X-Git-Url: http://git.pk910.de/?p=ircu2.10.12-pk.git;a=blobdiff_plain;f=ircd%2Fmsgq.c;fp=ircd%2Fmsgq.c;h=379ffae6a873261e63620d17e8b1a81ff8048e80;hp=0000000000000000000000000000000000000000;hb=0400a5a6479398d82526785c18c0df8bc8b92dce;hpb=d17e10da972ce5776c60b4c317267c6abe0e1ead diff --git a/ircd/msgq.c b/ircd/msgq.c new file mode 100644 index 0000000..379ffae --- /dev/null +++ b/ircd/msgq.c @@ -0,0 +1,628 @@ +/* + * IRC - Internet Relay Chat, ircd/msgq.c + * Copyright (C) 2000 Kevin L. Mitchell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 1, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ +/** @file + * @brief Outbound message queue implementation. + * @version $Id$ + */ +#include "config.h" + +#include "msgq.h" +#include "ircd.h" +#include "ircd_alloc.h" +#include "ircd_defs.h" +#include "ircd_features.h" +#include "ircd_log.h" +#include "ircd_reply.h" +#include "ircd_snprintf.h" +#include "numeric.h" +#include "send.h" +#include "s_debug.h" +#include "s_stats.h" + +/* #include -- Now using assert in ircd_log.h */ +#include +#include +#include +#include /* struct iovec */ + +#define MB_BASE_SHIFT 5 /**< Log2 of smallest message body to allocate. */ +#define MB_MAX_SHIFT 9 /**< Log2 of largest message body to allocate. */ + +/** Buffer for a single message. */ +struct MsgBuf { + struct MsgBuf *next; /**< next msg in global queue */ + struct MsgBuf **prev_p; /**< what points to us in linked list */ + struct MsgBuf *real; /**< the actual MsgBuf we're attaching */ + unsigned int ref; /**< reference count */ + unsigned int length; /**< length of message */ + unsigned int power; /**< size of buffer (power of 2) */ + char msg[1]; /**< the message */ +}; + +/** Return allocated length of the buffer of \a buf. */ +#define bufsize(buf) (1 << (buf)->power) + +/** Message body for a particular destination. */ +struct Msg { + struct Msg *next; /**< next msg */ + unsigned int sent; /**< bytes in msg that have already been sent */ + struct MsgBuf *msg; /**< actual message in queue */ +}; + +/** Statistics tracking for message sizes. */ +struct MsgSizes { + unsigned int msgs; /**< total number of messages */ + unsigned int sizes[BUFSIZE]; /**< histogram of message sizes */ +}; + +/** Global tracking data for message buffers. */ +static struct { + struct MsgBuf *msglist; /**< list of in-use MsgBuf's */ + struct { + unsigned int alloc; /**< number of Msg's allocated */ + unsigned int used; /**< number of Msg's in use */ + struct Msg *free; /**< freelist of Msg's */ + } msgs; /**< tracking info for Msg structs */ + size_t tot_bufsize; /**< total amount of memory in buffers */ + /** Array of MsgBuf information, one entry for each used bucket size. */ + struct { + unsigned int alloc; /**< total MsgBuf's of this size */ + unsigned int used; /**< number of MsgBuf's of this size in use */ + struct MsgBuf *free; /**< list of free MsgBuf's */ + } msgBufs[MB_MAX_SHIFT - MB_BASE_SHIFT + 1]; + struct MsgSizes sizes; /**< histogram of message sizes */ +} MQData; + +/* + * This routine is used to remove a certain amount of data from a given + * queue and release the Msg (and MsgBuf) structure if needed + */ +/** Remove some data from a list within a message queue. + * @param[in,out] mq Message queue to remove from. + * @param[in,out] qlist Particular list within queue to remove from. + * @param[in,out] length_p Number of bytes left to remove. + */ +static void +msgq_delmsg(struct MsgQ *mq, struct MsgQList *qlist, unsigned int *length_p) +{ + struct Msg *m; + unsigned int msglen; + + assert(0 != mq); + assert(0 != qlist); + assert(0 != qlist->head); + assert(0 != length_p); + + m = qlist->head; /* find the msg we're deleting from */ + + msglen = m->msg->length - m->sent; /* calculate how much is left */ + + if (*length_p >= msglen) { /* deleted it all? */ + mq->length -= msglen; /* decrement length */ + mq->count--; /* decrement the message