-C Abort\sthe\swindow\sfunction\stree\srewrite\searly\sfollowing\san\sOOM.
-D 2019-11-23T16:34:40.792
+C Experimental\sfile-controls\sfor\scontrolling\sthe\suse\sof\sthe\s-shm\sfile.
+D 2019-11-25T23:55:14.269
F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
F src/os.h 48388821692e87da174ea198bf96b1b2d9d83be5dfc908f673ee21fafbe0d432
F src/os_common.h b2f4707a603e36811d9b1a13278bffd757857b85
F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
-F src/os_unix.c 3e0e519f27683083a465e948e056759a8340728c222b5c394a135e0c57c220bc
+F src/os_unix.c 112995da72acac11ad335489acbbf7df097df5b496602e6ae5e08b9ed20d06ed
F src/os_win.c 035a813cbd17f355bdcad7ab894af214a9c13a1db8aeac902365350b98cd45a7
F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
F src/pager.c 30f20d2263d3717f41a0d9a40f7a3d0f48ce1cfab461b875c6187ead9d6ad1c7
F src/resolve.c 2f8fb48e61d0006031df27e53810b6767972526d768d3cc6888435dc350c4c7a
F src/rowset.c d977b011993aaea002cab3e0bb2ce50cf346000dff94e944d547b989f4b1fe93
F src/select.c f403b7bd2304d4dfd5ad2614cc0ad3386a97af707922882bdabba4c14ce12975
-F src/shell.c.in 4a3a9e1c11847b1904f2b01d087af1c052f660902755abab457cab1756817ded
-F src/sqlite.h.in 4fe42f27a7be44586bbd94f49f2b097ef8a1053c747d82f135456c7f5381c85a
+F src/shell.c.in 6ecf8033fccb57b47a86e2bb87b1918f1aa5602f74bb72b1ae8c8ad1f44d2f27
+F src/sqlite.h.in d4fd966968f89426afa3924398896748a3cd82e07e0eef70e87b4aca5002b2c2
F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
F src/sqlite3ext.h 72af51aa4e912e14cd495fb6e7fac65f0940db80ed950d90911aff292cc47ce2
F src/sqliteInt.h 98bc9562acfc361e34182aa25b00e2c73095732ddd3ba4158f984b94f5601f96
F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 57070c68bbe15fc1d19a765182432e844c082909bdbc63b58fd86b96e2c521dd
-R 5ec4b862f5e315c01dbee90c995a71d6
+P d66f95a51530259ab48f78c9f91acc38055caf338b6fee846b99a8c077466e95
+R 7963d80c0fc4f8462d1ea33f7ebfda99
+T *branch * reuse-shm
+T *sym-reuse-shm *
+T -sym-trunk *
U drh
-Z b069a61ef07a50420fc34a99d1dc8940
+Z 1fd8281bb0cf67f1ca29940be5022987
#endif
};
+
+/*
+** Object used to represent an shared memory buffer.
+**
+** When multiple threads all reference the same wal-index, each thread
+** has its own unixShm object, but they all point to a single instance
+** of this unixShmNode object. In other words, each wal-index is opened
+** only once per process.
+**
+** Each unixShmNode object is connected to a single unixInodeInfo object.
+** We could coalesce this object into unixInodeInfo, but that would mean
+** every open file that does not use shared memory (in other words, most
+** open files) would have to carry around this extra information. So
+** the unixInodeInfo object contains a pointer to this unixShmNode object
+** and the unixShmNode object is created only when needed.
+**
+** unixMutexHeld() must be true when creating or destroying
+** this object or while reading or writing the following fields:
+**
+** nRef
+**
+** The following fields are read-only after the object is created:
+**
+** hShm
+** zFilename
+**
+** Either unixShmNode.pShmMutex must be held or unixShmNode.nRef==0 and
+** unixMutexHeld() is true when reading or writing any other field
+** in this structure.
+*/
+struct unixShmNode {
+ unixInodeInfo *pInode; /* unixInodeInfo that owns this SHM node */
+ sqlite3_mutex *pShmMutex; /* Mutex to access this object */
+ char *zFilename; /* Name of the mmapped file */
+ int hShm; /* Open file descriptor */
+ int szRegion; /* Size of shared-memory regions */
+ u16 nRegion; /* Size of array apRegion */
+ u8 isReadonly; /* True if read-only */
+ u8 isUnlocked; /* True if no DMS lock held */
+ char **apRegion; /* Array of mapped shared-memory regions */
+ int nRef; /* Number of unixShm objects pointing to this */
+ unixShm *pFirst; /* All unixShm objects pointing to this */
+#ifdef SQLITE_DEBUG
+ u8 exclMask; /* Mask of exclusive locks held */
+ u8 sharedMask; /* Mask of shared locks held */
+ u8 nextShmId; /* Next available unixShm.id value */
+#endif
+};
+
+/*
+** Structure used internally by this VFS to record the state of an
+** open shared memory connection.
+**
+** The following fields are initialized when this object is created and
+** are read-only thereafter:
+**
+** unixShm.pShmNode
+** unixShm.id
+**
+** All other fields are read/write. The unixShm.pShmNode->pShmMutex must
+** be held while accessing any read/write fields.
