrooks0846
Replying to CallumAllen0273

Callum, useful question. We had a developer offer to turn off all logging when the extra trace was the noisy part. That cured the performance complaint and removed the evidence we needed for the next one.

12 points
MA
MayaAllen0301
Replying to CallumAllen0273

Basic sampled values and read outcomes are the normal record. The new trace repeats much more detail. Developer has separated the options so reducing trace doesn't remove the normal record

11 points
VI
VictorChen1142
Replying to MayaAllen0301

Does the exported file say when recording was incomplete? Someone may use that file without seeing the warning on your display.

16 points
BR
BrunoChen1148
Replying to VictorChen1142

Victor, yes, that needs an answer. A bounded queue protects the application, but the downstream reader still needs to know which interval is missing and why.

14 points
MA
MayaAllen0301
Replying to BrunoChen1148

Revised export includes recording-gap events. The offline slow-write test keeps the display responsive and reading age current; a delayed-read test makes the age rise even while recording continues normally

5 points
BE
BethBrooks0846
Replying to MayaAllen0301

Have somebody open the file away from the application. We found our gap explanation depended on a colour key that only existed on screen. The exported text looked like a perfectly ordinary sample with a strange value.

14 points
CA
CallumAllen0273
Replying to MayaAllen0301

What does it write when the queue actually fills, Maya?

5 points
MA
MayaAllen0301
Replying to CallumAllen0273

A separate gap record, not a made-up sample value. The reviewer found the affected interval from the exported file alone. We also checked repeated full-queue episodes rather than only the first warning

22 points
VI
VictorChen1142
Replying to MayaAllen0301

That is easier to hand over. Did the ordinary launch on the workshop laptop use the revised settings too? Development tests can run with a different trace level.

9 points
MA
MayaAllen0301
Replying to VictorChen1142

Normal shortcut checked on the workshop laptop. Same revised settings, live read-only display responsive during the file test, and the exported gap information matched what the reviewer expected

21 points
MA
MayaAllen0301
Replying to BethBrooks0846

We have closed the shared-lock fault. No replacement laptop. Thanks, Beth, reading the file separately caught a wording problem before the shift lead inherited it

10 points
BR
BrunoChen1148
Replying to MayaAllen0301

Keep the controlled read-delay and full-queue tests with this version. They cover different failures, even if the original complaint described both as a frozen screen.

24 points

Add to the discussion

Welcome to Application Robot

Everyone can read the forum. Sign in or create an account to start a discussion, reply, or upload photos.

Forgot your password?

By creating an account, you agree to our Terms and Conditions and community guidelines. Read our Privacy Policy for how your information is handled.