/*--- This software is copyrighted by the Regents of the University of California, and other parties. The following terms apply to all files associated with the software unless explicitly disclaimed in individual files. The authors hereby grant permission to use, copy, modify, distribute, and license this software and its documentation for any purpose, provided that existing copyright notices are retained in all copies and that this notice is included verbatim in any distributions. No written agreement, license, or royalty fee is required for any of the authorized uses. Modifications to this software may be copyrighted by their authors and need not follow the licensing terms described here, provided that the new terms are clearly indicated on the first page of each file where they apply. IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. GOVERNMENT USE: If you are acquiring this software on behalf of the U.S. government, the Government shall have only "Restricted Rights" in the software and related documentation as defined in the Federal Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2). If you are acquiring the software on behalf of the Department of Defense, the software shall be classified as "Commercial Computer Software" and the Government shall have only "Restricted Rights" as defined in Clause 252.227-7013 (c) (1) of DFARs. Notwithstanding the foregoing, the authors grant the U.S. Government and others acting in its behalf permission to use and distribute the software in accordance with the terms specified in this license. ---*/ /******************************* * $Id$ * * implementation of the page buffer * *************************************************/ #include #include #include #include #include #include "blobManager.h" #include #include "page.h" #include "pageFile.h" /** Invariant: This lock should be held while updating lastFreepage, or while performing any operation that may decrease the amount of freespace in the page that lastFreepage refers to. Since pageCompact and pageDeRalloc may only increase this value, they do not need to hold this lock. Since bufferManager is the only place where pageRalloc is called, pageRalloc does not obtain this lock. */ static pthread_mutex_t lastFreepage_mutex; static unsigned int lastFreepage = 0; /** * @param pageid ID of the page you want to load * @return fully formed Page type * @return page with -1 ID if page not found */ Page * loadPage(int pageid); int bufInit() { /* stable = NULL; */ pageInit(); openPageFile(); pageCacheInit(); openBlobStore(); lastFreepage = 0; pthread_mutex_init(&lastFreepage_mutex , NULL); return 0; } void bufDeinit() { closeBlobStore(); pageCacheDeinit(); closePageFile(); return; } /** Just close file descriptors, don't do any other clean up. (For testing.) */ void simulateBufferManagerCrash() { closeBlobStore(); closePageFile(); } /* ** No file I/O below this line. ** */ Page * loadPage (int pageid) { Page * p = loadPagePtr(pageid); assert (p->id == pageid); return p; } Page * lastRallocPage = 0; recordid ralloc(int xid, /*lsn_t lsn,*/ long size) { recordid ret; Page * p; DEBUG("Rallocing record of size %ld\n", (long int)size); assert(size < BLOB_THRESHOLD_SIZE || size == BLOB_SLOT); pthread_mutex_lock(&lastFreepage_mutex); while(freespace(p = loadPage(lastFreepage)) < size ) { unlock(p->loadlatch); lastFreepage++; } ret = pageRalloc(p, size); unlock(p->loadlatch); pthread_mutex_unlock(&lastFreepage_mutex); DEBUG("alloced rid = {%d, %d, %ld}\n", ret.page, ret.slot, ret.size); return ret; } void slotRalloc(int pageid, lsn_t lsn, recordid rid) { Page * loadedPage = loadPage(rid.page); pageSlotRalloc(loadedPage, lsn, rid); unlock(loadedPage->loadlatch); } long readLSN(int pageid) { Page *p; lsn_t lsn = pageReadLSN(p = loadPage(pageid)); unlock(p->loadlatch); return lsn; } void writeRecord(int xid, lsn_t lsn, recordid rid, const void *dat) { Page *p; if(rid.size > BLOB_THRESHOLD_SIZE) { /* DEBUG("Writing blob.\n"); */ writeBlob(xid, lsn, rid, dat); } else { /* DEBUG("Writing record.\n"); */ p = loadPage(rid.page); /* loadPagePtr(rid.page); */ assert( (p->id == rid.page) && (p->memAddr != NULL) ); /** @todo This assert should be here, but the tests are broken, so it causes bogus failures. */ /*assert(pageReadLSN(*p) <= lsn);*/ pageWriteRecord(xid, p, rid, lsn, dat); unlock(p->loadlatch); } } void readRecord(int xid, recordid rid, void *buf) { if(rid.size > BLOB_THRESHOLD_SIZE) { /* DEBUG("Reading blob. xid = %d rid = { %d %d %ld } buf = %x\n", xid, rid.page, rid.slot, rid.size, (unsigned int)buf); */ readBlob(xid, rid, buf); } else { Page * p = loadPage(rid.page); assert(rid.page == p->id); /* DEBUG("Reading record xid = %d rid = { %d %d %ld } buf = %x\n", xid, rid.page, rid.slot, rid.size, (unsigned int)buf); */ pageReadRecord(xid, p, rid, buf); assert(rid.page == p->id); unlock(p->loadlatch); } } int bufTransCommit(int xid, lsn_t lsn) { commitBlobs(xid); pageCommit(xid); return 0; } int bufTransAbort(int xid, lsn_t lsn) { abortBlobs(xid); /* abortBlobs doesn't write any log entries, so it doesn't need the lsn. */ pageAbort(xid); return 0; } void setSlotType(int pageid, int slot, int type) { Page * p = loadPage(pageid); pageSetSlotType(p, slot, type); unlock(p->loadlatch); } /** Inform bufferManager that a new event (such as an update) will be performed on page pageid. This function may not be called on a page after finalize() has been called on that page, and each call to this function must be followed by a corresponding call to removePendingEvent. This function is called by the logger when CLR or UPDATE records are written. @see finalize, removePendingEvent */ void addPendingEvent(int pageid){ Page * p = loadPage(pageid); pthread_mutex_lock(&(p->pending_mutex)); assert(!(p->waiting)); p->pending++; pthread_mutex_unlock(&(p->pending_mutex)); unlock(p->loadlatch); } /** Because updates to a page might not happen in order, we need to make sure that we've applied all updates to a page that we've heard about before we flush that page to disk. This method informs bufferManager that an update has been applied. It is called by operations.c every time doUpdate, redoUpdate, or undoUpdate is called. @todo as implemented, loadPage() ... doOperation is not atomic! */ void removePendingEvent(int pageid) { Page * p = loadPage(pageid); pthread_mutex_lock(&(p->pending_mutex)); p->pending--; assert(p->pending >= 0); if(p->waiting && !p->pending) { assert(p->waiting == 1); pthread_cond_signal(&(p->noMorePending)); } pthread_mutex_unlock(&(p->pending_mutex)); unlock(p->loadlatch); }