Introduce truly separate (sub)interpreter objects. For now, these
must be used by separate threads, created from C. See Demo/pysvr for
an example of how to use this. This also rationalizes Python's
initialization and finalization behavior:
Py_Initialize() -- initialize the whole interpreter
Py_Finalize() -- finalize the whole interpreter
tstate = Py_NewInterpreter() -- create a new (sub)interpreter
Py_EndInterpreter(tstate) -- delete a new (sub)interpreter
There are also new interfaces relating to threads and the interpreter
lock, which can be used to create new threads, and sometimes have to
be used to manipulate the interpreter lock when creating or deleting
sub-interpreters. These are only defined when WITH_THREAD is defined:
PyEval_AcquireLock() -- acquire the interpreter lock
PyEval_ReleaseLock() -- release the interpreter lock
PyEval_AcquireThread(tstate) -- acquire the lock and make the thread current
PyEval_ReleaseThread(tstate) -- release the lock and make NULL current
Other administrative changes:
- The header file bltinmodule.h is deleted.
- The init functions for Import, Sys and Builtin are now internal and
declared in pythonrun.h.
- Py_Setup() and Py_Cleanup() are no longer declared.
- The interpreter state and thread state structures are now linked
together in a chain (the chain of interpreters is a static variable
in pythonrun.c).
- Some members of the interpreter and thread structures have new,
shorter, more consistent, names.
- Added declarations for _PyImport_{Find,Fixup}Extension() to import.h.
PyThreadState pointer instead of a (frame) PyObject pointer. This
makes much more sense. It is backward incompatible, but that's no
problem, because (a) the heaviest users are the Py_{BEGIN,END}_
ALLOW_THREADS macros here, which have been fixed too; (b) there are
very few direct users; (c) those who use it are there will probably
appreciate the change.
Also, added new functions PyEval_AcquireThread() and
PyEval_ReleaseThread() which allows the threads created by the thread
module as well threads created by others (!) to set/reset the current
thread, and at the same time acquire/release the interpreter lock.
Much saner.
last variable to which a floating point expression is assigned. The
macro passes its address to a dummy function so that the optimizer
can't delay calculating its value until after the macro.
