While the previous approach of a static thread pool worked, it was sub-optimal in its resource usage. Many of the threads would never see a single task, and simply permanently sleep. This seems like a good idea, except that sleeping threads still end up in the scheduler, and thus waste a tiny amount of resources.
It is better to instead dynamically spawn threads when needed and only keeping the bare minimum around all the time. These dynamically spawned threads are also explicitly set to background priority which further reduces scheduling overhead. Finally optimizing the memory layout to prevent unwanted false sharing should also keep sporadic wake ups at a minimum.
This new model should be able to handle many more tasks than ever before, but is still not as optimal as it could be.
Using the obs_module_file and obs_module_config_path macros works okay, but it comes with a slight overhead as well as additional requirements when passing it to C++ functions that expect certain rules to be fulfilled. By instead wrapping the actual functionality into our own functions and using those we can avoid most of the issues that come with the old approach.
Related: #359
This header includes all common data between headers used in the plugin. This should improve cross-platform compiling support whenever possible, as all platform-dependent common includes and defines can be done here.
This thread pool can take large or small tasks and as such alleviates the burden of having a thread per source. Particularly for large setups, this drastically reduces the number of threads running in the background waiting for work.
This is a massive improvement to stability and safety when using the plugin, as all exceptions should now no longer be leaked into C controlled code, which can't actually handle exceptions at all.
Warnings fixed:
* Potentially throwing exception during library load.
* Possibly throwing function passed to C.
* Statement does nothing.
* Variable is initialized but not referenced.
* Variable overloads variable in parent scope.
While Linux was not an original goal of the project, it should still be supported out of the box. Therefore a number of changes are contained in this changeset:
- All C++ .h files were renamed to .hpp.
- All C includes (<....h>) were replaced with C++ includes (<c...>) and missing includes were added.
- std::memset and std::memcpy was replaced with memset and memcpy.
- All anonymous structs were removed where necessary.
- `extern "C"` was removed where it wasn't needed.
- #pragma warning was placed behind an #ifdef _MSC_VER
- The macros for `min`, `max` and `clamp` were removed as they were not used.
- `-fpedantic` was added to the GCC flags for bitmask support.
- `gs::rendertarget_op` is now declared before use.
- std::exception(const char*) was replaced with std::runtime_error(const char*).
- Added aligned_alloc and aligned_free macros for GCC and MSVC support.
- Replaced use of `sprintf_s` with `snprintf`.
- Placed additional guards around windows only code.
Additonally some changes were made that do not affect Linux:
- `NOMINMAX` and `NOINOUT` were removed.
Fixes: #27Fixes: #13
