diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/main.c | 10 | ||||
| -rw-r--r-- | src/sqlite.h.in | 7 | ||||
| -rw-r--r-- | src/test_malloc.c | 41 | ||||
| -rw-r--r-- | src/test_pcache.c | 438 |
4 files changed, 490 insertions, 6 deletions
diff --git a/src/main.c b/src/main.c index 3662697fe..16f89b785 100644 --- a/src/main.c +++ b/src/main.c @@ -14,7 +14,7 @@ ** other files are for internal use by SQLite and should not be ** accessed by users of the library. ** -** $Id: main.c,v 1.512 2008/11/13 14:28:29 danielk1977 Exp $ +** $Id: main.c,v 1.513 2008/11/19 01:20:26 drh Exp $ */ #include "sqliteInt.h" #include <ctype.h> @@ -315,6 +315,14 @@ int sqlite3_config(int op, ...){ break; } + case SQLITE_CONFIG_GETPCACHE: { + if( sqlite3GlobalConfig.pcache.xInit==0 ){ + sqlite3PCacheSetDefault(); + } + *va_arg(ap, sqlite3_pcache_methods*) = sqlite3GlobalConfig.pcache; + break; + } + #if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5) case SQLITE_CONFIG_HEAP: { /* Designate a buffer for heap memory space */ diff --git a/src/sqlite.h.in b/src/sqlite.h.in index 39070f737..8f1c73459 100644 --- a/src/sqlite.h.in +++ b/src/sqlite.h.in @@ -30,7 +30,7 @@ ** the version number) and changes its name to "sqlite3.h" as ** part of the build process. ** -** @(#) $Id: sqlite.h.in,v 1.414 2008/11/18 19:18:09 drh Exp $ +** @(#) $Id: sqlite.h.in,v 1.415 2008/11/19 01:20:26 drh Exp $ */ #ifndef _SQLITE3_H_ #define _SQLITE3_H_ @@ -6683,8 +6683,9 @@ typedef struct sqlite3_pcache sqlite3_pcache; ** ** The xRekey() method is used to change the key value associated with the ** page passed as the second argument from oldKey to newKey. If the cache -** contains an entry associated with oldKey, it should be discarded. Any -** cache entry associated with oldKey is guaranteed not to be pinned. +** previously contains an entry associated with newKey, it should be +** discarded. Any prior cache entry associated with newKey is guaranteed not +** to be pinned. ** ** When SQLite calls the xTruncate() method, the cache must discard all ** existing cache entries with page numbers (keys) greater than or equal diff --git a/src/test_malloc.c b/src/test_malloc.c index bcf18d2a0..2009f5428 100644 --- a/src/test_malloc.c +++ b/src/test_malloc.c @@ -13,7 +13,7 @@ ** This file contains code used to implement test interfaces to the ** memory allocation subsystem. ** -** $Id: test_malloc.c,v 1.50 2008/11/10 18:05:36 shane Exp $ +** $Id: test_malloc.c,v 1.51 2008/11/19 01:20:26 drh Exp $ */ #include "sqliteInt.h" #include "tcl.h" @@ -946,6 +946,42 @@ static int test_config_pagecache( } /* +** Usage: sqlite3_config_alt_pcache INSTALL_FLAG DISCARD_CHANCE PRNG_SEED +** +** Set up the alternative test page cache. Install if INSTALL_FLAG is +** true and uninstall (reverting to the default page cache) if INSTALL_FLAG +** is false. DISCARD_CHANGE is an integer between 0 and 100 inclusive +** which determines the chance of discarding a page when unpinned. 100 +** is certainty. 0 is never. PRNG_SEED is the pseudo-random number generator +** seed. +*/ +static int test_alt_pcache( + void * clientData, + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[] +){ + int installFlag; + int discardChance; + int prngSeed; + extern void installTestPCache(int,unsigned,unsigned); + if( objc!