Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Cherrypick [ec37ad6d08] into this branch. With this patch, if SQLITE_SHARED_MAPPING is defined at build-time SQLite will use a single memory mapping for multiple connections to the same database file within a single process. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | begin-concurrent |
| Files: | files | file ages | folders |
| SHA3-256: |
c7a5880d6d898299b4c9414b7702cfa4 |
| User & Date: | dan 2017-09-22 11:09:09.656 |
Context
|
2017-11-06
| ||
| 10:04 | Allow "BEGIN CONCURRENT" transactions to modify the temp schema. (check-in: 0fb6d91cea user: dan tags: begin-concurrent) | |
|
2017-09-22
| ||
| 11:09 | Cherrypick [ec37ad6d08] into this branch. With this patch, if SQLITE_SHARED_MAPPING is defined at build-time SQLite will use a single memory mapping for multiple connections to the same database file within a single process. (check-in: c7a5880d6d user: dan tags: begin-concurrent) | |
| 10:49 | Merge latest trunk changes into this branch. (check-in: 307b802e86 user: dan tags: begin-concurrent) | |
|
2017-09-12
| ||
| 18:03 | Hack to have multiple connections to a single file share a single memory mapping of the databse file. (check-in: ec37ad6d08 user: dan tags: shared-mapping-hack) | |
Changes
Changes to src/os_unix.c.
| ︙ | |||
1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 | 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 | + + + + | #if SQLITE_ENABLE_LOCKING_STYLE unsigned long long sharedByte; /* for AFP simulated shared lock */ #endif #if OS_VXWORKS sem_t *pSem; /* Named POSIX semaphore */ char aSemName[MAX_PATHNAME+2]; /* Name of that semaphore */ #endif #ifdef SQLITE_SHARED_MAPPING sqlite3_int64 nSharedMapping; /* Size of mapped region in bytes */ void *pSharedMapping; /* Memory mapped region */ #endif }; /* ** A lists of all unixInodeInfo objects. */ static unixInodeInfo *inodeList = 0; /* All unixInodeInfo objects */ static unsigned int nUnusedFd = 0; /* Total unused file descriptors */ |
| ︙ | |||
1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 | 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 | + + + + + + + |
static void releaseInodeInfo(unixFile *pFile){
unixInodeInfo *pInode = pFile->pInode;
assert( unixMutexHeld() );
if( ALWAYS(pInode) ){
pInode->nRef--;
if( pInode->nRef==0 ){
assert( pInode->pShmNode==0 );
#ifdef SQLITE_SHARED_MAPPING
if( pInode->pSharedMapping ){
osMunmap(pInode->pSharedMapping, pInode->nSharedMapping);
pInode->pSharedMapping = 0;
pInode->nSharedMapping = 0;
}
#endif
closePendingFds(pFile);
if( pInode->pPrev ){
assert( pInode->pPrev->pNext==pInode );
pInode->pPrev->pNext = pInode->pNext;
}else{
assert( inodeList==pInode );
inodeList = pInode->pNext;
|
| ︙ | |||
2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 | 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 | + + + + + + + + |
return SQLITE_OK;
}
/*
** Close the file.
*/
static int nolockClose(sqlite3_file *id) {
#ifdef SQLITE_SHARED_MAPPING
unixFile *pFd = (unixFile*)id;
if( pFd->pInode ){
unixEnterMutex();
releaseInodeInfo(pFd);
unixLeaveMutex();
}
#endif
return closeUnixFile(id);
}
/******************* End of the no-op lock implementation *********************
******************************************************************************/
/******************************************************************************
|
| ︙ | |||
3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 | 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 | + + + |
if( newLimit>0 && sizeof(size_t)<8 ){
newLimit = (newLimit & 0x7FFFFFFF);
}
*(i64*)pArg = pFile->mmapSizeMax;
if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
pFile->mmapSizeMax = newLimit;
#ifdef SQLITE_SHARED_MAPPING
if( pFile->pInode==0 )
#endif
if( pFile->mmapSize>0 ){
unixUnmapfile(pFile);
rc = unixMapfile(pFile, -1);
}
}
return rc;
}
|
| ︙ | |||
4770 4771 4772 4773 4774 4775 4776 4777 4778 4779 4780 4781 4782 4783 | 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 | + + + |
#if SQLITE_MAX_MMAP_SIZE>0
/*
** If it is currently memory mapped, unmap file pFd.
*/
static void unixUnmapfile(unixFile *pFd){
assert( pFd->nFetchOut==0 );
#ifdef SQLITE_SHARED_MAPPING
if( pFd->pInode ) return;
#endif
if( pFd->pMapRegion ){
osMunmap(pFd->pMapRegion, pFd->mmapSizeActual);
pFd->pMapRegion = 0;
pFd->mmapSize = 0;
pFd->mmapSizeActual = 0;
}
}
|
| ︙ | |||
4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 | 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960 | + + + + + + + + + + + + + + + + + + + + + + |
return SQLITE_IOERR_FSTAT;
}
nMap = statbuf.st_size;
}
if( nMap>pFd->mmapSizeMax ){
nMap = pFd->mmapSizeMax;
}
#ifdef SQLITE_SHARED_MAPPING
if( pFd->pInode ){
unixInodeInfo *pInode = pFd->pInode;
if( pFd->pMapRegion ) return SQLITE_OK;
unixEnterMutex();
if( pInode->pSharedMapping==0 ){
u8 *pNew = osMmap(0, nMap, PROT_READ, MAP_SHARED, pFd->h, 0);
if( pNew==MAP_FAILED ){
unixLogError(SQLITE_OK, "mmap", pFd->zPath);
pFd->mmapSizeMax = 0;
}else{
pInode->pSharedMapping = pNew;
pInode->nSharedMapping = nMap;
}
}
pFd->pMapRegion = pInode->pSharedMapping;
pFd->mmapSizeActual = pFd->mmapSize = pInode->nSharedMapping;
unixLeaveMutex();
return SQLITE_OK;
}
#endif
assert( nMap>0 || (pFd->mmapSize==0 && pFd->pMapRegion==0) );
if( nMap!=pFd->mmapSize ){
unixRemapfile(pFd, nMap);
}
return SQLITE_OK;
|
| ︙ | |||
5339 5340 5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351 5352 | 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 | + + + |
#endif
}
if( pLockingStyle == &posixIoMethods
#if defined(__APPLE__) && SQLITE_ENABLE_LOCKING_STYLE
|| pLockingStyle == &nfsIoMethods
#endif
#ifdef SQLITE_SHARED_MAPPING
|| pLockingStyle == &nolockIoMethods
#endif
){
unixEnterMutex();
rc = findInodeInfo(pNew, &pNew->pInode);
if( rc!=SQLITE_OK ){
/* If an error occurred in findInodeInfo(), close the file descriptor
** immediately, before releasing the mutex. findInodeInfo() may fail
** in two scenarios:
|
| ︙ |