+*/
+struct unixShm {
+ unixShmNode *pShmNode; /* The underlying unixShmNode object */
+ unixShm *pNext; /* Next unixShm with the same unixShmNode */
+ u8 hasMutex; /* True if holding the unixShmNode->pShmMutex */
+ u8 id; /* Id of this connection within its unixShmNode */
+ u16 sharedMask; /* Mask of shared locks held */
+ u16 exclMask; /* Mask of exclusive locks held */
+};
+
/* This variable holds the process id (pid) from when the xRandomness()
** method was called. If xOpen() is called from a different process id,
** indicating that a fork() has occurred, the PRNG will be reset.
#define UNIXFILE_DELETE 0x20 /* Delete on close */
#define UNIXFILE_URI 0x40 /* Filename might have query parameters */
#define UNIXFILE_NOLOCK 0x80 /* Do no file locking */
+#define UNIXFILE_REUSESHM 0x100 /* Reuse existing -shm file */
/*
** Include code that is common to all os_*.c files
return proxyFileControl(id,op,pArg);
}
#endif /* SQLITE_ENABLE_LOCKING_STYLE && defined(__APPLE__) */
+ case SQLITE_FCNTL_REUSE_SHM: {
+ /* Set the UNIXFILE_REUSESHM file. If this flag is set before
+ ** the database file is first read, and the database is in WAL-mode,
+ ** and this is the first connection to connect to the database, and
+ ** there exists a -shm file from some prior connection that terminated
+ ** asynchronous, then this connection will attempt to reuse the existing
+ ** -shm file. The default behavior (without this flag) is to scan
+ ** the entire -wal file and reconstruct the -shm file from scratch.
+ ** The default behavior is safer. But some embedded systems want the
+ ** option to live dangerously. */
+ pFile->ctrlFlags |= UNIXFILE_REUSESHM;
+ return SQLITE_OK;
+ }
+ case SQLITE_FCNTL_SHM_HANDLE: {
+ /* If this database connection has a -shm file open, then set
+ ** *pArg to the file descriptor for that file. If the -shm file is
+ ** not open for any reason (not opened yet, not in WAL mode, uses
+ ** an in-memory -shm file, etc) then set *pArg to -1. */
+ unixShm *pShm = pFile->pShm;
+ int h = -1;
+ if( pShm ){
+ unixShmNode *pNode = pShm->pShmNode;
+ if( pNode ) h = pNode->hShm;
+ }
+ *(int*)pArg = h;
+ return SQLITE_OK;
+ }
}
return SQLITE_NOTFOUND;
}
#ifndef SQLITE_OMIT_WAL
-/*
-** Object used to represent an shared memory buffer.
-**
-** When multiple threads all reference the same wal-index, each thread
-** has its own unixShm object, but they all point to a single instance
-** of this unixShmNode object. In other words, each wal-index is opened
-** only once per process.
-**
-** Each unixShmNode object is connected to a single unixInodeInfo object.
-** We could coalesce this object into unixInodeInfo, but that would mean
-** every open file that does not use shared memory (in other words, most
-** open files) would have to carry around this extra information. So
-** the unixInodeInfo object contains a pointer to this unixShmNode object
-** and the unixShmNode object is created only when needed.
-**
-** unixMutexHeld() must be true when creating or destroying
-** this object or while reading or writing the following fields:
-**
-** nRef
-**
-** The following fields are read-only after the object is created:
-**
-** hShm
-** zFilename
-**
-** Either unixShmNode.pShmMutex must be held or unixShmNode.nRef==0 and
-** unixMutexHeld() is true when reading or writing any other field
-** in this structure.
-*/
-struct unixShmNode {
- unixInodeInfo *pInode; /* unixInodeInfo that owns this SHM node */
- sqlite3_mutex *pShmMutex; /* Mutex to access this object */
- char *zFilename; /* Name of the mmapped file */
- int hShm; /* Open file descriptor */
- int szRegion; /* Size of shared-memory regions */
- u16 nRegion; /* Size of array apRegion */
- u8 isReadonly; /* True if read-only */
- u8 isUnlocked; /* True if no DMS lock held */
- char **apRegion; /* Array of mapped shared-memory regions */
- int nRef; /* Number of unixShm objects pointing to this */
- unixShm *pFirst; /* All unixShm objects pointing to this */
-#ifdef SQLITE_DEBUG
- u8 exclMask; /* Mask of exclusive locks held */
- u8 sharedMask; /* Mask of shared locks held */
- u8 nextShmId; /* Next available unixShm.id value */
-#endif
-};
-
-/*
-** Structure used internally by this VFS to record the state of an
-** open shared memory connection.
-**
-** The following fields are initialized when this object is created and
-** are read-only thereafter:
-**
-** unixShm.pShmNode
-** unixShm.id
-**
-** All other fields are read/write. The unixShm.pShmNode->pShmMutex must
-** be held while accessing any read/write fields.
-*/
-struct unixShm {
- unixShmNode *pShmNode; /* The underlying unixShmNode object */
- unixShm *pNext; /* Next unixShm with the same unixShmNode */
- u8 hasMutex; /* True if holding the unixShmNode->pShmMutex */
- u8 id; /* Id of this connection within its unixShmNode */
- u16 sharedMask; /* Mask of shared locks held */
- u16 exclMask; /* Mask of exclusive locks held */
-};
-
/*
** Constants used for locking
*/
** -shm header size) rather than 0 as a system debugging aid, to
** help detect if a -shm file truncation is legitimate or is the work
** or a rogue process. */
- if( rc==SQLITE_OK && robust_ftruncate(pShmNode->hShm, 3) ){
- rc = unixLogError(SQLITE_IOERR_SHMOPEN,"ftruncate",pShmNode->zFilename);
+ if( rc==SQLITE_OK
+ && (pDbFd->ctrlFlags & UNIXFILE_REUSESHM)==0
+ && robust_ftruncate(pShmNode->hShm, 3)
+ ){
+ rc = unixLogError(SQLITE_IOERR_SHMOPEN,"ftruncate",
+ pShmNode->zFilename);
}
}
}else if( lock.l_type==F_WRLCK ){
projects / thirdparty / sqlite.git / commitdiff
