Snap for 11685116 from e7617177a313cc9d9ad219424b41e8a58ee7dd15 to mainline-extservices-release
Change-Id: I9311248bd9da54a392418f574010709c05697a5d
diff --git a/include/fmq/MessageQueueBase.h b/include/fmq/MessageQueueBase.h
index f99e335..7a027ec 100644
--- a/include/fmq/MessageQueueBase.h
+++ b/include/fmq/MessageQueueBase.h
@@ -1044,8 +1044,16 @@
}
template <template <typename, MQFlavor> typename MQDescriptorType, typename T, MQFlavor flavor>
-size_t MessageQueueBase<MQDescriptorType, T, flavor>::availableToWriteBytes() const {
- return mDesc->getSize() - availableToReadBytes();
+inline size_t MessageQueueBase<MQDescriptorType, T, flavor>::availableToWriteBytes() const {
+ size_t queueSizeBytes = mDesc->getSize();
+ size_t availableBytes = availableToReadBytes();
+ if (queueSizeBytes < availableBytes) {
+ hardware::details::logError(
+ "The write or read pointer has become corrupted. Reading from the queue is no "
+ "longer possible.");
+ return 0;
+ }
+ return queueSizeBytes - availableBytes;
}
template <template <typename, MQFlavor> typename MQDescriptorType, typename T, MQFlavor flavor>
@@ -1127,13 +1135,21 @@
}
template <template <typename, MQFlavor> typename MQDescriptorType, typename T, MQFlavor flavor>
-size_t MessageQueueBase<MQDescriptorType, T, flavor>::availableToReadBytes() const {
+inline size_t MessageQueueBase<MQDescriptorType, T, flavor>::availableToReadBytes() const {
/*
* This method is invoked by implementations of both read() and write() and
* hence requires a memory_order_acquired load for both mReadPtr and
* mWritePtr.
*/
- return mWritePtr->load(std::memory_order_acquire) - mReadPtr->load(std::memory_order_acquire);
+ uint64_t writePtr = mWritePtr->load(std::memory_order_acquire);
+ uint64_t readPtr = mReadPtr->load(std::memory_order_acquire);
+ if (writePtr < readPtr) {
+ hardware::details::logError(
+ "The write or read pointer has become corrupted. Reading from the queue is no "
+ "longer possible.");
+ return 0;
+ }
+ return writePtr - readPtr;
}
template <template <typename, MQFlavor> typename MQDescriptorType, typename T, MQFlavor flavor>
