diff options
| author | unknown <monty@hundin.mysql.fi> | 2002-06-03 12:59:31 +0300 |
|---|---|---|
| committer | unknown <monty@hundin.mysql.fi> | 2002-06-03 12:59:31 +0300 |
| commit | f0409fa920c7908f2f9ef03919583a32bf84eaad (patch) | |
| tree | be04186411dc657ef6bbcbe01267d30f2675c914 /bdb/docs/ref/program/mt.html | |
| parent | ebbcb0f391d7df364e0ccc6bca706456e9aadbf7 (diff) | |
| parent | 7cb2e2d1dce2c7466388f4a6ade0614564be82fc (diff) | |
| download | mariadb-git-f0409fa920c7908f2f9ef03919583a32bf84eaad.tar.gz | |
merge with 4.0
BitKeeper/etc/ignore:
auto-union
BitKeeper/etc/logging_ok:
auto-union
BUILD/SETUP.sh:
Auto merged
BUILD/compile-pentium-debug:
Auto merged
BitKeeper/triggers/post-commit:
Auto merged
configure.in:
Auto merged
Docs/manual.texi:
Auto merged
client/mysql.cc:
Auto merged
client/mysqldump.c:
Auto merged
client/mysqltest.c:
Auto merged
extra/mysql_install.c:
Auto merged
extra/resolve_stack_dump.c:
Auto merged
extra/resolveip.c:
Auto merged
include/my_sys.h:
Auto merged
include/mysqld_error.h:
Auto merged
isam/pack_isam.c:
Auto merged
libmysql/Makefile.shared:
Auto merged
libmysql/libmysql.c:
Auto merged
myisam/ft_dump.c:
Auto merged
myisam/ft_test1.c:
Auto merged
myisam/ftdefs.h:
Auto merged
myisam/mi_check.c:
Auto merged
myisam/mi_test1.c:
Auto merged
myisam/mi_write.c:
Auto merged
myisam/myisamchk.c:
Auto merged
myisam/myisampack.c:
Auto merged
mysql-test/mysql-test-run.sh:
Auto merged
mysql-test/r/select_found.result:
Auto merged
mysql-test/t/select_found.test:
Auto merged
mysys/charset.c:
Auto merged
mysys/default.c:
Auto merged
mysys/hash.c:
Auto merged
sql/field.cc:
Auto merged
sql/gen_lex_hash.cc:
Auto merged
sql/ha_innodb.cc:
Auto merged
sql/hostname.cc:
Auto merged
sql/item_cmpfunc.h:
Auto merged
sql/item_strfunc.cc:
Auto merged
sql/item_timefunc.h:
Auto merged
sql/lex.h:
Auto merged
sql/log.cc:
Auto merged
sql/mysql_priv.h:
Auto merged
sql/repl_failsafe.cc:
Auto merged
sql/slave.cc:
Auto merged
sql/sql_acl.cc:
Auto merged
sql/sql_base.cc:
Auto merged
sql/sql_cache.cc:
Auto merged
sql/sql_class.cc:
Auto merged
sql/sql_class.h:
Auto merged
sql/sql_db.cc:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_select.cc:
Auto merged
sql/sql_string.cc:
Auto merged
sql/sql_table.cc:
Auto merged
sql/sql_union.cc:
Auto merged
sql/share/czech/errmsg.txt:
Auto merged
sql/share/danish/errmsg.txt:
Auto merged
sql/share/dutch/errmsg.txt:
Auto merged
sql/share/english/errmsg.txt:
Auto merged
sql/share/estonian/errmsg.txt:
Auto merged
sql/share/german/errmsg.txt:
Auto merged
sql/share/greek/errmsg.txt:
Auto merged
sql/share/hungarian/errmsg.txt:
Auto merged
sql/share/italian/errmsg.txt:
Auto merged
sql/share/japanese/errmsg.txt:
Auto merged
sql/share/korean/errmsg.txt:
Auto merged
sql/share/norwegian-ny/errmsg.txt:
Auto merged
sql/share/norwegian/errmsg.txt:
Auto merged
sql/sql_update.cc:
Auto merged
sql/structs.h:
Auto merged
sql/share/polish/errmsg.txt:
Auto merged
sql/share/portuguese/errmsg.txt:
Auto merged
sql/share/romanian/errmsg.txt:
Auto merged
sql/share/russian/errmsg.txt:
Auto merged
sql/share/slovak/errmsg.txt:
Auto merged
sql/share/spanish/errmsg.txt:
Auto merged
sql/share/swedish/errmsg.txt:
Auto merged
sql/share/ukrainian/errmsg.txt:
Auto merged
strings/Makefile.am:
Auto merged
strings/ctype-ujis.c:
Auto merged
tools/mysqlmanager.c:
Auto merged
Diffstat (limited to 'bdb/docs/ref/program/mt.html')
| -rw-r--r-- | bdb/docs/ref/program/mt.html | 95 |
1 files changed, 0 insertions, 95 deletions
