mwl:98 - libservices

CMakeLists.txt

@@ -325,6 +325,7 @@ ADD_SUBDIRECTORY(client)
 ADD_SUBDIRECTORY(sql)
 ADD_SUBDIRECTORY(server-tools/instance-manager)
 ADD_SUBDIRECTORY(libmysql)
+ADD_SUBDIRECTORY(libservices)
 ADD_SUBDIRECTORY(tests)
 ADD_SUBDIRECTORY(unittest/mytap)
 ADD_SUBDIRECTORY(unittest/examples)

Makefile.am

@@ -25,7 +25,7 @@ EXTRA_DIST =		INSTALL-SOURCE INSTALL-WIN-SOURCE \
 
 SUBDIRS =		. include @docs_dirs@ @zlib_dir@ \
 			@readline_topdir@ sql-common scripts \
-			@pstack_dir@ \
+ 			@pstack_dir@ libservices \
 			@sql_union_dirs@ storage \
 			@sql_server@ @man_dirs@ tests \
 			netware @libmysqld_dirs@ \
@@ -34,7 +34,7 @@ SUBDIRS =		. include @docs_dirs@ @zlib_dir@ \
 
 DIST_SUBDIRS =		. include Docs zlib \
 			cmd-line-utils sql-common scripts \
-			pstack \
+			pstack libservices \
 			strings mysys dbug extra regex libmysql libmysql_r client unittest storage plugin \
 			vio sql man tests \
 			netware libmysqld \

configure.in

@@ -2913,7 +2913,7 @@ AC_CONFIG_FILES(Makefile extra/Makefile mysys/Makefile dnl
  man/Makefile BUILD/Makefile vio/Makefile dnl
  libmysql/Makefile libmysql_r/Makefile client/Makefile dnl
  sql/Makefile sql/share/Makefile dnl
- sql/sql_builtin.cc sql-common/Makefile dnl
+ sql/sql_builtin.cc sql-common/Makefile libservices/Makefile dnl
  dbug/Makefile scripts/Makefile include/Makefile dnl
  tests/Makefile Docs/Makefile support-files/Makefile dnl
  support-files/MacOSX/Makefile support-files/RHEL4-SElinux/Makefile dnl

include/Makefile.am

@@ -21,7 +21,8 @@ HEADERS_GEN_MAKE =		my_config.h
 HEADERS_ABI =		mysql.h mysql_com.h mysql_time.h \
 			my_list.h my_alloc.h typelib.h mysql/plugin.h
 pkginclude_HEADERS =	$(HEADERS_ABI) my_dbug.h m_string.h my_sys.h \
-			my_xml.h mysql_embed.h \
+			my_xml.h mysql_embed.h mysql/services.h \
+			mysql/service_my_snprintf.h mysql/service_thd_alloc.h \
 		  	my_pthread.h my_no_pthread.h \
 			decimal.h errmsg.h my_global.h my_net.h \
 			my_getopt.h sslopt-longopts.h my_dir.h \
@@ -36,7 +37,7 @@ noinst_HEADERS =	config-win.h config-netware.h lf.h my_bit.h \
 			my_nosys.h my_alarm.h queues.h rijndael.h sha1.h \
 			my_aes.h my_tree.h my_trie.h hash.h thr_alarm.h \
 			thr_lock.h t_ctype.h violite.h my_md5.h base64.h \
-			my_handler.h my_time.h \
+			my_handler.h my_time.h service_versions.h \
 			my_vle.h my_user.h my_atomic.h atomic/nolock.h \
 			atomic/rwlock.h atomic/x86-gcc.h atomic/generic-msvc.h \
                         atomic/gcc_builtins.h my_libwrap.h my_stacktrace.h \

include/m_string.h

@@ -257,16 +257,10 @@ extern size_t my_snprintf(char *to, size_t n, const char *fmt, ...)
 
 /*
   LEX_STRING -- a pair of a C-string and its length.
+  (it's part of the plugin API as a MYSQL_LEX_STRING)
 */
 
-#ifndef _my_plugin_h
-/* This definition must match the one given in mysql/plugin.h */
-struct st_mysql_lex_string
-{
-  char *str;
-  size_t length;
-};
-#endif
+#include <mysql/plugin.h>
 typedef struct st_mysql_lex_string LEX_STRING;
 
 #define STRING_WITH_LEN(X) (X), ((size_t) (sizeof(X) - 1))

include/mysql/plugin.h

-/* Copyright (C) 2005 MySQL AB
+/* Copyright (C) 2005 MySQL AB, 2009 Sun Microsystems, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -34,15 +34,7 @@ class Item;
 #define MYSQL_THD void*
 #endif
 
-#ifndef _m_string_h
-/* This definition must match the one given in m_string.h */
-struct st_mysql_lex_string
-{
-  char *str;
-  unsigned int length;
-};
-#endif /* _m_string_h */
-typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
+#include <mysql/services.h>
 
 #define MYSQL_XIDDATASIZE 128
 /**
@@ -65,7 +57,7 @@ typedef struct st_mysql_xid MYSQL_XID;
   Plugin API. Common for all plugin types.
 */
 
