Have SQLITE_ENABLE_SETLK_TIMEOUT builds block when locking a read-lock slot.

FossilOrigin-Name: f797baf47cf7859cfd8ce248f4f3087af4551a7040af990333426e5a7c269504

3 files changed, 14 insertions, 11 deletions

diff --git a/manifest b/manifest
index 2ccefe87c..82af9ff68 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C In\sSQLITE_ENABLE_SETLK_TIMEOUT\sbuilds,\suse\sblocking\slocks\sin\splace\sof\ssleep()\swhen\sopening\sa\sread-transaction.
-D 2023-11-27T19:22:50.016
+C Have\sSQLITE_ENABLE_SETLK_TIMEOUT\sbuilds\sblock\swhen\slocking\sa\sread-lock\sslot.
+D 2023-11-27T20:37:03.543
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -810,7 +810,7 @@ F src/vdbetrace.c fe0bc29ebd4e02c8bc5c1945f1d2e6be5927ec12c06d89b03ef2a4def34bf8
 F src/vdbevtab.c 2143db7db0ceed69b21422581f434baffc507a08d831565193a7a02882a1b6a7
 F src/vtab.c 154725ebecd3bc02f7fbd7ad3974334f73fff76e02a964e828e48a7c5fb7efff
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
-F src/wal.c f64bf6799dbbd346a9e2aae9b96e51dbbb222d24a7e7509db85fb0144e8d9f38
+F src/wal.c 86eaddc56b124de2df14dfaff292ca7bfb862dbd68728105547ddd6a1e799227
 F src/wal.h ba252daaa94f889f4b2c17c027e823d9be47ce39da1d3799886bbd51f0490452
 F src/walker.c 7c7ea0115345851c3da4e04e2e239a29983b61fb5b038b94eede6aba462640e2
 F src/where.c 1fdc69ce1333e9bd6d7d3df9fa5af1373a3f5bfdd52108d1dbc0ca85a55f777e
@@ -2143,11 +2143,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P a0c87ae9d3db914d18e2c8811db0d0ae3ad7b15c63de84fa975efce28bace27e
-R 35e10752e16b85b0bde20be6e18f8d14
-T *branch * blocking-dms-lock
-T *sym-blocking-dms-lock *
-T -sym-trunk *
+P a51ef39998e25e86bd0600e71d15011b12e05f4319608018293bdaecb09e8c97
+R 50c3db5d407d996f614a56ca5cb31c30
 U dan
-Z fd8676cc431af47934a9227125e3da50
+Z 3f1449733c562fe4e5bdc1215442e17e
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 9745d59d7..8a036325f 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a51ef39998e25e86bd0600e71d15011b12e05f4319608018293bdaecb09e8c97
\ No newline at end of file
+f797baf47cf7859cfd8ce248f4f3087af4551a7040af990333426e5a7c269504
\ No newline at end of file
diff --git a/src/wal.c b/src/wal.c
index c610c14d0..a15114710 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -2959,6 +2959,9 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   int i;                          /* Loop counter */
   int rc = SQLITE_OK;             /* Return code  */
   u32 mxFrame;                    /* Wal frame to lock to */
+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+  int nBlockTmout = 0;
+#endif
 
   assert( pWal->readLock<0 );     /* Not currently locked */
 
@@ -2996,7 +2999,8 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
     ** attempted read fails and (b) the shared lock taken on the DMS slot
     ** in os_unix.c.  Both of these locks are attempted from within the 
     ** call to walIndexReadHdr() below.  */
-    if( cnt>=10 && !useWal && walEnableBlockingMs(pWal, (nDelay+999)/1000) ){
+    nBlockTmout = (nDelay+998) / 1000;
+    if( !useWal && walEnableBlockingMs(pWal, nBlockTmout) ){
       nDelay = 1;
     }
 #endif
@@ -3126,7 +3130,9 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
     return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTINIT;
   }
 
+  (void)walEnableBlockingMs(pWal, nBlockTmout);
   rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
+  walDisableBlocking(pWal);
   if( rc ){
     return rc==SQLITE_BUSY ? WAL_RETRY : rc;
   }