Merge enhancements from trunk.

FossilOrigin-Name: d1731385c077f298b0cf654d6183ed40f7e5c07e4e2ab7f69109cf951ce99d9e
2025-08-07 02:42:48 +03:00 · 2020-04-02 12:24:08 +00:00
parent 8f78a528d5 892edb69c4
commit e065a18a4b
14 changed files with 120 additions and 58 deletions
--- a/34
+++ b/34
@@ -1,5 +1,5 @@
-C Add\sthe\stables_used()\stable-valued\sfunction\sas\sa\svariation\son\sbytecode().
-D 2020-03-26T16:48:18.810
+C Merge\senhancements\sfrom\strunk.
+D 2020-04-02T12:24:08.483
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -472,14 +472,14 @@ F src/auth.c a3d5bfdba83d25abed1013a8c7a5f204e2e29b0c25242a56bc02bb0c07bf1e06
 F src/backup.c 5e617c087f1c2d6005c2ec694ce80d6e16bc68d906e1b1c556d7c7c2228b636b
 F src/bitvec.c 17ea48eff8ba979f1f5b04cc484c7bb2be632f33
 F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
-F src/btree.c 7271a120a66dfd12edcee942443fcd7b3860514a5621cb26a374781af1462117
+F src/btree.c 79ce96ab39fd2fc21ff00d03913587d5a08280a9eb081a08d0ffa9fa26f4f6fb
 F src/btree.h 6111552f19ed7a40f029cf4b33badc6fef9880314fffd80a945f0b7f43ab7471
 F src/btreeInt.h dee1a1d0c621524e006bb260bd6b66d5d1867da6fe38cba9ad7b6a9bb9c0c175
 F src/build.c 3d22f21c4701f62c1a191c6b6d17552fb1b593fe9a97c0613cca05ab104a9a51
 F src/callback.c d0b853dd413255d2e337b34545e54d888ea02f20da5ad0e63585b389624c4a6c
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 6892999ee100bd72b64f84dd7a8f737817d72872648705fbf8ed9575e1f1dd1a
-F src/date.c 6c408fdd2e9ddf6e8431aba76315a2d061bea2cec8fbb75e25d7c1ba08274712
+F src/date.c b29b349d277e3d579dcc295b24c0a2caed83fd8f090a9f7cbe6070c0fd662384
 F src/dbpage.c 8a01e865bf8bc6d7b1844b4314443a6436c07c3efe1d488ed89e81719047833a
 F src/dbstat.c 793deaf88a0904f88285d93d6713c636d55ede0ffd9f08d10f4ea825531d367f
 F src/delete.c 11000121c4281c0bce4e41db29addfaea0038eaa127ece02557c9207bc3e541d
@@ -495,8 +495,8 @@ F src/in-operator.md 10cd8f4bcd225a32518407c2fb2484089112fd71
 F src/insert.c 8e4211d04eb460c0694d486c6ba1c068d468c6f653c3f237869a802ad82854de
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c b179df50e6e8bb0c36c149e95d958d49bd8c6c7469e59c01b53d164360bc6c32
-F src/main.c ed15d7e6b73ac081cf354b3544e7792a775492b19b2abf95e9f8be06e8c1c5e5
-F src/malloc.c eaa4dc9602ce28b077f7de2eb275db2be270c5cc56d7fec5466301bd9b80e2f5
+F src/main.c 28f43ecf5132240b43be1c834329b2139bb9b8c42cd401159ce70fef8c68ca69
+F src/malloc.c cabfef0d725e04c8abfe0231a556ed8b78bf329dcc3fddbf903f6cdcd53cf4e6
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c c12a42539b1ba105e3707d0e628ad70e611040d8f5e38cf942cee30c867083de
 F src/mem2.c f1940d9e91948dd6a908fbb9ce3835c36b5d83c3
@@ -515,7 +515,7 @@ F src/os.c 669cc3839cc35d20f81faf0be1ab6d4581cea35e9d8f3a9d48a98d6571f7c285
 F src/os.h 48388821692e87da174ea198bf96b1b2d9d83be5dfc908f673ee21fafbe0d432
 F src/os_common.h b2f4707a603e36811d9b1a13278bffd757857b85
 F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
-F src/os_unix.c 238ad16109b4160d0fba2597ef71459995ab5e304b3d8bbe290a8d5d6d6000e0
+F src/os_unix.c 06593ba4bdfae42b30a897b3b4e59abb88a11d50dd0cad39003da955d822b8d1
 F src/os_win.c 035a813cbd17f355bdcad7ab894af214a9c13a1db8aeac902365350b98cd45a7
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c a71ffd145f55e28cbdc1bdabb5e6bef063da428a6c0de3c3a36e9a0c41d4c8c0
@@ -533,10 +533,10 @@ F src/resolve.c 903a70c48d0f72fdd657b225d499cf99ec01d575cf3fbc8196b43562045319ac
 F src/rowset.c ba9515a922af32abe1f7d39406b9d35730ed65efab9443dc5702693b60854c92
 F src/select.c 6908c059e4289149f88bfd641305b96ee34e500855fcd580ff8df1bd0885191a
 F src/shell.c.in 7bb9005bf876c4e1210257a63fa49b556f4eddf59f94b6eb310fcb5096bec0e9
-F src/sqlite.h.in 802957feeb249ede54f8dfe99b72aa19e70a0b7737969c46e625dc2f9f2d42b0
+F src/sqlite.h.in cc7d0949ac32bb68ed97acdb3e7ae91cd413a24d32d6ff049ef8308d620a4367
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 9c5269260409eb3275324ccace6a13a96f4ad330c708415f70ca6097901ff4ee
-F src/sqliteInt.h 24cc324de1a15b4ab0efdc74277be0b7f90e5f7d29ba2cc2173dea3878974c1b
