From e533ac495f7754c41fa52a2726c969489a31c412 Mon Sep 17 00:00:00 2001
From: Bryan Biedenkapp <gatekeep@gmail.com>
Date: Wed, 19 Mar 2025 15:31:44 -0400
Subject: [PATCH] fix potential nullptr problem with Log when used from
 multiple threads during shutdown; reduce the intercycle delay to 2ms from 5ms
 for all main FNE threads;

---
 src/common/Log.cpp  | 10 +++++++---
 src/fne/HostFNE.cpp | 29 +++++++++++++++++++++++++----
 2 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/src/common/Log.cpp b/src/common/Log.cpp
index 01553284..b1668f06 100644
--- a/src/common/Log.cpp
+++ b/src/common/Log.cpp
@@ -191,8 +191,10 @@ void LogFinalise()
 #if defined(CATCH2_TEST_COMPILATION)
     return;
 #endif
-    if (m_fpLog != nullptr)
+    if (m_fpLog != nullptr) {
         ::fclose(m_fpLog);
+        m_fpLog = nullptr;
+    }
 #if !defined(_WIN32)
     if (g_useSyslog)
         closelog();
@@ -330,8 +332,10 @@ void Log(uint32_t level, const char *module, const char* file, const int lineNo,
             if (!ret)
                 return;
 
-            ::fprintf(m_fpLog, "%s\n", buffer);
-            ::fflush(m_fpLog);
+            if (m_fpLog != nullptr) {
+                ::fprintf(m_fpLog, "%s\n", buffer);
+                ::fflush(m_fpLog);
+            }
         } else {
 #if !defined(_WIN32)
             // convert our log level into syslog level
diff --git a/src/fne/HostFNE.cpp b/src/fne/HostFNE.cpp
index 7709916e..82ca25c2 100644
--- a/src/fne/HostFNE.cpp
+++ b/src/fne/HostFNE.cpp
@@ -39,6 +39,8 @@ using namespace lookups;
 //  Constants
 // ---------------------------------------------------------------------------
 
+#define THREAD_CYCLE_THRESHOLD 2U
+
 #define IDLE_WARMUP_MS 5U
 #define DEFAULT_MTU_SIZE 496
 
@@ -646,10 +648,18 @@ void* HostFNE::threadMasterNetwork(void* arg)
         ::pthread_setname_np(th->thread, threadName.c_str());
 #endif // _GNU_SOURCE
 
+        StopWatch stopWatch;
+        stopWatch.start();
+
         if (fne->m_network != nullptr) {
             while (!g_killed) {
+                uint32_t ms = stopWatch.elapsed();
+                stopWatch.start();
+
                 fne->m_network->processNetwork();
-                Thread::sleep(5U);
+
+                if (ms < THREAD_CYCLE_THRESHOLD)
+                    Thread::sleep(THREAD_CYCLE_THRESHOLD);
             }
         }
 
@@ -694,10 +704,18 @@ void* HostFNE::threadDiagNetwork(void* arg)
         ::pthread_setname_np(th->thread, threadName.c_str());
 #endif // _GNU_SOURCE
 
+        StopWatch stopWatch;
+        stopWatch.start();
+
         if (fne->m_diagNetwork != nullptr) {
             while (!g_killed) {
+                uint32_t ms = stopWatch.elapsed();
+                stopWatch.start();
+
                 fne->m_diagNetwork->processNetwork();
-                Thread::sleep(5U);
+
+                if (ms < THREAD_CYCLE_THRESHOLD)
+                    Thread::sleep(THREAD_CYCLE_THRESHOLD);
             }
         }
 
@@ -890,6 +908,7 @@ void* HostFNE::threadVirtualNetworking(void* arg)
             stopWatch.start();
 
             while (!g_killed) {
+                uint32_t ms = stopWatch.elapsed();
                 stopWatch.start();
 
                 uint8_t packet[DEFAULT_MTU_SIZE];
@@ -908,7 +927,8 @@ void* HostFNE::threadVirtualNetworking(void* arg)
                     }
                 }
 
-                Thread::sleep(2U);
+                if (ms < THREAD_CYCLE_THRESHOLD)
+                    Thread::sleep(THREAD_CYCLE_THRESHOLD);
             }
         }
 
@@ -968,7 +988,8 @@ void* HostFNE::threadVirtualNetworkingClock(void* arg)
                     break;
                 }
 
-                Thread::sleep(2U);
+                if (ms < THREAD_CYCLE_THRESHOLD)
+                    Thread::sleep(THREAD_CYCLE_THRESHOLD);
             }
         }