Hi, among other less interesting things, I spent some time on existing PosixSharedMemory project. It is a UFFI binding for the LibC methods that provide support for the memory allocation between several separate processes. I significantly improved the performance by implementing the block access. Writing of 10MB byte array takes about 1 millisecond, reading of it from other image took me about 4 milliseconds. While serialization with Fuel is very fast, it opens interesting possibilities. To have a shared memory without synchronization tools is not very useful so I wrote a basic UFFI interface for the POSIX named semaphores. They are quite easy to use and work nicely with Pharo. The VM can all wait on the semaphore or it can check the status of it periodically in an image thread. It has two small disadvantages. It requires to dynamically link the next library (pthread) and they must be cleaned manually. I plan to look at System V alternative in future. Now we should write a nice framework for inter-image communication on top of it or/and adopt Seamless for it ;-)
Cheers, -- Pavel
