Have all FTS3 queries obtain a read or write table-lock at the shared-cache level...

FossilOrigin-Name: 018e82c775d0fb8c0d90cddf7a87c20c8c8172a9

diff --git a/ext/fts3/fts3.c b/ext/fts3/fts3.c
index bbb1b945a60eb92258c3bd7442a8fe1314bf9026..5323a5c1aecbba3face53ca47bffaba04c06596d 100644 (file)
--- a/ext/fts3/fts3.c
+++ b/ext/fts3/fts3.c
@@ -2203,6 +2203,9 @@ static int fts3FilterMethod(
       return rc;
     }
 
+    rc = sqlite3Fts3ReadLock(p);
+    if( rc!=SQLITE_OK ) return rc;
+
     rc = evalFts3Expr(p, pCsr->pExpr, &pCsr->aDoclist, &pCsr->nDoclist, 0);
     pCsr->pNextId = pCsr->aDoclist;
     pCsr->iPrevId = 0;

diff --git a/ext/fts3/fts3Int.h b/ext/fts3/fts3Int.h
index c5be598e14f50f23f42f386b7eb0bb3e052049d5..8ed31aedd882b59f5abc024138fda60a8221f170 100644 (file)
--- a/ext/fts3/fts3Int.h
+++ b/ext/fts3/fts3Int.h
@@ -273,6 +273,7 @@ int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char const**, int*);
 int sqlite3Fts3AllSegdirs(Fts3Table*, sqlite3_stmt **);
 int sqlite3Fts3MatchinfoDocsizeLocal(Fts3Cursor*, u32*);
 int sqlite3Fts3MatchinfoDocsizeGlobal(Fts3Cursor*, u32*);
+int sqlite3Fts3ReadLock(Fts3Table *);
 
 /* Flags allowed as part of the 4th argument to SegmentReaderIterate() */
 #define FTS3_SEGMENT_REQUIRE_POS   0x00000001

diff --git a/ext/fts3/fts3_write.c b/ext/fts3/fts3_write.c
index cc3c362c8e6118938707713414acf7e2175873fa..e434360953520774f699d76974c79145353505c1 100644 (file)
--- a/ext/fts3/fts3_write.c
+++ b/ext/fts3/fts3_write.c
@@ -322,6 +322,36 @@ int sqlite3Fts3ReadBlock(
   return SQLITE_OK;
 }
 
+/*
+** This function ensures that the caller has obtained a shared-cache
+** table-lock on the %_content table. This is required before reading
+** data from the fts3 table. If this lock is not acquired first, then
+** the caller may end up holding read-locks on the %_segments and %_segdir
+** tables, but no read-lock on the %_content table. If this happens 
+** a second connection will be able to write to the fts3 table, but
+** attempting to commit those writes might return SQLITE_LOCKED or
+** SQLITE_LOCKED_SHAREDCACHE (because the commit attempts to obtain 
+** write-locks on the %_segments and %_segdir ** tables). 
+**
+** We try to avoid this because if FTS3 returns any error when committing
+** a transaction, the whole transaction will be rolled back. And this is
+** not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. It can
+** still happen if the user reads data directly from the %_segments or
+** %_segdir tables instead of going through FTS3 though.
+*/
+int sqlite3Fts3ReadLock(Fts3Table *p){
+  int rc;                         /* Return code */
+  sqlite3_stmt *pStmt;            /* Statement used to obtain lock */
+
+  rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pStmt, 0);
+  if( rc==SQLITE_OK ){
+    sqlite3_bind_null(pStmt, 1);
+    sqlite3_step(pStmt);
+    rc = sqlite3_reset(pStmt);
+  }
+  return rc;
+}
+
 /*
 ** Set *ppStmt to a statement handle that may be used to iterate through
 ** all rows in the %_segdir table, from oldest to newest. If successful,