=4 ){ + Tcl_WrongNumArgs(interp, 1, objv, "INSTALLFLAG DISCARDCHANCE PRNGSEEED"); + return TCL_ERROR; + } + if( Tcl_GetIntFromObj(interp, objv[1], &installFlag) ) return TCL_ERROR; + if( Tcl_GetIntFromObj(interp, objv[2], &discardChance) ) return TCL_ERROR; + if( Tcl_GetIntFromObj(interp, objv[3], &prngSeed) ) return TCL_ERROR; + if( discardChance<0 || discardChance>100 ){ + Tcl_AppendResult(interp, "discard-chance should be between 0 and 100", + (char*)0); + return TCL_ERROR; + } + installTestPCache(installFlag, (unsigned)discardChance, (unsigned)prngSeed); + return TCL_OK; +} + +/* ** Usage: sqlite3_config_memstatus BOOLEAN ** ** Enable or disable memory status reporting using SQLITE_CONFIG_MEMSTATUS. @@ -1312,6 +1348,7 @@ int Sqlitetest_malloc_Init(Tcl_Interp *interp){ { "sqlite3_memdebug_log", test_memdebug_log ,0 }, { "sqlite3_config_scratch", test_config_scratch ,0 }, { "sqlite3_config_pagecache", test_config_pagecache ,0 }, + { "sqlite3_config_alt_pcache", test_alt_pcache ,0 }, { "sqlite3_status", test_status ,0 }, { "sqlite3_db_status", test_db_status ,0 }, { "install_malloc_faultsim", test_install_malloc_faultsim ,0 }, @@ -1321,7 +1358,7 @@ int Sqlitetest_malloc_Init(Tcl_Interp *interp){ { "sqlite3_config_error", test_config_error ,0 }, { "sqlite3_db_config_lookaside",test_db_config_lookaside ,0 }, { "sqlite3_dump_memsys3", test_dump_memsys3 ,3 }, - { "sqlite3_dump_memsys5", test_dump_memsys3 ,5 } + { "sqlite3_dump_memsys5", test_dump_memsys3 ,5 }, }; int i; for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){ diff --git a/src/test_pcache.c b/src/test_pcache.c new file mode 100644 index 000000000..58f5b3981 --- /dev/null +++ b/src/test_pcache.c @@ -0,0 +1,438 @@ +/* +** 2008 November 18 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** +** This file contains code used for testing the SQLite system. +** None of the code in this file goes into a deliverable build. +** +** This file contains an application-defined pager cache +** implementation that can be plugged in in place of the +** default pcache. This alternative pager cache will throw +** some errors that the default cache does not. +** +** This pagecache implementation is designed for simplicity +** not speed. +** +** $Id: test_pcache.c,v 1.1 2008/11/19 01:20:26 drh Exp $ +*/ +#include "sqlite3.h" +#include <string.h> +#include <assert.h> + +/* +** Global data used by this test implementation. There is no +** mutexing, which means this page cache will not work in a +** multi-threaded test. +*/ +typedef struct testpcacheGlobalType testpcacheGlobalType; +struct testpcacheGlobalType { + void *pDummy; /* Dummy allocation to simulate failures */ + int nInstance; /* Number of current instances */ + unsigned discardChance; /* Chance of discarding on an unpin */ + unsigned prngSeed; /* Seed for the PRNG */ +}; +static testpcacheGlobalType testpcacheGlobal; + +/* +** Initializer. +** +** Verify that the initializer is only called when the system is +** uninitialized. Allocate some memory and report SQLITE_NOMEM if +** the allocation fails. This provides a means to test the recovery +** from a failed initialization attempt. It also verifies that the +** the destructor always gets call - otherwise there would be a +** memory leak. +*/ +static int testpcacheInit(void *pArg){ + assert( pArg==(void*)&testpcacheGlobal ); + assert( testpcacheGlobal.pDummy==0 ); + assert( testpcacheGlobal.nInstance==0 ); + testpcacheGlobal.pDummy = sqlite3_malloc(10); + return testpcacheGlobal.pDummy==0 ? SQLITE_NOMEM : SQLITE_OK; +} + +/* +** Destructor +** +** Verify that this is only called after initialization. +** Free the memory allocated by the initializer. +*/ +static void testpcacheShutdown(void *pArg){ + assert( pArg==(void*)&testpcacheGlobal ); + assert( testpcacheGlobal.pDummy!