refactor: if failure, set previos priority back

Author: srvald

src/helpers.cpp

@@ -156,6 +156,31 @@ bool setProcessPriority(pprocess_t& process, DWORD priority)
                   "REALTIME_PRIORITY_CLASS may fail. Try 'Run as Administrator'.");
   }
 
+  DWORD old_process_priority = ::GetPriorityClass(process);
+  if (old_process_priority == 0)
+  {
+    DWORD err = GetLastError();
+    URCL_LOG_ERROR("Unsuccessful in retrieving the current process priority. Error: %lu (%s)", err,
+                   getLastWindowsErrorMsg(err).c_str());
+    return false;
+  }
+
+  auto restore_priority = [&]()
+  {
+    if (!::SetPriorityClass(process, old_process_priority))
+    {
+      DWORD err = GetLastError();
+      URCL_LOG_ERROR("Failed to restore previous process priority %s (0x%X). Error: %lu (%s)",
+                    processPriorityToString(old_process_priority), old_process_priority,
+                    err, getLastWindowsErrorMsg(err).c_str());
+    }
+    else
+    {
+      URCL_LOG_INFO("Previous process priority successfully restored to %s (0x%X)",
+                    processPriorityToString(old_process_priority), old_process_priority);
+    }
+  };
+
   if (!::SetPriorityClass(process, priority))
   {
     DWORD err = GetLastError();
@@ -170,6 +195,7 @@ bool setProcessPriority(pprocess_t& process, DWORD priority)
     DWORD err = GetLastError();
     URCL_LOG_ERROR("Unsuccessful in retrieving the process priority for verification. Error: %lu (%s)", err,
                    getLastWindowsErrorMsg(err).c_str());
+    restore_priority();
     return false;
   }
 
@@ -180,6 +206,7 @@ bool setProcessPriority(pprocess_t& process, DWORD priority)
   {
     URCL_LOG_WARN("Process priority mismatch. Expected %s (0x%X), got %s (0x%X)", processPriorityToString(priority),
                   priority, processPriorityToString(priority_applied), priority_applied);
+    restore_priority();
     return false;
   }
 
@@ -236,6 +263,31 @@ bool setThreadAffinity(pthread_t& thread, DWORD_PTR cpu_mask)
 
 bool setThreadPriority(pthread_t& thread, const int priority)
 {
+  int old_priority = ::GetThreadPriority(thread);
+  if (old_priority == THREAD_PRIORITY_ERROR_RETURN)
+  {
+    DWORD err = GetLastError();
+    URCL_LOG_ERROR("Unsuccessful in retrieving the current thread priority. Error: %lu (%s)",
+                  err, getLastWindowsErrorMsg(err).c_str());
+    return false;
+  }
+  
+  auto restore_priority = [&]()
+  {
+    if (!::SetThreadPriority(thread, old_priority))
+    {
+      DWORD err = GetLastError();
+      URCL_LOG_ERROR("Failed to restore previous thread priority %s (%d). Error: %lu (%s)",
+                     threadPriorityToString(old_priority), old_priority,
+                     err, getLastWindowsErrorMsg(err).c_str());
+    }
+    else
+    {
+      URCL_LOG_INFO("Previous thread priority successfully restored to %s (%d)",
+                    threadPriorityToString(old_priority), old_priority);
+    }
+  };
+
   if (!::SetThreadPriority(thread, priority))
   {
     DWORD err = GetLastError();
@@ -251,6 +303,7 @@ bool setThreadPriority(pthread_t& thread, const int priority)
     DWORD err = GetLastError();
     URCL_LOG_ERROR("Unsuccessful in retrieving the thread priority for verification. Error: %lu (%s)", err,
                    getLastWindowsErrorMsg(err).c_str());
+    restore_priority();
     return false;
   }
 
@@ -260,6 +313,7 @@ bool setThreadPriority(pthread_t& thread, const int priority)
   {
     URCL_LOG_WARN("Thread priority mismatch. Expected %s (%d), got %s (%d)", threadPriorityToString(priority), priority,
                   threadPriorityToString(applied), applied);
+    restore_priority();
     return false;
   }
 
@@ -358,11 +412,15 @@ bool setFiFoScheduling(pthread_t& thread, int priority)
   if (!setThreadPriority(thread, priority))
   {
     URCL_LOG_ERROR("Unsuccessful in setting thread priority to %s (%d)", threadPriorityToString(priority), priority);
+    URCL_LOG_INFO("Restoring previous process priority %s (0x%X)", 
+                   processPriorityToString(old_process_priority), old_process_priority);
 
-    if (!setProcessPriority(process, old_process_priority))
+    if (!::SetPriorityClass(process, old_process_priority))
     {
-      URCL_LOG_ERROR("Failed to restore previous process priority %s (0x%X)",
-                     processPriorityToString(old_process_priority), old_process_priority);
+      DWORD err = GetLastError();
+      URCL_LOG_ERROR("Failed to restore previous process priority %s (0x%X). Error: %lu (%s)",
+                     processPriorityToString(old_process_priority), old_process_priority,
+                     err, getLastWindowsErrorMsg(err).c_str());
     }
 
     return false;