-#define MYSQL_PLUGIN_INTERFACE_VERSION 0x0100
+#define MYSQL_PLUGIN_INTERFACE_VERSION 0x0101
 
 /*
   The allowable types of plugins
@@ -120,7 +112,8 @@ enum enum_mysql_show_type
 {
   SHOW_UNDEF, SHOW_BOOL, SHOW_INT, SHOW_LONG,
   SHOW_LONGLONG, SHOW_CHAR, SHOW_CHAR_PTR,
-  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE
+  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE,
+  SHOW_always_last
 };
 
 struct st_mysql_show_var {
@@ -739,54 +732,6 @@ int thd_killed(const MYSQL_THD thd);
 */
 unsigned long thd_get_thread_id(const MYSQL_THD thd);
 
-
-/**
-  Allocate memory in the connection's local memory pool
-
-  @details
-  When properly used in place of @c my_malloc(), this can significantly
-  improve concurrency. Don't use this or related functions to allocate
-  large chunks of memory. Use for temporary storage only. The memory
-  will be freed automatically at the end of the statement; no explicit
-  code is required to prevent memory leaks.
-
-  @see alloc_root()
-*/
-void *thd_alloc(MYSQL_THD thd, unsigned int size);
-/**
-  @see thd_alloc()
-*/
-void *thd_calloc(MYSQL_THD thd, unsigned int size);
-/**
-  @see thd_alloc()
-*/
-char *thd_strdup(MYSQL_THD thd, const char *str);
-/**
-  @see thd_alloc()
-*/
-char *thd_strmake(MYSQL_THD thd, const char *str, unsigned int size);
-/**
-  @see thd_alloc()
-*/
-void *thd_memdup(MYSQL_THD thd, const void* str, unsigned int size);
-
-/**
-  Create a LEX_STRING in this connection's local memory pool
-
-  @param thd      user thread connection handle
-  @param lex_str  pointer to LEX_STRING object to be initialized
-  @param str      initializer to be copied into lex_str
-  @param size     length of str, in bytes
-  @param allocate_lex_string  flag: if TRUE, allocate new LEX_STRING object,
-                              instead of using lex_str value
-  @return  NULL on failure, or pointer to the LEX_STRING object
-
-  @see thd_alloc()
-*/
-MYSQL_LEX_STRING *thd_make_lex_string(MYSQL_THD thd, MYSQL_LEX_STRING *lex_str,
-                                      const char *str, unsigned int size,
-                                      int allocate_lex_string);
-
 /**
   Get the XID for this connection's transaction
 

include/mysql/plugin.h.pp

+#include <mysql/services.h>
+#include <mysql/service_my_snprintf.h>
+#include <stdarg.h>
+#include <stdlib.h>
+extern struct my_snprintf_service_st {
+  size_t (*my_snprintf_type)(char*, size_t, const char*, ...);
+  size_t (*my_vsnprintf_type)(char *, size_t, const char*, va_list);
+} *my_snprintf_service;
+size_t my_snprintf(char* to, size_t n, const char* fmt, ...);
+size_t my_vsnprintf(char *to, size_t n, const char* fmt, va_list ap);
+#include <mysql/service_thd_alloc.h>
+#include <stdlib.h>
 struct st_mysql_lex_string
 {
   char *str;
-  unsigned int length;
+  size_t length;
 };
 typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
+extern struct thd_alloc_service_st {
+  void *(*thd_alloc_func)(void*, unsigned int);
+  void *(*thd_calloc_func)(void*, unsigned int);
+  char *(*thd_strdup_func)(void*, const char *);
+  char *(*thd_strmake_func)(void*, const char *, unsigned int);
+  void *(*thd_memdup_func)(void*, const void*, unsigned int);
+  MYSQL_LEX_STRING *(*thd_make_lex_string_func)(void*, MYSQL_LEX_STRING *,
+                                        const char *, unsigned int, int);
+} *thd_alloc_service;
+void *thd_alloc(void* thd, unsigned int size);
+void *thd_calloc(void* thd, unsigned int size);
+char *thd_strdup(void* thd, const char *str);
+char *thd_strmake(void* thd, const char *str, unsigned int size);
+void *thd_memdup(void* thd, const void* str, unsigned int size);
+MYSQL_LEX_STRING *thd_make_lex_string(void* thd, MYSQL_LEX_STRING *lex_str,
+                                      const char *str, unsigned int size,
+                                      int allocate_lex_string);
 struct st_mysql_xid {
   long formatID;
   long gtrid_length;
@@ -15,7 +44,8 @@ enum enum_mysql_show_type
 {
   SHOW_UNDEF, SHOW_BOOL, SHOW_INT, SHOW_LONG,
   SHOW_LONGLONG, SHOW_CHAR, SHOW_CHAR_PTR,
-  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE
+  SHOW_ARRAY, SHOW_FUNC, SHOW_DOUBLE,
+  SHOW_always_last
 };
 struct st_mysql_show_var {
   const char *name;
@@ -127,14 +157,6 @@ const char *set_thd_proc_info(void*, const char * info, const char *func,
 int mysql_tmpfile(const char *prefix);
 int thd_killed(const void* thd);
 unsigned long thd_get_thread_id(const void* thd);
-void *thd_alloc(void* thd, unsigned int size);
-void *thd_calloc(void* thd, unsigned int size);
-char *thd_strdup(void* thd, const char *str);
-char *thd_strmake(void* thd, const char *str, unsigned int size);
-void *thd_memdup(void* thd, const void* str, unsigned int size);
-MYSQL_LEX_STRING *thd_make_lex_string(void* thd, MYSQL_LEX_STRING *lex_str,
-                                      const char *str, unsigned int size,
-                                      int allocate_lex_string);
 void thd_get_xid(const void* thd, MYSQL_XID *xid);
 void mysql_query_cache_invalidate4(void* thd,
                                    const char *key, unsigned int key_length,

