mirror of https://github.com/python/cpython
Speed up with statements by storing the __exit__ method on the stack instead of in a temp variable (bumps the magic number for pyc files)
This commit is contained in:
parent
e75f59a578
commit
7af53be66f
|
@ -519,21 +519,24 @@ Miscellaneous opcodes.
|
|||
|
||||
.. opcode:: WITH_CLEANUP ()
|
||||
|
||||
Cleans up the stack when a :keyword:`with` statement block exits. TOS is the
|
||||
context manager's :meth:`__exit__` bound method. Below that are 1--3 values
|
||||
indicating how/why the finally clause was entered:
|
||||
Cleans up the stack when a :keyword:`with` statement block exits. On top of
|
||||
the stack are 1--3 values indicating how/why the finally clause was entered:
|
||||
|
||||
* SECOND = ``None``
|
||||
* (SECOND, THIRD) = (``WHY_{RETURN,CONTINUE}``), retval
|
||||
* SECOND = ``WHY_*``; no retval below it
|
||||
* (SECOND, THIRD, FOURTH) = exc_info()
|
||||
* TOP = ``None``
|
||||
* (TOP, SECOND) = (``WHY_{RETURN,CONTINUE}``), retval
|
||||
* TOP = ``WHY_*``; no retval below it
|
||||
* (TOP, SECOND, THIRD) = exc_info()
|
||||
|
||||
In the last case, ``TOS(SECOND, THIRD, FOURTH)`` is called, otherwise
|
||||
``TOS(None, None, None)``.
|
||||
Under them is EXIT, the context manager's :meth:`__exit__` bound method.
|
||||
|
||||
In addition, if the stack represents an exception, *and* the function call
|
||||
returns a 'true' value, this information is "zapped", to prevent ``END_FINALLY``
|
||||
from re-raising the exception. (But non-local gotos should still be resumed.)
|
||||
In the last case, ``EXIT(TOP, SECOND, THIRD)`` is called, otherwise
|
||||
``EXIT(None, None, None)``.
|
||||
|
||||
EXIT is removed from the stack, leaving the values above it in the same
|
||||
order. In addition, if the stack represents an exception, *and* the function
|
||||
call returns a 'true' value, this information is "zapped", to prevent
|
||||
``END_FINALLY`` from re-raising the exception. (But non-local gotos should
|
||||
still be resumed.)
|
||||
|
||||
.. XXX explain the WHY stuff!
|
||||
|
||||
|
|
|
@ -822,14 +822,13 @@ class CodeGenerator:
|
|||
def visitWith(self, node):
|
||||
body = self.newBlock()
|
||||
final = self.newBlock()
|
||||
exitvar = "$exit%d" % self.__with_count
|
||||
valuevar = "$value%d" % self.__with_count
|
||||
self.__with_count += 1
|
||||
self.set_lineno(node)
|
||||
self.visit(node.expr)
|
||||
self.emit('DUP_TOP')
|
||||
self.emit('LOAD_ATTR', '__exit__')
|
||||
self._implicitNameOp('STORE', exitvar)
|
||||
self.emit('ROT_TWO')
|
||||
self.emit('LOAD_ATTR', '__enter__')
|
||||
self.emit('CALL_FUNCTION', 0)
|
||||
if node.vars is None:
|
||||
|
@ -849,8 +848,6 @@ class CodeGenerator:
|
|||
self.emit('LOAD_CONST', None)
|
||||
self.nextBlock(final)
|
||||
self.setups.push((END_FINALLY, final))
|
||||
self._implicitNameOp('LOAD', exitvar)
|
||||
self._implicitNameOp('DELETE', exitvar)
|
||||
self.emit('WITH_CLEANUP')
|
||||
self.emit('END_FINALLY')
|
||||
self.setups.pop()
|
||||
|
|
|
@ -12,6 +12,9 @@ What's New in Python 2.6 alpha 2?
