ChangeLogTag: Sun Mar 18 02:09:31 UTC 2007 Krishnakumar B <kitty@nospam.invalid.domain>

2 files changed, 29 insertions, 6 deletions

diff --git a/ACE/ChangeLog b/ACE/ChangeLog
index 09ec872a792..3fa20483435 100644
--- a/ACE/ChangeLog
+++ b/ACE/ChangeLog
@@ -1,3 +1,17 @@
+Sun Mar 18 02:09:31 UTC 2007  Krishnakumar B  <kitty@nospam.invalid.domain>
+
+        * ace/OS_NS_stdlib.cpp:  Fixed a race condition in
+          ACE_OS::mkstemp_emulation() where the value from
+          ACE_OS::gettimeofday() was truncated due to the use of
+          ACE_Time_Value::msec(void) as opposed to
+          ACE_Time_Value::msec(ACE_UINT64&) to convert it to milliseconds.
+          This resulted in seed value passed to ACE_OS::rand_r() returning
+          the same sequence of numbers when ACE_OS::mkstemp() was called
+          successively from the same process.  As a result, the filenames
+          returned from ACE_OS::mkstemp() ended up being the same, if the
+          template passed in was the same between multiple successive
+          calls to ACE_OS::mkstemp().
+
 Thu Mar 15 14:44:21 UTC 2007  Carlos O'Ryan  <coryan@atdesk.com>
 
         * ace/Select_Reactor_Base.cpp:
diff --git a/ACE/ace/OS_NS_stdlib.cpp b/ACE/ace/OS_NS_stdlib.cpp
index 2964cbbb49c..622c57642b1 100644
--- a/ACE/ace/OS_NS_stdlib.cpp
+++ b/ACE/ace/OS_NS_stdlib.cpp
@@ -686,13 +686,23 @@ ACE_OS::mkstemp_emulation (ACE_TCHAR * s)
   static unsigned int const NUM_RETRIES = 50;
   static unsigned int const NUM_CHARS   = 6;  // Do not change!
 
+  // Use ACE_Time_Value::msec(ACE_UINT64&) as opposed to
+  // ACE_Time_Value::msec(void) to avoid truncation.
+  ACE_UINT64 msec;
+
+  // Use a const ACE_Time_Value to resolve ambiguity between
+  // ACE_Time_Value::msec (long) and ACE_Time_Value::msec(ACE_UINT64&) const.
+  const ACE_Time_Value now = ACE_OS::gettimeofday();
+  now.msec (msec);
+
+  // Add the process and thread ids to ensure uniqueness.
+  msec += ACE_OS::getpid();
+  msec += (size_t) ACE_OS::thr_self();
+
   // ACE_thread_t may be a char* (returned by ACE_OS::thr_self()) so
   // we need to use a C-style cast as a catch-all in order to use a
   // static_cast<> to an integral type.
-  ACE_RANDR_TYPE seed =
-    static_cast<ACE_RANDR_TYPE> (ACE_OS::gettimeofday ().msec ())
-    + static_cast<ACE_RANDR_TYPE> (ACE_OS::getpid ())
-    + static_cast<ACE_RANDR_TYPE> ((size_t)ACE_OS::thr_self ());
+  ACE_RANDR_TYPE seed = static_cast<ACE_RANDR_TYPE> (msec);
 
   // We only care about UTF-8 / ASCII characters in generated
   // filenames.  A UTF-16 or UTF-32 character could potentially cause
@@ -732,8 +742,7 @@ ACE_OS::mkstemp_emulation (ACE_TCHAR * s)
           // selection to work for EBCDIC, as well.
           do
             {
-              r =
-                static_cast<ACE_TCHAR> (coefficient * ACE_OS::rand_r (seed));
+              r = static_cast<ACE_TCHAR> (coefficient * ACE_OS::rand_r (seed));
             }
           while (!ACE_OS::ace_isalnum (r));