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Assertion `bitmap_is_set_all(&table->s->all_set)' failed in handler::ha_reset This assertion could be triggered if two connections simultaneously executed two bitmap test functions on the same bitmap. For example, the assertion could be triggered if one connection executed UPDATE while a second connection executed SELECT on the same table. Even if bitmap test functions have read-only semantics and have const bitmaps as parameter, several of them modified the internal state of the bitmap. With interleaved execution of two such functions it was possible for one function to modify the state of the same bitmap that the other function had just modified. This lead to an inconsistent state and could trigger the assert. Internally the bitmap uses 32 bit words for storage. Since bitmaps can contain any number of bits, the last word in the bitmap may not be fully used. A 32 bit mask is maintained where a bit is set if the corresponding bit in the last bitmap word is unused. The problem was that several test functions applied this mask to the last word. Sometimes the mask was negated and used to zero out the remainder of the last word and sometimes the mask was used as-is to fill the remainder of the last word with 1's. This meant that if a function first used the negated mask and another function then used the mask as-is (or vice-versa), the first function would then get the wrong result. This patch fixes the problem by changing the implementation of 9 bitmap functions that modified the bitmap state even if the bitmap was declared const. These functions now preserve the internal state of the bitmap. This makes it possible for two connections to concurrently execute two of these functions on the same bitmap without issues. The patch also removes dead testing code from my_bitmap.c. These tests have already been moved to unittest/mysys/bitmap-t.c. Existing test coverage of my_bitmap has been extended. No MTR test case added as this would require adding several sync points to the bitmap functions. The patch has been tested with a non-deterministic test case posted on the bug report. include/my_bit.h: Removed my_count_bits_ushort() which is not needed anymore. Added my_count_bits_uint32(). unittest/mysys/bitmap-t.c: Extended test coverage of my_bitmap.
Unit tests directory structure
------------------------------
This is the current structure of the unit tests. More directories
will be added over time.
mytap Source for the MyTAP library
mysys Tests for mysys components
bitmap-t.c Unit test for MY_BITMAP
base64-t.c Unit test for base64 encoding functions
examples Example unit tests.
core-t.c Example of raising a signal in the middle of the test
THIS TEST WILL STOP ALL FURTHER TESTING!
simple-t.c Example of a standard TAP unit test
skip-t.c Example where some test points are skipped
skip_all-t.c Example of a test where the entire test is skipped
todo-t.c Example where test contain test points that are TODO
no_plan-t.c Example of a test with no plan (avoid this)
Executing unit tests
--------------------
To make and execute all unit tests in the directory:
make test
Observe that the tests in the examples/ directory are just various
examples of tests and are not expected to pass.
Adding unit tests
-----------------
Add a file with a name of the format "foo-t.c" to the appropriate
directory and add the following to the Makefile.am in that directory
(where ... denotes stuff already there):
noinst_PROGRAMS = ... foo-t
Note, it's important to have "-t" at the end of the filename, otherwise the
test won't be executed by 'make test' !
Documentation
-------------
The generated documentation is temporarily placed at:
http://www.kindahl.net/mytap/doc/
I will move it to a better place once I figure out where and how.