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13<b>DbEnv::set_thread_id_string</b>
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21<b><pre>
22#include &lt;db_cxx.h&gt;
23<p>
24int
25DbEnv::set_thread_id(char *(*thread_id_string)(DbEnv *dbenv,
26    pid_t pid, db_threadid_t tid, char *buf));
27</pre></b>
28<hr size=1 noshade>
29<b>Description: DbEnv::set_thread_id_string</b>
30<p>Declare a function that formats a process ID and thread ID identifier
31pair for display into a caller-supplied buffer.  The function must
32return a reference to the caller-specified buffer.  The
33DbEnv::set_thread_id_string method supports the
34<a href="../api_cxx/env_set_thread_id.html">DbEnv::set_thread_id</a> method.</p>
35<p>The DbEnv::set_thread_id_string method configures operations performed using the specified
36<a href="../api_cxx/env_class.html">DbEnv</a> handle, not all operations performed on the underlying
37database environment.</p>
38<p>The DbEnv::set_thread_id_string method may be called at any time during the life of the
39application.</p>
40<p>The DbEnv::set_thread_id_string method
41either returns a non-zero error value
42or throws an exception that encapsulates a non-zero error value on
43failure, and returns 0 on success.
44</p>
45<b>Parameters</b> <br>
46 <b>thread_id_string</b><ul compact><li>The <b>thread_id_string</b> parameter is a function which returns a
47buffer in which is an identifier pair formatted for display.  The
48function takes four arguments:</ul>
49<br>
50<b><b>dbenv</b></b><ul compact><li>The <b>dbenv</b> parameter is the enclosing database environment
51handle, allowing application access to the application-private fields
52of that object.</ul>
53<b><b>pid</b></b><ul compact><li>The <b>pid</b> argument is a process ID.</ul>
54<b><b>tid</b></b><ul compact><li>The <b>tid</b> argument is a thread ID.</ul>
55<b><b>buf</b></b><ul compact><li><a name="2"><!--meow--></a>
56The <b>buf</b> argument is character array of at least
57DB_THREADID_STRLEN bytes in length, into which the identifier
58pair should be formatted.</ul>
59<br>
60<br>
61<p>If no <b>thread_id_string</b> function is specified, the default
62routine displays the identifier pair as "pid/tid", that is, the process
63ID represented as an unsigned integer value, a slash ('/') character,
64then the thread ID represented as an unsigned integer value.</p>
65<br><b>Errors</b>
66<p>The DbEnv::set_thread_id_string method
67may fail and throw
68<a href="../api_cxx/except_class.html">DbException</a>,
69encapsulating one of the following non-zero errors, or return one of
70the following non-zero errors:</p>
71<br>
72<b>EINVAL</b><ul compact><li>An
73invalid flag value or parameter was specified.</ul>
74<br>
75<hr size=1 noshade>
76<br><b>Class</b>
77<a href="../api_cxx/env_class.html">DbEnv</a>
78<br><b>See Also</b>
79<a href="../api_cxx/env_list.html">Database Environments and Related Methods</a>
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