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.
The reason for the bug is that mysqtest as well as other client tools
running in test suite (mysqlbinlog, mysqldump) will first try to connect
whatever database has created shared memory with default base name
"MySQL" and use this. (Same effect could be seen on Unix if mtr would
not care to calculate "port" and "socket" parameter).
The fix ensures that all client tools and running in mtr use unique
per-database shared memory base parameters, so there is no possibility
to clash with already installed one. We use socket name for shared memory
base (it's known to be unique). This shared-memory-base is written to the
MTR config file to the [client] and [mysqld] sections. Fix made also made
sure all client tools understand and correctly handle --shared-memory-base.
Prior to this patch it was not the case for mysqltest, mysqlbinlog and
mysql_client_test.
All new connections done from mtr scripts via connect() will by default
set shared-memory-base. And finally, there is a possibility to force
shared memory or pipe connection and overwrite shared memory/pipe base name
from within mtr scripts via optional PIPE or SHM modifier. This functionality
was manually backported from 6.0
(original patch http://lists.mysql.com/commits/74749)
Improve test for shm on windows
mysql-test/include/windows.inc:
improve "skip message" and don't require a result file
mysql-test/r/shm.result:
Update result after adding more tests
mysql-test/t/shm-master.opt:
Add $MTR_BUILD_THREAD to get a unique shared memory base name
mysql-test/t/shm.test:
Run a bunch of more test to check shm
mysql-test/r/named_pipe.result:
New BitKeeper file ``mysql-test/r/named_pipe.result''
mysql-test/t/named_pipe-master.opt:
New BitKeeper file ``mysql-test/t/named_pipe-master.opt''
mysql-test/t/named_pipe.test:
New BitKeeper file ``mysql-test/t/named_pipe.test''
