Problem: The functions my_like_range_xxx() returned
badly formed maximum strings for Asian character sets,
which made problems for storage engines.
Fix:
- Removed a number my_like_range_xxx() implementations,
which were in fact dumplicate code pieces.
- Using generic my_like_range_mb() instead.
- Setting max_sort_char member properly for Asian character sets
- Adding unittest/strings/strings-t.c,
to test that my_like_range_xxx() return well-formed
min and max strings.
Notes:
- No additional tests in mysql/t/ available.
Old tests cover the affected code well enough.
Bug#52261: 64 bit atomic operations do not work on Solaris i386
gcc in debug compilation
One of the various problems was that the source operand to
CMPXCHG8b was marked as a input/output operand, causing GCC
to use the EBX register as the destination register for the
CMPXCHG8b instruction. This could lead to crashes as the EBX
register is also implicitly used by the instruction, causing
the value to be potentially garbaged and a protection fault
once the value is used to access a position in memory.
Another problem was the lack of proper clobbers for the atomic
operations and, also, a discrepancy between the implementations
for the Compare and Set operation. The specific problems are
described and fixed by Kristian Nielsen patches:
Patch: 1
Fix bugs in my_atomic_cas*(val,cmp,new) that *cmp is accessed
after CAS succeds.
In the gcc builtin implementation, problem was that *cmp was
read again after atomic CAS to check if old *val == *cmp;
this fails if CAS is successful and another thread modifies
*cmp in-between.
In the x86-gcc implementation, problem was that *cmp was set
also in the case of successful CAS; this means there is a
window where it can clobber a value written by another thread
after successful CAS.
Patch 2:
Add a GCC asm "memory" clobber to primitives that imply a
memory barrier.
This signifies to GCC that any potentially aliased memory
must be flushed before the operation, and re-read after the
operation, so that read or modification in other threads of
such memory values will work as intended.
In effect, it makes these primitives work as memory barriers
for the compiler as well as the CPU. This is better and more
correct than adding "volatile" to variables.
Essentially, the problem is that safemalloc is excruciatingly
slow as it checks all allocated blocks for overrun at each
memory management primitive, yielding a almost exponential
slowdown for the memory management functions (malloc, realloc,
free). The overrun check basically consists of verifying some
bytes of a block for certain magic keys, which catches some
simple forms of overrun. Another minor problem is violation
of aliasing rules and that its own internal list of blocks
is prone to corruption.
Another issue with safemalloc is rather the maintenance cost
as the tool has a significant impact on the server code.
Given the magnitude of memory debuggers available nowadays,
especially those that are provided with the platform malloc
implementation, maintenance of a in-house and largely obsolete
memory debugger becomes a burden that is not worth the effort
due to its slowness and lack of support for detecting more
common forms of heap corruption.
Since there are third-party tools that can provide the same
functionality at a lower or comparable performance cost, the
solution is to simply remove safemalloc. Third-party tools
can provide the same functionality at a lower or comparable
performance cost.
The removal of safemalloc also allows a simplification of the
malloc wrappers, removing quite a bit of kludge: redefinition
of my_malloc, my_free and the removal of the unused second
argument of my_free. Since free() always check whether the
supplied pointer is null, redudant checks are also removed.
Also, this patch adds unit testing for my_malloc and moves
my_realloc implementation into the same file as the other
memory allocation primitives.
The atomic operations implementation on 5.1 has a few problems,
which might cause tests to abort randomly. Since no code in 5.1
uses atomic operations, simply remove the code.
The bug was caused by buffered output. Flushing resolved it.
We still recommend to allways call plan().
Also fix some compile warnings (formal parameter different from declaration)
(make relies GNU extentions). The patch was partially
backport from 6.0.
Original comment:
bug#30708: make relies GNU extensions. Now that we no longer use
BitKeeper we can safely remove the SCCS handling with no loss of
functionality.
