--- a/src/os/solaris/vm/os_solaris.cpp	Fri Nov 19 17:01:34 2010 -0800
+++ b/src/os/solaris/vm/os_solaris.cpp	Fri Nov 19 23:46:06 2010 -0500
@@ -3375,7 +3375,12 @@
     // INTERRUPTIBLE_NORESTART_VM_ALWAYS returns res == OS_INTRPT for
     // thread.Interrupt.
 
-    if((res == OS_ERR) && (errno == EINTR)) {
+    // See c/r 6751923. Poll can return 0 before time
+    // has elapsed if time is set via clock_settime (as NTP does).
+    // res == 0 if poll timed out (see man poll RETURN VALUES)
+    // using the logic below checks that we really did
+    // sleep at least "millis" if not we'll sleep again.
+    if( ( res == 0 ) || ((res == OS_ERR) && (errno == EINTR))) {
       newtime = getTimeMillis();
       assert(newtime >= prevtime, "time moving backwards");
     /* Doing prevtime and newtime in microseconds doesn't help precision,

--- a/src/os/windows/vm/perfMemory_windows.cpp	Fri Nov 19 17:01:34 2010 -0800
+++ b/src/os/windows/vm/perfMemory_windows.cpp	Fri Nov 19 23:46:06 2010 -0500
@@ -889,6 +889,7 @@
   DWORD newACLsize = aclinfo.AclBytesInUse +
                         (sizeof(ACCESS_ALLOWED_ACE) - sizeof(DWORD)) * ace_count;
   for (int i = 0; i < ace_count; i++) {
+     assert(aces[i].pSid != 0, "pSid should not be 0");
      newACLsize += GetLengthSid(aces[i].pSid);
   }
 
@@ -1084,6 +1085,9 @@
   aces[0].pSid = get_user_sid(GetCurrentProcess());
   aces[0].mask = umask;
 
+  if (aces[0].pSid == 0)
+    return NULL;
+
   // get the well known SID for BUILTIN\Administrators
   PSID administratorsSid = NULL;
   SID_IDENTIFIER_AUTHORITY SIDAuthAdministrators = SECURITY_NT_AUTHORITY;