Make m_scheduledUploadTime atomic for explicit thread safety

Declare m_scheduledUploadTime as std::atomic<uint64_t> and move its
update back outside the LOCKGUARD, consistent with m_runningLatency.
All accesses were already under LOCKGUARD(m_scheduledUploadMutex), but
atomic makes the thread-safe intent self-documenting and guards against
future accesses that might omit the lock.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: bmehta001

lib/tpm/TransmissionPolicyManager.cpp

@@ -147,7 +147,7 @@ namespace MAT_NS_BEGIN {
                 m_runningLatency = latency;
             }
             auto now = PAL::getMonotonicTimeMs();
-            auto delta = Abs64(m_scheduledUploadTime, now);
+            auto delta = Abs64(m_scheduledUploadTime.load(), now);
             if (delta <= static_cast<uint64_t>(delay.count()))
             {
                 // Don't need to cancel and reschedule if it's about to happen now anyways.
@@ -185,9 +185,9 @@ namespace MAT_NS_BEGIN {
             return;
         }
         m_runningLatency = latency;
+        m_scheduledUploadTime = std::numeric_limits<uint64_t>::max();
         {
             LOCKGUARD(m_scheduledUploadMutex);
-            m_scheduledUploadTime = std::numeric_limits<uint64_t>::max();
             m_isUploadScheduled = false;  // Allow to schedule another uploadAsync
             if ((m_isPaused) || (m_scheduledUploadAborted))
             {

lib/tpm/TransmissionPolicyManager.hpp

@@ -91,7 +91,7 @@ constexpr const char* const DefaultBackoffConfig = "E,3000,300000,2,1";
 
         std::atomic<bool>                m_isPaused { true };
         std::atomic<bool>                m_isUploadScheduled { false };
-        uint64_t                         m_scheduledUploadTime { std::numeric_limits<uint64_t>::max() };
+        std::atomic<uint64_t>            m_scheduledUploadTime { std::numeric_limits<uint64_t>::max() };
         std::mutex                       m_scheduledUploadMutex;
         PAL::DeferredCallbackHandle      m_scheduledUpload;
         bool                             m_scheduledUploadAborted { false };