stdThreadLocalLog does not print log and trace logs
#9870
Labels
Comments
kinke commented on 2024-03-29T22:25:48ZAccording to the docs (https://dlang.org/phobos/std_logger_core.html#.stdThreadLocalLog), `stdThreadLocalLog` just forwards to `sharedLog`. The latter has a default LogLevel of info. So in your example, you'd need to set the `sharedLog.logLevel` *before* logging to `stdThreadLocalLog` (which defaults to `LogLevel.all`, forwarding everything to the shared logger).
The key info is in the std.logger package docs (https://dlang.org/phobos/std_logger.html):
> The LogLevel of the stdThreadLocalLog can be used to filter log calls before they reach the sharedLog Logger.
Perhaps this should be duplicated in the documentation for the `stdThreadLocalLog` property. |
ttanjo (@tom-tan) commented on 2024-03-30T03:37:33ZThank you for the information.
It works when I set `Loglevel.all` to both logger before calling logging methods as follows.
```dlang
...
(cast()sharedLog).logLevel = LogLevel.all;
stdThreadLocalLog.logLevel = LogLevel.all;
writeln("==== stdThreadLocalLog ====");
stdThreadLocalLog.log("log");
...
```
> Perhaps this should be duplicated in the documentation for the `stdThreadLocalLog` property.
I guess the information of default logLevel in each logger should be in the `Thread Local Redirection` section in std.logger because most users read the documents in std.logger first.
Can I close this issue or leave it opened until the document is improved?
If the case of latter, I will send a pull request for it. |
forestix commented on 2024-05-28T23:13:54ZThe experience I had today as a newcomer to Phobos logging:
- Read the std.logger docs.
- Create a StdForwardLogger for each of my modules.
(I want to control each module's log level separately.)
- Discover that trace log messages are silently discarded.
- Set my logger's log level.
- Discover that trace log messages are still silently discarded.
- Read the std.logger docs again.
- Set globalLogLevel.
- Discover that trace log messages are still silently discarded.
- Read the std.logger docs again.
- Set sharedLog.logLevel.
- Discover that the compiler won't let me
(none of the overloads of `logLevel` are callable using a `shared` mutable object)
- Read the std.logger docs again.
- Notice how much time this basic task is taking, and swear in exasperation.
- Grovel through the dlang forum archive in search of help.
- Find the magic incantation here:
https://forum.dlang.org/post/mveqddfktkykwvhombsl@forum.dlang.org
(cast()sharedLog).logLevel = LogLevel.all;
- Try the magic incantation.
- Discover that the compiler won't let me use it in @safe code.
A default log level higher than `trace` is no surprise; that's reasonably common in logging libraries. However, dealing with it in Phobos is surprisingly painful.
In particular, the solution has at least these problems:
- It's nonintuitive.
- It's not clearly documented.
- It's unreasonably awkward for something as common as logging.
- It doesn't work at all in @safe code.
After finally getting to the bottom of it (and nearly giving up on D because this is far from the first Phobos usability problem to bite me) I see that I could work around it in my own programs by using @trusted code. However, I'm writing a library, and I really don't want to require that its users resort to library-specific functions or @trusted shenanigans to control such basic functionality as logging.
It would be nice if this was either fixed by a revised std.logger design, or at least hidden behind a clearly documented standard interface. |
forestix commented on 2024-05-29T01:36:00ZAlso, is `(cast()sharedLog).logLevel = LogLevel.all` thread-safe?
If so, how is the user supposed to know that?
If not, where is the thread-safe equivalent? |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
ttanjo (@tom-tan) reported this on 2024-03-29T18:56:10Z
Transfered from https://issues.dlang.org/show_bug.cgi?id=24468
CC List
Description
The text was updated successfully, but these errors were encountered: