From 7133196d6b90f71926af0ba69190dc5fb26fb328 Mon Sep 17 00:00:00 2001
From: Mathias Stearn <mathias@10gen.com>
Date: Tue, 1 Dec 2009 19:28:27 -0500
Subject: [PATCH 1/3] Make OID and MSGID increments atomic

---
 db/jsobj.cpp     |  7 +++----
 util/goodies.h   | 20 ++++++++++++++++----
 util/message.cpp |  3 +--
 3 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/db/jsobj.cpp b/db/jsobj.cpp
index e1cbb55fbe4..17cdf4db533 100644
--- a/db/jsobj.cpp
+++ b/db/jsobj.cpp
@@ -1430,7 +1430,7 @@ namespace mongo {
     }
     
     void OID::init() {
-        static unsigned inc = (unsigned) security.getNonce();
+        static WrappingInt inc = (unsigned) security.getNonce();
         unsigned t = (unsigned) time(0);
         char *T = (char *) &t;
         data[0] = T[3];
@@ -1440,9 +1440,8 @@ namespace mongo {
 
         (unsigned&) data[4] = _machine;
 
-        // TODO: use compiler intrinsic atomic increment instead of inc++
-        int old_inc = inc++;
-        T = (char *) &old_inc;
+        int new_inc = inc.atomicIncrement();
+        T = (char *) &new_inc;
         char * raw = (char*)&b;
         raw[0] = T[3];
         raw[1] = T[2];
diff --git a/util/goodies.h b/util/goodies.h
index 23a214b2a60..eb0631061a6 100644
--- a/util/goodies.h
+++ b/util/goodies.h
@@ -19,6 +19,10 @@
 
 #pragma once
 
+#if defined(__MSCV__)
+#  include <windows.h>
+#endif
+
 namespace mongo {
 
 #if !defined(_WIN32) && !defined(NOEXECINFO)
@@ -112,14 +116,22 @@ namespace mongo {
             x = 0;
         }
         WrappingInt(unsigned z) : x(z) { }
-        unsigned x;
+        volatile unsigned x;
         operator unsigned() const {
             return x;
         }
-        WrappingInt& operator++() {
-            x++;
-            return *this;
+
+        WrappingInt atomicIncrement(){
+#if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
+            return __sync_add_and_fetch(&x, 1);
+#elif defined(__MSCV__)
+            return InterlockedIncrement((long*)&x); //long is 32bits in Win64
+#else
+#  warning "OID and MSGID generation will not be thread safe"
+            return ++inc;
+#endif
         }
+
         static int diff(unsigned a, unsigned b) {
             return a-b;
         }
diff --git a/util/message.cpp b/util/message.cpp
index a483df42569..cfb03a53168 100644
--- a/util/message.cpp
+++ b/util/message.cpp
@@ -429,8 +429,7 @@ again:
     } msgstart;
     
     MSGID nextMessageId(){
-        MSGID msgid = NextMsgId;
-        ++NextMsgId;
+        MSGID msgid = NextMsgId.atomicIncrement();
         
         if ( usingClientIds ){
             msgid = msgid & 0xFFFF;

From 31723f3d28d9c8b2d08a3ffcce23751f70a8b153 Mon Sep 17 00:00:00 2001
From: Mathias Stearn <mathias@10gen.com>
Date: Tue, 1 Dec 2009 20:06:50 -0500
Subject: [PATCH 2/3] working atomic increment

---
 stdafx.h       |  1 +
 util/goodies.h | 13 +------------
 2 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/stdafx.h b/stdafx.h
index 5352c5e4d58..f0558378ff9 100644
--- a/stdafx.h
+++ b/stdafx.h
@@ -99,6 +99,7 @@ namespace mongo {
 #include <boost/program_options.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/smart_ptr.hpp>
+#include <boost/interprocess/detail/atomic.hpp>
 #define BOOST_SPIRIT_THREADSAFE
 
 #include <boost/version.hpp>
diff --git a/util/goodies.h b/util/goodies.h
index eb0631061a6..30013de867b 100644
--- a/util/goodies.h
+++ b/util/goodies.h
@@ -19,10 +19,6 @@
 
 #pragma once
 
-#if defined(__MSCV__)
-#  include <windows.h>
-#endif
-
 namespace mongo {
 
 #if !defined(_WIN32) && !defined(NOEXECINFO)
@@ -122,14 +118,7 @@ namespace mongo {
         }
 
         WrappingInt atomicIncrement(){
-#if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
-            return __sync_add_and_fetch(&x, 1);
-#elif defined(__MSCV__)
-            return InterlockedIncrement((long*)&x); //long is 32bits in Win64
-#else
-#  warning "OID and MSGID generation will not be thread safe"
-            return ++inc;
-#endif
+            return boost::interprocess::detail::atomic_inc32(&x);
         }
 
         static int diff(unsigned a, unsigned b) {

From c0e79bf1d4b6a2813a0aa93bc63fdb6c89c281c0 Mon Sep 17 00:00:00 2001
From: Mathias Stearn <mathias@10gen.com>
Date: Tue, 1 Dec 2009 20:25:48 -0500
Subject: [PATCH 3/3] removing atomic increment for now

---
 stdafx.h       | 1 -
 util/goodies.h | 3 ++-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/stdafx.h b/stdafx.h
index f0558378ff9..5352c5e4d58 100644
--- a/stdafx.h
+++ b/stdafx.h
@@ -99,7 +99,6 @@ namespace mongo {
 #include <boost/program_options.hpp>
 #include <boost/shared_ptr.hpp>
 #include <boost/smart_ptr.hpp>
-#include <boost/interprocess/detail/atomic.hpp>
 #define BOOST_SPIRIT_THREADSAFE
 
 #include <boost/version.hpp>
diff --git a/util/goodies.h b/util/goodies.h
index 30013de867b..3d34715a430 100644
--- a/util/goodies.h
+++ b/util/goodies.h
@@ -117,8 +117,9 @@ namespace mongo {
             return x;
         }
 
+        // TODO: make atomic
         WrappingInt atomicIncrement(){
-            return boost::interprocess::detail::atomic_inc32(&x);
+            return x++;
         }
 
         static int diff(unsigned a, unsigned b) {