I checked all stack overflow potential problems found with
gcc -Wstack-usage=16384
and
clang -Wframe-larger-than=16384 -no-inline
Fixes:
Added '#pragma clang diagnostic ignored "-Wframe-larger-than="'
to a lot of function to where stack usage large but resonable.
- Added stack check warnings to BUILD scrips when using clang and debug.
Function changed to use malloc instead allocating things on stack:
- read_bootstrap_query() now allocates line_buffer (20000 bytes) with
malloc() instead of using stack. This has a small performance impact
but this is not releant for bootstrap.
- mroonga grn_select() used 65856 bytes on stack. Changed it to use
malloc().
- Wsrep_schema::replay_transaction() and
Wsrep_schema::recover_sr_transactions().
- Connect zipOpen3()
Not fixed:
- mroonga/vendor/groonga/lib/expr.c grn_proc_call() uses
43712 byte on stack. However this is not easy to fix as the stack
used is caused by a lot of code generated by defines.
- Most changes in mroonga/groonga where only adding of pragmas to disable
stack warnings.
- rocksdb/options/options_helper.cc uses 20288 of stack space.
(no reason to fix except to get rid of the compiler warning)
- Causes using alloca() where the allocation size is resonable.
- An issue in libmariadb (reported to connectors).
One should not change the program arguments!
This change also reduces warnings from the icc compiler.
Almost all changes are just syntax changes (adding const to
'get_one_option function' declarations).
Other changes:
- Added a few cast of 'argument' from 'const char*' to 'char *'. This
was mainly in calls to 'external' functions we don't have control of.
- Ensure that all reset of 'password command line argument' are similar.
(In almost all cases it was just adding a comment and a cast)
- In mysqlbinlog.cc and mysqld.cc there was a few cases that changed
the command line argument. These places where changed to instead allocate
the option in a MEM_ROOT to avoid changing the argument. Some of this
code was changed to ensure that different programs did parsing the
same way. Added a test case for the changes in mysqlbinlog.cc
- Changed a few variables that took their value from command line options
from 'char *' to 'const char *'.
stat structure (from <sys/stat.h>) is conditionally defined
to have different layout and size depending on the defined macros.
The correct macro is defined in my_config.h, which means it MUST be
included first (or, at least before <features.h> - so, practically,
before including any system headers).
Main change is that non-blocking operation is now an option that must be
explicitly enabled with mysql_option(mysql, MYSQL_OPT_NONBLOCK, ...)
before any non-blocing operation can be used.
Also the CLIENT_REMEMBER_OPTIONS flag is now always enabled and thus
effectively ignored (it was not really useful anyway, and this simplifies
things when non-blocking mysql_real_connect() fails).
All client functions that can block on I/O have alternate _start() and
_cont() versions that do not block but return control back to the
application, which can then issue I/O wait in its own fashion and later
call back into the library to continue the operation.
Works behind the scenes by spawning a co-routine/fiber to run the
blocking operation and suspend it while waiting for I/O. This
co-routine/fiber use is invisible to applications.
For i368/x86_64 on GCC, uses very fast assembler co-routine support. On
Windows uses native Win32 Fibers. Falls back to POSIX ucontext on other
platforms. Assembler routines for more platforms are relatively easy to
add by extending mysys/my_context.c, eg. similar to the Lua lcoco
library.
For testing, mysqltest and mysql_client_test are extended with the
option --non-blocking-api. This causes the programs to use the
non-blocking API for database access. mysql-test-run.pl has a similar
option --non-blocking-api that uses this, as well as additional
testcases.
An example program tests/async_queries.c is included that uses the new
non-blocking API with libevent to show how, in a single-threaded
program, to issue many queries in parallel against a database.
client/async_example.c:
Fix const warning
******
Fix bug with wrong timeout value for poll().
include/Makefile.am:
Fix missing include for `make dist`
include/mysql.h:
Add prototypes for all non-blocking API calls.
include/mysql.h.pp:
Add prototypes for all non-blocking API calls.
mysys/my_context.c:
Fix type warning for makecontext() function pointer argument.
sql-common/mysql_async.c:
Fix crashes in the non-blocking API for functions that can take MYSQL argument
that is NULL.
tests/Makefile.am:
Add header file to `make dist`
tests/mysql_client_test.c:
Replace blocking calls with wrappers around the non-blocking calls, used in
mysql_client_test to test the new non-blocking API.
tests/nonblock-wrappers.h:
Replace blocking calls with wrappers around the non-blocking calls, used in
mysql_client_test to test the new non-blocking API.