count */ + *length_p -= msglen; + + msgq_clean(m->msg); /* free up the struct MsgBuf */ + m->msg = 0; /* don't let it point anywhere nasty, please */ + + if (qlist->head == qlist->tail) /* figure out if we emptied the queue */ + qlist->head = qlist->tail = 0; + else + qlist->head = m->next; /* just shift the list down some */ + + MQData.msgs.used--; /* struct Msg is not in use anymore */ + + m->next = MQData.msgs.free; /* throw it onto the free list */ + MQData.msgs.free = m; + } else { + mq->length -= *length_p; /* decrement queue length */ + m->sent += *length_p; /* this much of the message has been sent */ + *length_p = 0; /* we've dealt with it all */ + } +} + +/** Initialize \a mq. + * @param[in] mq MsgQ to initialize. + */ +void +msgq_init(struct MsgQ *mq) +{ + assert(0 != mq); + + mq->length = 0; + mq->count = 0; + mq->queue.head = 0; + mq->queue.tail = 0; + mq->prio.head = 0; + mq->prio.tail = 0; +} + +/** Delete bytes from the front of a message queue. + * @param[in] mq Queue to drop data from. + * @param[in] length Number of bytes to drop. + */ +void +msgq_delete(struct MsgQ *mq, unsigned int length) +{ + assert(0 != mq); + + while (length > 0) { + if (mq->queue.head && mq->queue.head->sent > 0) /* partial msg on norm q */ + msgq_delmsg(mq, &mq->queue, &length); + else if (mq->prio.head) /* message (partial or complete) on prio queue */ + msgq_delmsg(mq, &mq->prio, &length); + else if (mq->queue.head) /* message on normal queue */ + msgq_delmsg(mq, &mq->queue, &length); + else + break; + } +} + +/** Map data from a message queue to an I/O vector. + * @param[in] mq Message queue to send from. + * @param[out] iov Output vector. + * @param[in] count Number of elements in \a iov. + * @param[out] len Number of bytes mapped from \a mq to \a iov. + * @return Number of elements filled in \a iov. + */ +int +msgq_mapiov(const struct MsgQ *mq, struct iovec *iov, int count, + unsigned int *len) +{ + struct Msg *queue; + struct Msg *prio; + int i = 0; + + assert(0 != mq); + assert(0 != iov); + assert(0 != count); + assert(0 != len); + + if (mq->length <= 0) /* no data to map */ + return 0; + + if (mq->queue.head && mq->queue.head->sent > 0) { /* partial msg on norm q */ + iov[i].iov_base = mq->queue.head->msg->msg + mq->queue.head->sent; + iov[i].iov_len = mq->queue.head->msg->length - mq->queue.head->sent; + *len += iov[i].iov_len; + + queue = mq->queue.head->next; /* where we start later... */ + + i++; /* filled an iovec... */ + if (!--count) /* check for space */ + return i; + } else + queue = mq->queue.head; /* start at head of queue */ + + if (mq->prio.head && mq->prio.head->sent > 0) { /* partial msg on prio q */ + iov[i].iov_base = mq->prio.head->msg->msg + mq->prio.head->sent; + iov[i].iov_len = mq->prio.head->msg->length - mq->prio.head->sent; + *len += iov[i].iov_len; + + prio = mq->prio.head->next; /* where we start later... */ + + i++; /* filled an iovec... */ + if (!--count) /* check for space */ + return i; + } else + prio = mq->prio.head; /* start at head of prio */ + + for (; prio; prio = prio->next) { /* go through prio queue */ + iov[i].iov_base = prio->msg->msg; /* store message */ + iov[i].iov_len = prio->msg->length; + *len += iov[i].iov_len; + + i++; /* filled an iovec... */ + if (!--count) /* check for space */ + return i; + } + + for (; queue; queue = queue->next) { /* go through normal queue */ + iov[i].iov_base = queue->msg->msg; + iov[i].iov_len = queue->msg->length; + *len += iov[i].iov_len; + + i++; /* filled an iovec... */ + if (!