Fix a segfault in sqlite3OsLock() (CVS 1525)

FossilOrigin-Name: 51348b82c4d5801091537b80059d770410774905

manifest

@@ -1,5 +1,5 @@
-C Work\stoward\scombining\sthe\sOP_MakeKey,\sOP_MakeIdxKey,\sand\sOP_MakeRecord\nopcodes\sinto\sone.\s\sThe\swork\sis\sincomplete.\s(CVS\s1524)
+C Fix\sa\ssegfault\sin\ssqlite3OsLock()\s(CVS\s1525)
-D 2004-06-02T01:22:02
+D 2004-06-02T06:30:16
 F Makefile.in ab7b0d5118e2da97bac66be8684a1034e3500f5a
 F Makefile.linux-gcc b86a99c493a5bfb402d1d9178dcdc4bd4b32f906
 F README f1de682fbbd94899d50aca13d387d1b3fd3be2dd
@@ -43,7 +43,7 @@ F src/os.h 833b9639720d1602d9bfa4ca69c615ec2bfe625a
 F src/os_common.h 744286a27de55c52f1b18921e8d17abbf7fafc0f
 F src/os_mac.c b823874690615ace0dd520d3ad1fe8bfd864b7e0
 F src/os_mac.h 51d2445f47e182ed32d3bd6937f81070c6fd9bd4
-F src/os_unix.c 3dc2868d7ff477323f2eaedda0e05921afb6f124
+F src/os_unix.c 36682ee5e93c2fdad63ff44f7e10ac7d4a39f746
 F src/os_unix.h 426e1480f0847a7f8ba22aa9ac5115520875610b
 F src/os_win.c 92b51a38437b98d8aa3ac05b57c71e1d1092e5be
 F src/os_win.h 5d41af24caaef6c13a2d8e2399caa1c57d45c84d
@@ -148,7 +148,7 @@ F test/tableapi.test e0c4cce61e58343caa84dab33fa6823cb35fe1e1
 F test/tclsqlite.test 853e4372004d209e2ff0d4b0b35c91d4f64cd7d8
 F test/temptable.test a770ba6308d7f7332fce985086b8e06bed6430c2
 F test/tester.tcl fc10520db0d3ce4ef6a8b5ab91bd102fc3f4280a
-F test/thread1.test 53f050d5be6932d9430df7756edd379366508ff6
+F test/thread1.test 2fd5c10e82434f6b03be77b61fde5a050668abf2
 F test/threadtest1.c f7f896e62ed46feae1dc411114a48c15a0f82ee2
 F test/threadtest2.c d94ca4114fd1504f7e0ae724bcd83d4b40931d86
 F test/trans.test 45fa0ed87ee487797ea6a30f3ec298a6618531b9
@@ -214,7 +214,7 @@ F www/support.tcl 1801397edd271cc39a2aadd54e701184b5181248
 F www/tclsqlite.tcl 19191cf2a1010eaeff74c51d83fd5f5a4d899075
 F www/vdbe.tcl 59288db1ac5c0616296b26dce071c36cb611dfe9
 F www/whentouse.tcl a8335bce47cc2fddb07f19052cb0cb4d9129a8e4
-P b53640ed2232aaf173a71636073477d80407d11f
+P 165d69a04cca719dec2b042117f848f153721a1d
-R 65e9a4b0c9422591cc77c047015d1b85
+R e34294435e363d8121bbbf40938d6dd7
-U drh
+U danielk1977
-Z f635685494f9f4de060c8aaaeeb301d1
+Z cf403c13a566790d4729e792131db901

manifest.uuid

@@ -1 +1 @@
-165d69a04cca719dec2b042117f848f153721a1d
+51348b82c4d5801091537b80059d770410774905

src/os_unix.c

@@ -61,7 +61,6 @@
 */
 #include "os_common.h"
 
-
 /*
 ** Here is the dirt on POSIX advisory locks:  ANSI STD 1003.1 (1996)
 ** section 6.5.2.2 lines 483 through 490 specify that when a process
@@ -649,7 +648,6 @@ int sqlite3OsFileSize(OsFile *id, off_t *pSize){
 ** available on the host, then an SQLITE_NOLFS is returned.
 */
 int sqlite3OsReadLock(OsFile *id){
-  int rc;
   return sqlite3OsLock(id, SHARED_LOCK);
 }
 
