memlib.html

Vxworks API操作系统和驱动程序设计API。压缩的HTML文件

This routine allocates a buffer of <i>size</i> bytes from the system memory
partition.  Additionally, it insures that the allocated buffer
begins on a page boundary.  Page sizes are architecture-dependent.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
A pointer to the newly allocated block, or NULL if the buffer could not be
allocated or the memory management unit (MMU) support library has not been
initialized.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_memLib_PAGE_SIZE_UNAVAILABLE</b>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./memLib.html#top">memLib</a></b>

<hr>
<a name="memPartRealloc"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>memPartRealloc(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>memPartRealloc(&nbsp;)</strong> - reallocate a block of memory in a specified partition</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>void *memPartRealloc
    (
    PART_ID  partId,          /* partition ID */
    char *   pBlock,          /* block to be reallocated */
    unsigned nBytes           /* new block size in bytes */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine changes the size of a specified block of memory and returns a
pointer to the new block.  The contents that fit inside the new size (or
old size if smaller) remain unchanged.  The memory alignment of the new
block is not guaranteed to be the same as the original block.
<p>
If <i>pBlock</i> is NULL, this call is equivalent to <b><a href="./memPartLib.html#memPartAlloc">memPartAlloc</a>(&nbsp;)</b>.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
A pointer to the new block of memory, or NULL if the call fails.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_smObjLib_NOT_INITIALIZED</b>
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./memLib.html#top">memLib</a></b>, <b><a href="./smMemLib.html#top">smMemLib</a></b>

<hr>
<a name="memPartFindMax"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>memPartFindMax(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>memPartFindMax(&nbsp;)</strong> - find the size of the largest available free block</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>int memPartFindMax
    (
    PART_ID partId            /* partition ID */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine searches for the largest block in the memory partition free
list and returns its size.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The size, in bytes, of the largest available block.
<p>
</blockquote><h4>ERRNO</h4><blockquote><p>
<b>S_smObjLib_NOT_INITIALIZED</b>
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./memLib.html#top">memLib</a></b>, <b><a href="./smMemLib.html#top">smMemLib</a></b>

<hr>
<a name="memOptionsSet"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>memOptionsSet(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>memOptionsSet(&nbsp;)</strong> - set the debug options for the system memory partition</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>void memOptionsSet
    (
    unsigned options          /* options for system partition */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine sets the debug options for the system memory partition.
Two kinds of errors are detected:  attempts to allocate more memory than
is available, and bad blocks found when memory is freed.  In both cases,
the following options can be selected for actions to be taken when the error
is detected:  (1) return the error status, (2) log an error message and
return the error status, or (3) log an error message and suspend the
calling task.
<p>
These options are discussed in detail in the library manual
entry for <b><a href="./memLib.html#top">memLib</a></b>.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
N/A
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./memLib.html#top">memLib</a></b>, <b><a href="./memLib.html#memPartOptionsSet">memPartOptionsSet</a>(&nbsp;)</b>

<hr>
<a name="calloc"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>calloc(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>calloc(&nbsp;)</strong> - allocate space for an array (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>void *calloc
    (
    size_t elemNum,           /* number of elements */
    size_t elemSize           /* size of elements */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine allocates a block of memory for an array that contains
<i>elemNum</i> elements of size <i>elemSize</i>.  This space is initialized to
zeros.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
A pointer to the block, or NULL if the call fails.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./memLib.html#top">memLib</a></b>, <i>American National Standard for Information Systems -</i>
<i>Programming Language - C, ANSI X3.159-1989: General Utilities (<b>stdlib.h</b>)</i>

<hr>
<a name="realloc"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>realloc(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>realloc(&nbsp;)</strong> - reallocate a block of memory (ANSI)</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>void *realloc
    (
    void * pBlock,            /* block to reallocate */
    size_t newSize            /* new block size */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine changes the size of a specified block of memory and returns a
pointer to the new block of memory.  The contents that fit inside the new
size (or old size if smaller) remain unchanged.  The memory alignment of
the new block is not guaranteed to be the same as the original block.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
<p>
A pointer to the new block of memory, or NULL if the call fails.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./memLib.html#top">memLib</a></b>, <i>American National Standard for Information Systems -</i>
<i>Programming Language - C, ANSI X3.159-1989: General Utilities (<b>stdlib.h</b>)</i>

<hr>
<a name="cfree"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>cfree(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>cfree(&nbsp;)</strong> - free a block of memory</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>STATUS cfree
    (
    char * pBlock             /* pointer to block of memory to free */
    )
</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine returns to the free memory pool a block of memory 
previously allocated with <b><a href="./memLib.html#calloc">calloc</a>(&nbsp;)</b>.
<p>
It is an error to free a memory block that was not previously allocated.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
OK, or ERROR if the the block is invalid.
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./memLib.html#top">memLib</a></b>

<hr>
<a name="memFindMax"></a>
<p align=right>
<a href="rtnIndex.htm"><i>OS Libraries :  Routines</i></a></p>

</blockquote><h1>memFindMax(&nbsp;)</h1> <blockquote></a></blockquote><h4>NAME</h4><blockquote>  
<p><strong>memFindMax(&nbsp;)</strong> - find the largest free block in the system memory partition</p>

</blockquote><h4>SYNOPSIS</h4><blockquote><p>
<pre>int memFindMax (void)</pre>

</blockquote><h4>DESCRIPTION</h4><blockquote><p>
This routine searches for the largest block in the system memory partition
free list and returns its size.
<p>
</blockquote><h4>RETURNS</h4><blockquote><p>
The size, in bytes, of the largest available block.
<p>
</blockquote><h4>SEE ALSO</h4><blockquote><p>
<b><a href="./memLib.html#top">memLib</a></b>, <b><a href="./memLib.html#memPartFindMax">memPartFindMax</a>(&nbsp;)</b>

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