--count) /* check for space */ + return i; + } + + return i; +} + +/** Allocate a message buffer large enough to hold \a length bytes. + * TODO: \a in_mb needs better documentation. + * @param[in] in_mb Some other message buffer(?). + * @param[in] length Number of bytes of space to reserve in output. + * @return Pointer to some usable message buffer. + */ +static struct MsgBuf * +msgq_alloc(struct MsgBuf *in_mb, int length) +{ + struct MsgBuf *mb; + int power; + + /* Find the power of two size that will accommodate the message */ + for (power = MB_BASE_SHIFT; power < MB_MAX_SHIFT + 1; power++) + if ((length - 1) >> power == 0) + break; + assert((1 << power) >= length); + assert((1 << power) <= 512); + length = 1 << power; /* reset the length */ + + /* If the message needs a buffer of exactly the existing size, just use it */ + if (in_mb && in_mb->power == power) { + in_mb->real = in_mb; /* real buffer is this buffer */ + return in_mb; + } + + /* Try popping one off the freelist first */ + if ((mb = MQData.msgBufs[power - MB_BASE_SHIFT].free)) { + MQData.msgBufs[power - MB_BASE_SHIFT].free = mb->next; + } else if (MQData.tot_bufsize < feature_int(FEAT_BUFFERPOOL)) { + /* Allocate another if we won't bust the BUFFERPOOL */ + Debug((DEBUG_MALLOC, "Allocating MsgBuf of length %d (total size %zu)", + length, sizeof(struct MsgBuf) + length)); + mb = (struct MsgBuf *)MyMalloc(sizeof(struct MsgBuf) + length); + MQData.msgBufs[power - MB_BASE_SHIFT].alloc++; + mb->power = power; /* remember size */ + MQData.tot_bufsize += length; + } + + if (mb) { + MQData.msgBufs[power - MB_BASE_SHIFT].used++; /* how many are we using? */ + + mb->real = 0; /* essential initializations */ + mb->ref = 1; + + if (in_mb) /* remember who's the *real* buffer */ + in_mb->real = mb; + } else if (in_mb) /* just use the input buffer */ + mb = in_mb->real = in_mb; + + return mb; /* return the buffer */ +} + +/** Deallocate unused message buffers. + */ +static void +msgq_clear_freembs(void) +{ + struct MsgBuf *mb; + int i; + + /* Walk through the various size classes */ + for (i = MB_BASE_SHIFT; i < MB_MAX_SHIFT + 1; i++) + /* walk down the free list */ + while ((mb = MQData.msgBufs[i - MB_BASE_SHIFT].free)) { + MQData.msgBufs[i - MB_BASE_SHIFT].free = mb->next; /* shift free list */ + MQData.msgBufs[i - MB_BASE_SHIFT].alloc--; /* reduce allocation count */ + MQData.tot_bufsize -= 1 << i; /* reduce total buffer allocation count */ + MyFree(mb); /* and free the buffer */ + } +} + +/** Format a message buffer for a client from a format string. + * @param[in] dest %Client that receives the data (may be NULL). + * @param[in] format Format string for message. + * @param[in] vl Argument list for \a format. + * @return Allocated MsgBuf. + */ +struct MsgBuf * +msgq_vmake(struct Client *dest, const char *format, va_list vl) +{ + struct MsgBuf *mb; + + assert(0 != format); + + if (!(mb = msgq_alloc(0, BUFSIZE))) { + if (feature_bool(FEAT_HAS_FERGUSON_FLUSHER)) { + /* + * from "Married With Children" episode were Al bought a REAL toilet + * on the black market because he was tired of the wimpy water + * conserving toilets they make these days --Bleep + */ + /* + * Apparently this doesn't work, the server _has_ to + * dump a few clients to handle the load. A fully loaded + * server cannot handle a net break without dumping some + * clients. If we flush the connections here under a full + * load we may end up starving the kernel for mbufs and + * crash the machine + */ + /* + * attempt to recover from buffer starvation before + * bailing this may help servers running out of memory + */ + flush_connections(0); + mb = msgq_alloc(0, BUFSIZE); + } + if (!mb) { /* OK, try clearing the buffer free list */ + msgq_clear_freembs(); + mb = msgq_alloc(0, BUFSIZE); + } + if (!mb) { /* OK, try killing a client */ + kill_highest_sendq(0); /* Don't kill any server connections */ + msgq_clear_freembs(); /* Release whatever was just freelisted */ + mb = msgq_alloc(0, BUFSIZE); + } + if (!mb) { /* hmmm... */ + kill_highest_sendq(1); /* Try killing a server connection now */ + msgq_clear_freembs(); /* Clear freelist again */ + mb = msgq_alloc(0, BUFSIZE); + } + if (!mb) /* AIEEEE! */ + server_panic("Unable to allocate buffers!"); + } + + mb->next = MQData.msglist; /* initialize