My plugin loads about 20 PNG files in threads at startup. Since switching to Direct2D, I’ve noticed rare crashes on startup.
I can repro it in Debug build in Windows with the minimal test code below.
- This usually crashes in juce_HeapBlock (called via void addListener (DxgiAdapterListener& l) in juce_DirectX_windows.h), see screenshot
- However it reliably succeeds if I force SoftwareImageType in createImageFromData in juce_PNGLoader.cpp (where the juce::Image is created). Also pretty slow though.
// add other includes as needed...
// sorry for grubby code, was trying to minimize the test case.
#include <future>
#include <thread>
#include <vector>
// f should point to a valid PNG file
void TestPNGLoader(const juce::File& f) {
const int num_iters = 10000;
std::vector<juce::Image> images{};
std::vector<juce::FileInputStream*> streams;
std::vector<std::future<juce::Image>> loaders{};
for (int i = 0; i < num_iters; ++i) {
auto stream = new juce::FileInputStream{f};
auto cb = [stream] {
return juce::ImageFileFormat::loadFrom(*stream);
};
streams.emplace_back(stream);
loaders.emplace_back(std::async(std::launch::async, cb));
}
// store
for (auto& loader : loaders) {
images.push_back(loader.get());
}
// cleanup
for (auto stream : streams) {
delete stream;
}
}
While I figure this out, I’ve made my resource loader single threaded, but this adds about a second to my load path. Am I doing something dodgy, or have I stumbled into a previously-unknown re-entrancy bug? If this is the wrong way, is there a better way to quickly bulk load resources? (edit: My backup plan is to somehow force the image load using SoftwareImageType, but then convert them to NativeImageType afterwards in a single thread - the PNG decode seems to be the slow bit).
Thanks.