diff --git a/bdb/docs/ref/program/mt.html b/bdb/docs/ref/program/mt.html deleted file mode 100644 index 31110920aa9..00000000000 --- a/bdb/docs/ref/program/mt.html +++ /dev/null @@ -1,95 +0,0 @@ -<!--$Id: mt.so,v 10.37 2000/12/04 18:05:42 bostic Exp $--> -<!--Copyright 1997, 1998, 1999, 2000 by Sleepycat Software, Inc.--> -<!--All rights reserved.--> -<html> -<head> -<title>Berkeley DB Reference Guide: Building multi-threaded applications</title> -<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> -<meta name="keywords" content="embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++"> -</head> -<body bgcolor=white> - <a name="2"><!--meow--></a> -<table><tr valign=top> -<td><h3><dl><dt>Berkeley DB Reference Guide:<dd>Programmer Notes</dl></h3></td> -<td width="1%"><a href="../../ref/program/environ.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../ref/toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/program/scope.html"><img src="../../images/next.gif" alt="Next"></a> -</td></tr></table> -<p> -<h1 align=center>Building multi-threaded applications</h1> -<p>The Berkeley DB library is not itself multi-threaded. The library was -deliberately architected to not use threads internally because of the -portability problems that using threads within the library would -introduce. -<p>Berkeley DB supports multi-threaded applications with the caveat that it loads -and calls functions that are commonly available in C language environments. -Other than this usage, Berkeley DB has no static data and maintains no local -context between calls to Berkeley DB functions. -<p>Environment and database object handles returned from Berkeley DB library -functions are free-threaded. No other object handles returned from -the Berkeley DB library are free-threaded. -<p>The following rules should be observed when using threads to -access the Berkeley DB library: -<p><ol> -<p><li>The <a href="../../api_c/env_open.html#DB_THREAD">DB_THREAD</a> flag must be specified to the <a href="../../api_c/env_open.html">DBENV->open</a> -and <a href="../../api_c/db_open.html">DB->open</a> functions if the Berkeley DB handles returned by those interfaces -will be used in the context of more than one thread. Setting the -<a href="../../api_c/env_open.html#DB_THREAD">DB_THREAD</a> flag inconsistently may result in database corruption. -<p>Threading is assumed in the Java API, so no special flags are required, -and Berkeley DB functions will always behave as if the <a href="../../api_c/env_open.html#DB_THREAD">DB_THREAD</a> flag -was specified. -<p>Only a single thread may call the <a href="../../api_c/env_close.html">DBENV->close</a> or <a href="../../api_c/db_close.html">DB->close</a> functions -for a returned environment or database handle. -<p>No other Berkeley DB handles are free-threaded, for example, cursors and -transactions may not span threads as their returned handles are not -free-threaded. -<p><li>When using the non-cursor Berkeley DB calls to retrieve key/data items (e.g., -<a href="../../api_c/db_get.html">DB->get</a>), the memory referenced by the pointer stored into the -Dbt is only valid until the next call to Berkeley DB using the DB handle -returned by <a href="../../api_c/db_open.html">DB->open</a>. This includes any use of the returned -DB handle, including by another thread of control within the -process. -<p>For this reason, if the <a href="../../api_c/env_open.html#DB_THREAD">DB_THREAD</a> handle was specified to the -<a