<!--$Id: env_set_isalive.so,v 10.4 2006/01/27 16:13:48 bostic Exp $--> <!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: DbEnv::set_isalive</title> <meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> <meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> </head> <body bgcolor=white> <table width="100%"><tr valign=top> <td> <b>DbEnv::set_isalive</b> </td> <td align=right> <a href="../../db47-devel-4.7.25/api_cxx/api_core.html"><img src="../../db47-devel-4.7.25/images/api.gif" alt="API"></a> <a href="../../db47-devel-4.7.25/ref/toc.html"><img src="../../db47-devel-4.7.25/images/ref.gif" alt="Ref"></a></td> </tr></table> <hr size=1 noshade> <tt> <b><pre> #include <db_cxx.h> <p> int DbEnv::set_isalive(int (*is_alive)(DbEnv *dbenv, pid_t pid, db_threadid_t tid, u_int32_t flags)); </pre></b> <hr size=1 noshade> <b>Description: DbEnv::set_isalive</b> <p>Declare a function that returns if a thread of control (either a true thread or a process) is still running. The DbEnv::set_isalive method supports the <a href="../../db47-devel-4.7.25/api_cxx/env_failchk.html">DbEnv::failchk</a> method. For more information, see <a href="../../db47-devel-4.7.25/ref/cam/app.html">Architecting Data Store and Concurrent Data Store applications</a>, and <a href="../../db47-devel-4.7.25/ref/transapp/app.html">Architecting Transactional Data Store applications</a>.</p> <p>The DbEnv::set_isalive method configures operations performed using the specified <a href="../../db47-devel-4.7.25/api_cxx/env_class.html">DbEnv</a> handle, not all operations performed on the underlying database environment.</p> <p>The DbEnv::set_isalive method may be called at any time during the life of the application.</p> <p>The DbEnv::set_isalive method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </p> <b>Parameters</b> <br> <b>is_alive</b><ul compact><li>The <b>is_alive</b> parameter is a function which returns non-zero if the thread of control, identified by the <b>pid</b> and <b>tid</b> arguments, is still running. The function takes four arguments:</ul> <br> <b><b>dbenv</b></b><ul compact><li>The <b>dbenv</b> parameter is the enclosing database environment handle, allowing application access to the application-private fields of that object.</ul> <b><b>pid</b></b><ul compact><li>The <b>pid</b> parameter is a process ID returned by the function specified to the <a href="../../db47-devel-4.7.25/api_cxx/env_set_thread_id.html">DbEnv::set_thread_id</a> method.</ul> <b><b>tid</b></b><ul compact><li>The <b>tid</b> parameter is a thread ID returned by the function specified to the <a href="../../db47-devel-4.7.25/api_cxx/env_set_thread_id.html">DbEnv::set_thread_id</a> method.</ul> <b><b>flags</b></b><ul compact><li>The <b>flags</b> parameter must be set to 0 or the following value: <br> <b><a name="DB_MUTEX_PROCESS_ONLY">DB_MUTEX_PROCESS_ONLY</a></b><ul compact><li>Return only if the process is alive, the thread ID should be ignored.</ul> <br></ul> <br> <br> <br><b>Errors</b> <p>The DbEnv::set_isalive method may fail and throw <a href="../../db47-devel-4.7.25/api_cxx/except_class.html">DbException</a>, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:</p> <br> <b>EINVAL</b><ul compact><li>An invalid flag value or parameter was specified.</ul> <br> <hr size=1 noshade> <br><b>Class</b> <a href="../../db47-devel-4.7.25/api_cxx/env_class.html">DbEnv</a> <br><b>See Also</b> <a href="../../db47-devel-4.7.25/api_cxx/env_list.html">Database Environments and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <a href="../../db47-devel-4.7.25/api_cxx/api_core.html"><img src="../../db47-devel-4.7.25/images/api.gif" alt="API"></a><a href="../../db47-devel-4.7.25/ref/toc.html"><img src="../../db47-devel-4.7.25/images/ref.gif" alt="Ref"></a> </td></tr></table> <p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> </body> </html>