📄 malloc-pools.html
字号:
<!-- Copyright (C) 2009 Free Software Foundation, Inc. -->
<!-- This material may be distributed only subject to the terms -->
<!-- and conditions set forth in the Open Publication License, v1.0 -->
<!-- or later (the latest version is presently available at -->
<!-- http://www.opencontent.org/openpub/). -->
<!-- Distribution of the work or derivative of the work in any -->
<!-- standard (paper) book form is prohibited unless prior -->
<!-- permission is obtained from the copyright holder. -->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>stdlib malloc Pools</TITLE
><meta name="MSSmartTagsPreventParsing" content="TRUE">
<META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="eCos Reference Manual"
HREF="ecos-ref.html"><LINK
REL="UP"
TITLE="eCos Memory pools"
HREF="memalloc.html#ECOS-MEMORY-POOLS"><LINK
REL="PREVIOUS"
TITLE="Fixed Size Allocation Pools"
HREF="fixed-pools.html"><LINK
REL="NEXT"
TITLE="CRC Algorithms"
HREF="services-crc.html"></HEAD
><BODY
CLASS="REFENTRY"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>eCos Reference Manual</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="fixed-pools.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="services-crc.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="MALLOC-POOLS"
></A
>stdlib malloc Pools</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN15147"
></A
><H2
>Name</H2
>malloc, calloc, free, realloc, mallinfo -- stdlib malloc pool</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN15154"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><P
></P
><A
NAME="AEN15155"
></A
><TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include <stdlib.h>
</PRE
></TD
></TR
></TABLE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>void *malloc</CODE
>(size_t size);</CODE
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>void *calloc</CODE
>(size_t nmemb, size_t size);</CODE
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>void free</CODE
>(void *ptr);</CODE
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>void *realloc</CODE
>(void *ptr, size_t size);</CODE
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>struct mallinfo mallinfo</CODE
>(void);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="MEMALLOC-STDLIB-DESCRIPTION"
></A
><H2
>Description</H2
><P
> eCos provides the standard library functions used for allocating
memory from the heap. <CODE
CLASS="FUNCTION"
>malloc()</CODE
> allocates a
block of memory of
<CODE
CLASS="PARAMETER"
>size</CODE
> bytes. <CODE
CLASS="FUNCTION"
>calloc()</CODE
>
performs the same, but also sets the memory to zero. The
function <CODE
CLASS="FUNCTION"
>free()</CODE
> returns a block to the
pool. <CODE
CLASS="FUNCTION"
>realloc</CODE
> resizes a block of
memory. Lastly, <CODE
CLASS="FUNCTION"
>mallinfo()</CODE
> returns
information about the heap, as described by the structure
<CODE
CLASS="STRUCTNAME"
>mallinfo</CODE
>:
<TABLE
BORDER="5"
BGCOLOR="#E0E0F0"
WIDTH="70%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>struct mallinfo {
int arena; /* total size of memory arena */
int ordblks; /* number of ordinary memory blocks */
int smblks; /* number of small memory blocks */
int hblks; /* number of mmapped regions */
int hblkhd; /* total space in mmapped regions */
int usmblks; /* space used by small memory blocks */
int fsmblks; /* space available for small memory blocks */
int uordblks; /* space used by ordinary memory blocks */
int fordblks; /* space free for ordinary blocks */
int keepcost; /* top-most, releasable (via malloc_trim) space */
int maxfree; /* (NON-STANDARD EXTENSION) size of largest free block */
};
</PRE
></TD
></TR
></TABLE
>
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="fixed-pools.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="ecos-ref.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="services-crc.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Fixed Size Allocation Pools</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="memalloc.html#ECOS-MEMORY-POOLS"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>CRC Algorithms</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -