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Reformat _tkinter code to follow PEP7

This commit is contained in:
Andrew Svetlov 2012-10-16 22:50:34 +03:00
parent cfc22b4a9b
commit d0ad0b3ae2
1 changed files with 66 additions and 50 deletions
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116
Modules/_tkinter.c
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@ -125,52 +125,60 @@ Copyright (C) 1994 Steen Lumholt.
/* The threading situation is complicated. Tcl is not thread-safe, except
when configured with --enable-threads.
So we need to use a lock around all uses of Tcl. Previously, the Python
interpreter lock was used for this. However, this causes problems when
other Python threads need to run while Tcl is blocked waiting for events.
To solve this problem, a separate lock for Tcl is introduced. Holding it
is incompatible with holding Python's interpreter lock. The following four
macros manipulate both locks together.
So we need to use a lock around all uses of Tcl. Previously, the
Python interpreter lock was used for this. However, this causes
problems when other Python threads need to run while Tcl is blocked
waiting for events.
ENTER_TCL and LEAVE_TCL are brackets, just like Py_BEGIN_ALLOW_THREADS and
Py_END_ALLOW_THREADS. They should be used whenever a call into Tcl is made
that could call an event handler, or otherwise affect the state of a Tcl
interpreter. These assume that the surrounding code has the Python
interpreter lock; inside the brackets, the Python interpreter lock has been
released and the lock for Tcl has been acquired.
To solve this problem, a separate lock for Tcl is introduced.
Holding it is incompatible with holding Python's interpreter lock.
The following four macros manipulate both locks together.
Sometimes, it is necessary to have both the Python lock and the Tcl lock.
(For example, when transferring data from the Tcl interpreter result to a
Python string object.) This can be done by using different macros to close
the ENTER_TCL block: ENTER_OVERLAP reacquires the Python lock (and restores
the thread state) but doesn't release the Tcl lock; LEAVE_OVERLAP_TCL
releases the Tcl lock.
ENTER_TCL and LEAVE_TCL are brackets, just like
Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW_THREADS. They should be
used whenever a call into Tcl is made that could call an event
handler, or otherwise affect the state of a Tcl interpreter. These
assume that the surrounding code has the Python interpreter lock;
inside the brackets, the Python interpreter lock has been released
and the lock for Tcl has been acquired.
Sometimes, it is necessary to have both the Python lock and the Tcl
lock. (For example, when transferring data from the Tcl
interpreter result to a Python string object.) This can be done by
using different macros to close the ENTER_TCL block: ENTER_OVERLAP
reacquires the Python lock (and restores the thread state) but
doesn't release the Tcl lock; LEAVE_OVERLAP_TCL releases the Tcl
lock.
By contrast, ENTER_PYTHON and LEAVE_PYTHON are used in Tcl event
handlers when the handler needs to use Python. Such event handlers are
entered while the lock for Tcl is held; the event handler presumably needs
to use Python. ENTER_PYTHON releases the lock for Tcl and acquires
the Python interpreter lock, restoring the appropriate thread state, and
LEAVE_PYTHON releases the Python interpreter lock and re-acquires the lock
for Tcl. It is okay for ENTER_TCL/LEAVE_TCL pairs to be contained inside
the code between ENTER_PYTHON and LEAVE_PYTHON.
handlers when the handler needs to use Python. Such event handlers
are entered while the lock for Tcl is held; the event handler
presumably needs to use Python. ENTER_PYTHON releases the lock for
Tcl and acquires the Python interpreter lock, restoring the
appropriate thread state, and LEAVE_PYTHON releases the Python
interpreter lock and re-acquires the lock for Tcl. It is okay for
ENTER_TCL/LEAVE_TCL pairs to be contained inside the code between
ENTER_PYTHON and LEAVE_PYTHON.
These locks expand to several statements and brackets; they should not be
used in branches of if statements and the like.
These locks expand to several statements and brackets; they should
not be used in branches of if statements and the like.
If Tcl is threaded, this approach won't work anymore. The Tcl interpreter is
only valid in the thread that created it, and all Tk activity must happen in this
thread, also. That means that the mainloop must be invoked in the thread that
created the interpreter. Invoking commands from other threads is possible;
_tkinter will queue an event for the interpreter thread, which will then
execute the command and pass back the result. If the main thread is not in the
mainloop, and invoking commands causes an exception; if the main loop is running
but not processing events, the command invocation will block.
If Tcl is threaded, this approach won't work anymore. The Tcl
interpreter is only valid in the thread that created it, and all Tk
activity must happen in this thread, also. That means that the
mainloop must be invoked in the thread that created the
interpreter. Invoking commands from other threads is possible;
_tkinter will queue an event for the interpreter thread, which will
then execute the command and pass back the result. If the main
thread is not in the mainloop, and invoking commands causes an
exception; if the main loop is running but not processing events,
the command invocation will block.
In addition, for a threaded Tcl, a single global tcl_tstate won't be sufficient
anymore, since multiple Tcl interpreters may simultaneously dispatch in different
threads. So we use the Tcl TLS API.
