From a3fad6f5f3f480dc891d8d3df372bbc4e3da9e20 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 18 Jan 2006 14:06:37 +0000
Subject: [PATCH] Convert the unix driver to use a recusive mutex.  Similar
 changes to the windows driver are pending. (CVS 2968)

FossilOrigin-Name: 8830bbbac8e0c9243956aac42dc9f86a0bd1fa07
---
 manifest      | 14 +++++++-------
 manifest.uuid |  2 +-
 src/os_unix.c | 31 ++++++++++++++++++++++++-------
 3 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/manifest b/manifest
index c7036ac93d..587c62a281 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Handle\smalloc()\sfailures\sthat\soccur\sin\sopen16()\sand\serrmsg16().\s(CVS\s2967)
-D 2006-01-18T05:51:58
+C Convert\sthe\sunix\sdriver\sto\suse\sa\srecusive\smutex.\s\sSimilar\schanges\sto\sthe\nwindows\sdriver\sare\spending.\s(CVS\s2968)
+D 2006-01-18T14:06:38
 F Makefile.in ab3ffd8d469cef4477257169b82810030a6bb967
 F Makefile.linux-gcc aee18d8a05546dcf1888bd4547e442008a49a092
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -55,7 +55,7 @@ F src/os.h 9debc3d3ca4cdafde222a0ea74a4c8415aef4f22
 F src/os_common.h 95b29ca6f3e6636cb33c9219b3f91a96fa7224b1
 F src/os_test.c 49833426101f99aee4bb5f6a44b7c4b2029fda1c
 F src/os_test.h 903c93554c23d88f34f667f1979e4a1cee792af3
-F src/os_unix.c 5f1ce55c0264114219cb9ae8e95b8624376c4fcb
+F src/os_unix.c 7c085f807922309006f00b5fd8963865b92ff939
 F src/os_unix.h 5768d56d28240d3fe4537fac08cc85e4fb52279e
 F src/os_win.c b9cb6254698cd7c2587c27e65b78c585473c6ffa
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
@@ -341,7 +341,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P 95c5903f368413019af83aa73263e0e9d1204b62
-R 6a825d2cc0d8c1f698b4dde375d79ff9
-U danielk1977
-Z 11afff1c430074d91a3b87b617dd2674
+P 86eab9e53db8d7fecc789fe3d8cd8d7be3196fed
+R 79ed702da5352631a14fd5c72072c4b8
+U drh
+Z d577dbc25e956de86c8f9b79929b1f93
diff --git a/manifest.uuid b/manifest.uuid
index 4c8b05804e..f6a576c10e 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-86eab9e53db8d7fecc789fe3d8cd8d7be3196fed
\ No newline at end of file
+8830bbbac8e0c9243956aac42dc9f86a0bd1fa07
\ No newline at end of file
diff --git a/src/os_unix.c b/src/os_unix.c
index 9263744b36..35d29ad3cf 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -1667,7 +1667,9 @@ int sqlite3UnixSleep(int ms){
 */
 static int inMutex = 0;
 #ifdef SQLITE_UNIX_THREADS
-static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_t mutexOwner;
+static pthread_mutex_t mutex1 = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t mutex2 = PTHREAD_MUTEX_INITIALIZER;
 #endif
 
 /*
@@ -1682,16 +1684,27 @@ static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 */
 void sqlite3UnixEnterMutex(){
 #ifdef SQLITE_UNIX_THREADS
-  pthread_mutex_lock(&mutex);
+  pthread_mutex_lock(&mutex1);
+  if( inMutex==0 ){
+    pthread_mutex_lock(&mutex2);
+    mutexOwner = pthread_self();
+  }
+  pthread_mutex_unlock(&mutex1);
 #endif
-  assert( !inMutex );
-  inMutex = 1;
+  inMutex++;
 }
 void sqlite3UnixLeaveMutex(){
-  assert( inMutex );
-  inMutex = 0;
+  assert( inMutex>0 );
 #ifdef SQLITE_UNIX_THREADS
-  pthread_mutex_unlock(&mutex);
+  assert( pthread_equal(mutexOwner, pthread_self()) );
+  pthread_mutex_lock(&mutex1);
+  inMutex--;
+  if( inMutex==0 ){
+    pthread_mutex_unlock(&mutex2);
+  }
+  pthread_mutex_unlock(&mutex1);
+#else
+  inMutex--;
 #endif
 }
 
@@ -1699,7 +1712,11 @@ void sqlite3UnixLeaveMutex(){
 ** Return TRUE if we are currently within the mutex and FALSE if not.
 */
 int sqlite3UnixInMutex(){
+#ifdef SQLITE_UNIX_THREADS
+  return inMutex && pthread_equal(mutexOwner, pthread_self());
+#else
   return inMutex;
+#endif
 }
 
 /*