THR_LOCK_open reduce usage #241
Closed
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Change the following to statistic counters:
* my_file_opened
* my_file_total_opened
* my_stream_opened
* my_tmp_file_created
A file descriptor is already a unique element per process - in Windows,
protection occurs at fd allocation using THR_LOCK_open in my_win_{,f}open
and in other OSes, a unique fd to file map exists at the OS level.
So accesses to my_file_info[fd] don't need to be protected by the
THR_LOCK_open.
my_close/my_fclose where restructured to clear out the my_file_info
before the close/my_win_close/my_win_fclose. After these calls another
thread could gain the same file descriptor. So for Windows this
the file_info elements available to the my_win_{,f}_open are released
during the invalidate_fd call within my_win_close. No locking is needed
as the my_win_{,f}open is searching for a invalidate entry which is
determined by a single value change.
There is one non-statistics use of my_file_opened/my_stream_opened
in my_end which prints a warning if we shutdown and its still open.
my_file_opened are now my_stream_opened incremented without locks so there is a small chance that they will not be statisticly accurate. As my_end error messages should be accurate, lets not take a chance and iterate the array, displaying each open file under EXTRA_DEBUG, and display a warning if a mismatch of files/streams opened occurred.
|
I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it. |
|
Hi, thank you for your contribution. Please confirm this code is submitted under the terms of the OCA (Oracle's Contribution Agreement) you have previously signed by cutting and pasting the following text as a comment: |
|
Hi, thank you for your contribution. Your code has been assigned to an internal queue. Please follow |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
By considering
my_*_openedas statistical counters and file descriptors as unique with a little restructuring we can eliminate lots of THR_LOCK_open usage.