@@ -660,7 +658,6 @@ int sqlite3OsReadLock(OsFile *id){
 ** available on the host, then an SQLITE_NOLFS is returned.
 */
 int sqlite3OsWriteLock(OsFile *id){
-  int rc;
   return sqlite3OsLock(id, EXCLUSIVE_LOCK);
 }
 
@@ -715,13 +712,14 @@ int sqlite3OsLock(OsFile *id, int locktype){
       (pLock->locktype==SHARED_LOCK || pLock->locktype==RESERVED_LOCK) ){
     assert( locktype==SHARED_LOCK );
     assert( id->locked==0 );
+    assert( pLock->cnt>0 );
     id->locked = SHARED_LOCK;
     pLock->cnt++;
     id->pOpen->nLock++;
     goto end_lock;
   }
 
-  lock.l_len = 1L;
+  lock.l_len = 0L;
   lock.l_whence = SEEK_SET;
 
   /* If control gets to this point, then actually go ahead and make
@@ -729,7 +727,6 @@ int sqlite3OsLock(OsFile *id, int locktype){
   */
   if( locktype==SHARED_LOCK ){
     assert( pLock->cnt==0 );
-    assert( id->pOpen->nLock==0 );
     assert( pLock->locktype==0 );
   
     /* Grab a read-lock on byte 2. This ensures that no other process
@@ -753,7 +750,7 @@ int sqlite3OsLock(OsFile *id, int locktype){
       rc = (errno==EINVAL) ? SQLITE_NOLFS : SQLITE_BUSY;
     }else{
       id->locked = SHARED_LOCK;
-      id->pOpen->nLock = 1;
+      id->pOpen->nLock++;
       pLock->cnt = 1;
     }
   }else{
@@ -782,9 +779,11 @@ int sqlite3OsLock(OsFile *id, int locktype){
     }
   }
   
-  id->locked = locktype;
+  if( rc==SQLITE_OK ){
-  pLock->locktype = locktype;
+    id->locked = locktype;
-  assert(pLock->locktype==RESERVED_LOCK||(id->pOpen->nLock==1&&pLock->cnt==1));
+    pLock->locktype = locktype;
+    assert( pLock->locktype==RESERVED_LOCK || pLock->cnt==1 );
+  }
 
 end_lock:
   sqlite3OsLeaveMutex();
@@ -800,10 +799,10 @@ end_lock:
 int sqlite3OsUnlock(OsFile *id){
   int rc;
   if( !id->locked ) return SQLITE_OK;
+  id->locked = 0;
   sqlite3OsEnterMutex();
   assert( id->pLock->cnt!=0 );
   if( id->pLock->cnt>1 ){
-    id->locked = 0;
     id->pLock->cnt--;
     rc = SQLITE_OK;
   }else{
@@ -819,9 +818,9 @@ int sqlite3OsUnlock(OsFile *id){
       rc = SQLITE_OK;
       id->pLock->cnt = 0;
       id->pLock->locktype = 0;
-      id->locked = 0;
     }
   }
+
   if( rc==SQLITE_OK ){
     /* Decrement the count of locks against this same file.  When the
     ** count reaches zero, close any other file descriptors whose close

test/thread1.test

@@ -11,7 +11,7 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this script is multithreading behavior
 #
-# $Id: thread1.test,v 1.3 2004/02/11 02:18:07 drh Exp $
+# $Id: thread1.test,v 1.4 2004/06/02 06:30:18 danielk1977 Exp $
 
 
 set testdir [file dirname $argv0]
@@ -147,12 +147,12 @@ do_test thread1-2.9 {
   thread_result C
 } SQLITE_DONE
 do_test thread1-2.10 {
-  execsql {SELECT * FROM t2}
-} {98 99}
-do_test thread1-2.11 {
   thread_finalize C
   thread_result C
 } SQLITE_OK
+do_test thread1-2.11 {
+  execsql {SELECT * FROM t2}
+} {98 99}
 
 thread_halt *   
 finish_test