1 DM is like GM, but multithreaded. It doesn't do everything GM does. 2 3 DM's design is based around Tasks and a TaskRunner. 4 5 A Task represents an independent unit of work that might fail. We make a task 6 for each GM/configuration pair we want to run. Tasks can kick off new tasks 7 themselves. For example, a CpuTask can kick off a ReplayTask to make sure 8 recording and playing back an SkPicture gives the same result as direct 9 rendering. 10 11 The TaskRunner runs all tasks on one of two threadpools, whose sizes are 12 configurable by --cpuThreads and --gpuThreads. Ideally we'd run these on a 13 single threadpool but it can swamp the GPU if we shove too much work into it at 14 once. --cpuThreads defaults to the number of cores on the machine. 15 --gpuThreads defaults to 1, but you may find 2 or 4 runs a little faster. 16 17 So the main flow of DM is: 18 19 for each GM: 20 for each configuration: 21 kick off a new task 22 < tasks run, maybe fail, and maybe kick off new tasks > 23 wait for all tasks to finish 24 report failures 25 26