=0 ); + assert( testpcacheGlobal.nInstance==0 ); + sqlite3_free( testpcacheGlobal.pDummy ); + testpcacheGlobal.pDummy = 0; +} + +/* +** Number of pages in a cache +*/ +#define TESTPCACHE_NPAGE 217 +#define TESTPCACHE_RESERVE 17 + +/* +** Magic numbers used to determine validity of the page cache. +*/ +#define TESTPCACHE_VALID 0x364585fd +#define TESTPCACHE_CLEAR 0xd42670d4 + +/* +** Private implementation of a page cache. +*/ +typedef struct testpcache testpcache; +struct testpcache { + int szPage; /* Size of each page. Multiple of 8. */ + int bPurgeable; /* True if the page cache is purgeable */ + int nFree; /* Number of unused slots in a[] */ + int nPinned; /* Number of pinned slots in a[] */ + unsigned iRand; /* State of the PRNG */ + unsigned iMagic; /* Magic number for sanity checking */ + struct testpcachePage { + unsigned key; /* The key for this page. 0 means unallocated */ + int isPinned; /* True if the page is pinned */ + void *pData; /* Data for this page */ + } a[TESTPCACHE_NPAGE]; /* All pages in the cache */ +}; + +/* +** Get a random number using the PRNG in the given page cache. +*/ +static unsigned testpcacheRandom(testpcache *p){ + unsigned x = 0; + int i; + for(i=0; i<4; i++){ + p->iRand = (p->iRand*69069 + 5); + x = (x<<8) | ((p->iRand>>16)&0xff); + } + return x; +} + + +/* +** Allocate a new page cache instance. +*/ +static sqlite3_pcache *testpcacheCreate(int szPage, int bPurgeable){ + int nMem; + char *x; + testpcache *p; + int i; + assert( testpcacheGlobal.pDummy!=0 ); + szPage = (szPage+7)&~7; + nMem = sizeof(testpcache) + TESTPCACHE_NPAGE*szPage; + p = sqlite3_malloc( nMem ); + if( p==0 ) return 0; + x = (char*)&p[1]; + p->szPage = szPage; + p->nFree = TESTPCACHE_NPAGE; + p->nPinned = 0; + p->iRand = testpcacheGlobal.prngSeed; + p->bPurgeable = bPurgeable; + p->iMagic = TESTPCACHE_VALID; + for(i=0; i<TESTPCACHE_NPAGE; i++, x += szPage){ + p->a[i].key = 0; + p->a[i].isPinned = 0; + p->a[i].pData = (void*)x; + } + testpcacheGlobal.nInstance++; + return (sqlite3_pcache*)p; +} + +/* +** Set the cache size +*/ +static void testpcacheCachesize(sqlite3_pcache *pCache, int newSize){ + testpcache *p = (testpcache*)pCache; + assert( p->iMagic==TESTPCACHE_VALID ); + assert( newSize>=1 ); + assert( testpcacheGlobal.pDummy!=0 ); + assert( testpcacheGlobal.nInstance>0 ); +} + +/* +** Return the number of pages in the cache that are being used. +** This includes both pinned and unpinned pages. +*/ +static int testpcachePagecount(sqlite3_pcache *pCache){ + testpcache *p = (testpcache*)pCache; + assert( p->iMagic==TESTPCACHE_VALID ); + assert( testpcacheGlobal.pDummy!=0 ); + assert( testpcacheGlobal.nInstance>0 ); + return TESTPCACHE_NPAGE - p->nFree; +} + +/* +** Fetch a page. +*/ +static void *testpcacheFetch( + sqlite3_pcache *pCache, + unsigned key, + int createFlag +){ + testpcache *p = (testpcache*)pCache; + int i, j; + assert( p->iMagic==TESTPCACHE_VALID ); + assert( testpcacheGlobal.pDummy!