JIT hooks¶
There are several hooks in the pypyjit
module that may help you with
understanding what's pypy's JIT doing while running your program. There
are three functions related to that coming from the pypyjit
module:
-
set_compile_hook
(callable, operations=True)¶ Set a compiling hook that will be called each time a loop is compiled.
The callable will be called with the
pypyjit.JitLoopInfo
object. Refer to it's documentation for details.Note that jit hook is not reentrant. It means that if the code inside the jit hook is itself jitted, it will get compiled, but the jit hook won't be called for that.
if operations=False, no list of operations will be available. Useful if the hook is supposed to be very lighweight.
-
set_abort_hook
(hook)¶ Set a hook (callable) that will be called each time there is tracing aborted due to some reason.
The hook will be invoked with the siagnture:
hook(jitdriver_name, greenkey, reason, oplist)
Reason is a string, the meaning of other arguments is the same as attributes on JitLoopInfo object
-
enable_debug
()¶ Start recording debugging counters for
get_stats_snapshot
-
disable_debug
()¶ Stop recording debugging counters for
get_stats_snapshot
-
get_stats_snapshot
()¶ Get the jit status in the specific moment in time. Note that this is eager - the attribute access is not lazy, if you need new stats you need to call this function again. You might want to call
enable_debug
to get more information. It returns an instance ofJitInfoSnapshot
-
class
JitInfoSnapshot
¶ A class describing current snapshot. Usable attributes:
counters
- internal JIT integer counterscounter_times
- internal JIT float counters, notably time spent TRACING and in the JIT BACKENDloop_run_times
- counters for number of times loops are run, only works whenenable_debug
is called.
-
class
JitLoopInfo
¶ A class containing information about the compiled loop. Usable attributes:
operations
- list of operations, if requestedjitdriver_name
- the name of jitdriver associated with this loopgreenkey
- a key at which the loop got compiled (e.g. code position, is_being_profiled, pycode tuple for python jitdriver)loop_no
- loop cardinal numberbridge_no
- id of the fail descrtype
- "entry bridge", "loop" or "bridge"asmaddr
- an address in raw memory where assembler residesasmlen
- length of raw memory with assembler associated