separate function, code less confusing

linux/ipcore/PdecHandler.cpp

@@ -146,8 +146,6 @@ ReturnValue_t PdecHandler::irqOperation() {
 
   // Used to unmask IRQ
   uint32_t info = 1;
-  ssize_t nb = 0;
-  int ret = 0;
 
   interruptWindowCd.resetTimer();
 
@@ -171,62 +169,7 @@ ReturnValue_t PdecHandler::irqOperation() {
         state = State::RUNNING;
         break;
       case State::RUNNING: {
-        nb = write(fd, &info, sizeof(info));
+        checkAndHandleIrqs(fd, info);
-        if (nb != static_cast<ssize_t>(sizeof(info))) {
-          sif::error << "PdecHandler::irqOperation: Unmasking IRQ failed" << std::endl;
-          triggerEvent(WRITE_SYSCALL_ERROR_PDEC, errno);
-          close(fd);
-          state = State::INIT;
-          return returnvalue::FAILED;
-        }
-        struct pollfd fds = {.fd = fd, .events = POLLIN, .revents = 0};
-        ret = poll(&fds, 1, IRQ_TIMEOUT_MS);
-        if (ret == 0) {
-          // No TCs for timeout period
-          checkLocks();
-          genericCheckCd.resetTimer();
-          resetIrqLimiters();
-        } else if (ret >= 1) {
-          nb = read(fd, &info, sizeof(info));
-          interruptCounter++;
-          if (nb == static_cast<ssize_t>(sizeof(info))) {
-            uint32_t pisr = *(registerBaseAddress + PDEC_PISR_OFFSET);
-            if ((pisr & TC_NEW_MASK) == TC_NEW_MASK) {
-              // handle TC
-              handleNewTc();
-            }
-            if ((pisr & TC_ABORT_MASK) == TC_ABORT_MASK) {
-              tcAbortCounter += 1;
-            }
-            if ((pisr & NEW_FAR_MASK) == NEW_FAR_MASK) {
-              // Read FAR here
-              CURRENT_FAR = readFar();
-              checkFrameAna(CURRENT_FAR);
-            }
-            if (genericCheckCd.hasTimedOut()) {
-              checkLocks();
-              genericCheckCd.resetTimer();
-              if (interruptWindowCd.timeOut()) {
-                if (interruptCounter >= MAX_ALLOWED_IRQS_PER_WINDOW) {
-                  sif::error << "PdecHandler::irqOperation: Possible IRQ storm" << std::endl;
-                  triggerEvent(TOO_MANY_IRQS, MAX_ALLOWED_IRQS_PER_WINDOW);
-                  TaskFactory::delayTask(400);
-                  break;
-                }
-                resetIrqLimiters();
-              }
-            }
-            // Clear interrupts with dummy read
-            dummy = *(registerBaseAddress + PDEC_PIR_OFFSET);
-          }
-        } else {
-          sif::error << "PdecHandler::irqOperation: Poll error with errno " << errno << ": "
-                     << strerror(errno) << std::endl;
-          triggerEvent(POLL_SYSCALL_ERROR_PDEC, errno);
-          close(fd);
-          state = State::INIT;
-          return returnvalue::FAILED;
-        }
         break;
       }
       case State::WAIT_FOR_RECOVERY:
@@ -244,6 +187,71 @@ ReturnValue_t PdecHandler::irqOperation() {
   return returnvalue::OK;
 }
 
+ReturnValue_t PdecHandler::checkAndHandleIrqs(int fd, uint32_t& info) {
+  ssize_t nb = write(fd, &info, sizeof(info));
+  if (nb != static_cast<ssize_t>(sizeof(info))) {
+    sif::error << "PdecHandler::irqOperation: Unmasking IRQ failed" << std::endl;
+    triggerEvent(WRITE_SYSCALL_ERROR_PDEC, errno);
+    close(fd);
+    state = State::INIT;
+    return returnvalue::FAILED;
+  }
+  struct pollfd fds = {.fd = fd, .events = POLLIN, .revents = 0};
+  int ret = poll(&fds, 1, IRQ_TIMEOUT_MS);
+  if (ret == 0) {
+    // No TCs for timeout period
+    checkLocks();
+    genericCheckCd.resetTimer();
+    resetIrqLimiters();
+  } else if (ret >= 1) {
+    // Interrupt handling.
+    nb = read(fd, &info, sizeof(info));
+    interruptCounter++;
+    if (nb == static_cast<ssize_t>(sizeof(info))) {
+      uint32_t pisr = *(registerBaseAddress + PDEC_PISR_OFFSET);
+      if ((pisr & TC_NEW_MASK) == TC_NEW_MASK) {
+        // handle TC
+        handleNewTc();
+      }
+      if ((pisr & TC_ABORT_MASK) == TC_ABORT_MASK) {
+        tcAbortCounter += 1;
+      }
+      if ((pisr & NEW_FAR_MASK) == NEW_FAR_MASK) {
+        // Read FAR here
+        CURRENT_FAR = readFar();
+        checkFrameAna(CURRENT_FAR);
+      }
+      // Clear interrupts with dummy read. Volatile is important here to prevent
+      // compiler opitmizations in release builds!
+      volatile uint32_t dummy = *(registerBaseAddress + PDEC_PIR_OFFSET);
+      static_cast<void>(dummy);
+
+      if (genericCheckCd.hasTimedOut()) {
+        checkLocks();
+        genericCheckCd.resetTimer();
+        if (interruptWindowCd.hasTimedOut()) {
+          if (interruptCounter >= MAX_ALLOWED_IRQS_PER_WINDOW) {
+            sif::error << "PdecHandler::irqOperation: Possible IRQ storm" << std::endl;
+            triggerEvent(TOO_MANY_IRQS, MAX_ALLOWED_IRQS_PER_WINDOW);
+            resetIrqLimiters();
+            TaskFactory::delayTask(400);
+            return returnvalue::FAILED;
+          }
+          resetIrqLimiters();
+        }
+      }
+    }
+  } else {
+    sif::error << "PdecHandler::irqOperation: Poll error with errno " << errno << ": "
+               << strerror(errno) << std::endl;
+    triggerEvent(POLL_SYSCALL_ERROR_PDEC, errno);
+    close(fd);
+    state = State::INIT;
+    return returnvalue::FAILED;
+  }
+  return returnvalue::OK;
+}
+
 void PdecHandler::readCommandQueue(void) {
   CommandMessage commandMessage;
   ReturnValue_t result = returnvalue::FAILED;

linux/ipcore/PdecHandler.h

@@ -266,6 +266,7 @@ class PdecHandler : public SystemObject, public ExecutableObjectIF, public HasAc
 
   ReturnValue_t polledOperation();
   ReturnValue_t irqOperation();
+  ReturnValue_t checkAndHandleIrqs(int fd, uint32_t& info);
 
   uint32_t readFar();