+F src/sqliteInt.h b0165686885990e29622f56b2f95b93c12c6f84be4cf1ee60797d80a0dcd7f15
 F src/sqliteLimit.h 95cb8479ca459496d9c1c6a9f76b38aee12203a56ce1092fe13e50ae2454c032
 F src/status.c 9ff2210207c6c3b4d9631a8241a7d45ab1b26a0e9c84cb07a9b5ce2de9a3b278
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -595,7 +595,7 @@ F src/test_windirent.h 90dfbe95442c9762357fe128dc7ae3dc199d006de93eb33ba3972e0a9
 F src/test_window.c cdae419fdcea5bad6dcd9368c685abdad6deb59e9fc8b84b153de513d394ba3f
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
-F src/tokenize.c 7b17f6e2f20f6cbcb0b215025a86b7457c38451fc7622f705e553d7a488c572d
+F src/tokenize.c eee7bae3ec0bc4abee951554bf46a8ba567c0f7752ac90c820ed8afff4c612dc
 F src/treeview.c 82c6391a3ba76215d4185fd4719a56ec4caf186a40c8a7b6e6ba4ae4467c2742
 F src/trigger.c 4ada1037cc99777f647a882cdacbd1a4deb6567b69daf02946286401b88cdc04
 F src/update.c 3eb778c42155d944377a4ee5e440b04520f07094804ed6ce63d2528f619614d9
@@ -603,11 +603,11 @@ F src/upsert.c 2920de71b20f04fe25eb00b655d086f0ba60ea133c59d7fa3325c49838818e78
 F src/utf.c 95fb6e03a5ca679045c5adccd05380f0addccabef5911abddcb06af069500ab7
 F src/util.c a285c1e026907b69fa2592bd05047a565a1d8a1aef2b73c924b6a8ffe772871a
 F src/vacuum.c 813b510ba887fee6492bcb11f2bf77d7eb58b232b83649136372e0a2fc17f4b9
-F src/vdbe.c c1c123c6248fa88940b932a00bcc75056921b6d046d45a82566cb97415d2299c
+F src/vdbe.c 972999395eee88702091fb5d50cf4effd07889c371807d222a7f517388e6378e
 F src/vdbe.h 07b8c636a87df8b6e58f29d6badd7f10d5844353deff1d7c88ed1c2bfe3bbd35
 F src/vdbeInt.h 5f36e2261731e6a39c66c6902634e474d4a98ed14ca10be6dea5c3776ece4342
-F src/vdbeapi.c 1252d80c548711e47a6d84dae88ed4e95d3fbb4e7bd0eaa1347299af7efddf02
-F src/vdbeaux.c 2b81b42788e718786817fe339eb728e81401542fb221c7f95b24ce39a735eff8
+F src/vdbeapi.c d176ee7251d5344de7bb2a0d2dd0fe536834e5843d9bc2389e0f5cdcd5374141
+F src/vdbeaux.c 07b697900b22bd2717cee24ff4cfc3c7433a7e1c62979e687a0d23f2668b9904
 F src/vdbeblob.c 253ed82894924c362a7fa3079551d3554cd1cdace39aa833da77d3bc67e7c1b1
 F src/vdbemem.c 39b942ecca179f4f30a32b54579a85d74ccaefa5af2a0ad2700abe5ef0768b22
 F src/vdbesort.c 2be76d26998ce2b3324cdcc9f6443728e54b6c7677c553ad909c7d7cfab587df
@@ -615,7 +615,7 @@ F src/vdbetrace.c fa3bf238002f0bbbdfb66cc8afb0cea284ff9f148d6439bc1f6f2b4c3b7143
 F src/vdbevtab.c 3f7fd339425729f6cef36ef0bc576bf42641d2a664c746b54a6e2c045ae1a248
 F src/vtab.c 7b704a90515a239c6cdba6a66b1bb3a385e62326cceb5ecb05ec7a091d6b8515
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
-F src/wal.c 697424314e40d99f93f548c7bfa526c10e87f4bdf64d5a76a96b999dd7133ebc
+F src/wal.c ea8dad28bb0e2b85ac1ab7618968687ff5fd522af8a1a38d6960ec176ebc8ee6
 F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
 F src/walker.c 7c429c694abd12413a5c17aec9f47cfe9eba6807e6b0a32df883e8e3a14835ed
 F src/where.c 9546c82056e8cdb27291f98cf1adca5d271240b399bb97b32f77fc2bea6146c9
@@ -1861,7 +1861,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P d7db09101878102e192ee7a81437e8f6f2e317ddf110852673a2e81d1f80ae0e
-R 97037e53b3358656d7c80bf175451cab
+P 6283c677d57220e54375a6463f453c6d068e042263558df16cff1055d1b0d3f5 a49f8ec552bede7da731e0571ccf49de1a30e7be3a5673150436c8b411ba6ffc
+R 3169d95f383859bfa6626ea7d2fa0b6d
 U drh
-Z 77036c852e70ef7951f1cc73bc25be37
+Z 88bed112404a5cfaec60f425ff57b550
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-6283c677d57220e54375a6463f453c6d068e042263558df16cff1055d1b0d3f5
+d1731385c077f298b0cf654d6183ed40f7e5c07e4e2ab7f69109cf951ce99d9e
--- a/src/btree.c
+++ b/src/btree.c
@@ -9530,7 +9530,7 @@ int sqlite3BtreeCount(sqlite3 *db, BtCursor *pCur, i64 *pnEntry){
  /* Unless an error occurs, the following loop runs one iteration for each
  ** page in the B-Tree structure (not including overflow pages). 
  */
-  while( rc==SQLITE_OK && !db->u1.isInterrupted ){
+  while( rc==SQLITE_OK && !AtomicLoad(&db->u1.isInterrupted) ){
    int iIdx;                          /* Index of child node in parent */
    MemPage *pPage;                    /* Current page of the b-tree */

