From 561158937bab6dcd057026dc554d28a35c7e0bd6 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Mon, 5 Feb 2018 16:39:12 +0000
Subject: [PATCH] Allocation the mutex used by the unix VFS only once at
 initialization, instead of every time it is needed.

FossilOrigin-Name: 5764dc160783f5c4017204b3e26a89d31240c868484ced8214c9ad872bd77bd4
---
 manifest      | 14 +++++++-------
 manifest.uuid |  2 +-
 src/os_unix.c | 10 ++++++----
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/manifest b/manifest
index 5a2f7c7320..265850e6d9 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sanother\sminor\sproblem\sin\swalro2.test.
-D 2018-02-05T13:42:45.777
+C Allocation\sthe\smutex\sused\sby\sthe\sunix\sVFS\sonly\sonce\sat\sinitialization,\sinstead\nof\severy\stime\sit\sis\sneeded.
+D 2018-02-05T16:39:12.754
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 7a3f714b4fcf793108042b7b0a5c720b0b310ec84314d61ba7f3f49f27e550ea
@@ -471,7 +471,7 @@ F src/os.c 22d31db3ca5a96a408fbf1ceeaaebcaf64c87024d2ff9fe1cf2ddbec3e75c104
 F src/os.h 48388821692e87da174ea198bf96b1b2d9d83be5dfc908f673ee21fafbe0d432
 F src/os_common.h b2f4707a603e36811d9b1a13278bffd757857b85
 F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
-F src/os_unix.c a82505be158d8ce42b38dcc9b426187d776904c12cdc68dc8925e1dfcc5cb6ce
+F src/os_unix.c ce491421b3a54b63094a155eeac668a3bc8e5b86a5a58551d906e5b5affb443f
 F src/os_win.c 501dde1ee770f4ffa458bfe1cf376a556de3ab00bb8320d659c5984403991d62
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c cd194a8793ce061e184ddc369fadbc1020c6f431014d22093f6c5e55c9234033
@@ -1704,7 +1704,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P d9e59cfb8476e1ec1ca458b8382172526c0557ab785f41e31971d03045c9344c
-R f3585ddda6ecfb38609942de6c6ce298
-U dan
-Z 93b8cc01dad51cf808b345d2ca0944f2
+P ba0631de60ca38bf7efa6dbd86ec8774bf6f438c804155968e97f17eabe3b20a
+R 07658fd89f10e428329340f4fdba337c
+U drh
+Z f93cbf0dc0e4b2bfb043a63cd29cee7e
diff --git a/manifest.uuid b/manifest.uuid
index b8f8b2f481..2da9ca7d0a 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-ba0631de60ca38bf7efa6dbd86ec8774bf6f438c804155968e97f17eabe3b20a
\ No newline at end of file
+5764dc160783f5c4017204b3e26a89d31240c868484ced8214c9ad872bd77bd4
\ No newline at end of file
diff --git a/src/os_unix.c b/src/os_unix.c
index 94b1efd87d..b24c6861d3 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -696,15 +696,16 @@ static int robust_open(const char *z, int f, mode_t m){
 **     assert( unixMutexHeld() );
 **   unixEnterLeave()
 */
+static sqlite3_mutex *unixBigLock = 0;
 static void unixEnterMutex(void){
-  sqlite3_mutex_enter(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
+  sqlite3_mutex_enter(unixBigLock);
 }
 static void unixLeaveMutex(void){
-  sqlite3_mutex_leave(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
+  sqlite3_mutex_leave(unixBigLock);
 }
 #ifdef SQLITE_DEBUG
 static int unixMutexHeld(void) {
-  return sqlite3_mutex_held(sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1));
+  return sqlite3_mutex_held(unixBigLock);
 }
 #endif
 
@@ -5846,7 +5847,6 @@ static int unixOpen(
     randomnessPid = osGetpid(0);
     sqlite3_randomness(0,0);
   }
-
   memset(p, 0, sizeof(unixFile));
 
   if( eType==SQLITE_OPEN_MAIN_DB ){
@@ -7721,6 +7721,7 @@ int sqlite3_os_init(void){
   for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){
     sqlite3_vfs_register(&aVfs[i], i==0);
   }
+  unixBigLock = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_VFS1);
   return SQLITE_OK; 
 }
 
@@ -7732,6 +7733,7 @@ int sqlite3_os_init(void){
 ** This routine is a no-op for unix.
 */
 int sqlite3_os_end(void){ 
+  unixBigLock = 0;
   return SQLITE_OK; 
 }