Take out the special handling of nolock=true in os_win.c and add it to

pager.c, so that it works for all VFSes.  Add the pPager->noLock boolean
for clarity.

FossilOrigin-Name: 725c1c14be331bce9bf074960dbfa7b6d4c1ba87

manifest

@@ -1,5 +1,5 @@
-C Avoid\sunnecessary\sxUnlock\soperations\son\stemp\sfile.
-D 2014-05-01T01:20:05.808
+C Take\sout\sthe\sspecial\shandling\sof\snolock=true\sin\sos_win.c\sand\sadd\sit\sto\npager.c,\sso\sthat\sit\sworks\sfor\sall\sVFSes.\s\sAdd\sthe\spPager->noLock\sboolean\nfor\sclarity.
+D 2014-05-01T01:49:22.279
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -205,8 +205,8 @@ F src/os.c 1b147e4cf7cc39e618115c14a086aed44bc91ace
 F src/os.h 4a46270a64e9193af4a0aaa3bc2c66dc07c29b3f
 F src/os_common.h 92815ed65f805560b66166e3583470ff94478f04
 F src/os_unix.c ae4b5240af4619d711301d7992396e182585269f
-F src/os_win.c 1662c40d22be162698a31725e836eede09e841ed
-F src/pager.c 52b7f435cb06063ccb52ff7089dfbc7be613b9b2
+F src/os_win.c e71678ac927d0a0fb11d993db20a9748eabf808e
+F src/pager.c 6ed54e169933200b8d113674d5da46a5cbd32c6c
 F src/pager.h ffd5607f7b3e4590b415b007a4382f693334d428
 F src/parse.y 22d6a074e5f5a7258947a1dc55a9bf946b765dd0
 F src/pcache.c d8eafac28290d4bb80332005435db44991d07fc2
@@ -1166,7 +1166,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P 71f152c85d79ebd9ca48bc9c4c71fc4debaf2437
-R 936969710ee66727ffa03c716e1344c2
+P 1829c38c3233c8cb194fae6d560d35a8916b1348
+R 9585bcff14fbe775451a3a647d896079
 U drh
-Z b6af320858436be94ae3e128e461e236
+Z 3dae204f6c4a7be4483961b87ae0c17a

manifest.uuid

@@ -1 +1 @@
-1829c38c3233c8cb194fae6d560d35a8916b1348
+725c1c14be331bce9bf074960dbfa7b6d4c1ba87

src/os_win.c

@@ -275,7 +275,6 @@ struct winFile {
 #define WINFILE_RDONLY          0x02   /* Connection is read only */
 #define WINFILE_PERSIST_WAL     0x04   /* Persistent WAL mode */
 #define WINFILE_PSOW            0x10   /* SQLITE_IOCAP_POWERSAFE_OVERWRITE */
-#define WINFILE_NOLOCK          0x20   /* Never do any real locking */
 
 /*
  * The size of the buffer used by sqlite3_win32_write_debug().
@@ -2860,10 +2859,6 @@ static int winLock(sqlite3_file *id, int locktype){
   assert( id!=0 );
   OSTRACE(("LOCK file=%p, oldLock=%d(%d), newLock=%d\n",
            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
-  if( pFile->ctrlFlags & WINFILE_NOLOCK ){
-    OSTRACE(("LOCK-NOP file=%p, rc=SQLITE_OK\n", pFile->h));
-    return SQLITE_OK;
-  }
 
   /* If there is already a lock of this type or more restrictive on the
   ** OsFile, do nothing. Don't use the end_lock: exit path, as
@@ -2991,10 +2986,7 @@ static int winCheckReservedLock(sqlite3_file *id, int *pResOut){
   OSTRACE(("TEST-WR-LOCK file=%p, pResOut=%p\n", pFile->h, pResOut));
 