@@ -9656,7 +9656,7 @@ static int checkRef(IntegrityCk *pCheck, Pgno iPage){
    checkAppendMsg(pCheck, "2nd reference to page %d", iPage);
    return 1;
  }
-  if( pCheck->db->u1.isInterrupted ) return 1;
+  if( AtomicLoad(&pCheck->db->u1.isInterrupted) ) return 1;
  setPageReferenced(pCheck, iPage);
  return 0;
 }
--- a/src/date.c
+++ b/src/date.c
@@ -621,12 +621,12 @@ static const struct {
  double rLimit;      /* Maximum NNN value for this transform */
  double rXform;      /* Constant used for this transform */
 } aXformType[] = {
-  { 0, 6, "second", 464269060800.0, 86400000.0/(24.0*60.0*60.0) },
-  { 0, 6, "minute", 7737817680.0,   86400000.0/(24.0*60.0)      },
-  { 0, 4, "hour",   128963628.0,    86400000.0/24.0             },
+  { 0, 6, "second", 464269060800.0, 1000.0         },
+  { 0, 6, "minute", 7737817680.0,   60000.0        },
+  { 0, 4, "hour",   128963628.0,    3600000.0      },
  { 0, 3, "day",    5373485.0,      86400000.0     },
-  { 1, 5, "month",  176546.0,       30.0*86400000.0             },
-  { 2, 4, "year",   14713.0,        365.0*86400000.0            },
+  { 1, 5, "month",  176546.0,       2592000000.0   },
+  { 2, 4, "year",   14713.0,        31536000000.0  },
 };