include/mysql/service_my_snprintf.h

+#ifndef MYSQL_SERVICE_MY_SNPRINTF_INCLUDED
+/* Copyright (C) 2009 Sun Microsystems, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+/**
+  @file
+  my_snprintf service
+
+  Portable and limited vsnprintf() implementation.
+
+  This is a portable, limited vsnprintf() implementation, with some
+  extra features. "Portable" means that it'll produce identical result
+  on all platforms (for example, on Windows and Linux system printf %e
+  formats the exponent differently, on different systems %p either
+  prints leading 0x or not, %s may accept null pointer or crash on
+  it). "Limited" means that it does not support all the C89 features.
+  But it supports few extensions, not in any standard.
+
+  my_vsnprintf(to, n, fmt, ap)
+
+  @param[out] to     A buffer to store the result in
+  @param[in]  n      Store up to n-1 characters, followed by an end 0
+  @param[in]  fmt    printf-like format string
+  @param[in]  ap     Arguments
+
+  @return a number of bytes written to a buffer *excluding* terminating '\0'
+
+  @post
+  The syntax of a format string is generally the same:
+  % <flag> <width> <precision> <length modifier> <format>
+  where everithing but the format is optional.
+
+  Three one-character flags are recognized:
+    '0' has the standard zero-padding semantics;
+    '-' is parsed, but silently ignored;
+    '`' (backtick) is only supported for strings (%s) and means that the
+        string will be quoted according to MySQL identifier quoting rules.
+
+  Both <width> and <precision> can be specified as numbers or '*'.
+
+  <length modifier> can be 'l', 'll', or 'z'.
+
+  Supported formats are 's' (null pointer is accepted, printed as
+  "(null)"), 'b' (extension, see below), 'c', 'd', 'u', 'x',
+  'X', 'p' (works as 0x%x).
+
+  Standard syntax for positional arguments $n is supported.
+
+  Extensions:
+
+  Flag '`' (backtick): see above.
+
+  Format 'b': binary buffer, prints exactly <precision> bytes from the
+  argument, without stopping at '\0'.
+*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdarg.h>
+#include <stdlib.h>
+extern struct my_snprintf_service_st {
+  size_t (*my_snprintf_type)(char*, size_t, const char*, ...);
+  size_t (*my_vsnprintf_type)(char *, size_t, const char*, va_list);
+} *my_snprintf_service;
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+
+#define my_vsnprintf my_snprintf_service->my_vsnprintf_type
+#define my_snprintf my_snprintf_service->my_snprintf_type
+
+#else
+
+size_t my_snprintf(char* to, size_t n, const char* fmt, ...);
+size_t my_vsnprintf(char *to, size_t n, const char* fmt, va_list ap);
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#define MYSQL_SERVICE_MY_SNPRINTF_INCLUDED
+#endif
+

