database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-12 13:01:09 +03:00
Code Activity

Experimental change to the xShmXXX parts of the VFS interface.

Browse Source 
FossilOrigin-Name: ca68472db01c14a899892007d1cbaff5e86ae193
This commit is contained in:
dan
2010-06-11 19:04:21 +00:00
parent 0b9b4301b8
commit 13a3cb82ce
12 changed files with 428 additions and 395 deletions
Download Patch File Download Diff File Expand all files Collapse all files

80
src/os_unix.c
View File

@@ -3141,8 +3141,14 @@ struct unixShmNode {
sqlite3_mutex *mutexBuf; /* Mutex to access zBuf[] */
char *zFilename; /* Name of the mmapped file */
int h; /* Open file descriptor */
int szMap; /* Size of the mapping into memory */
char *pMMapBuf; /* Where currently mmapped(). NULL if unmapped */
int pgsz; /* Size of shared-memory pages */
int nPage; /* Size of array apPage */
char **apPage; /* Array of mapped shared-memory pages */
int nRef; /* Number of unixShm objects pointing to this */
unixShm *pFirst; /* All unixShm objects pointing to this */
#ifdef SQLITE_DEBUG
@@ -3266,10 +3272,15 @@ static void unixShmPurge(unixFile *pFd){
unixShmNode *p = pFd->pInode->pShmNode;
assert( unixMutexHeld() );
if( p && p->nRef==0 ){
int i;
assert( p->pInode==pFd->pInode );
if( p->mutex ) sqlite3_mutex_free(p->mutex);
if( p->mutexBuf ) sqlite3_mutex_free(p->mutexBuf);
if( p->pMMapBuf ) munmap(p->pMMapBuf, p->szMap);
for(i=0; i<p->nPage; i++){
munmap(p->apPage[i], p->pgsz);
}
sqlite3_free(p->apPage);
if( p->h>=0 ) close(p->h);
p->pInode->pShmNode = 0;
sqlite3_free(p);
@@ -3706,6 +3717,71 @@ static void unixShmBarrier(
unixLeaveMutex();
}
static int unixShmPage(
sqlite3_file *fd, /* Handle open on database file */
int iPage, /* Page to retrieve */
int pgsz, /* Size of pages */
int isWrite, /* True to extend file if necessary */
void volatile **pp /* OUT: Mapped memory */
){
unixFile *pDbFd = (unixFile*)fd;
unixShm *p = pDbFd->pShm;
unixShmNode *pShmNode = p->pShmNode;
int rc = SQLITE_OK;
assert( p->hasMutexBuf==0 );
sqlite3_mutex_enter(pShmNode->mutexBuf);
assert( pgsz==pShmNode->pgsz || pShmNode->nPage==0 );
if( pShmNode->nPage<=iPage ){
char **apNew; /* New apPage[] array */
int nByte = (iPage+1)*pgsz; /* Minimum required file size */
struct stat sStat;
pShmNode->pgsz = pgsz;
/* Make sure the underlying file is large enough (or fail) */
if( fstat(pShmNode->h, &sStat) ){
rc = SQLITE_IOERR_SHMSIZE;
goto shmpage_out;
}else if( sStat.st_size<nByte ){
if( !isWrite ) goto shmpage_out;
if( ftruncate(pShmNode->h, nByte) ){
rc = SQLITE_IOERR_SHMSIZE;
goto shmpage_out;
}
}
apNew = (char**)sqlite3_realloc(pShmNode->apPage, (iPage+1)*sizeof(char *));
if( !apNew ){
rc = SQLITE_IOERR_NOMEM;
goto shmpage_out;
}
pShmNode->apPage = apNew;
while(pShmNode->nPage<=iPage){
void *pMem = mmap(
0, pgsz, PROT_READ|PROT_WRITE, MAP_SHARED, pShmNode->h, iPage*pgsz
);
if( pMem==MAP_FAILED ){
assert(0);
rc = SQLITE_IOERR;
goto shmpage_out;
}
pShmNode->apPage[pShmNode->nPage] = pMem;
pShmNode->nPage++;
}
}
shmpage_out:
if( pShmNode->nPage>iPage ){
*pp = pShmNode->apPage[iPage];
}else{
*pp = 0;
}
sqlite3_mutex_leave(pShmNode->mutexBuf);
return rc;
}
#else
# define unixShmOpen 0
@@ -3715,6 +3791,7 @@ static void unixShmBarrier(
# define unixShmLock 0
# define unixShmBarrier 0
# define unixShmClose 0
# define unixShmPage 0
#endif /* #ifndef SQLITE_OMIT_WAL */
/*
@@ -3778,7 +3855,8 @@ static const sqlite3_io_methods METHOD = { \
unixShmRelease, /* xShmRelease */ \
unixShmLock, /* xShmLock */ \
unixShmBarrier, /* xShmBarrier */ \
unixShmClose /* xShmClose */ \
unixShmClose, /* xShmClose */ \
unixShmPage /* xShmPage */ \
}; \
static const sqlite3_io_methods *FINDER##Impl(const char *z, unixFile *p){ \
UNUSED_PARAMETER(z); UNUSED_PARAMETER(p); \