diff --git a/manifest b/manifest
index fde65b172244f41f12df8f2dde7e0597469a9f32..4104052df4590d583141d7510a8e7a5c6936f731 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,8 +1,5 @@
------BEGIN PGP SIGNED MESSAGE-----
-Hash: SHA1
-
-C Completely\sremove\sall\strace\sof\sctype.h\sfrom\sFTS2.
-D 2010-09-17T01:07:54
+C Have\sall\sFTS3\squeries\sobtain\sa\sread\sor\swrite\stable-lock\sat\sthe\sshared-cache\slevel\sbefore\sdoing\sanything\selse.
+D 2010-09-17T15:28:42
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in c599a15d268b1db2aeadea19df2adc3bf2eb6bee
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -64,9 +61,9 @@ F ext/fts2/mkfts2amal.tcl 974d5d438cb3f7c4a652639262f82418c1e4cff0
 F ext/fts3/README.syntax a19711dc5458c20734b8e485e75fb1981ec2427a
 F ext/fts3/README.tokenizers 998756696647400de63d5ba60e9655036cb966e9
 F ext/fts3/README.txt 8c18f41574404623b76917b9da66fcb0ab38328d
-F ext/fts3/fts3.c f6436b3bcd67f8638f2acd80583d26d3fcd81de5
+F ext/fts3/fts3.c 03be86c59ac1a60d448c6eda460a8975ff2f170d
 F ext/fts3/fts3.h 3a10a0af180d502cecc50df77b1b22df142817fe
-F ext/fts3/fts3Int.h 70528ba8c33991699f96ecc64112122833cdbdb5
+F ext/fts3/fts3Int.h b4f0b05ccafe1e5b4be2f052e9840dbd78a0395f
 F ext/fts3/fts3_expr.c 42d5697731cd30fbeabd081bb3e6d3df5531f606
 F ext/fts3/fts3_hash.c 3c8f6387a4a7f5305588b203fa7c887d753e1f1c
 F ext/fts3/fts3_hash.h 8331fb2206c609f9fc4c4735b9ab5ad6137c88ec
@@ -76,7 +73,7 @@ F ext/fts3/fts3_snippet.c 2c4c921155e4b6befd272041fb903d999ac07d30
 F ext/fts3/fts3_tokenizer.c b4f2d01c24573852755bc92864816785dae39318
 F ext/fts3/fts3_tokenizer.h 13ffd9fcb397fec32a05ef5cd9e0fa659bf3dbd3
 F ext/fts3/fts3_tokenizer1.c 6e5cbaa588924ac578263a598e4fb9f5c9bb179d
-F ext/fts3/fts3_write.c 4b21a0c6f2772b261f14e3a2e80e1e3e849268b0
+F ext/fts3/fts3_write.c 97a583b9e1d23d5af4278f3ee3c16a37c3e077f4
 F ext/fts3/mkfts3amal.tcl 252ecb7fe6467854f2aa237bf2c390b74e71f100
 F ext/icu/README.txt bf8461d8cdc6b8f514c080e4e10dc3b2bbdfefa9
 F ext/icu/icu.c 850e9a36567bbcce6bd85a4b68243cad8e3c2de2
@@ -860,14 +857,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 9b272ed46fc704cb818b71d18ae8ee73a752a881
-R ec9abff0e1e30c45c3aa3ccb3e02d4e5
-U drh
-Z eaed35cb764a960456de79e5b47e09e6
------BEGIN PGP SIGNATURE-----
-Version: GnuPG v1.4.6 (GNU/Linux)
-
-iD8DBQFMkr9toxKgR168RlERAqDrAJ0UIliZKF7boeq4kfRQpga7FkaNtACfdx1m
-EV1qqSjczz5T1tIS01ADlXI=
-=CBtt
------END PGP SIGNATURE-----
+P 876845661a944ec1c841d1e2486d070efb76e5cd
+R 401b1a82d59ba178c1657b3c6769d891
+U dan
+Z abafac0893458198170055470419f700

diff --git a/manifest.uuid b/manifest.uuid
index f03abcb4c60fda6c7dd358a7e5b1b9580147264a..a1a5e14c13fef52bcac611744413718d3f0bdf5d 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-876845661a944ec1c841d1e2486d070efb76e5cd
\ No newline at end of file
+018e82c775d0fb8c0d90cddf7a87c20c8c8172a9
\ No newline at end of file