include/mysql/service_thd_alloc.h

+#ifndef MYSQL_SERVICE_THD_ALLOC_INCLUDED
+/* Copyright (C) 2009 Sun Microsystems, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+/**
+  @file
+  This service provdes functions to allocate memory in a connection local
+  memory pool. The memory allocated there will be automatically freed at the
+  end of the statement, don't use it for allocations that should live longer
+  than that. For short living allocations this is more efficient than
+  using my_malloc and friends, and automatic "garbage collection" allows not
+  to think about memory leaks.
+
+  The pool is best for small to medium objects, don't use it for large
+  allocations - they are better served with my_malloc.
+*/
+
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct st_mysql_lex_string
+{
+  char *str;
+  size_t length;
+};
+typedef struct st_mysql_lex_string MYSQL_LEX_STRING;
+
+extern struct thd_alloc_service_st {
+  void *(*thd_alloc_func)(MYSQL_THD, unsigned int);
+  void *(*thd_calloc_func)(MYSQL_THD, unsigned int);
+  char *(*thd_strdup_func)(MYSQL_THD, const char *);
+  char *(*thd_strmake_func)(MYSQL_THD, const char *, unsigned int);
+  void *(*thd_memdup_func)(MYSQL_THD, const void*, unsigned int);
+  MYSQL_LEX_STRING *(*thd_make_lex_string_func)(MYSQL_THD, MYSQL_LEX_STRING *,
+                                        const char *, unsigned int, int);
+} *thd_alloc_service;
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+
+#define thd_alloc(thd,size) (thd_alloc_service->thd_alloc_func((thd), (size)))
+
+#define thd_calloc(thd,size) (thd_alloc_service->thd_calloc_func((thd), (size)))
+
+#define thd_strdup(thd,str) (thd_alloc_service->thd_strdup_func((thd), (str)))
+
+#define thd_strmake(thd,str,size) \
+  (thd_alloc_service->thd_strmake_func((thd), (str), (size)))
+
+#define thd_memdup(thd,str,size) \
+  (thd_alloc_service->thd_memdup_func((thd), (str), (size)))
+
+#define thd_make_lex_string(thd, lex_str, str, size, allocate_lex_string) \
+  (thd_alloc_service->thd_make_lex_string_func((thd), (lex_str), (str), \
+                                               (size), (allocate_lex_string)))
+
+#else
+
+/**
+  Allocate memory in the connection's local memory pool
+
+  @details
+  When properly used in place of @c my_malloc(), this can significantly
+  improve concurrency. Don't use this or related functions to allocate
+  large chunks of memory. Use for temporary storage only. The memory
+  will be freed automatically at the end of the statement; no explicit
+  code is required to prevent memory leaks.
+
+  @see alloc_root()
+*/
+void *thd_alloc(MYSQL_THD thd, unsigned int size);
+/**
+  @see thd_alloc()
+*/
+void *thd_calloc(MYSQL_THD thd, unsigned int size);
+/**
+  @see thd_alloc()
+*/
+char *thd_strdup(MYSQL_THD thd, const char *str);
+/**
+  @see thd_alloc()
+*/
+char *thd_strmake(MYSQL_THD thd, const char *str, unsigned int size);
+/**
+  @see thd_alloc()
+*/
+void *thd_memdup(MYSQL_THD thd, const void* str, unsigned int size);
+
+/**
+  Create a LEX_STRING in this connection's local memory pool
+
+  @param thd      user thread connection handle
+  @param lex_str  pointer to LEX_STRING object to be initialized
+  @param str      initializer to be copied into lex_str
+  @param size     length of str, in bytes
+  @param allocate_lex_string  flag: if TRUE, allocate new LEX_STRING object,
+                              instead of using lex_str value
+  @return  NULL on failure, or pointer to the LEX_STRING object
+
+  @see thd_alloc()
+*/
+MYSQL_LEX_STRING *thd_make_lex_string(MYSQL_THD thd, MYSQL_LEX_STRING *lex_str,
+                                      const char *str, unsigned int size,
+                                      int allocate_lex_string);
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#define MYSQL_SERVICE_THD_ALLOC_INCLUDED
+#endif
+

include/mysql/services.h

+#ifndef MYSQL_SERVICES_INCLUDED
+/* Copyright (C) 2009 Sun Microsystems, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <mysql/service_my_snprintf.h>
+#include <mysql/service_thd_alloc.h>
+
+#ifdef __cplusplus
+}
+#endif
+
+#define MYSQL_SERVICES_INCLUDED
+#endif
+

include/service_versions.h

+/* Copyright (C) 2009 Sun Microsystems, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#ifdef _WIN32
+#define SERVICE_VERSION __declspec(dllexport) void *
+#else
+#define SERVICE_VERSION void *
+#endif
+
+#define VERSION_my_snprintf     0x0100
+#define VERSION_thd_alloc       0x0100
+

libservices/CMakeLists.txt

+# Copyright (C) 2006 MySQL AB
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/include)
+
+SET(MYSQLSERVICES_SOURCES my_snprintf_service.c thd_alloc_service.c)
+
+ADD_LIBRARY(mysqlservices ${MYSQLSERVICES_SOURCES})

