diff options
Diffstat (limited to 'contrib/ntp/libntp/recvbuff.c')
| -rw-r--r-- | contrib/ntp/libntp/recvbuff.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/contrib/ntp/libntp/recvbuff.c b/contrib/ntp/libntp/recvbuff.c new file mode 100644 index 000000000000..37166a4a5c42 --- /dev/null +++ b/contrib/ntp/libntp/recvbuff.c @@ -0,0 +1,277 @@ +#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 "ntp_io.h" +#include "recvbuff.h" +#include "iosignal.h" + +/* + * Memory allocation + */ +static u_long volatile full_recvbufs; /* number of recvbufs on fulllist */ +static u_long volatile free_recvbufs; /* number of recvbufs on freelist */ +static u_long volatile total_recvbufs; /* total recvbufs currently in use */ +static u_long volatile lowater_adds; /* number of times we have added memory */ + +static struct recvbuf *volatile freelist; /* free buffers */ +static struct recvbuf *volatile fulllist; /* lifo buffers with data */ +static struct recvbuf *volatile beginlist; /* fifo buffers with data */ + +#if defined(HAVE_IO_COMPLETION_PORT) +static HANDLE fulldatabufferevent; +static CRITICAL_SECTION RecvCritSection; +# define RECV_BLOCK_IO() EnterCriticalSection(&RecvCritSection) +# define RECV_UNBLOCK_IO() LeaveCriticalSection(&RecvCritSection) +#else +# define RECV_BLOCK_IO() +# define RECV_UNBLOCK_IO() +#endif + +u_long +free_recvbuffs (void) +{ + return free_recvbufs; +} + +u_long +full_recvbuffs (void) +{ + return free_recvbufs; +} + +u_long +total_recvbuffs (void) +{ + return free_recvbufs; +} + +u_long +lowater_additions(void) +{ + return lowater_adds; +} + +static void +initialise_buffer(struct recvbuf *buff) +{ + memset((char *) buff, 0, sizeof(struct recvbuf)); + +#if defined HAVE_IO_COMPLETION_PORT + buff->iocompletioninfo.overlapped.hEvent = CreateEvent(NULL, FALSE,FALSE, NULL); + buff->wsabuff.len = RX_BUFF_SIZE; + buff->wsabuff.buf = (char *) buff->recv_buffer; +#endif +} + +static void +create_buffers(void) +{ + register struct recvbuf *buf; + int i; + buf = (struct recvbuf *) + emalloc(RECV_INC*sizeof(struct recvbuf)); + for (i = 0; i < RECV_INC; i++) + { + initialise_buffer(buf); + buf->next = (struct recvbuf *) freelist; + freelist = buf; + buf++; + } + + free_recvbufs += RECV_INC; + total_recvbufs += RECV_INC; + lowater_adds++; +} + +void +init_recvbuff(int nbufs) +{ + register struct recvbuf *buf; + int i; + + /* + * Init buffer free list and stat counters + */ + freelist = 0; + + buf = (struct recvbuf *) + emalloc(nbufs*sizeof(struct recvbuf)); + for (i = 0; i < nbufs; i++) + { + initialise_buffer(buf); + buf->next = (struct recvbuf *) freelist; + freelist = buf; + buf++; + } + + fulllist = 0; + free_recvbufs = total_recvbufs = nbufs; + full_recvbufs = lowater_adds = 0; + +#if defined(HAVE_IO_COMPLETION_PORT) + InitializeCriticalSection(&RecvCritSection); + fulldatabufferevent = CreateEvent(NULL, FALSE,FALSE, NULL); +#endif + +} + +#if defined(HAVE_IO_COMPLETION_PORT) + +/* Return the new full buffer event handle . This handle is + * signalled when a recv buffer is placed in the full list. + */ +HANDLE +get_recv_buff_event() +{ + return fulldatabufferevent; +} +#endif + +/* + * getrecvbufs - get receive buffers which have data in them + * + * + */ + +struct recvbuf * +getrecvbufs(void) +{ + struct recvbuf *rb = NULL; /* nothing has arrived */; + + RECV_BLOCK_IO(); + if (full_recvbufs == 0) + { +#ifdef DEBUG + if (debug > 4) + printf("getrecvbufs called, no action here\n"); +#endif + } + else { + + /* + * Get the fulllist chain and mark it empty + */ +#ifdef DEBUG + if (debug > 4) + printf("getrecvbufs returning %ld buffers\n", full_recvbufs); +#endif + rb = beginlist; + fulllist = 0; + full_recvbufs = 0; + + /* + * Check to see if we're below the low water mark. + */ + if (free_recvbufs <= RECV_LOWAT) + { + if (total_recvbufs >= RECV_TOOMANY) + msyslog(LOG_ERR, "too many recvbufs allocated (%ld)", + total_recvbufs); + else + { + create_buffers(); + } + } + } + RECV_UNBLOCK_IO(); + + /* + * Return the chain + */ + return rb; +} + +/* + * freerecvbuf - make a single recvbuf available for reuse + */ +void +freerecvbuf( + struct recvbuf *rb + ) +{ + RECV_BLOCK_IO(); + BLOCKIO(); + rb->next = (struct recvbuf *) freelist; + freelist = rb; + free_recvbufs++; + UNBLOCKIO(); + RECV_UNBLOCK_IO(); +} + + +void +add_full_recv_buffer( + struct recvbuf *rb + ) +{ + RECV_BLOCK_IO(); + if (full_recvbufs == 0) + { + beginlist = rb; + rb->next = 0; + } + else + { + rb->next = fulllist->next; + fulllist->next = rb; + } + fulllist = rb; + full_recvbufs++; + +#if defined(HAVE_IO_COMPLETION_PORT) + if (!SetEvent(fulldatabufferevent)) { + msyslog(LOG_ERR, "Can't set receive buffer event"); + } +#endif + RECV_UNBLOCK_IO(); +} + +struct recvbuf * +get_free_recv_buffer(void) +{ + struct recvbuf * buffer = NULL; + RECV_BLOCK_IO(); + if (free_recvbufs <= RECV_LOWAT) + { + if (total_recvbufs >= RECV_TOOMANY) { + msyslog(LOG_ERR, "too many recvbufs allocated (%ld)", + total_recvbufs); + } + else + { + create_buffers(); + } + } + + if (free_recvbufs > 0) + { + buffer = freelist; + freelist = buffer->next; + buffer->next = NULL; + --free_recvbufs; + } + + RECV_UNBLOCK_IO(); + return buffer; +} + +struct recvbuf * +get_full_recv_buffer(void) +{ + struct recvbuf * buffer = NULL; + RECV_BLOCK_IO(); + if (full_recvbufs > 0) { + --full_recvbufs; + buffer = beginlist; + beginlist = buffer->next; + buffer->next = NULL; + } + RECV_UNBLOCK_IO(); + return buffer; +} |