the msgbuf */ + mb->prev_p = &MQData.msglist; + + /* fill the buffer */ + mb->length = ircd_vsnprintf(dest, mb->msg, bufsize(mb) - 1, format, vl); + + if (mb->length > bufsize(mb) - 2) + mb->length = bufsize(mb) - 2; + + mb->msg[mb->length++] = '\r'; /* add \r\n to buffer */ + mb->msg[mb->length++] = '\n'; + mb->msg[mb->length] = '\0'; /* not strictly necessary */ + + assert(mb->length <= bufsize(mb)); + + if (MQData.msglist) /* link it into the list */ + MQData.msglist->prev_p = &mb->next; + MQData.msglist = mb; + + return mb; +} + +/** Format a message buffer for a client from a format string. + * @param[in] dest %Client that receives the data (may be NULL). + * @param[in] format Format string for message. + * @return Allocated MsgBuf. + */ +struct MsgBuf * +msgq_make(struct Client *dest, const char *format, ...) +{ + va_list vl; + struct MsgBuf *mb; + + va_start(vl, format); + mb = msgq_vmake(dest, format, vl); + va_end(vl); + + return mb; +} + +/** Append text to an existing message buffer. + * @param[in] dest %Client for whom to format the message. + * @param[in] mb Message buffer to append to. + * @param[in] format Format string of what to append. + */ +void +msgq_append(struct Client *dest, struct MsgBuf *mb, const char *format, ...) +{ + va_list vl; + + assert(0 != mb); + assert(0 != format); + assert(0 == mb->real); + + assert(2 < mb->length); + assert(bufsize(mb) >= mb->length); + + mb->length -= 2; /* back up to before \r\n */ + + va_start(vl, format); /* append to the buffer */ + mb->length += ircd_vsnprintf(dest, mb->msg + mb->length, + bufsize(mb) - mb->length - 1, format, vl); + va_end(vl); + + if (mb->length > bufsize(mb) - 2) + mb->length = bufsize(mb) - 2; + + mb->msg[mb->length++] = '\r'; /* add \r\n to buffer */ + mb->msg[mb->length++] = '\n'; + mb->msg[mb->length] = '\0'; /* not strictly necessary */ + + assert(mb->length <= bufsize(mb)); +} + +/** Decrement the reference count on \a mb, freeing it if needed. + * @param[in] mb MsgBuf to release. + */ +void +msgq_clean(struct MsgBuf *mb) +{ + assert(0 != mb); + assert(0 < mb->ref); + + if (!--mb->ref) { /* deallocate the message */ + if (mb->prev_p) { + *mb->prev_p = mb->next; /* clip it out of active MsgBuf's list */ + if (mb->next) + mb->next->prev_p = mb->prev_p; + } + + if (mb->real && mb->real != mb) /* clean up the real buffer */ + msgq_clean(mb->real); + + mb->next = MQData.msgBufs[mb->power - MB_BASE_SHIFT].free; + MQData.msgBufs[mb->power - MB_BASE_SHIFT].free = mb; + MQData.msgBufs[mb->power - MB_BASE_SHIFT].used--; + + mb->prev_p = 0; + } +} + +/** Append a message to a peer's message queue. + * @param[in] mq Message queue to append to. + * @param[in] mb Message to append. + * @param[in] prio If non-zero, use the high-priority (lag-busting) message list; else use the normal list. + */ +void +msgq_add(struct MsgQ *mq, struct MsgBuf *mb, int prio) +{ + struct MsgQList *qlist; + struct Msg *msg; + + assert(0 != mq); + assert(0 != mb); + assert(0 < mb->ref); + assert(0 < mb->length); + + Debug((DEBUG_SEND, "Adding buffer %p [%.*s] length %u to %s queue", mb, + mb->length - 2, mb->msg, mb->length, prio ? "priority" : "normal")); + + qlist = prio ? &mq->prio : &mq->queue; + + if (!(msg = MQData.msgs.free)) { /* do I need to allocate one? */ + msg = (struct Msg *)MyMalloc(sizeof(struct Msg)); + MQData.msgs.alloc++; /* we allocated another */ + } else /* shift the free list */ + MQData.msgs.free = MQData.msgs.free->next; + + MQData.msgs.used++; /* we're using another */ + + msg->next = 0; /* initialize the msg */ + msg->sent = 0; + + /* Get the real buffer, allocating one if necessary */ + if (!mb->real) { + struct MsgBuf *tmp; + + MQData.sizes.msgs++; /* update histogram counts */ + MQData.sizes.sizes[mb->length - 1]++; + + tmp = msgq_alloc(mb, mb->length); /* allocate a close-fitting buffer */ + + if (tmp != mb) { /* OK, prepare the new "real" buffer */ + Debug((DEBUG_SEND, "Copying old buffer %p [%.