=0 ); + assert( testpcacheGlobal.nInstance>0 ); + + /* See if the page is already in cache. Return immediately if it is */ + for(i=0; i<TESTPCACHE_NPAGE; i++){ + if( p->a[i].key==key ){ + if( !p->a[i].isPinned ){ + p->nPinned++; + assert( p->nPinned <= TESTPCACHE_NPAGE - p->nFree ); + p->a[i].isPinned = 1; + } + return p->a[i].pData; + } + } + + /* If createFlag is 0, never allocate a new page */ + if( createFlag==0 ){ + return 0; + } + + /* If no pages are available, always fail */ + if( p->nPinned==TESTPCACHE_NPAGE ){ + return 0; + } + + /* Do not allocate the last TESTPCACHE_RESERVE pages unless createFlag is 2 */ + if( p->nPinned>=TESTPCACHE_NPAGE-TESTPCACHE_RESERVE && createFlag<2 ){ + return 0; + } + + /* Find a free page to allocate if there are any free pages. + ** Withhold TESTPCACHE_RESERVE free pages until createFlag is 2. + */ + if( p->nFree>TESTPCACHE_RESERVE || (createFlag==2 && p->nFree>0) ){ + j = testpcacheRandom(p) % TESTPCACHE_NPAGE; + for(i=0; i<TESTPCACHE_NPAGE; i++, j = (j+1)%TESTPCACHE_NPAGE){ + if( p->a[j].key==0 ){ + p->a[j].key = key; + p->a[j].isPinned = 1; + memset(p->a[j].pData, 0, p->szPage); + p->nPinned++; + p->nFree--; + assert( p->nPinned <= TESTPCACHE_NPAGE - p->nFree ); + return p->a[j].pData; + } + } + + /* The prior loop always finds a freepage to allocate */ + assert( 0 ); + } + + /* If this cache is not purgeable then we have to fail. + */ + if( p->bPurgeable==0 ){ + return 0; + } + + /* If there are no free pages, recycle a page. The page to + ** recycle is selected at random from all unpinned pages. + */ + j = testpcacheRandom(p) % TESTPCACHE_NPAGE; + for(i=0; i<TESTPCACHE_NPAGE; i++, j = (j+1)%TESTPCACHE_NPAGE){ + if( p->a[j].key>0 && p->a[j].isPinned==0 ){ + p->a[j].key = key; + p->a[j].isPinned = 1; + memset(p->a[j].pData, 0, p->szPage); + p->nPinned++; + assert( p->nPinned <= TESTPCACHE_NPAGE - p->nFree ); + return p->a[j].pData; + } + } + + /* The previous loop always finds a page to recycle. */ + assert(0); + return 0; +} + +/* +** Unpin a page. +*/ +static void testpcacheUnpin( + sqlite3_pcache *pCache, + void *pOldPage, + int discard +){ + testpcache *p = (testpcache*)pCache; + int i; + assert( p->iMagic==TESTPCACHE_VALID ); + assert( testpcacheGlobal.pDummy!=0 ); + assert( testpcacheGlobal.nInstance>0 ); + + /* Randomly discard pages as they are unpinned according to the + ** discardChance setting. If discardChance is 0, the random discard + ** never happens. If discardChance is 100, it always happens. + */ + if( p->bPurgeable + && (100-testpcacheGlobal.discardChance) <= (testpcacheRandom(p)%100) + ){ + discard = 1; + } + + for(i=0; i<TESTPCACHE_NPAGE; i++){ + if( p->a[i].pData==pOldPage ){ + /* The pOldPage pointer always points to a pinned page */ + assert( p->a[i].isPinned ); + p->a[i].isPinned = 0; + p->nPinned--; + assert( p->nPinned>=0 ); + if( discard ){ + p->a[i].key = 0; + p->nFree++; + assert( p->nFree<=TESTPCACHE_NPAGE ); + } + return; + } + } + + /* The pOldPage pointer always points to a valid page */ + assert( 0 ); +} + + +/* +** Rekey a single page. +*/ +static void testpcacheRekey( + sqlite3_pcache *pCache, + void *pOldPage, + unsigned oldKey, + unsigned newKey +){ + testpcache *p = (testpcache*)pCache; + int i; + assert( p->iMagic==TESTPCACHE_VALID ); + assert( testpcacheGlobal.pDummy!