libservices/HOWTO

+How to create a new service
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+A "service" is a set of C functions in a structure that a
+service dynamic linker uses when a dynamic plugin is loaded.
+
+If you want to export C++ class you need to provide an
+extern "C" function that will create a new instance of your class,
+and put it in a service.
+
+Data structures are not part of the service structure, but they are part
+of the API you create and usually need to be declared in the same
+service_*.h file.
+
+To turn a set of functions (foo_func1, foo_func2)
+into a service "foo" you need to
+
+1. create a new file include/mysql/service_foo.h
+
+2. the template is
+==================================================================
+  #ifndef MYSQL_SERVICE_FOO_INCLUDED
+  /* standard GPL header */
+
+  /**
+    @file
+    *exhaustive* description of the interface you provide.
+    This file is the main user documentation of the new service
+  */
+  #ifdef __cplusplus
+  extern "C" {
+  #endif
+
+  extern struct foo_service_st {
+    int (*foo_func1_type)(...);  /* fix the prototype as appropriate */
+    void (*foo_func2_type)(...); /* fix the prototype as appropriate */
+  } *foo_service;
+
+  #ifdef MYSQL_DYNAMIC_PLUGIN
+
+  #define foo_func1(...) foo_service->foo_func1_type(...)
+  #define foo_func2(...) foo_service->foo_func2_type(...)
+
+  #else
+
+  int foo_func1(...);  /* fix the prototype as appropriate */
+  void foo_func2(...); /* fix the prototype as appropriate */
+
+  #endif
+
+  #ifdef __cplusplus
+  }
+  #endif
+
+  #define MYSQL_SERVICE_FOO_INCLUDED
+  #endif
+==================================================================
+
+the service_foo.h file should be self-contained, if it needs system headers -
+include them in it, e.g. if you use size_t - #include <stdlib.h>
+
+it should also declare all the accompanying data structures, as necessary
+(e.g. thd_alloc_service declares MYSQL_LEX_STRING).
+
+3. add the new file to include/Makefile.am (pkginclude_HEADERS)
+4. add the new file to include/mysql/services.h
+5. increase the minor plugin ABI version in include/mysql/plugin.h
+   (MYSQL_PLUGIN_INTERFACE_VERSION = MYSQL_PLUGIN_INTERFACE_VERSION+1)
+6. add the version of your service to include/service_versions.h:
+==================================================================
+    #define VERSION_foo 0x0100
+==================================================================
+
+7. create a new file libservices/foo_service.c using the following template:
+==================================================================
+  /* GPL header */
+  #include <service_versions.h>
+  SERVICE_VERSION *foo_service= (void*)VERSION_foo;
+==================================================================
+
+8. add the new file to libservices/CMakeLists.txt (MYSQLSERVICES_SOURCES)
+9. add the new file to libservices/Makefile.am (libmysqlservices_a_SOURCES)
+10. and finally, register your service for dynamic linking in
+    sql/sql_plugin_services.h
+10.1 fill in the service structure:
+==================================================================
+  static struct foo_service_st foo_handler = {
+    foo_func1,
+    foo_func2
+  }
+==================================================================
+
+10.2 and add it to the list of services
+
+==================================================================
+    { "foo_service", VERSION_foo, &foo_handler }
+==================================================================
+
+that's all.
+

libservices/Makefile.am

+# Copyright 2009 Sun Microsystems, Inc.
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+AM_CPPFLAGS =		-I$(top_srcdir)/include
+pkglib_LIBRARIES =	libmysqlservices.a
+libmysqlservices_a_SOURCES =  my_snprintf_service.c thd_alloc_service.c
+EXTRA_DIST = CMakeLists.txt

libservices/my_snprintf_service.c

+/* Copyright (C) 2009 Sun Microsystems, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include <service_versions.h>
+SERVICE_VERSION my_snprintf_service= (void*)VERSION_my_snprintf;

libservices/thd_alloc_service.c

+/* Copyright (C) 2009 Sun Microsystems, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include <service_versions.h>
+SERVICE_VERSION *thd_alloc_service= (void*)VERSION_thd_alloc;

mysql-test/r/plugin.result

@@ -12,6 +12,15 @@ CREATE TABLE t1(a int) ENGINE=EXAMPLE;
 SELECT * FROM t1;
 a
 DROP TABLE t1;
+set global example_ulong_var=500;
+set global example_enum_var= e1;
+show status like 'example%';
+Variable_name	Value
+example_func_example	enum_var is 0, ulong_var is 500, really
+show variables like 'example%';
+Variable_name	Value
+example_enum_var	e1
+example_ulong_var	500
 UNINSTALL PLUGIN example;
 UNINSTALL PLUGIN EXAMPLE;
 ERROR 42000: PLUGIN EXAMPLE does not exist

mysql-test/t/plugin.test

@@ -22,6 +22,12 @@ SELECT * FROM t1;
 
 DROP TABLE t1;
 
+# a couple of tests for variables
+set global example_ulong_var=500;
+set global example_enum_var= e1;
+show status like 'example%';
+show variables like 'example%';
+
 UNINSTALL PLUGIN example;
 --error 1305
 UNINSTALL PLUGIN EXAMPLE;

plugin/daemon_example/Makefile.am

@@ -26,7 +26,8 @@ INCLUDES =              -I$(top_srcdir)/include -I$(top_builddir)/include \
 
 EXTRA_LTLIBRARIES =	libdaemon_example.la
 pkgplugin_LTLIBRARIES =	@plugin_daemon_example_shared_target@
-libdaemon_example_la_LDFLAGS =	-module -rpath $(pkgplugindir)
+libdaemon_example_la_LDFLAGS =	-module -rpath $(pkgplugindir) -L$(top_builddir)/libservices -lmysqlservices
+
 libdaemon_example_la_CXXFLAGS=	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
 libdaemon_example_la_CFLAGS =	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
 libdaemon_example_la_SOURCES =	daemon_example.cc

sql/CMakeLists.txt

@@ -46,7 +46,7 @@ SET (SQL_SOURCE
                discover.cc ../libmysql/errmsg.c field.cc  field_conv.cc 
                filesort.cc gstream.cc
                ha_partition.cc
-               handler.cc hash_filo.cc hash_filo.h 
+               handler.cc hash_filo.cc hash_filo.h sql_plugin_services.h
                hostname.cc init.cc item.cc item_buff.cc item_cmpfunc.cc 
                item_create.cc item_func.cc item_geofunc.cc item_row.cc 
                item_strfunc.cc item_subselect.cc item_sum.cc item_timefunc.cc 

