multithreading_support3

Multithreading support in coin the support in coin for using multiple threads in application programs and the coin library itself, consists of two main features: the classes in question are sbthread, sbmutex, sbstorage, sbbarrier, sbcondvar, sbfifo, sbthreadautolock, sbrwmutex, and sbtypedstorage. see their respective documentation for the detailed information. the classes fully hides the system-specific implementation, which is either done on top of native win32 (if on microsoft windows), or over posix threads (on unix and unix-like systems). thread-safe render traversals are off by default, because there is a small overhead involved which would make rendering (very) slightly slower on single-threaded invocations. to get a coin library built with thread-safe rendering, one must actively re-configure coin and build a special, local version. for configure-based builds (unix and unix-like systems, or with cygwin on microsoft windows) this is done with the option '--enable-threadsafe' to autoconf configure. to change the configuration and re-build with visual studio, you will need to change the preprocessor directive coin_threadsafe to defined in the file src/setup.h located in the same folder as you found your solution file. there are some restrictions and other issues which it is important to be aware of: we are aware of at least issues with qt3 (and thereby soqt), where you should not modify the scene graph in any way in a thread separate from the main qt thread. this because it will trigger operations where qt3 is not thread-safe. for qt4, we have not been aware of such problems. since: