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| <h5 class="subsubsection">3.2.4.4 Freeing Objects in an Obstack</h5> |
| |
| <p><a name="index-freeing-_0028obstacks_0029-311"></a> |
| To free an object allocated in an obstack, use the function |
| <code>obstack_free</code>. Since the obstack is a stack of objects, freeing |
| one object automatically frees all other objects allocated more recently |
| in the same obstack. |
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| <!-- obstack.h --> |
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| <div class="defun"> |
| — Function: void <b>obstack_free</b> (<var>struct obstack *obstack-ptr, void *object</var>)<var><a name="index-obstack_005ffree-312"></a></var><br> |
| <blockquote><p>If <var>object</var> is a null pointer, everything allocated in the obstack |
| is freed. Otherwise, <var>object</var> must be the address of an object |
| allocated in the obstack. Then <var>object</var> is freed, along with |
| everything allocated in <var>obstack</var> since <var>object</var>. |
| </p></blockquote></div> |
| |
| <p>Note that if <var>object</var> is a null pointer, the result is an |
| uninitialized obstack. To free all memory in an obstack but leave it |
| valid for further allocation, call <code>obstack_free</code> with the address |
| of the first object allocated on the obstack: |
| |
| <pre class="smallexample"> obstack_free (obstack_ptr, first_object_allocated_ptr); |
| </pre> |
| <p>Recall that the objects in an obstack are grouped into chunks. When all |
| the objects in a chunk become free, the obstack library automatically |
| frees the chunk (see <a href="Preparing-for-Obstacks.html#Preparing-for-Obstacks">Preparing for Obstacks</a>). Then other |
| obstacks, or non-obstack allocation, can reuse the space of the chunk. |
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