 /*
--- a/src/main.c
+++ b/src/main.c
@@ -1569,9 +1569,21 @@ static int sqliteDefaultBusyCallback(
 #ifdef SQLITE_ENABLE_SETLK_TIMEOUT
  if( sqlite3OsFileControl(pFile,SQLITE_FCNTL_LOCK_TIMEOUT,&tmout)==SQLITE_OK ){
    if( count ){
+      /* If this is the second or later invocation of the busy-handler,
+      ** but tmout==0, then code in wal.c must have disabled the blocking
+      ** lock before the SQLITE_BUSY error was hit. In this case, no delay
+      ** occurred while waiting for the lock, so fall through to the xSleep()
+      ** code below to delay a while before retrying the lock.  
+      **
+      ** Alternatively, if tmout!=0, then SQLite has already waited 
+      ** sqlite3.busyTimeout ms for a lock. In this case, return 0 to 
+      ** indicate that the lock should not be retried and the SQLITE_BUSY 
+      ** error returned to the application.  */
+      if( tmout ){
        tmout = 0;
        sqlite3OsFileControl(pFile, SQLITE_FCNTL_LOCK_TIMEOUT, &tmout);
        return 0;
+      }
    }else{
      return 1;
    }
@@ -1721,7 +1733,7 @@ void sqlite3_interrupt(sqlite3 *db){
    return;
  }
 #endif
-  db->u1.isInterrupted = 1;
+  AtomicStore(&db->u1.isInterrupted, 1);
 }


@@ -2343,7 +2355,7 @@ int sqlite3_wal_checkpoint_v2(
  /* If there are no active statements, clear the interrupt flag at this
  ** point.  */
  if( db->nVdbeActive==0 ){
-    db->u1.isInterrupted = 0;
+    AtomicStore(&db->u1.isInterrupted, 0);
  }

  sqlite3_mutex_leave(db->mutex);
--- a/src/malloc.c
+++ b/src/malloc.c
@@ -760,7 +760,7 @@ void sqlite3OomFault(sqlite3 *db){
  if( db->mallocFailed==0 && db->bBenignMalloc==0 ){
    db->mallocFailed = 1;
    if( db->nVdbeExec>0 ){
-      db->u1.isInterrupted = 1;
+      AtomicStore(&db->u1.isInterrupted, 1);
    }
    DisableLookaside;
    if( db->pParse ){
@@ -779,7 +779,7 @@ void sqlite3OomFault(sqlite3 *db){
 void sqlite3OomClear(sqlite3 *db){
  if( db->mallocFailed && db->nVdbeExec==0 ){
    db->mallocFailed = 0;
-    db->u1.isInterrupted = 0;
+    AtomicStore(&db->u1.isInterrupted, 0);
    assert( db->lookaside.bDisable>0 );
    EnableLookaside;
  }
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3995,7 +3995,9 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
    }
 #ifdef SQLITE_ENABLE_SETLK_TIMEOUT
    case SQLITE_FCNTL_LOCK_TIMEOUT: {
+      int iOld = pFile->iBusyTimeout;
      pFile->iBusyTimeout = *(int*)pArg;
+      *(int*)pArg = iOld;
      return SQLITE_OK;
    }
 #endif
@@ -4817,6 +4819,24 @@ static int unixShmLock(
  assert( pShmNode->hShm>=0 || pDbFd->pInode->bProcessLock==1 );
  assert( pShmNode->hShm<0 || pDbFd->pInode->bProcessLock==0 );

