This fixed the MySQL bug# 20338 about misuse of double underscore
prefix __WIN__, which was old MySQL's idea of identifying Windows
Replace it by _WIN32 standard symbol for targeting Windows OS
(both 32 and 64 bit)
Not that connect storage engine is not fixed in this patch (must be
fixed in "upstream" branch)
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.