memcpy in ISR Context when another memcpy() was already running on main thread or another ISR

[pranjalk197]

Is it safe to use memcpy() in an ISR when another memcpy() was already running on main thread or another ISR?

I am getting conflicting info on web about using memcpy() in an ISR to copy data between two uint32_t buffers.

MCU: STM32H723

CubeIDE V: 1.16.0

[TDK · Accepted solution]

Yes, it's thread safe. The operations are independent, there is no shared configuration data or internal state to worry about.

[Tesla DeLorean]

The problem would come if the structure ends up with partially old data and partially new data.

In RTOS systems you might want to lock the operations with a semaphore or mutex, so you can recover content in a more atomic fashion.