Tying Everything Together

Example 2-1 is a revision of Example 1-2 that uses its own malloc_type structure instead of the kernel-defined M_TEMP.[2] Example 2-1 should clarify any misunderstandings you may have about MALLOC_DEFINE and MALLOC_DECLARE.

Note

To save space, the functions echo_open, echo_close, echo_write, and echo_read aren’t listed here, as they haven’t been changed.

Example 2-1. echo-2.0.c

#include <sys/param.h>
  #include <sys/module.h>
  #include <sys/kernel.h>
  #include <sys/systm.h>

  #include <sys/conf.h>
  #include <sys/uio.h>
  #include <sys/malloc.h>

  #define BUFFER_SIZE     256

 MALLOC_DECLARE(M_ECHO);
 MALLOC_DEFINE(M_ECHO, "echo_buffer", "buffer ...

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