href="../../api_c/db_open.html">DB->open</a> function, either <a href="../../api_c/dbt.html#DB_DBT_MALLOC">DB_DBT_MALLOC</a>, <a href="../../api_c/dbt.html#DB_DBT_REALLOC">DB_DBT_REALLOC</a> -or <a href="../../api_c/dbt.html#DB_DBT_USERMEM">DB_DBT_USERMEM</a> must be specified in the <a href="../../api_c/dbt.html">DBT</a> when -performing any non-cursor key or data retrieval. -<p><li>The <a href="../../api_c/dbc_get.html#DB_CURRENT">DB_CURRENT</a>, <a href="../../api_c/dbc_get.html#DB_NEXT">DB_NEXT</a> and <a href="../../api_c/dbc_get.html#DB_PREV">DB_PREV</a> flags to the -<a href="../../api_c/log_get.html">log_get</a> function may not be used by a free-threaded handle. If -such calls are necessary, a thread should explicitly create a unique -environment handle by separately calling <a href="../../api_c/env_open.html">DBENV->open</a> without -specifying <a href="../../api_c/env_open.html#DB_THREAD">DB_THREAD</a>. -<p><li>Each database operation (i.e., any call to a function underlying the -handles returned by <a href="../../api_c/db_open.html">DB->open</a> and <a href="../../api_c/db_cursor.html">DB->cursor</a>) is normally -performed on behalf of a unique locker. If, within a single thread of -control, multiple calls on behalf of the same locker are desired, then -transactions must be used. For example, consider the case where a -cursor scan locates a record, and then based on that record, accesses -some other item in the database. If these operations are done using -the default lockers for the handle, they may conflict. If the -application wishes to guarantee that the operations do not conflict, -locks must be obtained on behalf of a transaction, instead of the -default locker ID, and a transaction must be specified to subsequent -<a href="../../api_c/db_cursor.html">DB->cursor</a> and other Berkeley DB calls. -<p><li>Transactions may not span threads. Each transaction must begin and end -in the same thread, and each transaction may only be used by a single -thread. -<p>Cursors may not span transactions or threads. Each cursor must be -allocated and de-allocated within the same transaction and within -the same thread. -<p><li>User-level synchronization mutexes must have been implemented for the -compiler/architecture combination. Attempting to specify the DB_THREAD -flag will fail if fast mutexes are not available. -<p>If blocking mutexes are available, for example POSIX pthreads, they will -be used. Otherwise, the Berkeley DB library will make a system call to pause -for some amount of time when it is necessary to wait on a lock. This may -not be optimal, especially in a thread-only environment where it will be -more efficient to explicitly yield the processor to another thread. -<p>It is possible to specify a yield function on an per-application basis. -See <a href="../../api_c/set_func_yield.html">db_env_set_func_yield</a> for more information. -<p>It is possible to specify the number of attempts that will be made to -acquire the mutex before waiting. Se <a href="../../api_c/env_set_tas_spins.html">db_env_set_tas_spins</a> for -more information. -</ol> -<table><tr><td><br></td><td width="1%"><a href="../../ref/program/environ.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../../ref/toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../../ref/program/scope.html"><img src="../../images/next.gif" alt="Next"></a> -</td></tr></table> -<p><font size=1><a href="http://www.sleepycat.com">Copyright Sleepycat Software</a></font> -</body> -</html> |