   assert( id!=0 );
-  if( pFile->ctrlFlags & WINFILE_NOLOCK ){
-    rc = 0;
-    OSTRACE(("TEST-WR-LOCK file=%p, rc=%d (nop)\n", pFile->h, rc));
-  }else if( pFile->locktype>=RESERVED_LOCK ){
+  if( pFile->locktype>=RESERVED_LOCK ){
     rc = 1;
     OSTRACE(("TEST-WR-LOCK file=%p, rc=%d (local)\n", pFile->h, rc));
   }else{
@@ -3030,10 +3022,6 @@ static int winUnlock(sqlite3_file *id, int locktype){
   assert( locktype<=SHARED_LOCK );
   OSTRACE(("UNLOCK file=%p, oldLock=%d(%d), newLock=%d\n",
            pFile->h, pFile->locktype, pFile->sharedLockByte, locktype));
-  if( pFile->ctrlFlags & WINFILE_NOLOCK ){
-    OSTRACE(("UNLOCK-NOP file=%p, rc=SQLITE_OK\n", pFile->h));
-    return SQLITE_OK;
-  }
   type = pFile->locktype;
   if( type>=EXCLUSIVE_LOCK ){
     winUnlockFile(&pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
@@ -4704,9 +4692,6 @@ static int winOpen(
   if( sqlite3_uri_boolean(zName, "psow", SQLITE_POWERSAFE_OVERWRITE) ){
     pFile->ctrlFlags |= WINFILE_PSOW;
   }
-  if( sqlite3_uri_boolean(zName, "nolock", 0) ){
-    pFile->ctrlFlags |= WINFILE_NOLOCK;
-  }
   pFile->lastErrno = NO_ERROR;
   pFile->zPath = zName;
 #if SQLITE_MAX_MMAP_SIZE>0

src/pager.c

@@ -626,7 +626,8 @@ struct Pager {
   u8 ckptSyncFlags;           /* SYNC_NORMAL or SYNC_FULL for checkpoint */
   u8 walSyncFlags;            /* SYNC_NORMAL or SYNC_FULL for wal writes */
   u8 syncFlags;               /* SYNC_NORMAL or SYNC_FULL otherwise */
-  u8 tempFile;                /* zFilename is a temporary file */
+  u8 tempFile;                /* zFilename is a temporary or immutable file */
+  u8 noLock;                  /* Do not lock (except in WAL mode) */
   u8 readOnly;                /* True for a read-only database */
   u8 memDb;                   /* True to inhibit all file I/O */
 
@@ -1089,9 +1090,9 @@ static int pagerUnlockDb(Pager *pPager, int eLock){
   assert( !pPager->exclusiveMode || pPager->eLock==eLock );
   assert( eLock==NO_LOCK || eLock==SHARED_LOCK );
   assert( eLock!=NO_LOCK || pagerUseWal(pPager)==0 );
-  if( isOpen(pPager->fd) && !pPager->tempFile ){
+  if( isOpen(pPager->fd) ){
     assert( pPager->eLock>=eLock );
-    rc = sqlite3OsUnlock(pPager->fd, eLock);
+    rc = pPager->noLock ? SQLITE_OK : sqlite3OsUnlock(pPager->fd, eLock);
     if( pPager->eLock!=UNKNOWN_LOCK ){
       pPager->eLock = (u8)eLock;
     }
@@ -1115,7 +1116,7 @@ static int pagerLockDb(Pager *pPager, int eLock){
 
   assert( eLock==SHARED_LOCK || eLock==RESERVED_LOCK || eLock==EXCLUSIVE_LOCK );
   if( pPager->eLock<eLock || pPager->eLock==UNKNOWN_LOCK ){
-    rc = sqlite3OsLock(pPager->fd, eLock);
+    rc = pPager->noLock ? SQLITE_OK : sqlite3OsLock(pPager->fd, eLock);
     if( rc==SQLITE_OK && (pPager->eLock!=UNKNOWN_LOCK||eLock==EXCLUSIVE_LOCK) ){
       pPager->eLock = (u8)eLock;
       IOTRACE(("LOCK %p %d\n", pPager, eLock))
@@ -4699,6 +4700,7 @@ int sqlite3PagerOpen(
           }
         }
 #endif
+        pPager->noLock = sqlite3_uri_boolean(zFilename, "nolock", 0);
         if( (iDc & SQLITE_IOCAP_IMMUTABLE)!=0
          || sqlite3_uri_boolean(zFilename, "immutable", 0) ){
             vfsFlags |= SQLITE_OPEN_READONLY;
@@ -4714,11 +4716,14 @@ int sqlite3PagerOpen(
     ** This branch is also run for an in-memory database. An in-memory
     ** database is the same as a temp-file that is never written out to
     ** disk and uses an in-memory rollback journal.
+    **
+    ** This branch also runs for files marked as immutable.
     */ 
 act_like_temp_file:
     tempFile = 1;
-    pPager->eState = PAGER_READER;
-    pPager->eLock = EXCLUSIVE_LOCK;
+    pPager->eState = PAGER_READER;     /* Pretend we already have a lock */
+    pPager->eLock = EXCLUSIVE_LOCK;    /* Pretend we are in EXCLUSIVE locking mode */
+    pPager->noLock = 1;                /* Do no locking */
     readOnly = (vfsFlags&SQLITE_OPEN_READONLY);
   }