sql/Makefile.am

@@ -49,7 +49,7 @@ mysqld_LDADD =		libndb.la \
 
 noinst_HEADERS =	item.h item_func.h item_sum.h item_cmpfunc.h \
 			item_strfunc.h item_timefunc.h \
-			item_xmlfunc.h \
+			item_xmlfunc.h sql_plugin_services.h \
 			item_create.h item_subselect.h item_row.h \
 			mysql_priv.h item_geofunc.h sql_bitmap.h \
 			procedure.h sql_class.h sql_lex.h sql_list.h \

sql/mysql_priv.h

@@ -28,6 +28,16 @@
 
 #ifndef MYSQL_CLIENT
 
+/*
+  the following #define adds server-only members to enum_mysql_show_type,
+  that is defined in mysql/plugin.h
+  it has to be before mysql/plugin.h is included.
+*/
+#define SHOW_always_last SHOW_KEY_CACHE_LONG, \
+            SHOW_KEY_CACHE_LONGLONG, SHOW_LONG_STATUS, SHOW_DOUBLE_STATUS, \
+            SHOW_HAVE, SHOW_MY_BOOL, SHOW_HA_ROWS, SHOW_SYS, \
+            SHOW_LONG_NOFLUSH, SHOW_LONGLONG_STATUS
+
 #include <my_global.h>
 #include <mysql_version.h>
 #include <mysql_embed.h>

sql/mysqld.cc

@@ -1508,20 +1508,23 @@ static void clean_up_mutexes()
    mysys/thr_mutex.c, will give a warning on first wrong mutex usage!
 */
 
+#ifdef SAFE_MUTEX
+#define always_in_that_order(A,B)               \
+  pthread_mutex_lock(A); pthread_mutex_lock(B); \
+  pthread_mutex_unlock(B); pthread_mutex_unlock(A)
+#else
+#define always_in_that_order(A,B)
+#endif
+
 static void register_mutex_order()
 {
-#ifdef SAFE_MUTEX
   /*
     We must have LOCK_open before LOCK_global_system_variables because
     LOCK_open is hold while sql_plugin.c::intern_sys_var_ptr() is called.
   */
-  pthread_mutex_lock(&LOCK_open);
-  pthread_mutex_lock(&LOCK_global_system_variables);
-
-  pthread_mutex_unlock(&LOCK_global_system_variables);
-  pthread_mutex_unlock(&LOCK_open);
-#endif
+  always_in_that_order(&LOCK_open, &LOCK_global_system_variables);
 }
+#undef always_in_that_order
 
 
 /****************************************************************************

sql/sql_plugin.h

@@ -27,16 +27,6 @@ class sys_var;
 
 #define INITIAL_LEX_PLUGIN_LIST_SIZE    16
 
-/*
-  the following #define adds server-only members to enum_mysql_show_type,
-  that is defined in plugin.h
-*/
-#define SHOW_FUNC    SHOW_FUNC, SHOW_KEY_CACHE_LONG, SHOW_KEY_CACHE_LONGLONG, \
-                     SHOW_LONG_STATUS, SHOW_DOUBLE_STATUS, SHOW_HAVE,   \
-                     SHOW_MY_BOOL, SHOW_HA_ROWS, SHOW_SYS, SHOW_LONG_NOFLUSH, \
-                     SHOW_LONGLONG_STATUS
-#include <mysql/plugin.h>
-#undef SHOW_FUNC
 typedef enum enum_mysql_show_type SHOW_TYPE;
 typedef struct st_mysql_show_var SHOW_VAR;
 

sql/sql_plugin_services.h

+/* Copyright (C) 2009 Sun Microsystems, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+/* support for Services */
+#include <service_versions.h>
+
+struct st_service_ref {
+  const char *name;
+  uint version;
+  void *service;
+};
+
+static struct my_snprintf_service_st my_snprintf_handler = {
+  my_snprintf,
+  my_vsnprintf
+};
+
+static struct thd_alloc_service_st thd_alloc_handler= {
+  thd_alloc,
+  thd_calloc,
+  thd_strdup,
+  thd_strmake,
+  thd_memdup,
+  thd_make_lex_string
+};
+
+static struct st_service_ref list_of_services[]=
+{
+  { "my_snprintf_service", VERSION_my_snprintf, &my_snprintf_handler },
+  { "thd_alloc_service",   VERSION_thd_alloc,   &thd_alloc_handler }
+};
+

storage/example/Makefile.am

@@ -34,7 +34,7 @@ noinst_HEADERS =	ha_example.h
 
 EXTRA_LTLIBRARIES =	ha_example.la
 pkgplugin_LTLIBRARIES =	@plugin_example_shared_target@
-ha_example_la_LDFLAGS =	-module -rpath $(pkgplugindir)
+ha_example_la_LDFLAGS =	-module -rpath $(pkgplugindir) -L$(top_builddir)/libservices -lmysqlservices
 ha_example_la_CXXFLAGS=	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
 ha_example_la_CFLAGS =	$(AM_CFLAGS) -DMYSQL_DYNAMIC_PLUGIN
 ha_example_la_SOURCES =	ha_example.cc

storage/example/ha_example.cc

-/* Copyright (C) 2003 MySQL AB
+/* Copyright (C) 2003 MySQL AB, 2009 Sun Microsystems, Inc.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -890,6 +890,24 @@ static struct st_mysql_sys_var* example_system_variables[]= {
   NULL
 };
 
