/***********************************************************

Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,

The Netherlands.

All Rights Reserved

Permission to use, copy, modify, and distribute this software and its

documentation for any purpose and without fee is hereby granted,

provided that the above copyright notice appear in all copies and that

both that copyright notice and this permission notice appear in

supporting documentation, and that the names of Stichting Mathematisch

Centrum or CWI or Corporation for National Research Initiatives or

CNRI not be used in advertising or publicity pertaining to

distribution of the software without specific, written prior

permission.

While CWI is the initial source for this software, a modified version

is made available by the Corporation for National Research Initiatives

(CNRI) at the Internet address ftp://ftp.python.org.

STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH

REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF

MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH

CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL

DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR

PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER

TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR

PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

/* Thread and interpreter state structures and their interfaces */

#include "Python.h"

#define ZAP(x) { \

PyObject *tmp = (PyObject *)(x); \

(x) = NULL; \

Py_XDECREF(tmp); \

}

#ifdef WITH_THREAD

#include "pythread.h"

static PyThread_type_lock head_mutex = NULL; /* Protects interp->tstate_head */

#define HEAD_INIT() (head_mutex || (head_mutex = PyThread_allocate_lock()))

#define HEAD_LOCK() PyThread_acquire_lock(head_mutex, WAIT_LOCK)

#define HEAD_UNLOCK() PyThread_release_lock(head_mutex)

#else

#define HEAD_INIT() /* Nothing */

#define HEAD_LOCK() /* Nothing */

#define HEAD_UNLOCK() /* Nothing */

#endif

static PyInterpreterState *interp_head = NULL;

PyThreadState *_PyThreadState_Current = NULL;

PyInterpreterState *

PyInterpreterState_New()

{

PyInterpreterState *interp = PyMem_NEW(PyInterpreterState, 1);

if (interp != NULL) {

HEAD_INIT();

interp->modules = NULL;

interp->sysdict = NULL;

interp->builtins = NULL;

interp->checkinterval = 10;

interp->tstate_head = NULL;

interp->next = interp_head;

interp_head = interp;

}

return interp;

}

void

PyInterpreterState_Clear(interp)

PyInterpreterState *interp;

{

PyThreadState *p;

HEAD_LOCK();

for (p = interp->tstate_head; p != NULL; p = p->next)

PyThreadState_Clear(p);

HEAD_UNLOCK();

ZAP(interp->modules);

ZAP(interp->sysdict);

ZAP(interp->builtins);

}

static void

zapthreads(interp)

PyInterpreterState *interp;

{

PyThreadState *p;

/* No need to lock the mutex here because this should only happen

when the threads are all really dead (XXX famous last words). */

while ((p = interp->tstate_head) != NULL) {

PyThreadState_Delete(p);

}

}

void

PyInterpreterState_Delete(interp)

PyInterpreterState *interp;

{

PyInterpreterState **p;

zapthreads(interp);

for (p = &interp_head; ; p = &(*p)->next) {

if (*p == NULL)

Py_FatalError(

"PyInterpreterState_Delete: invalid interp");

if (*p == interp)

break;

}

if (interp->tstate_head != NULL)

Py_FatalError("PyInterpreterState_Delete: remaining threads");

*p = interp->next;

PyMem_DEL(interp);

}

PyThreadState *

PyThreadState_New(interp)

PyInterpreterState *interp;

{

PyThreadState *tstate = PyMem_NEW(PyThreadState, 1);

if (tstate != NULL) {

tstate->interp = interp;

tstate->frame = NULL;

tstate->recursion_depth = 0;

tstate->ticker = 0;

tstate->tracing = 0;

tstate->dict = NULL;

tstate->curexc_type = NULL;

tstate->curexc_value = NULL;

tstate->curexc_traceback = NULL;

tstate->exc_type = NULL;

tstate->exc_value = NULL;

tstate->exc_traceback = NULL;

tstate->sys_profilefunc = NULL;

tstate->sys_tracefunc = NULL;

HEAD_LOCK();

tstate->next = interp->tstate_head;

interp->tstate_head = tstate;

HEAD_UNLOCK();

}

return tstate;

}

void

PyThreadState_Clear(tstate)

PyThreadState *tstate;

{

if (Py_VerboseFlag && tstate->frame != NULL)

fprintf(stderr,

"PyThreadState_Clear: warning: thread still has a frame\n");

ZAP(tstate->frame);

ZAP(tstate->dict);

ZAP(tstate->curexc_type);

ZAP(tstate->curexc_value);

ZAP(tstate->curexc_traceback);

ZAP(tstate->exc_type);

ZAP(tstate->exc_value);

ZAP(tstate->exc_traceback);

ZAP(tstate->sys_profilefunc);

ZAP(tstate->sys_tracefunc);

}

void

PyThreadState_Delete(tstate)

PyThreadState *tstate;

{

PyInterpreterState *interp;

PyThreadState **p;

if (tstate == NULL)

Py_FatalError("PyThreadState_Delete: NULL tstate");

if (tstate == _PyThreadState_Current)

Py_FatalError("PyThreadState_Delete: tstate is still current");

interp = tstate->interp;

if (interp == NULL)

Py_FatalError("PyThreadState_Delete: NULL interp");

HEAD_LOCK();

for (p = &interp->tstate_head; ; p = &(*p)->next) {

if (*p == NULL)

Py_FatalError(

"PyThreadState_Delete: invalid tstate");

if (*p == tstate)

break;

}

*p = tstate->next;

HEAD_UNLOCK();

PyMem_DEL(tstate);

}

PyThreadState *

PyThreadState_Get()

{

if (_PyThreadState_Current == NULL)

Py_FatalError("PyThreadState_Get: no current thread");

return _PyThreadState_Current;

}

PyThreadState *

PyThreadState_Swap(new)

PyThreadState *new;

{

PyThreadState *old = _PyThreadState_Current;

_PyThreadState_Current = new;

return old;

}

/* An extension mechanism to store arbitrary additional per-thread state.

PyThreadState_GetDict() returns a dictionary that can be used to hold such

state; the caller should pick a unique key and store its state there. If

PyThreadState_GetDict() returns NULL, an exception has been raised (most

likely MemoryError) and the caller should pass on the exception. */

PyObject *

PyThreadState_GetDict()

{

if (_PyThreadState_Current == NULL)

Py_FatalError("PyThreadState_GetDict: no current thread");

if (_PyThreadState_Current->dict == NULL)

_PyThreadState_Current->dict = PyDict_New();

return _PyThreadState_Current->dict;

}