In addition, for a threaded Tcl, a single global tcl_tstate won't
be sufficient anymore, since multiple Tcl interpreters may
simultaneously dispatch in different threads. So we use the Tcl TLS
API.
*/
@ -179,7 +187,8 @@ static PyThread_type_lock tcl_lock = 0;
#ifdef TCL_THREADS
static Tcl_ThreadDataKey state_key;
typedef PyThreadState *ThreadSpecificData;
#define tcl_tstate (*(PyThreadState**)Tcl_GetThreadData(&state_key, sizeof(PyThreadState*)))
#define tcl_tstate \
(*(PyThreadState**)Tcl_GetThreadData(&state_key, sizeof(PyThreadState*)))
#else
static PyThreadState *tcl_tstate = NULL;
#endif
@ -189,7 +198,8 @@ static PyThreadState *tcl_tstate = NULL;
if(tcl_lock)PyThread_acquire_lock(tcl_lock, 1); tcl_tstate = tstate;
#define LEAVE_TCL \
tcl_tstate = NULL; if(tcl_lock)PyThread_release_lock(tcl_lock); Py_END_ALLOW_THREADS}
tcl_tstate = NULL; \
if(tcl_lock)PyThread_release_lock(tcl_lock); Py_END_ALLOW_THREADS}
#define ENTER_OVERLAP \
Py_END_ALLOW_THREADS
@ -199,7 +209,8 @@ static PyThreadState *tcl_tstate = NULL;
#define ENTER_PYTHON \
{ PyThreadState *tstate = tcl_tstate; tcl_tstate = NULL; \
if(tcl_lock)PyThread_release_lock(tcl_lock); PyEval_RestoreThread((tstate)); }
if(tcl_lock) \
PyThread_release_lock(tcl_lock); PyEval_RestoreThread((tstate)); }
#define LEAVE_PYTHON \
{ PyThreadState *tstate = PyEval_SaveThread(); \
@ -208,7 +219,8 @@ static PyThreadState *tcl_tstate = NULL;
#define CHECK_TCL_APPARTMENT \
if (((TkappObject *)self)->threaded && \
((TkappObject *)self)->thread_id != Tcl_GetCurrentThread()) { \
PyErr_SetString(PyExc_RuntimeError, "Calling Tcl from different appartment"); \
PyErr_SetString(PyExc_RuntimeError, \
"Calling Tcl from different appartment"); \
return 0; \
}
@ -367,9 +379,9 @@ Split(char *list)
return v;
}
/* In some cases, Tcl will still return strings that are supposed to be
lists. SplitObj walks through a nested tuple, finding string objects that
need to be split. */
/* In some cases, Tcl will still return strings that are supposed to
be lists. SplitObj walks through a nested tuple, finding string
objects that need to be split. */
static PyObject *
SplitObj(PyObject *arg)
@ -499,7 +511,8 @@ Tkapp_New(char *screenName, char *className,
#ifndef TCL_THREADS
if (v->threaded) {
PyErr_SetString(PyExc_RuntimeError, "Tcl is threaded but _tkinter is not");
PyErr_SetString(PyExc_RuntimeError,
"Tcl is threaded but _tkinter is not");
Py_DECREF(v);
return 0;
}
@ -1479,7 +1492,8 @@ GetVar(PyObject *self, PyObject *args, int flags)
tres = Tcl_GetVar2Ex(Tkapp_Interp(self), name1, name2, flags);
ENTER_OVERLAP
if (tres == NULL) {
PyErr_SetString(Tkinter_TclError, Tcl_GetStringResult(Tkapp_Interp(self)));
PyErr_SetString(Tkinter_TclError,
Tcl_GetStringResult(Tkapp_Interp(self)));
} else {
if (((TkappObject*)self)->wantobjects) {
res = FromObj(self, tres);
@ -1538,7 +1552,8 @@ Tkapp_UnsetVar(PyObject *self, PyObject *args)
static PyObject *
Tkapp_GlobalUnsetVar(PyObject *self, PyObject *args)
{
return var_invoke(UnsetVar, self, args, TCL_LEAVE_ERR_MSG | TCL_GLOBAL_ONLY);
return var_invoke(UnsetVar, self, args,
TCL_LEAVE_ERR_MSG | TCL_GLOBAL_ONLY);
}
@ -2407,7 +2422,8 @@ Tkapp_TkInit(PyObject *self, PyObject *args)
}
if (_tk_exists == NULL || strcmp(_tk_exists, "1") != 0) {
if (Tk_Init(interp) == TCL_ERROR) {
PyErr_SetString(Tkinter_TclError, Tcl_GetStringResult(Tkapp_Interp(self)));
PyErr_SetString(Tkinter_TclError,
Tcl_GetStringResult(Tkapp_Interp(self)));
#ifdef TKINTER_PROTECT_LOADTK
tk_load_failed = 1;
#endif
@ -2649,7 +2665,7 @@ Tkinter_Create(PyObject *self, PyObject *args)
return NULL;
return (PyObject *) Tkapp_New(screenName, className,
interactive, wantobjects, wantTk,
interactive, wantobjects, wantTk,
sync, use);
}