+// this is an example of SHOW_FUNC and of my_snprintf() service
+static int show_func_example(MYSQL_THD thd, struct st_mysql_show_var *var,
+                             char *buf)
+{
+  var->type= SHOW_CHAR;
+  var->value= buf; // it's of SHOW_VAR_FUNC_BUFF_SIZE bytes
+  my_snprintf(buf, SHOW_VAR_FUNC_BUFF_SIZE,
+              "enum_var is %u, ulong_var is %lu, %.6b", // %b is MySQL extension
+              srv_enum_var, srv_ulong_var, "really");
+  return 0;
+}
+
+static struct st_mysql_show_var func_status[]=
+{
+  {"example_func_example",  (char *)show_func_example, SHOW_FUNC},
+  {0,0,SHOW_UNDEF}
+};
+
 mysql_declare_plugin(example)
 {
   MYSQL_STORAGE_ENGINE_PLUGIN,
@@ -901,7 +919,7 @@ mysql_declare_plugin(example)
   example_init_func,                            /* Plugin Init */
   example_done_func,                            /* Plugin Deinit */
   0x0001 /* 0.1 */,
-  NULL,                                         /* status variables */
+  func_status,                                  /* status variables */
   example_system_variables,                     /* system variables */
   NULL                                          /* config options */
 }

storage/mysql_storage_engine.cmake

@@ -34,7 +34,7 @@ IF(NOT SOURCE_SUBLIBS)
     #The dll is linked to the mysqld executable
     SET(dyn_libname ha_${libname})
     ADD_LIBRARY(${dyn_libname} SHARED ${${engine}_SOURCES})
-    TARGET_LINK_LIBRARIES (${dyn_libname}  mysqld)
+    TARGET_LINK_LIBRARIES (${dyn_libname} mysqlservices mysqld)
     IF(${engine}_LIBS)
       TARGET_LINK_LIBRARIES(${dyn_libname} ${${engine}_LIBS})
     ENDIF(${engine}_LIBS)

storage/pbxt/src/ha_pbxt.cc

@@ -1233,9 +1233,6 @@ static int pbxt_init(void *p)
 				 * Only real problem, 2 threads try to load the same
 				 * plugin at the same time.
 				 */
-#if MYSQL_VERSION_ID < 60014
-				myxt_mutex_unlock(&LOCK_plugin);
-#endif
 #endif
 
 				/* Can't do this here yet, because I need a THD! */
@@ -1269,11 +1266,6 @@ static int pbxt_init(void *p)
 
 				if (thd)
 					myxt_destroy_thread(thd, FALSE);
-#ifndef DRIZZLED
-#if MYSQL_VERSION_ID < 60014
-				myxt_mutex_lock(&LOCK_plugin);
-#endif
-#endif
 			}
 #endif
 		}

unittest/mysys/Makefile.am

@@ -24,7 +24,8 @@ LDADD 		= $(top_builddir)/unittest/mytap/libmytap.a \
 		  $(top_builddir)/strings/libmystrings.a
 
 EXTRA_DIST       = CMakeLists.txt 
-noinst_PROGRAMS  = bitmap-t base64-t my_atomic-t lf-t waiting_threads-t
+noinst_PROGRAMS  = bitmap-t base64-t my_atomic-t lf-t waiting_threads-t \
+		   my_vsnprintf-t
 
 if NEED_THREAD
 # my_atomic-t is used to check thread functions, so it is safe to 