|
|||
Core and builtins
|
||||
-----------------
|
||||
|
||||
- Issue #2179: speed up with statement execution by storing the exit method
|
||||
on the stack instead of in a temporary variable (patch by Jeffrey Yaskin)
|
||||
|
||||
- Issue #2238: Some syntax errors in *args and **kwargs expressions could give
|
||||
bogus error messages.
|
||||
|
||||
|
|
|
@ -2254,17 +2254,20 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
|
|||
|
||||
case WITH_CLEANUP:
|
||||
{
|
||||
/* TOP is the context.__exit__ bound method.
|
||||
Below that are 1-3 values indicating how/why
|
||||
we entered the finally clause:
|
||||
- SECOND = None
|
||||
- (SECOND, THIRD) = (WHY_{RETURN,CONTINUE}), retval
|
||||
- SECOND = WHY_*; no retval below it
|
||||
- (SECOND, THIRD, FOURTH) = exc_info()
|
||||
/* At the top of the stack are 1-3 values indicating
|
||||
how/why we entered the finally clause:
|
||||
- TOP = None
|
||||
- (TOP, SECOND) = (WHY_{RETURN,CONTINUE}), retval
|
||||
- TOP = WHY_*; no retval below it
|
||||
- (TOP, SECOND, THIRD) = exc_info()
|
||||
Below them is EXIT, the context.__exit__ bound method.
|
||||
In the last case, we must call
|
||||
TOP(SECOND, THIRD, FOURTH)
|
||||
EXIT(TOP, SECOND, THIRD)
|
||||
otherwise we must call
|
||||
TOP(None, None, None)
|
||||
EXIT(None, None, None)
|
||||
|
||||
In all cases, we remove EXIT from the stack, leaving
|
||||
the rest in the same order.
|
||||
|
||||
In addition, if the stack represents an exception,
|
||||
*and* the function call returns a 'true' value, we
|
||||
|
@ -2273,36 +2276,59 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
|
|||
should still be resumed.)
|
||||
*/
|
||||
|
||||
x = TOP();
|
||||
u = SECOND();
|
||||
if (PyInt_Check(u) || u == Py_None) {
|
||||
PyObject *exit_func;
|
||||
|
||||
u = POP();
|
||||
if (u == Py_None) {
|
||||
exit_func = TOP();
|
||||
SET_TOP(u);
|
||||
v = w = Py_None;
|
||||
}
|
||||
else if (PyInt_Check(u)) {
|
||||
switch(PyInt_AS_LONG(u)) {
|
||||
case WHY_RETURN:
|
||||
case WHY_CONTINUE:
|
||||
/* Retval in TOP. */
|
||||
exit_func = SECOND();
|
||||
SET_SECOND(TOP());
|
||||
SET_TOP(u);
|
||||
break;
|
||||
default:
|
||||
exit_func = TOP();
|
||||
SET_TOP(u);
|
||||
break;
|
||||
}
|
||||
u = v = w = Py_None;
|
||||
}
|
||||
else {
|
||||
v = THIRD();
|
||||
w = FOURTH();
|
||||
v = TOP();
|
||||
w = SECOND();
|
||||
exit_func = THIRD();
|
||||
SET_TOP(u);
|
||||
SET_SECOND(v);
|
||||
SET_THIRD(w);
|
||||
}
|
||||
/* XXX Not the fastest way to call it... */
|
||||
x = PyObject_CallFunctionObjArgs(x, u, v, w, NULL);
|
||||
if (x == NULL)
|
||||
x = PyObject_CallFunctionObjArgs(exit_func, u, v, w,
|
||||
NULL);
|
||||
if (x == NULL) {
|
||||
Py_DECREF(exit_func);
|
||||
break; /* Go to error exit */
|
||||
}
|
||||
if (u != Py_None && PyObject_IsTrue(x)) {
|
||||
/* There was an exception and a true return */
|
||||
Py_DECREF(x);
|
||||
x = TOP(); /* Again */
|
||||
STACKADJ(-3);
|
||||
STACKADJ(-2);
|
||||
Py_INCREF(Py_None);
|
||||