=0 ); + assert( testpcacheGlobal.nInstance>0 ); + + /* If there already exists another page at newKey, verify that + ** the other page is unpinned and discard it. + */ + for(i=0; i<TESTPCACHE_NPAGE; i++){ + if( p->a[i].key==newKey ){ + /* The new key is never a page that is already pinned */ + assert( p->a[i].isPinned==0 ); + p->a[i].key = 0; + p->nFree++; + assert( p->nFree<=TESTPCACHE_NPAGE ); + break; + } + } + + /* Find the page to be rekeyed and rekey it. + */ + for(i=0; i<TESTPCACHE_NPAGE; i++){ + if( p->a[i].key==oldKey ){ + /* The oldKey and pOldPage parameters match */ + assert( p->a[i].pData==pOldPage ); + /* Page to be rekeyed must be pinned */ + assert( p->a[i].isPinned ); + p->a[i].key = newKey; + return; + } + } + + /* Rekey is always given a valid page to work with */ + assert( 0 ); +} + + +/* +** Truncate the page cache. Every page with a key of iLimit or larger +** is discarded. +*/ +static void testpcacheTruncate(sqlite3_pcache *pCache, unsigned iLimit){ + testpcache *p = (testpcache*)pCache; + unsigned int i; + assert( p->iMagic==TESTPCACHE_VALID ); + assert( testpcacheGlobal.pDummy!=0 ); + assert( testpcacheGlobal.nInstance>0 ); + for(i=0; i<TESTPCACHE_NPAGE; i++){ + if( p->a[i].key>=iLimit ){ + p->a[i].key = 0; + if( p->a[i].isPinned ){ + p->nPinned--; + assert( p->nPinned>=0 ); + } + p->nFree++; + assert( p->nFree<=TESTPCACHE_NPAGE ); + } + } +} + +/* +** Destroy a page cache. +*/ +static void testpcacheDestroy(sqlite3_pcache *pCache){ + testpcache *p = (testpcache*)pCache; + assert( p->iMagic==TESTPCACHE_VALID ); + assert( testpcacheGlobal.pDummy!=0 ); + assert( testpcacheGlobal.nInstance>0 ); + p->iMagic = TESTPCACHE_CLEAR; + sqlite3_free(p); + testpcacheGlobal.nInstance--; +} + + +/* +** Invoke this routine to register or unregister the testing pager cache +** implemented by this file. +** +** Install the test pager cache if installFlag is 1 and uninstall it if +** installFlag is 0. +** +** When installing, discardChance is a number between 0 and 100 that +** indicates the probability of discarding a page when unpinning the +** page. 0 means never discard (unless the discard flag is set). +** 100 means always discard. +*/ +void installTestPCache( + int installFlag, /* True to install. False to uninstall. */ + unsigned discardChance, /* 0-100. Chance to discard on unpin */ + unsigned prngSeed /* Seed for the PRNG */ +){ + static const sqlite3_pcache_methods testPcache = { + (void*)&testpcacheGlobal, + testpcacheInit, + testpcacheShutdown, + testpcacheCreate, + testpcacheCachesize, + testpcachePagecount, + testpcacheFetch, + testpcacheUnpin, + testpcacheRekey, + testpcacheTruncate, + testpcacheDestroy, + }; + static sqlite3_pcache_methods defaultPcache; + static int isInstalled = 0; + + assert( testpcacheGlobal.nInstance==0 ); + assert( testpcacheGlobal.pDummy==0 ); + assert( discardChance<=100 ); + testpcacheGlobal.discardChance = discardChance; + testpcacheGlobal.prngSeed = prngSeed ^ (prngSeed<<16); + if( installFlag!=isInstalled ){ + if( installFlag ){ + sqlite3_config(SQLITE_CONFIG_GETPCACHE, &defaultPcache); + assert( defaultPcache.xCreate!=testpcacheCreate ); + sqlite3_config(SQLITE_CONFIG_PCACHE, &testPcache); + }else{ + assert( defaultPcache.xCreate!=0 ); + sqlite3_config(SQLITE_CONFIG_PCACHE, &defaultPcache); + } + isInstalled = installFlag; + } +} |