Patch 1145039.
set_exc_info(), reset_exc_info(): By exploiting the likely (who knows?) invariant that when an exception's `type` is NULL, its `value` and `traceback` are also NULL, save some cycles in heavily-executed code. This is a "a kronar saved is a kronar earned" patch: the speedup isn't reliably measurable, but it obviously does reduce the operation count in the normal (no exception raised) path through PyEval_EvalFrameEx(). The tim-exc_sanity branch tries to push this harder, but is still blowing up (at least in part due to pre-existing subtle bugs that appear to have no other visible consequences!). Not a bugfix candidate.
This commit is contained in:
Tim Peters
parent
7e0a62ea90
commit
7df5e7f4b2
|
|
@ -26,7 +26,16 @@ typedef struct _frame {
|
|||
to the current stack top. */
|
||||
PyObject **f_stacktop;
|
||||
PyObject *f_trace; /* Trace function */
|
||||
|
||||
/* If an exception is raised in this frame, the next three are used to
|
||||
* record the exception info (if any) originally in the thread state. See
|
||||
* comments before set_exc_info() -- it's not obvious.
|
||||
* Invariant: if _type is NULL, then so are _value and _traceback.
|
||||
* Desired invariant: all three are NULL, or all three are non-NULL. That
|
||||
* one isn't currently true, but "should be".
|
||||
*/
|
||||
PyObject *f_exc_type, *f_exc_value, *f_exc_traceback;
|
||||
|
||||
PyThreadState *f_tstate;
|
||||
int f_lasti; /* Last instruction if called */
|
||||
/* As of 2.3 f_lineno is only valid when tracing is active (i.e. when
|
||||
|
|
|
|||
|
|
@ -24,7 +24,7 @@
|
|||
#pragma optimize("agtw", on)
|
||||
#endif
|
||||
|
||||
#ifndef WITH_TSC
|
||||
#ifndef WITH_TSC
|
||||
|
||||
#define READ_TIMESTAMP(var)
|
||||
|
||||
|
|
@ -49,7 +49,7 @@ ppc_getcounter(uint64 *v)
|
|||
asm volatile ("mftbu %0" : "=r" (tbu2));
|
||||
if (__builtin_expect(tbu != tbu2, 0)) goto loop;
|
||||
|
||||
/* The slightly peculiar way of writing the next lines is
|
||||
/* The slightly peculiar way of writing the next lines is
|
||||
compiled better by GCC than any other way I tried. */
|
||||
((long*)(v))[0] = tbu;
|
||||
((long*)(v))[1] = tb;
|
||||
|
|
@ -62,7 +62,7 @@ ppc_getcounter(uint64 *v)
|
|||
|
||||
#endif
|
||||
|
||||
void dump_tsc(int opcode, int ticked, uint64 inst0, uint64 inst1,
|
||||
void dump_tsc(int opcode, int ticked, uint64 inst0, uint64 inst1,
|
||||
uint64 loop0, uint64 loop1, uint64 intr0, uint64 intr1)
|
||||
{
|
||||
uint64 intr, inst, loop;
|
||||
|
|
@ -567,7 +567,7 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
|
|||
inst0 -- beginning of switch statement for opcode dispatch
|
||||
inst1 -- end of switch statement (may be skipped)
|
||||
loop0 -- the top of the mainloop
|
||||
loop1 -- place where control returns again to top of mainloop
|
||||
loop1 -- place where control returns again to top of mainloop
|
||||
(may be skipped)
|
||||
intr1 -- beginning of long interruption
|
||||
intr2 -- end of long interruption
|
||||
|
|
@ -768,7 +768,7 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
|
|||
why = WHY_EXCEPTION;
|
||||
goto on_error;
|
||||
}
|
||||
|
||||
|
||||
for (;;) {
|
||||
#ifdef WITH_TSC
|
||||
if (inst1 == 0) {
|
||||
|
|
@ -2218,7 +2218,7 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
|
|||
re-raising the exception. (But non-local gotos
|
||||
should still be resumed.)