- backported code that handles %f/%g arguments in
my_vsnprintf.c from 6.0
- backported %f/%g tests in unittest/mysys/my_vsnprintf-t.c
from 6.0
- replaced snprintf("%g") in sql/set_var.cc with my_gcvt()
- removed unnecessary "--replace-result"s for Windows in
mysql-test/suite/sys_vars/t/long_query_time_basic.test
- some test results adjustments
Bug#16565 mysqld --help --verbose does not order variablesBug#20413 sql_slave_skip_counter is not shown in show variables
Bug#20415 Output of mysqld --help --verbose is incomplete
Bug#25430 variable not found in SELECT @@global.ft_max_word_len;
Bug#32902 plugin variables don't know their names
Bug#34599 MySQLD Option and Variable Reference need to be consistent in formatting!
Bug#34829 No default value for variable and setting default does not raise error
Bug#34834 ? Is accepted as a valid sql mode
Bug#34878 Few variables have default value according to documentation but error occurs
Bug#34883 ft_boolean_syntax cant be assigned from user variable to global var.
Bug#37187 `INFORMATION_SCHEMA`.`GLOBAL_VARIABLES`: inconsistent status
Bug#40988 log_output_basic.test succeeded though syntactically false.
Bug#41010 enum-style command-line options are not honoured (maria.maria-recover fails)
Bug#42103 Setting key_buffer_size to a negative value may lead to very large allocations
Bug#44691 Some plugins configured as MYSQL_PLUGIN_MANDATORY in can be disabled
Bug#44797 plugins w/o command-line options have no disabling option in --help
Bug#46314 string system variables don't support expressions
Bug#46470 sys_vars.max_binlog_cache_size_basic_32 is broken
Bug#46586 When using the plugin interface the type "set" for options caused a crash.
Bug#47212 Crash in DBUG_PRINT in mysqltest.cc when trying to print octal number
Bug#48758 mysqltest crashes on sys_vars.collation_server_basic in gcov builds
Bug#49417 some complaints about mysqld --help --verbose output
Bug#49540 DEFAULT value of binlog_format isn't the default value
Bug#49640 ambiguous option '--skip-skip-myisam' (double skip prefix)
Bug#49644 init_connect and \0
Bug#49645 init_slave and multi-byte characters
Bug#49646 mysql --show-warnings crashes when server dies
Option "--without-server" still not working in 5.1
The general approach is to make sure that source files
which require thread support are only compiled if the build
really needs thread support,
which means when the server is built or a thread-safe client
library.
This required several changes:
- Make sure the subdirectories "storage/" and "plugin/" are
only processed if the server is built, not ifclient-only.
- Make the compilation of some modules which inherently
require threading depend on thread supportin the build.
- Separate the handling of threading in "configure.in" from
that of server issues, threading is also needed in a
non-server build of a thread-safe client library.
Also, "libdbug" must get built even in a client-only build,
so "dbug/" must be in the list of client directories.
In addition, calls to thread functions in source files which
can be built without thread support must use the wrapper
functions which handle the non-threaded build.
So the modules "client/mysqlimport.c" and "client/mysqlslap.c"
must call "my_thread_end()" only via "mysql_thread_end()".
value" error even though the value was correct): a C function in my_getopt.c
was taking bool* in parameter and was called from C++ sql_plugin.cc,
but on some Mac OS X sizeof(bool) is 1 in C and 4 in C++, giving funny
mismatches. Fixed, all other occurences of bool in C are removed, future
ones are blocked by a "C-bool-catcher" in my_global.h (use my_bool).
Fixed compiler warnings, errors and link errors
Fixed new bug on Solaris with gethrtime()
Added --debug-check option to all mysql clients to print errors and memory leaks
Added --debug-info to all clients. This now works as --debug-check but also prints memory and cpu usage
Added missing DBUG_RETURN statements (in mysqldump.c)
Added missing enums
Fixed a lot of wrong DBUG_PRINT() statements, some of which could cause crashes
Removed usage of %lld and %p in printf strings as these are not portable or produces different results on different systems.