SET_TOP(Py_None);
|
||||
Py_DECREF(x);
|
||||
Py_DECREF(u);
|
||||
Py_DECREF(v);
|
||||
Py_DECREF(w);
|
||||
} else {
|
||||
/* Let END_FINALLY do its thing */
|
||||
Py_DECREF(x);
|
||||
x = POP();
|
||||
Py_DECREF(x);
|
||||
/* The stack was rearranged to remove EXIT
|
||||
above. Let END_FINALLY do its thing */
|
||||
}
|
||||
Py_DECREF(x);
|
||||
Py_DECREF(exit_func);
|
||||
PREDICT(END_FINALLY);
|
||||
break;
|
||||
}
|
||||
|
|
|
@ -2842,7 +2842,7 @@ compiler_with(struct compiler *c, stmt_ty s)
|
|||
{
|
||||
static identifier enter_attr, exit_attr;
|
||||
basicblock *block, *finally;
|
||||
identifier tmpexit, tmpvalue = NULL;
|
||||
identifier tmpvalue = NULL;
|
||||
|
||||
assert(s->kind == With_kind);
|
||||
|
||||
|
@ -2862,12 +2862,6 @@ compiler_with(struct compiler *c, stmt_ty s)
|
|||
if (!block || !finally)
|
||||
return 0;
|
||||
|
||||
/* Create a temporary variable to hold context.__exit__ */
|
||||
tmpexit = compiler_new_tmpname(c);
|
||||
if (tmpexit == NULL)
|
||||
return 0;
|
||||
PyArena_AddPyObject(c->c_arena, tmpexit);
|
||||
|
||||
if (s->v.With.optional_vars) {
|
||||
/* Create a temporary variable to hold context.__enter__().
|
||||
We need to do this rather than preserving it on the stack
|
||||
|
@ -2887,11 +2881,10 @@ compiler_with(struct compiler *c, stmt_ty s)
|
|||
/* Evaluate EXPR */
|
||||
VISIT(c, expr, s->v.With.context_expr);
|
||||
|
||||
/* Squirrel away context.__exit__ */
|
||||
/* Squirrel away context.__exit__ by stuffing it under context */
|
||||
ADDOP(c, DUP_TOP);
|
||||
ADDOP_O(c, LOAD_ATTR, exit_attr, names);
|
||||
if (!compiler_nameop(c, tmpexit, Store))
|
||||
return 0;
|
||||
ADDOP(c, ROT_TWO);
|
||||
|
||||
/* Call context.__enter__() */
|
||||
ADDOP_O(c, LOAD_ATTR, enter_attr, names);
|
||||
|
@ -2935,10 +2928,9 @@ compiler_with(struct compiler *c, stmt_ty s)
|
|||
if (!compiler_push_fblock(c, FINALLY_END, finally))
|
||||
return 0;
|
||||
|
||||
/* Finally block starts; push tmpexit and issue our magic opcode. */
|
||||
if (!compiler_nameop(c, tmpexit, Load) ||
|
||||
!compiler_nameop(c, tmpexit, Del))
|
||||
return 0;
|
||||
/* Finally block starts; context.__exit__ is on the stack under
|
||||
the exception or return information. Just issue our magic
|
||||
opcode. */
|
||||
ADDOP(c, WITH_CLEANUP);
|
||||
|
||||
/* Finally block ends. */
|
||||
|
|
|
@ -72,9 +72,10 @@ extern time_t PyOS_GetLastModificationTime(char *, FILE *);
|
|||
storing constants that should have been removed)
|
||||
Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp)
|
||||
Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode)
|
||||
Python 2.6a1: 62161 (WITH_CLEANUP optimization)
|
||||
.
|
||||
*/
|
||||
#define MAGIC (62151 | ((long)'\r'<<16) | ((long)'\n'<<24))
|
||||
#define MAGIC (62161 | ((long)'\r'<<16) | ((long)'\n'<<24))
|
||||
|
||||
/* Magic word as global; note that _PyImport_Init() can change the
|
||||
value of this global to accommodate for alterations of how the
|
||||
|
|
Loading…
Reference in New Issue