|
||||
*/
|
||||
|
||||
|
||||
x = TOP();
|
||||
u = SECOND();
|
||||
if (PyInt_Check(u) || u == Py_None) {
|
||||
|
|
@ -2581,7 +2581,12 @@ fast_yield:
|
|||
}
|
||||
}
|
||||
|
||||
reset_exc_info(tstate);
|
||||
if (tstate->frame->f_exc_type != NULL)
|
||||
reset_exc_info(tstate);
|
||||
else {
|
||||
assert(tstate->frame->f_exc_value == NULL);
|
||||
assert(tstate->frame->f_exc_traceback == NULL);
|
||||
}
|
||||
|
||||
/* pop frame */
|
||||
exit_eval_frame:
|
||||
|
|
@ -2846,6 +2851,7 @@ PyEval_EvalCodeEx(PyCodeObject *co, PyObject *globals, PyObject *locals,
|
|||
- Once an exception is caught by an except clause, it is transferred
|
||||
from tstate->curexc_ZZZ to tstate->exc_ZZZ, from which sys.exc_info()
|
||||
can pick it up. This is the primary task of set_exc_info().
|
||||
XXX That can't be right: set_exc_info() doesn't look at tstate->curexc_ZZZ.
|
||||
|
||||
- Now let me explain the complicated dance with frame->f_exc_ZZZ.
|
||||
|
||||
|
|
@ -2900,33 +2906,33 @@ Py_LOCAL(void)
|
|||
set_exc_info(PyThreadState *tstate,
|
||||
PyObject *type, PyObject *value, PyObject *tb)
|
||||
{
|
||||
PyFrameObject *frame;
|
||||
PyFrameObject *frame = tstate->frame;
|
||||
PyObject *tmp_type, *tmp_value, *tmp_tb;
|
||||
|
||||
frame = tstate->frame;
|
||||
assert(type != NULL);
|
||||
assert(frame != NULL);
|
||||
if (frame->f_exc_type == NULL) {
|
||||
/* This frame didn't catch an exception before */
|
||||
/* Save previous exception of this thread in this frame */
|
||||
assert(frame->f_exc_value == NULL);
|
||||
assert(frame->f_exc_traceback == NULL);
|
||||
/* This frame didn't catch an exception before. */
|
||||
/* Save previous exception of this thread in this frame. */
|
||||
if (tstate->exc_type == NULL) {
|
||||
/* XXX Why is this set to Py_None? */
|
||||
Py_INCREF(Py_None);
|
||||
tstate->exc_type = Py_None;
|
||||
}
|
||||
tmp_value = frame->f_exc_value;
|
||||
tmp_tb = frame->f_exc_traceback;
|
||||
Py_XINCREF(tstate->exc_type);
|
||||
Py_INCREF(tstate->exc_type);
|
||||
Py_XINCREF(tstate->exc_value);
|
||||
Py_XINCREF(tstate->exc_traceback);
|
||||
frame->f_exc_type = tstate->exc_type;
|
||||
frame->f_exc_value = tstate->exc_value;
|
||||
frame->f_exc_traceback = tstate->exc_traceback;
|
||||
Py_XDECREF(tmp_value);
|
||||
Py_XDECREF(tmp_tb);
|
||||
}
|
||||
/* Set new exception for this thread */
|
||||
/* Set new exception for this thread. */
|
||||
tmp_type = tstate->exc_type;
|
||||
tmp_value = tstate->exc_value;
|
||||
tmp_tb = tstate->exc_traceback;
|
||||
Py_XINCREF(type);
|
||||
Py_INCREF(type);
|
||||
Py_XINCREF(value);
|
||||
Py_XINCREF(tb);
|
||||
tstate->exc_type = type;
|
||||
|
|
@ -2946,33 +2952,42 @@ reset_exc_info(PyThreadState *tstate)
|
|||
{
|
||||
PyFrameObject *frame;
|
||||
PyObject *tmp_type, *tmp_value, *tmp_tb;
|
||||
|
||||
/* It's a precondition that the thread state's frame caught an
|
||||
* exception -- verify in a debug build.
