'\" t
.\"     Title: coap_lwip
.\"    Author: [see the "AUTHORS" section]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 10/28/2023
.\"    Manual: libcoap Manual
.\"    Source: coap_lwip 4.3.4
.\"  Language: English
.\"
.TH "COAP_LWIP" "3" "10/28/2023" "coap_lwip 4\&.3\&.4" "libcoap Manual"
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.SH "NAME"
coap_lwip, coap_lwip_dump_memory_pools, coap_lwip_set_input_wait_handler \- Work with CoAP lwip specific API handler 
.SH "SYNOPSIS"
.sp
\fB#include <coap3/coap\&.h>\fR
.sp
\fBvoid coap_lwip_set_input_wait_handler(coap_context_t *\fR\fB\fIcontext\fR\fR\fB, coap_lwip_input_wait_handler_t \fR\fB\fIhandler\fR\fR\fB, void *\fR\fB\fIinput_arg\fR\fR\fB);\fR
.sp
\fBvoid coap_lwip_dump_memory_pools(coap_log_t \fR\fB\fIlog_level\fR\fR\fB);\fR
.SH "DESCRIPTION"
.sp
This man page describes the additional libcoap functions that are available for working with LwIP implementations\&.
.sp
\fBNOTE:\fR If the following line is defined in lwipopts\&.h, then libcoap will reserve space for one response PDU when allocating coap_pdu_t structures\&.
.sp
.if n \{\
.RS 4
.\}
.nf
#define MEMP_STATS 1
.fi
.if n \{\
.RE
.\}
.SH "CALLBACK HANDLER"
.sp
\fBCallback Type: coap_lwip_input_wait_handler_t\fR
.sp
.if n \{\
.RS 4
.\}
.nf
/**
 * LwIP callback handler that can be used to wait / timeout for the
 * next input packet\&.
 *
 * @param arg The argument passed to the coap_lwip_set_input_wait_handler()
 *            function\&.
 * @param milli_secs Suggested number of milli secs to wait before returning
 *                   if no input\&.
 *
 * @return @c 1 if packet received, @c 0 for timeout, else @c \-1 on error\&.
 */
typedef int (*coap_lwip_input_wait_handler_t)(void* arg, uint32_t milli_secs);
.fi
.if n \{\
.RE
.\}
.SH "FUNCTIONS"
.sp
\fBFunction: coap_lwip_set_input_wait_handler()\fR
.sp
The \fBcoap_lwip_set_input_wait_handler\fR() function is used to define a callback \fIhandler\fR that is invoked by \fBcoap_io_process\fR(3) which passes in the \fIinput_arg\fR parameter along with a suggested milli\-sec wait time parameter in case there is no input\&. This callback \fIhandler\fR is used to wait for (and probably times out) the next input packet\&. This allows the application to define whatever mechanism it wants use for this process\&.
.sp
\fBFunction: coap_lwip_dump_memory_pools()\fR
.sp
The \fBcoap_lwip_dump_memory_pools\fR() function is used to dump out the current state of the LwIP memory pools at logging level \fIlog_level\fR\&.
.sp
This function is always invoked by \fBcoap_free_context\fR(3) with a \fIlog_level\fR of COAP_LOG_DEBUG\&.
.sp
\fBNOTE:\fR For information to be printed out, you need the following two lines in lwipopts\&.h
.sp
.if n \{\
.RS 4
.\}
.nf
#define MEMP_STATS         1
#define LWIP_STATS_DISPLAY 1
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
.sp
\fBcoap_context\fR(3) and \fBcoap_io\fR(3)
.SH "FURTHER INFORMATION"
.sp
See
.sp
"RFC7252: The Constrained Application Protocol (CoAP)"
.sp
for further information\&.
.SH "BUGS"
.sp
Please report bugs on the mailing list for libcoap: libcoap\-developers@lists\&.sourceforge\&.net or raise an issue on GitHub at https://github\&.com/obgm/libcoap/issues
.SH "AUTHORS"
.sp
The libcoap project <libcoap\-developers@lists\&.sourceforge\&.net>