Massive changes for separate thread state management.

All per-thread globals are moved into a struct which is manipulated
separately.

1 files changed, 163 insertions, 0 deletions

diff --git a/Python/pystate.c b/Python/pystate.c
new file mode 100644
index 0000000..7ce499a
--- /dev/null
+++ b/Python/pystate.c
@@ -0,0 +1,163 @@
+/***********************************************************
+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"
+
+
+static PyThreadState *current_tstate = NULL;
+
+
+PyInterpreterState *
+PyInterpreterState_New()
+{
+	PyInterpreterState *interp = PyMem_NEW(PyInterpreterState, 1);
+	if (interp != NULL) {
+		interp->import_modules = NULL;
+		interp->sysdict = NULL;
+		interp->nthreads = 0;
+		interp->nexitfuncs = 0;
+	}
+	return interp;
+}
+
+
+void
+PyInterpreterState_Delete(PyInterpreterState *interp)
+{
+	Py_XDECREF(interp->import_modules);
+	Py_XDECREF(interp->sysdict);
+
+	PyMem_DEL(interp);
+}
+
+
+PyThreadState *
+PyThreadState_New(PyInterpreterState *interp)
+{
+	PyThreadState *tstate = PyMem_NEW(PyThreadState, 1);
+	/* fprintf(stderr, "new tstate -> %p\n", tstate); */
+	if (tstate != NULL) {
+		tstate->interpreter_state = interp;
+
+		tstate->frame = NULL;
+		tstate->recursion_depth = 0;
+		tstate->ticker = 0;
+		tstate->tracing = 0;
+
+		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;
+		tstate->sys_checkinterval = 0;
+
+		interp->nthreads++;
+	}
+	return tstate;
+}
+
+
+void
+PyThreadState_Delete(PyThreadState *tstate)
+{
+	/* fprintf(stderr, "delete tstate %p\n", tstate); */
+	if (tstate == current_tstate)
+		current_tstate = NULL;
+	tstate->interpreter_state->nthreads--;
+
+	Py_XDECREF((PyObject *) (tstate->frame)); /* XXX really? */
+
+	Py_XDECREF(tstate->curexc_type);
+	Py_XDECREF(tstate->curexc_value);
+	Py_XDECREF(tstate->curexc_traceback);
+
+	Py_XDECREF(tstate->exc_type);
+	Py_XDECREF(tstate->exc_value);
+	Py_XDECREF(tstate->exc_traceback);
+
+	Py_XDECREF(tstate->sys_profilefunc);
+	Py_XDECREF(tstate->sys_tracefunc);
+
+	PyMem_DEL(tstate);
+}
+
+
+PyThreadState *
+PyThreadState_Get()
+{
+	/* fprintf(stderr, "get tstate -> %p\n", current_tstate); */
+	return current_tstate;
+}
+
+
+PyThreadState *
+PyThreadState_Swap(PyThreadState *new)
+{
+	PyThreadState *old = current_tstate;
+	/* fprintf(stderr, "swap tstate new=%p <--> old=%p\n", new, old); */
+	current_tstate = new;
+	return old;
+}
+
+
+/* How should one use this code?
+
+   1. Standard Python interpreter, assuming no other interpreters or threads:
+
+      PyInterpreterState *interp;
+      PyThreadState *tstate;
+      interp = PyInterpreterState_New();
+      if (interp == NULL)
+          Py_FatalError("...");
+      tstate = PyThreadState_New(interp);
+      if (tstate == NULL)
+          Py_FatalError("...");
+      (void) PyThreadState_Swap(tstate);
+      PyInitialize();
+      .
+      . (use the interpreter here)
+      .
+      Py_Cleanup();
+      PyThreadState_Delete(tstate);
+      PyInterpreterState_Delete(interp);
+
+   2. Totally indepent interpreter invocation in a separate C thread:
+
+      XXX Need to interact with the thread lock nevertheless!!!
+
+*/