sporadic crashes in multi-thread programs when several long deallocator
chains ran concurrently and involved subclasses of built-in container
types.
Because of this change, a couple extension modules compiled for 2.7.4
(those which use the trashcan mechanism, despite it being undocumented)
will not be loadable by 2.7.3 and earlier. However, extension modules
compiled for 2.7.3 and earlier will be loadable by 2.7.4.
TLS implementations, and fails with the ad-hoc TLS implementation when a thread
doesn't have an auto thread state (e.g. a thread created outside of Python
calling into a subinterpreter).
A new API (only accessible from C) to interrupt a thread by sending it
an exception. This is not always effective, but might help some people.
Requested by Just van Rossum and Alex Martelli. It is intentional
that you have to write your own C extension to call it from Python.
Docs will have to wait.
variables to store internal data. As a result, any atempts to use the
unicode system with multiple active interpreters, or successive
interpreter executions, would fail.
Now that information is stored into members of the PyInterpreterState
structure.
globals, _Py_Ticker and _Py_CheckInterval. This also implements Jeremy's
shortcut in Py_AddPendingCall that zeroes out _Py_Ticker. This allows the
test in the main loop to only test a single value.
The gory details are at
http://python.org/sf/602191
path (with no profile/trace function) through eval_code2() and
eval_frame() avoids several checks.
In the common cases of calls, returns, and exception propogation,
eval_code2() and eval_frame() used to test two values in the
thread-state: the profiling function and the tracing function. With
this change, a flag is set in the thread-state if either of these is
active, allowing a single check to suffice when both are NULL. This
also simplifies the code needed when either function is in use but is
already active (to avoid profiling/tracing the profiler/tracer); the
flag is set to 0 when the profile/trace code is entered, allowing the
same check to suffice for "already in the tracer" for call/return/
exception events.
Python interpreter.
This change adds two new C-level APIs: PyEval_SetProfile() and
PyEval_SetTrace(). These can be used to install profile and trace
functions implemented in C, which can operate at much higher speeds
than Python-based functions. The overhead for calling a C-based
profile function is a very small fraction of a percent of the overhead
involved in calling a Python-based function.
The machinery required to call a Python-based profile or trace
function been moved to sysmodule.c, where sys.setprofile() and
sys.setprofile() simply become users of the new interface.
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.
Antoine Pitrou
Charles-François Natali
Sandro Tosi
Victor Stinner
Collin Winter
Tim Peters
Brett Cannon
Martin v. Löwis
Nicholas Bastin
Raymond Hettinger
Guido van Rossum
Mark Hammond
Gustavo Niemeyer
Michael W. Hudson
Skip Montanaro
Fred Drake