Bug #47923 New "mf_keycache.c" requires thread support

Description:
The current code of "mf_keycache.c" will not compile unless there is thread support, the error is:
gcc -DDEFAULT_BASEDIR=\"/usr/local\" -DMYSQL_DATADIR="\"/usr/local/var\"" -DDEFAULT_CHARSET_HOME="\"/usr/local\"" -DSHAREDIR="\"/usr/local/share/mysql\"" -DDEFAULT_HOME_ENV=MYSQL_HOME -DDEFAULT_GROUP_SUFFIX_ENV=MYSQL_GROUP_SUFFIX -DDEFAULT_SYSCONFDIR="\"/usr/local/etc\"" -DHAVE_CONFIG_H -I. -I../include -I../include -I../include -I.    -O3 -DDBUG_OFF    -MT mf_keycache.o -MD -MP -MF .deps/mf_keycache.Tpo -c -o mf_keycache.o mf_keycache.c
mf_keycache.c: In function ‘find_key_block’:
mf_keycache.c:1782: error: ‘my_thread_var’ undeclared (first use in this function)
mf_keycache.c:1782: error: (Each undeclared identifier is reported only once
mf_keycache.c:1782: error: for each function it appears in.)
mf_keycache.c:1783: error: dereferencing pointer to incomplete type
mf_keycache.c:1789: error: dereferencing pointer to incomplete type
mf_keycache.c:1791: error: dereferencing pointer to incomplete type
mf_keycache.c:1792: error: dereferencing pointer to incomplete type
make[2]: *** [mf_keycache.o] Error 1
make[2]: Leaving directory `/MySQL/REPO/V50/platform/mysql-5.0.87/mysys'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/MySQL/REPO/V50/platform/mysql-5.0.87'
make: *** [all] Error 2

This is no issue in a server build (which has thread support, so it doesn't happen), but it happens (in 5.0.87) when you specify "--without-server".

While I see no use for this module in "libmysys" unless we build a server, it still is contained.

How to repeat:
Configure "--without-server", try to build.

Suggested fix:
Enclose the whole section dealing with a key cache resize in "#ifdef THREAD":
If there is no thread support (single-threaded), a resize operation cannot be in progress when another request is processed in the key cache.

In 6.0, this would be the patch; 5.0 is identical (except for a slight line number shift):

--- /V60/push-6.0/mysys/mf_keycache.c   2009-09-28 15:47:56.000000000 +0200
+++ mysys/mf_keycache.c 2009-10-05 12:13:50.000000000 +0200
@@ -1757,6 +1757,7 @@
       - block assigned but not yet read from file (invalid data).
   */

+#if THREAD
   if (keycache->in_resize)
   {
     /* This is a request during a resize operation */
@@ -1998,6 +1999,9 @@
     }
     DBUG_RETURN(0);
   }
+#else /* THREAD */
+DBUG_ASSERT(!keycache->in_resize);
+#endif

   if (page_status == PAGE_READ &&
       (block->status & (BLOCK_IN_EVICTION | BLOCK_IN_SWITCH |

In the long run, a restructuring of the server file grouping that puts this module into a server-only library would be even better.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/86246

2817 Joerg Bruehe	2009-10-08
      Fix bug#47923  New "mf_keycache.c" requires thread support
      
      The bug is a compilation issue:
      Function "find_key_block()" had thread operations
      which were not guarded by "#if THREAD", add that now.
     @ mysys/mf_keycache.c
        Without thread-support, we are in a single-threaded world,
        so there is no parallelism, and the keycache cannot be
        within a resize operation while this request is being processed.

Running local tests with various "configure" combinations.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/86460

3639 Joerg Bruehe	2009-10-09 [merge]
      Upmerge the fixes for bug#47923 and bug#47957 from 5.1.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/87019

3639 Joerg Bruehe	2009-10-15 [merge]
      Upmerge the fixes for bug#47923 and bug#47957 from 5.1.
      
      This includes further changes which are needed in 6.0,
      see the comments for "storage/archive/Makefile.am"
      and "unittest/backup/Makefile.am".
     @ configure.in
        Upmerge from 5.1
        
        Specific in 6.0, we need a conditional "SERVER"
        which is used in "unittest/backup/" to not build some
        server-related tests if the build is "--without-server".
     @ mysys/mf_keycache.c
        Upmerge from 5.1
     @ storage/archive/Makefile.am
        See comment in "concurrency_test.c":
        That test cannot be used unless there is thread support
        in the client library.
        
        The code treated this as a runtime issue, but that is wrong:
        It is even a linkage issue, because the test program needs
        both "libmysqlclient" (from "concurrency_test.c") and
        "libmysyslt" (from "azio.c"), and these two will conflict
        unless it is the threaded client library.
        
        The solution is to make the build of this test program
        depend on "THREAD_SAFE_CLIENT".
     @ unittest/backup/Makefile.am
        The necessary "libbackupstream" will not be built
        unless the build includes the server, so building
        the test program must be restricted to that case.

Patch is pushed to the bugteam trees,
currently set at versions 5.0.88 and 5.1.41.

Pushed into 5.0.88 (revid:joerg@mysql.com-20091016122941-rf6z0keqvmlgjfto) (version source revid:joerg@mysql.com-20091016122941-rf6z0keqvmlgjfto) (merge vers: 5.0.88) (pib:13)

Noted in 5.0.88 changelog.

mysys/mf_keycache.c requires threading, but no test was made for
thread support. 

Setting report to NDI pending push to 5.1.x+.

Pushed into 6.0.14-alpha (revid:alik@sun.com-20091022063126-l0qzirh9xyhp0bpc) (version source revid:alik@sun.com-20091019135554-s1pvptt6i750lfhv) (merge vers: 6.0.14-alpha) (pib:13)

Pushed into 5.5.0-beta (revid:alik@sun.com-20091022060553-znkmxm0g0gm6ckvw) (version source revid:alik@sun.com-20091019132831-5j6xs19ld16m7r8j) (merge vers: 5.5.0-beta) (pib:13)

Noted in 5.1.41, 5.5.0, 6.0.14 changelogs.

Pushed into 5.1.41-ndb-7.1.0 (revid:jonas@mysql.com-20091218102229-64tk47xonu3dv6r6) (version source revid:jonas@mysql.com-20091218095730-26gwjidfsdw45dto) (merge vers: 5.1.41-ndb-7.1.0) (pib:15)

Pushed into 5.1.41-ndb-6.2.19 (revid:jonas@mysql.com-20091218100224-vtzr0fahhsuhjsmt) (version source revid:jonas@mysql.com-20091217101452-qwzyaig50w74xmye) (merge vers: 5.1.41-ndb-6.2.19) (pib:15)

Added entry to 5.1.40-ndb-7.1.0

Pushed into 5.1.41-ndb-6.3.31 (revid:jonas@mysql.com-20091218100616-75d9tek96o6ob6k0) (version source revid:jonas@mysql.com-20091217154335-290no45qdins5bwo) (merge vers: 5.1.41-ndb-6.3.31) (pib:15)

Added entry to 5.1.41-ndb-6.2.19 and 5.1.42-ndb-6.3.31

Pushed into 5.1.41-ndb-7.0.11 (revid:jonas@mysql.com-20091218101303-ga32mrnr15jsa606) (version source revid:jonas@mysql.com-20091218064304-ezreonykd9f4kelk) (merge vers: 5.1.41-ndb-7.0.11) (pib:15)

Already in 5.1.41