+  /* Check that, if this to be a blocking lock, that locks have been
+  ** obtained in the following order.
+  **
+  **   1. Checkpointer lock (ofst==1).
+  **   2. Recover lock (ofst==2).
+  **   3. Read locks (ofst>=3 && ofst<SQLITE_SHM_NLOCK).
+  **   4. Write lock (ofst==0).
+  **
+  ** In other words, if this is a blocking lock, none of the locks that
+  ** occur later in the above list than the lock being obtained may be
+  ** held.  */
+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+  assert( pDbFd->iBusyTimeout==0 
+       || (flags & SQLITE_SHM_UNLOCK) || ofst==0
+       || ((p->exclMask|p->sharedMask)&~((1<<ofst)-2))==0
+  );
+#endif
+
  mask = (1<<(ofst+n)) - (1<<ofst);
  assert( n>1 || mask==(1<<ofst) );
  sqlite3_mutex_enter(pShmNode->pShmMutex);
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -1087,10 +1087,12 @@ struct sqlite3_io_methods {
 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
 **
 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
-** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain
-** a file lock using the xLock or xShmLock methods of the VFS to wait
-** for up to M milliseconds before failing, where M is the single 
-** unsigned integer parameter.
+** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
+** to block for up to M milliseconds before failing when attempting to 
+** obtain a file lock using the xLock or xShmLock methods of the VFS. 
+** The parameter is a pointer to a 32-bit signed integer that contains
+** the value that M is to be set to. Before returning, the 32-bit signed
+** integer is overwritten with the previous value of M.
 **
 ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -186,6 +186,21 @@
 #pragma warn -spa /* Suspicious pointer arithmetic */
 #endif

+/*
+** WAL mode depends on atomic aligned 32-bit loads and stores in a few
+** places.  The following macros try to make this explicit.
+*/
+#ifndef __has_feature
+# define __has_feature(x) 0       /* compatibility with non-clang compilers */
+#endif
+#if GCC_VERSION>=4007000 || __has_feature(c_atomic)
+# define AtomicLoad(PTR)       __atomic_load_n((PTR),__ATOMIC_RELAXED)
+# define AtomicStore(PTR,VAL)  __atomic_store_n((PTR),(VAL),__ATOMIC_RELAXED)
+#else
+# define AtomicLoad(PTR)       (*(PTR))
+# define AtomicStore(PTR,VAL)  (*(PTR) = (VAL))
+#endif
+
 /*
 ** Include standard header files as necessary
 */
--- a/src/tokenize.c
+++ b/src/tokenize.c
@@ -568,7 +568,7 @@ int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
  assert( zSql!=0 );
  mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
  if( db->nVdbeActive==0 ){
-    db->u1.isInterrupted = 0;
+    AtomicStore(&db->u1.isInterrupted, 0);
  }
  pParse->rc = SQLITE_OK;
  pParse->zTail = zSql;
@@ -613,7 +613,7 @@ int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
    if( tokenType>=TK_SPACE ){
      assert( tokenType==TK_SPACE || tokenType==TK_ILLEGAL );
 #endif /* SQLITE_OMIT_WINDOWFUNC */
-      if( db->u1.isInterrupted ){
+      if( AtomicLoad(&db->u1.isInterrupted) ){
        pParse->rc = SQLITE_INTERRUPT;
        break;
      }
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -707,7 +707,7 @@ int sqlite3VdbeExec(
  assert( p->explain==0 );
  p->pResultSet = 0;
  db->busyHandler.nBusy = 0;
-  if( db->u1.isInterrupted ) goto abort_due_to_interrupt;
+  if( AtomicLoad(&db->u1.isInterrupted) ) goto abort_due_to_interrupt;
  sqlite3VdbeIOTraceSql(p);
 #ifdef SQLITE_DEBUG
  sqlite3BeginBenignMalloc();
@@ -891,7 +891,7 @@ jump_to_p2_and_check_for_interrupt:
  ** checks on every opcode.  This helps sqlite3_step() to run about 1.5%
  ** faster according to "valgrind --tool=cachegrind" */
 check_for_interrupt:
-  if( db->u1.isInterrupted ) goto abort_due_to_interrupt;
+  if( AtomicLoad(&db->u1.isInterrupted) ) goto abort_due_to_interrupt;
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  /* Call the progress callback if it is configured and the required number
  ** of VDBE ops have been executed (either since this invocation of
@@ -7999,7 +7999,7 @@ no_mem:
  ** flag.
  */
 abort_due_to_interrupt:
-  assert( db->u1.isInterrupted );
+  assert( AtomicLoad(&db->u1.isInterrupted) );
  rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_INTERRUPT;
  p->rc = rc;
  sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -663,7 +663,7 @@ static int sqlite3Step(Vdbe *p){
    ** from interrupting a statement that has not yet started.
    */
    if( db->nVdbeActive==0 ){
-      db->u1.isInterrupted = 0;
+      AtomicStore(&db->u1.isInterrupted, 0);
    }

    assert( db->nVdbeWrite>0 || db->autoCommit==0 
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -2140,7 +2140,7 @@ int sqlite3VdbeList(

  if( rc==SQLITE_OK ){
    pOp = aOp + i;
-    if( db->u1.isInterrupted ){
+    if( AtomicLoad(&db->u1.isInterrupted) ){
      p->rc = SQLITE_INTERRUPT;
      rc = SQLITE_ERROR;
      sqlite3VdbeError(p, sqlite3ErrStr(p->rc));
--- a/src/wal.c
+++ b/src/wal.c
@@ -258,18 +258,6 @@ int sqlite3WalTrace = 0;
 # define WALTRACE(X)
 #endif

