Change #265541

Comments

Redesign DotRunner as a single global queue with per-format batching
Replace the per-.dot-file DotRunner/ThreadPool architecture with a single
DotRunner that holds a global queue of all jobs across all source files.
Running dot is now batched as one invocation per output format using -O
(auto-naming) instead of -o: `dot -Tpng -O file1.dot file2.dot ...`

Remove ThreadPool and DOT_NUM_THREADS usage from DotManager. The cmapx
map output extension changes from .map to .cmapx to match -O naming.

The DOT_NUM_THREADS could be restored by splitting up `system` into a
loop for `spawn` and a loop for `waitpid` each taking a fixed proportion
of the graphs, but that isn't currently expected to provide significant
difference in performance.

The DOT_MULTI_TARGETS setting is now ignored (old default OFF, now
assumed ON) since the corresponding feature in graphviz is now over 20
years old (1.8.10).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Replaces: #12028

Changed files

• src/dot.cpp
• src/dot.h
• src/dotgraph.cpp
• src/dotgraph.h
• src/dotrunner.cpp
• src/dotrunner.h