|
||||
*/
|
||||
assert(tstate != NULL);
|
||||
frame = tstate->frame;
|
||||
if (frame->f_exc_type != NULL) {
|
||||
/* This frame caught an exception */
|
||||
tmp_type = tstate->exc_type;
|
||||
tmp_value = tstate->exc_value;
|
||||
tmp_tb = tstate->exc_traceback;
|
||||
Py_INCREF(frame->f_exc_type);
|
||||
Py_XINCREF(frame->f_exc_value);
|
||||
Py_XINCREF(frame->f_exc_traceback);
|
||||
tstate->exc_type = frame->f_exc_type;
|
||||
tstate->exc_value = frame->f_exc_value;
|
||||
tstate->exc_traceback = frame->f_exc_traceback;
|
||||
Py_XDECREF(tmp_type);
|
||||
Py_XDECREF(tmp_value);
|
||||
Py_XDECREF(tmp_tb);
|
||||
/* For b/w compatibility */
|
||||
PySys_SetObject("exc_type", frame->f_exc_type);
|
||||
PySys_SetObject("exc_value", frame->f_exc_value);
|
||||
PySys_SetObject("exc_traceback", frame->f_exc_traceback);
|
||||
}
|
||||
assert(frame != NULL);
|
||||
assert(frame->f_exc_type != NULL);
|
||||
|
||||
/* Copy the frame's exception info back to the thread state. */
|
||||
tmp_type = tstate->exc_type;
|
||||
tmp_value = tstate->exc_value;
|
||||
tmp_tb = tstate->exc_traceback;
|
||||
Py_INCREF(frame->f_exc_type);
|
||||
Py_XINCREF(frame->f_exc_value);
|
||||
Py_XINCREF(frame->f_exc_traceback);
|
||||
tstate->exc_type = frame->f_exc_type;
|
||||
tstate->exc_value = frame->f_exc_value;
|
||||
tstate->exc_traceback = frame->f_exc_traceback;
|
||||
Py_XDECREF(tmp_type);
|
||||
Py_XDECREF(tmp_value);
|
||||
Py_XDECREF(tmp_tb);
|
||||
|
||||
/* For b/w compatibility */
|
||||
PySys_SetObject("exc_type", frame->f_exc_type);
|
||||
PySys_SetObject("exc_value", frame->f_exc_value);
|
||||
PySys_SetObject("exc_traceback", frame->f_exc_traceback);
|
||||
|
||||
/* Clear the frame's exception info. */
|
||||
tmp_type = frame->f_exc_type;
|
||||
tmp_value = frame->f_exc_value;
|
||||
tmp_tb = frame->f_exc_traceback;
|
||||
frame->f_exc_type = NULL;
|
||||
frame->f_exc_value = NULL;
|
||||
frame->f_exc_traceback = NULL;
|
||||
Py_XDECREF(tmp_type);
|
||||
Py_DECREF(tmp_type);
|
||||
Py_XDECREF(tmp_value);
|
||||
Py_XDECREF(tmp_tb);
|
||||
}
|
||||
|
|
@ -3846,7 +3861,7 @@ _PyEval_SliceIndex(PyObject *v, Py_ssize_t *pi)
|
|||
Py_ssize_t x;
|
||||
if (PyInt_Check(v)) {
|
||||
x = PyInt_AsSsize_t(v);
|
||||
}
|
||||
}
|
||||
else if (v->ob_type->tp_as_number &&
|
||||
PyType_HasFeature(v->ob_type, Py_TPFLAGS_HAVE_INDEX)
|
||||
&& v->ob_type->tp_as_number->nb_index) {
|
||||
|
|
@ -4064,7 +4079,7 @@ build_class(PyObject *methods, PyObject *bases, PyObject *name)
|
|||
result = PyObject_CallFunctionObjArgs(metaclass, name, bases, methods, NULL);
|
||||
Py_DECREF(metaclass);
|
||||
if (result == NULL && PyErr_ExceptionMatches(PyExc_TypeError)) {
|
||||
/* A type error here likely means that the user passed
|
||||
/* A type error here likely means that the user passed
|
||||
in a base that was not a class (such the random module
|
||||
instead of the random.random type). Help them out with
|
||||
by augmenting the error message with more information.*/
|
||||
|
|
@ -4204,7 +4219,7 @@ string_concatenate(PyObject *v, PyObject *w,
|
|||
{
|
||||
/* This function implements 'variable += expr' when both arguments
|
||||
are strings. */
|
||||
|
||||
|
||||
if (v->ob_refcnt == 2) {
|
||||
/* In the common case, there are 2 references to the value
|
||||
* stored in 'variable' when the += is performed: one on the
|
||||
|
|
|
|||
Loading…
Reference in New Issue