unittest/mysys/my_vsnprintf-t.c

+/* Copyright (C) 2003 MySQL AB
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA */
+
+#include <my_global.h>
+#include <m_string.h>
+#include <tap.h>
+
+char buf[1024]; /* let's hope that's enough */
+
+void test1(const char *res, const char *fmt, ...)
+{
+  va_list args;
+  size_t len;
+  va_start(args,fmt);
+  len= my_vsnprintf(buf, sizeof(buf)-1, fmt, args);
+  va_end(args);
+  ok(strlen(res) == len && strcmp(buf, res) == 0, "\"%s\"", buf);
+}
+
+int main(void)
+{
+  plan(47);
+
+  test1("Constant string",
+        "Constant string");
+
+  test1("Format specifier s works",
+        "Format specifier s %s", "works");
+  test1("Format specifier b works (mysql extension)",
+        "Format specifier b %.5b (mysql extension)", "works!!!");
+  test1("Format specifier c !",
+        "Format specifier c %c", '!');
+  test1("Format specifier d 1",
+        "Format specifier d %d", 1);
+  test1("Format specifier u 2",
+        "Format specifier u %u", 2);
+  test1("Format specifier x a",
+        "Format specifier x %x", 10);
+  test1("Format specifier X B",
+        "Format specifier X %X", 11);
+  test1("Format specifier p 0x5",
+        "Format specifier p %p", 5);
+
+  test1("Flag '-' is ignored <   1>",
+        "Flag '-' is ignored <%-4d>", 1);
+  test1("Flag '0' works <0006>",
+        "Flag '0' works <%04d>", 6);
+
+  test1("Width is ignored for strings <x> <y>",
+        "Width is ignored for strings <%04s> <%5s>", "x", "y");
+
+  test1("Precision works for strings <abcde>",
+        "Precision works for strings <%.5s>", "abcdef!");
+
+  test1("Flag '`' (backtick) works: `abcd` `op``q` (mysql extension)",
+        "Flag '`' (backtick) works: %`s %`.4s (mysql extension)",
+        "abcd", "op`qrst");
+
+  test1("Length modifiers work: 1 * -1 * 2 * 3",
+        "Length modifiers work: %d * %ld * %lld * %zd", 1, -1L, 2LL, (size_t)3);
+
+  test1("(null) pointer is fine",
+        "%s pointer is fine", NULL);
+
+  test1("Positional arguments work: on the dark side they are",
+        "Positional arguments work: %3$s %1$s %2$s",
+        "they", "are", "on the dark side");
+
+  test1("Asterisk '*' as a width works: <    4>",
+        "Asterisk '*' as a width works: <%*d>", 5, 4);
+
+  test1("Asterisk '*' as a precision works: <qwerty>",
+        "Asterisk '*' as a precision works: <%.*s>", 6, "qwertyuiop");
+
+  test1("Positional arguments for a width: <    4>",
+        "Positional arguments for a width: <%1$*2$d>", 4, 5);
+
+  test1("Positional arguments for a precision: <qwerty>",
+        "Positional arguments for a precision: <%1$.*2$s>", "qwertyuiop", 6);
+
+  test1("Positional arguments and a width: <0000ab>",
+        "Positional arguments and a width: <%1$06x>", 0xab);
+
+  test1("Padding and %p <0x12> <0x034> <0x0000ab> <    0xcd>",
+        "Padding and %%p <%04p> <%05p> <%08p> <%8p>", 0x12, 0x34, 0xab, 0xcd);
+
+#if MYSQL_VERSION_ID > 60000
+#error %f/%g tests go here
+#endif
+
+  test1("Hello",
+        "Hello");
+  test1("Hello int, 1",
+        "Hello int, %d", 1);
+  test1("Hello int, -1",
+        "Hello int, %d", -1);
+  test1("Hello string 'I am a string'",
+        "Hello string '%s'", "I am a string");
+  test1("Hello hack hack hack hack hack hack hack 1",
+        "Hello hack hack hack hack hack hack hack %d", 1);
+  test1("Hello 1 hack 4",
+        "Hello %d hack %d", 1, 4);
+  test1("Hello 1 hack hack hack hack hack 4",
+        "Hello %d hack hack hack hack hack %d", 1, 4);
+  test1("Hello 'hack' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh",
+        "Hello '%s' hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh", "hack");
+  test1("Hello hhhhhhhhhhhhhh 1 sssssssssssssss",
+        "Hello hhhhhhhhhhhhhh %d sssssssssssssss", 1);
+  test1("Hello 1",
+        "Hello %u", 1);
+  test1("Hello 4294967295",
+        "Hello %u", -1);
+  test1("Hex:   20  '    41'",
+        "Hex:   %lx  '%6lx'", 32, 65);
+  test1("conn 1 to: '(null)' user: '(null)' host: '(null)' ((null))",
+        "conn %ld to: '%-.64s' user: '%-.32s' host: '%-.64s' (%-.64s)",
+                   1L,     NULL,          NULL,          NULL,    NULL);
+  test1("Hello string `I am a string`",
+        "Hello string %`s", "I am a string");
+  test1("Hello TEST",
+        "Hello %05s", "TEST");
+  test1("My `Q` test",
+        "My %1$`-.1s test", "QQQQ");
+  test1("My AAAA test done DDDD",
+        "My %2$s test done %1$s", "DDDD", "AAAA");
+  test1("My DDDD test CCCC, DDD",
+        "My %1$s test %2$s, %1$-.3s", "DDDD", "CCCC");
+  test1("My QQQQ test",
+        "My %1$`-.4b test", "QQQQ");
+  test1("My X test",
+        "My %1$c test", 'X');
+  test1("My <0000000010> test1 <   a> test2 <   A>",
+        "My <%010d> test1 <%4x> test2 <%4X>", 10, 10, 10);
+  test1("My <0000000010> test1 <   a> test2 <   a>",
+        "My <%1$010d> test1 <%2$4x> test2 <%2$4x>", 10, 10);
+  test1("My 00010 test",
+        "My %1$*02$d test", 10, 5);
+  test1("My `DDDD` test CCCC, `DDD`",
+        "My %1$`s test %2$s, %1$`-.3s", "DDDD", "CCCC");
+
+  return exit_status();
+}
+