1IO::Async::Debug(3pm) User Contributed Perl DocumentationIO::Async::Debug(3pm)
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NAME

6       "IO::Async::Debug" - debugging control and support for IO::Async
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DESCRIPTION

9       The following methods and behaviours are still experimental and may
10       change or even be removed in future.
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12       Debugging support is enabled by an environment variable called
13       "IO_ASYNC_DEBUG" having a true value.
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15       When debugging is enabled, the "make_event_cb" and "invoke_event"
16       methods on IO::Async::Notifier (and their "maybe_" variants) are
17       altered such that when the event is fired, a debugging line is printed,
18       using the "debug_printf" method. This identifes the name of the event.
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20       By default, the line is only printed if the caller of one of these
21       methods is the same package as the object is blessed into, allowing it
22       to print the events of the most-derived class, without the extra
23       verbosity of the lower-level events of its parent class used to create
24       it. All calls regardless of caller can be printed by setting a number
25       greater than 1 as the value of "IO_ASYNC_DEBUG".
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27       By default the debugging log goes to "STDERR", but two other
28       environment variables can redirect it. If "IO_ASYNC_DEBUG_FILE" is set,
29       it names a file which will be opened for writing, and logging written
30       into it. Otherwise, if "IO_ASYNC_DEBUG_FD" is set, it gives a file
31       descriptor number that logging should be written to. If opening the
32       named file or file descriptor fails then the log will be written to
33       "STDERR" as normal.
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35       Extra debugging flags can be set in a comma-separated list in an
36       environment variable called "IO_ASYNC_DEBUG_FLAGS". The presence of
37       these flags can cause extra information to be written to the log. Full
38       details on these flags will be documented by the implementing classes.
39       Typically these flags take the form of one or more capital letters
40       indicating the class, followed by one or more lowercase letters
41       enabling some particular feature within that class.
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AUTHOR

44       Paul Evans <leonerd@leonerd.org.uk>
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48perl v5.36.1                      2023-05-14             IO::Async::Debug(3pm)
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