-/*
-** WAL mode depends on atomic aligned 32-bit loads and stores in a few
-** places.  The following macros try to make this explicit.
-*/
-#if GCC_VESRION>=5004000
-# define AtomicLoad(PTR)       __atomic_load_n((PTR),__ATOMIC_RELAXED)
-# define AtomicStore(PTR,VAL)  __atomic_store_n((PTR),(VAL),__ATOMIC_RELAXED)
-#else
-# define AtomicLoad(PTR)       (*(PTR))
-# define AtomicStore(PTR,VAL)  (*(PTR) = (VAL))
-#endif
-
 /*
 ** The maximum (and only) versions of the wal and wal-index formats
 ** that may be interpreted by this version of SQLite.
@@ -1140,6 +1128,11 @@ static int walIndexRecover(Wal *pWal){
  u32 aFrameCksum[2] = {0, 0};
  int iLock;                      /* Lock offset to lock for checkpoint */

+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+  int tmout = 0;
+  sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_LOCK_TIMEOUT, (void*)&tmout);
+#endif
+
  /* Obtain an exclusive lock on all byte in the locking range not already
  ** locked by the caller. The caller is guaranteed to have locked the
  ** WAL_WRITE_LOCK byte, and may have also locked the WAL_CKPT_LOCK byte.
@@ -1886,7 +1879,7 @@ static int walCheckpoint(
      while( rc==SQLITE_OK && 0==walIteratorNext(pIter, &iDbpage, &iFrame) ){
        i64 iOffset;
        assert( walFramePgno(pWal, iFrame)==iDbpage );
-        if( db->u1.isInterrupted ){
+        if( AtomicLoad(&db->u1.isInterrupted) ){
          rc = db->mallocFailed ? SQLITE_NOMEM_BKPT : SQLITE_INTERRUPT;
          break;
        }
@@ -2599,7 +2592,8 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
    for(i=1; i<WAL_NREADER; i++){
      rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
      if( rc==SQLITE_OK ){
-        mxReadMark = AtomicStore(pInfo->aReadMark+i,mxFrame);
+        AtomicStore(pInfo->aReadMark+i,mxFrame);
+        mxReadMark = mxFrame;
        mxI = i;
        walUnlockExclusive(pWal, WAL_READ_LOCK(i), 1);
        break;
@@ -2758,6 +2752,9 @@ int sqlite3WalSnapshotRecover(Wal *pWal){
 int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
  int rc;                         /* Return code */
  int cnt = 0;                    /* Number of TryBeginRead attempts */
+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+  int tmout = 0;
+#endif

 #ifdef SQLITE_ENABLE_SNAPSHOT
  int bChanged = 0;
@@ -2767,6 +2764,12 @@ int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
  }
 #endif

+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+  /* Disable blocking locks. They are not useful when trying to open a
+  ** read-transaction, and blocking may cause deadlock anyway. */
+  sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_LOCK_TIMEOUT, (void*)&tmout);
+#endif
+
  do{
    rc = walTryBeginRead(pWal, pChanged, 0, ++cnt);
  }while( rc==WAL_RETRY );
@@ -2775,6 +2778,16 @@ int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
  testcase( rc==SQLITE_PROTOCOL );
  testcase( rc==SQLITE_OK );

+#ifdef SQLITE_ENABLE_SETLK_TIMEOUT
+  /* If they were disabled earlier and the read-transaction has been
+  ** successfully opened, re-enable blocking locks. This is because the
+  ** connection may attempt to upgrade to a write-transaction, which does
+  ** benefit from using blocking locks.  */
+  if( rc==SQLITE_OK ){
+    sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_LOCK_TIMEOUT, (void*)&tmout);
+  }
+#endif
+
 #ifdef SQLITE_ENABLE_SNAPSHOT
  if( rc==SQLITE_OK ){
    if( pSnapshot && memcmp(pSnapshot, &pWal->hdr, sizeof(WalIndexHdr))!=0 ){