Subzero: Fix timers for multithreaded translation.
Now that multithreaded parsing and translation is in place, timer operations have to be made thread-local. After the non-main threads end, their thread-local timer data needs to be merged into the global timer data, which resides in the GlobalContext object. The merge is a bit tricky because the internal timer stack structure is built up dynamically as items are pushed and popped. Two threads may have radically different timing data:
1. The parser thread profile is completely different from a translator thread.
2. For -timing-funcs, two translator threads hold data for entirely different sets of functions.
A bit more tweaking will need to be done to make the timing output fully usable in a multithreaded run. Because of multiple threads, times may add up to >100%. Also, time spent blocked is being "unfairly" attributed to the caller of the blocking operation - we should either count the user time instead of wall-clock time, or add a special timer marker for blocking locking operations.
BUG= none
R=jvoung@chromium.org
Review URL: https://codereview.chromium.org/878383004
7 files changed
