Changes to the interface design for the xShmLock method of the VFS.

FossilOrigin-Name: 348409de26eafe12f5cb1236e8e167a4183d4051

diff --git a/manifest b/manifest
index fec9e7d2508d69e1704a581fc8e20a920def532f..e87f3103a809a12f83ec3978294dd8bc4ef6000f 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,8 +1,8 @@
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA1
 
-C Rename\sthe\ssqlite3_log_hook()\sto\ssqlite3_wal_hook().\s\sAdded\scomments\sto\nwal.h.
-D 2010-04-28T14:42:19
+C Changes\sto\sthe\sinterface\sdesign\sfor\sthe\sxShmLock\smethod\sof\sthe\sVFS.
+D 2010-04-28T17:21:33
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in d83a0ffef3dcbfb08b410a6c6dd6c009ec9167fb
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -153,7 +153,7 @@ F src/os.c 8bc63cf91e9802e2b807198e54e50227fa889306
 F src/os.h 534b082c3cb349ad05fa6fa0b06087e022af282c
 F src/os_common.h 240c88b163b02c21a9f21f87d49678a0aa21ff30
 F src/os_os2.c 8ad77a418630d7dee91d1bb04f79c2096301d3a0
-F src/os_unix.c 332ff9185aedcbd25568a06ddbdb51f5496b9756
+F src/os_unix.c c8b7d1e0f4315e08cf54324ca706e1a1a80f5fc2
 F src/os_win.c a8fc01d8483be472e495793c01064fd87e56a5c1
 F src/pager.c b4a41030860229e80295fa1f37addab24d21799c
 F src/pager.h cee4487ab4f0911dd9f22a40e3cd55afdb7ef444
@@ -169,7 +169,7 @@ F src/resolve.c ac5f1a713cd1ae77f08b83cc69581e11bf5ae6f9
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c c03d8a0565febcde8c6a12c5d77d065fddae889b
 F src/shell.c c40427c7245535a04a9cb4a417b6cc05c022e6a4
-F src/sqlite.h.in 9529106a7608b57bbe9e290cdddb203bd383f888
+F src/sqlite.h.in caf60df0991a14e22cce8243b9caa1c1dbd09d42
 F src/sqlite3ext.h 69dfb8116af51b84a029cddb3b35062354270c89
 F src/sqliteInt.h 700a2df7b8dfe57c3b8d83c52ff40928e026220c
 F src/sqliteLimit.h 3afab2291762b5d09ae20c18feb8e9fa935a60a6
@@ -811,14 +811,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
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+P bbc385111b19071e20fe963fab814262c815b3e9
+R 8707e56d2016564dc168df33cbfc8185
 U drh
-Z 7c95869a158e03c8e63f0877555a0133
+Z 76427138e798af79dc3cb019d4766cfc
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diff --git a/manifest.uuid b/manifest.uuid
index 9760418781e52d2e643add1d4e029d2d3e2ee695..aa96371448de9bc8de714fe1f211c956a0d001ab 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-bbc385111b19071e20fe963fab814262c815b3e9
\ No newline at end of file
+348409de26eafe12f5cb1236e8e167a4183d4051
\ No newline at end of file

diff --git a/src/os_unix.c b/src/os_unix.c
index d603caa0d07d1bd20aafdce50f198fbb6298e619..7e3930a1e63123846b23865d0bf5f7b95b82ab2a 100644 (file)
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -4697,26 +4697,11 @@ static int unixShmRelease(sqlite3_shm *pSharedMem){
 */
 static int unixShmLock(
   sqlite3_shm *pSharedMem,   /* Pointer from unixShmOpen() */
-  int lockType,              /* _RDLK, _WRLK, or _UNLK, possibly ORed _BLOCK */
-  int ofst,                  /* Start of lock region */
-  int nByte                  /* Size of lock region in bytes */
+  int desiredLock,           /* The locking state desired */
+  int *pGotLock,             /* The locking state actually obtained */
+  int shouldBlock            /* Block for the lock if true and possible */
 ){
-  struct unixShm *p = (struct unixShm*)pSharedMem;
-  struct flock f;
-  int op;
-  int rc;
-  
-  f.l_whence = SEEK_SET;
-  f.l_start = ofst;
-  f.l_len = nByte;
-  switch( lockType & 0x07 ){
-    case SQLITE_SHM_RDLK:  f.l_type = F_RDLCK;   break;
-    case SQLITE_SHM_WRLK:  f.l_type = F_WRLCK;   break;
-    case SQLITE_SHM_UNLK:  f.l_type = F_UNLCK;   break;
-  }
-  op = (lockType & 0x08)!=0 ? F_SETLKW : F_SETLK;
-  rc = fcntl(p->fd.h, op, &f);
-  return (rc==0) ? SQLITE_OK : SQLITE_BUSY;
+  return SQLITE_OK;
 }
 
 /*

diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 225007780b69912237750312ac3af96c6844fbc6..9f6f1bc967248a95e8a011247c41da955e152dbc 100644 (file)
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -848,7 +848,7 @@ struct sqlite3_vfs {
   int (*xShmRelease)(sqlite3_shm*);
   int (*xShmPush)(sqlite3_shm*);
   int (*xShmPull)(sqlite3_shm*);
-  int (*xShmLock)(sqlite3_shm*, int lockType, int ofst, int nByte);
+  int (*xShmLock)(sqlite3_shm*, int desiredLock, int *gotLock, int shouldBlock);
   int (*xShmClose)(sqlite3_shm*);
   int (*xShmDelete)(sqlite3_vfs*, const char *zName);
   int (*xRename)(sqlite3_vfs*, const char *zOld, const char *zNew, int dirSync);
@@ -880,18 +880,20 @@ struct sqlite3_vfs {
 /*
 ** CAPI3REF: Flags for the xShmLock VFS method
 **
-** These integer constants can be used as the second parameter to
-** the xShmLock method of an [sqlite3_vfs] object.  They determine
-** the specific locking action.  Exactly one of the first three
-** values must be used ini the lockType parameter.  The fourth
-** value (SQLITE_SHM_BLOCK) can optionally be ORed into the lockType
-** parameter to cause the thread to block until the lock becomes
-** available.
-*/
-#define SQLITE_SHM_RDLK   0x01
-#define SQLITE_SHM_WRLK   0x02
-#define SQLITE_SHM_UNLK   0x04
-#define SQLITE_SHM_BLOCK  0x08
+** These integer constants define the various locking states that
+** an sqlite3_shm object can be in.  The SQLITE_SHM_QUERY integer
+** is not a valid data - it is a constant pasted to the 
+** sqlite3_vfs.xShmLock() method for querying the current lock
+** state.
+*/
+#define SQLITE_SHM_UNLOCK       0
+#define SQLITE_SHM_READ_PREFIX  1
+#define SQLITE_SHM_READ_FULL    2
+#define SQLITE_SHM_WRITE        3
+#define SQLITE_SHM_PENDING      4
+#define SQLITE_SHM_CHECKPOINT   5
+#define SQLITE_SHM_RECOVER      6
+#define SQLITE_SHM_QUERY        (-1)
 
 /*
 ** CAPI3REF: Initialize The SQLite Library