*s] length %u into new " + "buffer %p size %u", mb, mb->length - 2, mb->msg, mb->length, + tmp, bufsize(tmp))); + memcpy(tmp->msg, mb->msg, mb->length + 1); /* copy string over */ + tmp->length = mb->length; + + tmp->next = mb->next; /* replace it in the list, now */ + if (tmp->next) + tmp->next->prev_p = &tmp->next; + tmp->prev_p = mb->prev_p; + *tmp->prev_p = tmp; + + mb->next = 0; /* this one's no longer in the list */ + mb->prev_p = 0; + } + } + + mb = mb->real; /* work with the real buffer */ + mb->ref++; /* increment the ref count on the buffer */ + + msg->msg = mb; /* point at the real message buffer now */ + + if (!qlist->head) /* queue list was empty; head and tail point to msg */ + qlist->head = qlist->tail = msg; + else { + assert(0 != qlist->tail); + + qlist->tail->next = msg; /* queue had something in it; add to end */ + qlist->tail = msg; + } + + mq->length += mb->length; /* update the queue length */ + mq->count++; /* and the queue count */ +} + +/** Report memory statistics for message buffers. + * @param[in] cptr Client requesting information. + * @param[out] msg_alloc Receives number of bytes allocated in Msg structs. + * @param[out] msgbuf_alloc Receives number of bytes allocated in MsgBuf structs. + */ +void +msgq_count_memory(struct Client *cptr, size_t *msg_alloc, size_t *msgbuf_alloc) +{ + int i; + size_t total = 0, size; + + assert(0 != cptr); + assert(0 != msg_alloc); + assert(0 != msgbuf_alloc); + + /* Data for Msg's is simple, so just send it */ + send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, + ":Msgs allocated %d(%zu) used %d(%zu) text %zu", + MQData.msgs.alloc, MQData.msgs.alloc * sizeof(struct Msg), + MQData.msgs.used, MQData.msgs.used * sizeof(struct Msg), + MQData.tot_bufsize); + /* count_memory() wants to know the total */ + *msg_alloc = MQData.msgs.alloc * sizeof(struct Msg); + + /* Ok, now walk through each size class */ + for (i = MB_BASE_SHIFT; i < MB_MAX_SHIFT + 1; i++) { + size = sizeof(struct MsgBuf) + (1 << i); /* total size of a buffer */ + + /* Send information for this buffer size class */ + send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, + ":MsgBufs of size %zu allocated %d(%zu) used %d(%zu)", 1 << i, + MQData.msgBufs[i - MB_BASE_SHIFT].alloc, + MQData.msgBufs[i - MB_BASE_SHIFT].alloc * size, + MQData.msgBufs[i - MB_BASE_SHIFT].used, + MQData.msgBufs[i - MB_BASE_SHIFT].used * size); + + /* count_memory() wants to know the total */ + total += MQData.msgBufs[i - MB_BASE_SHIFT].alloc * size; + } + *msgbuf_alloc = total; +} + +/** Report remaining space in a MsgBuf. + * @param[in] mb Message buffer to check. + * @return Number of additional bytes that can be appended to the message. + */ +unsigned int +msgq_bufleft(struct MsgBuf *mb) +{ + assert(0 != mb); + + return bufsize(mb) - mb->length; /* \r\n counted in mb->length */ +} + +/** Send histogram of message lengths to a client. + * @param[in] cptr Client requesting statistics. + * @param[in] sd Stats descriptor for request (ignored). + * @param[in] param Extra parameter from user (ignored). + */ +void +msgq_histogram(struct Client *cptr, const struct StatDesc *sd, char *param) +{ + struct MsgSizes tmp = MQData.sizes; /* All hail structure copy! */ + int i; + + send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, + ":Histogram of message lengths (%lu messages)", tmp.msgs); + for (i = 0; i + 16 <= BUFSIZE; i += 16) + send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, ":% 4d: %u %u %u %u " + "%u %u %u %u %u %u %u %u %u %u %u %u", i + 1, + tmp.sizes[i + 0], tmp.sizes[i + 1], tmp.sizes[i + 2], + tmp.sizes[i + 3], tmp.sizes[i + 4], tmp.sizes[i + 5], + tmp.sizes[i + 6], tmp.sizes[i + 7], tmp.sizes[i + 8], + tmp.sizes[i + 9], tmp.sizes[i + 10], tmp.sizes[i + 11], + tmp.sizes[i + 12], tmp.sizes[i + 13], tmp.sizes[i + 14], + tmp.sizes[i + 15]); +}