From bc674334e5e18a9b2e824d4b02c65ec2a09d0637 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 7 Nov 2007 15:13:25 +0000
Subject: [PATCH] Add asserts on sqlite3_mutex_held() to the zero-malloc memory
 allocator, in order to prove that the mutex is held when it is needed. (CVS
 4534)

FossilOrigin-Name: 31eb4abc89e9c0fd90fde5486d4008f9d09fdf4e
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/mem3.c    | 12 +++++++++++-
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index 8b9abe5c05..3ea526d264 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Changes\sthe\sasynchronous\sI/O\stest\smodule\sso\sthat\sit\scan\sbe\sappended\sto\sthe\nend\sof\sthe\samalgamation.\s(CVS\s4533)
-D 2007-11-07T01:23:12
+C Add\sasserts\son\ssqlite3_mutex_held()\sto\sthe\szero-malloc\smemory\sallocator,\nin\sorder\sto\sprove\sthat\sthe\smutex\sis\sheld\swhen\sit\sis\sneeded.\s(CVS\s4534)
+D 2007-11-07T15:13:25
 F Makefile.in 30c7e3ba426ddb253b8ef037d1873425da6009a8
 F Makefile.linux-gcc 65241babba6faf1152bf86574477baab19190499
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -104,7 +104,7 @@ F src/malloc.c 60e392a4c12c839517f9b0db7b995f825444fb35
 F src/md5.c c5fdfa5c2593eaee2e32a5ce6c6927c986eaf217
 F src/mem1.c ad348eedd829528e66f4a5aead464d88e6b08d69
 F src/mem2.c 2a1da2e8debcfd0097188470f04573107a018116
-F src/mem3.c df13c608e8dfb54f62e3448eb126e760aecbacf1
+F src/mem3.c a9857cf92c9e4c889184b2cf1ca1839c801fc942
 F src/mutex.c 3259f62c2429967aee6dc112117a6d2f499ef061
 F src/mutex.h 079fa6fe9da18ceb89e79012c010594c6672addb
 F src/mutex_os2.c 7fe4773e98ed74a63b2e54fc557929eb155f6269
@@ -584,7 +584,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P 08a685abc149cd29c3595a61c9bc1a04e6d95c4d
-R 3b0bda0e6456e1bdcf3962caf8e375c7
+P c1fe27de7b6f0080466cc3f827979db9997e22a4
+R 4d22767fe7548ed57a40b50ba1b3d0b1
 U drh
-Z 8393b2be25309ab5b02c9ff46dbdc791
+Z 591ee87bae6e45cc97f6c36812f304cb
diff --git a/manifest.uuid b/manifest.uuid
index 612b57c9e6..03ac0b94c0 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c1fe27de7b6f0080466cc3f827979db9997e22a4
\ No newline at end of file
+31eb4abc89e9c0fd90fde5486d4008f9d09fdf4e
\ No newline at end of file
diff --git a/src/mem3.c b/src/mem3.c
index 8cbafe37ac..c006b5eeb7 100644
--- a/src/mem3.c
+++ b/src/mem3.c
@@ -20,7 +20,7 @@
 ** This version of the memory allocation subsystem is used if
 ** and only if SQLITE_MEMORY_SIZE is defined.
 **
-** $Id: mem3.c,v 1.5 2007/10/20 16:36:31 drh Exp $
+** $Id: mem3.c,v 1.6 2007/11/07 15:13:25 drh Exp $
 */
 
 /*
@@ -133,6 +133,7 @@ static struct {
 static void memsys3UnlinkFromList(int i, int *pRoot){
   int next = mem.aPool[i].u.list.next;
   int prev = mem.aPool[i].u.list.prev;
+  assert( sqlite3_mutex_held(mem.mutex) );
   if( prev==0 ){
     *pRoot = next;
   }else{
@@ -151,6 +152,7 @@ static void memsys3UnlinkFromList(int i, int *pRoot){
 */
 static void memsys3Unlink(int i){
   int size, hash;
+  assert( sqlite3_mutex_held(mem.mutex) );
   size = mem.aPool[i-1].u.hdr.size;
   assert( size==mem.aPool[i+size-1].u.hdr.prevSize );
   assert( size>=2 );
@@ -167,6 +169,7 @@ static void memsys3Unlink(int i){
 ** at *pRoot.
 */
 static void memsys3LinkIntoList(int i, int *pRoot){
+  assert( sqlite3_mutex_held(mem.mutex) );
   mem.aPool[i].u.list.next = *pRoot;
   mem.aPool[i].u.list.prev = 0;
   if( *pRoot ){
@@ -181,6 +184,7 @@ static void memsys3LinkIntoList(int i, int *pRoot){
 */
 static void memsys3Link(int i){
   int size, hash;
+  assert( sqlite3_mutex_held(mem.mutex) );
   size = mem.aPool[i-1].u.hdr.size;
   assert( size==mem.aPool[i+size-1].u.hdr.prevSize );
   assert( size>=2 );
@@ -259,6 +263,7 @@ int sqlite3_memory_alarm(
 static void memsys3OutOfMemory(int nByte){
   if( !mem.alarmBusy ){
     mem.alarmBusy = 1;
+    assert( sqlite3_mutex_held(mem.mutex) );
     sqlite3_mutex_leave(mem.mutex);
     sqlite3_release_memory(nByte);
     sqlite3_mutex_enter(mem.mutex);
@@ -283,6 +288,7 @@ static int memsys3Size(void *p){
 ** user portion of the chunk.
 */
 static void *memsys3Checkout(int i, int nBlock){
+  assert( sqlite3_mutex_held(mem.mutex) );
   assert( mem.aPool[i-1].u.hdr.size==nBlock );
   assert( mem.aPool[i+nBlock-1].u.hdr.prevSize==nBlock );
   mem.aPool[i-1].u.hdr.size = -nBlock;
@@ -296,6 +302,7 @@ static void *memsys3Checkout(int i, int nBlock){
 ** is not large enough, return 0.
 */
 static void *memsys3FromMaster(int nBlock){
+  assert( sqlite3_mutex_held(mem.mutex) );
   assert( mem.szMaster>=nBlock );
   if( nBlock>=mem.szMaster-1 ){
     /* Use the entire master */
@@ -340,6 +347,7 @@ static void *memsys3FromMaster(int nBlock){
 static void memsys3Merge(int *pRoot){
   int iNext, prev, size, i;
 
+  assert( sqlite3_mutex_held(mem.mutex) );
   for(i=*pRoot; i>0; i=iNext){
     iNext = mem.aPool[i].u.list.next;
     size = mem.aPool[i-1].u.hdr.size;
@@ -374,6 +382,7 @@ static void *memsys3Malloc(int nByte){
   int nBlock;
   int toFree;
 
+  assert( sqlite3_mutex_held(mem.mutex) );
   assert( sizeof(Mem3Block)==8 );
   if( nByte<=0 ){
     nBlock = 2;
@@ -451,6 +460,7 @@ void memsys3Free(void *pOld){
   Mem3Block *p = (Mem3Block*)pOld;
   int i;
   int size;
+  assert( sqlite3_mutex_held(mem.mutex) );
   assert( p>mem.aPool && p<&mem.aPool[SQLITE_MEMORY_SIZE/8] );
   i = p - mem.aPool;
   size = -mem.aPool[i-1].u.hdr.size;
-- 
2.47.3