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| <a name="Thread_002dsafety-of-the-runtime-library-1"></a> |
| <h3 class="section">5.3 Thread-safety of the runtime library</h3> |
| <a name="index-thread_002dsafety_002c-threads"></a> |
| |
| <p>GNU Fortran can be used in programs with multiple threads, e.g. by |
| using OpenMP, by calling OS thread handling functions via the |
| <code>ISO_C_BINDING</code> facility, or by GNU Fortran compiled library code |
| being called from a multi-threaded program. |
| </p> |
| <p>The GNU Fortran runtime library, (<code>libgfortran</code>), supports being |
| called concurrently from multiple threads with the following |
| exceptions. |
| </p> |
| <p>During library initialization, the C <code>getenv</code> function is used, |
| which need not be thread-safe. Similarly, the <code>getenv</code> |
| function is used to implement the <code>GET_ENVIRONMENT_VARIABLE</code> and |
| <code>GETENV</code> intrinsics. It is the responsibility of the user to |
| ensure that the environment is not being updated concurrently when any |
| of these actions are taking place. |
| </p> |
| <p>The <code>EXECUTE_COMMAND_LINE</code> and <code>SYSTEM</code> intrinsics are |
| implemented with the <code>system</code> function, which need not be |
| thread-safe. It is the responsibility of the user to ensure that |
| <code>system</code> is not called concurrently. |
| </p> |
| <p>Finally, for platforms not supporting thread-safe POSIX functions, |
| further functionality might not be thread-safe. For details, please |
| consult the documentation for your operating system. |
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