#ifdef HAVE_CONFIG_H# include <config.h>#endif#include <stdio.h>#include "ntp_machine.h"#include "ntp_fp.h"#include "ntp_stdlib.h"#include "ntp_syslog.h"#include "transmitbuff.h"/* * transmitbuf memory management */#define TRANSMIT_INIT	10	/* 10 buffers initially */#define TRANSMIT_LOWAT	3	/* when we're down to three buffers get more */#define TRANSMIT_INC	5	/* get 5 more at a time */#define TRANSMIT_TOOMANY	40	/* this is way too many buffers *//* * Memory allocation */static volatile u_long full_transmitbufs = 0;		/* number of transmitbufs on fulllist */static volatile u_long free_transmitbufs = 0;		/* number of transmitbufs on freelist */static	struct transmitbuf *volatile freelist = NULL;  /* free buffers */static	struct transmitbuf *volatile fulllist = NULL;  /* lifo buffers with data */static	struct transmitbuf *volatile beginlist = NULL; /* fifo buffers with data */static u_long total_transmitbufs = 0;		/* total transmitbufs currently in use */static u_long lowater_additions = 0;	/* number of times we have added memory */static	struct transmitbuf initial_bufs[TRANSMIT_INIT]; /* initial allocation */#if defined(HAVE_SIGNALED_IO)# define TRANSMIT_BLOCK_IO()	BLOCKIO()# define TRANSMIT_UNBLOCK_IO()	UNBLOCKIO()#elif defined(HAVE_IO_COMPLETION_PORT)static CRITICAL_SECTION TransmitCritSection;# define TRANSMIT_BLOCK_IO()	EnterCriticalSection(&TransmitCritSection)# define TRANSMIT_UNBLOCK_IO()	LeaveCriticalSection(&TransmitCritSection)#else# define TRANSMIT_BLOCK_IO()# define TRANSMIT_UNBLOCK_IO()#endifstatic void initialise_buffer(struct transmitbuf *buff){	memset((char *) buff, 0, sizeof(struct transmitbuf));#if defined HAVE_IO_COMPLETION_PORT	buff->iocompletioninfo.overlapped.hEvent = CreateEvent(NULL, FALSE,FALSE, NULL);	buff->wsabuf.len = 0;	buff->wsabuf.buf = (char *) &buff->pkt;#endif}extern voidinit_transmitbuff(void){	int i;	/*	 * Init buffer free list and stat counters	 */	freelist = 0;	for (i = 0; i < TRANSMIT_INIT; i++)	{		initialise_buffer(&initial_bufs[i]);		initial_bufs[i].next = (struct transmitbuf *) freelist;		freelist = &initial_bufs[i];	}	fulllist = 0;	free_transmitbufs = total_transmitbufs = TRANSMIT_INIT;	full_transmitbufs = lowater_additions = 0;#if defined(HAVE_IO_COMPLETION_PORT)	InitializeCriticalSection(&TransmitCritSection);#endif}static voidcreate_buffers(void){	register struct transmitbuf *buf;	int i;	buf = (struct transmitbuf *)	    emalloc(TRANSMIT_INC*sizeof(struct transmitbuf));	for (i = 0; i < TRANSMIT_INC; i++)	{		initialise_buffer(buf);		buf->next = (struct transmitbuf *) freelist;		freelist = buf;		buf++;	}	free_transmitbufs += TRANSMIT_INC;	total_transmitbufs += TRANSMIT_INC;	lowater_additions++;}extern voidfree_transmit_buffer(	struct transmitbuf *rb	){	TRANSMIT_BLOCK_IO();	rb->next = freelist;	freelist = rb;	free_transmitbufs++;	TRANSMIT_UNBLOCK_IO();}extern struct transmitbuf *get_free_transmit_buffer(void){	struct transmitbuf * buffer = NULL;	TRANSMIT_BLOCK_IO();	if (free_transmitbufs <= 0) {		create_buffers();	}	buffer = freelist;	freelist = buffer->next;	buffer->next = NULL;	--free_transmitbufs;	TRANSMIT_UNBLOCK_IO();	return buffer;}