If a thread different than the main thread gets a signal, the
bytecode evaluation loop is no longer interrupted at each bytecode
instruction to check for pending signals which cannot be handled.
Only the main thread of the main interpreter can handle signals.
Previously, the bytecode evaluation loop was interrupted at each
instruction until the main thread handles signals.
Changes:
* COMPUTE_EVAL_BREAKER() and SIGNAL_PENDING_SIGNALS() no longer set
eval_breaker to 1 if the current thread cannot handle signals.
* take_gil() now always recomputes eval_breaker.
If Py_AddPendingCall() is called in a subinterpreter, the function is
now scheduled to be called from the subinterpreter, rather than being
called from the main interpreter.
Each subinterpreter now has its own list of scheduled calls.
* Move pending and eval_breaker fields from _PyRuntimeState.ceval
to PyInterpreterState.ceval.
* new_interpreter() now calls _PyEval_InitThreads() to create
pending calls lock.
* Fix Py_AddPendingCall() for subinterpreters. It now calls
_PyThreadState_GET() which works in a subinterpreter if the
caller holds the GIL, and only falls back on
PyGILState_GetThisThreadState() if _PyThreadState_GET()
returns NULL.
* Remove ceval parameter of take_gil(): get it from tstate.
* Move exit_thread_if_finalizing() call inside take_gil(). Replace
exit_thread_if_finalizing() with tstate_must_exit(): the caller is
now responsible to call PyThread_exit_thread().
* Move is_tstate_valid() assertion inside take_gil(). Remove
is_tstate_valid(): inline code into take_gil().
* Move gil_created() assertion inside take_gil().
* exit_thread_if_finalizing() does now access directly _PyRuntime
variable, rather than using tstate->interp->runtime since tstate
can be a dangling pointer after Py_Finalize() has been called.
* exit_thread_if_finalizing() is now called *before* calling
take_gil(). _PyRuntime.finalizing is an atomic variable,
we don't need to hold the GIL to access it.
* Add ensure_tstate_not_null() function to check that tstate is not
NULL at runtime. Check tstate earlier. take_gil() does not longer
check if tstate is NULL.
Cleanup:
* PyEval_RestoreThread() no longer saves/restores errno: it's already
done inside take_gil().
* PyEval_AcquireLock(), PyEval_AcquireThread(),
PyEval_RestoreThread() and _PyEval_EvalFrameDefault() now check if
tstate is valid with the new is_tstate_valid() function which uses
_PyMem_IsPtrFreed().
Add "struct _ceval_runtime_state *ceval = &_PyRuntime.ceval;" local
variables to function to better highlight the dependency on the
global variable _PyRuntime and to point directly to _PyRuntime.ceval
field rather than on the larger _PyRuntime.
Changes:
* Add _PyRuntimeState_GetThreadState(runtime) macro.
* Add _PyEval_AddPendingCall(ceval, ...) and
_PyThreadState_Swap(gilstate, ...) functions.
* _PyThreadState_GET() macro now calls
_PyRuntimeState_GetThreadState() using &_PyRuntime.
* Add 'ceval' parameter to COMPUTE_EVAL_BREAKER(),
SIGNAL_PENDING_SIGNALS(), _PyEval_SignalAsyncExc(),
_PyEval_SignalReceived() and _PyEval_FiniThreads() macros and
functions.
* Add 'tstate' parameter to call_function(), do_call_core() and
do_raise().
* Add 'runtime' parameter to _Py_CURRENTLY_FINALIZING(),
_Py_FinishPendingCalls() and _PyThreadState_DeleteExcept()
macros and functions.
* Declare 'runtime', 'tstate', 'ceval' and 'eval_breaker' variables
as constant.
This is effectively an un-revert of #11617 and #12024 (reverted in #12159). Portions of those were merged in other PRs (with lower risk) and this represents the remainder. Note that I found 3 different bugs in the original PRs and have fixed them here.
* Revert "bpo-36097: Use only public C-API in the_xxsubinterpreters module (adding as necessary). (#12003)"
This reverts commit bcfa450f21.
* Revert "bpo-33608: Simplify ceval's DISPATCH by hoisting eval_breaker ahead of time. (gh-12062)"
This reverts commit bda918bf65.
* Revert "bpo-33608: Use _Py_AddPendingCall() in _PyCrossInterpreterData_Release(). (gh-12024)"
This reverts commit b05b711a2c.
* Revert "bpo-33608: Factor out a private, per-interpreter _Py_AddPendingCall(). (GH-11617)"
This reverts commit ef4ac967e2.
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
Issue #26161: Use Py_uintptr_t instead of void* for atomic pointers in
pyatomic.h. Use atomic_uintptr_t when <stdatomic.h> is used.
Using void* causes compilation warnings depending on which implementation of
atomic types is used.
http://code.google.com/p/data-race-test/wiki/ThreadSanitizer is a dynamic data
race detector that runs on top of valgrind. With this patch, the binaries at
http://code.google.com/p/data-race-test/wiki/ThreadSanitizer#Binaries pass many
but not all of the Python tests. All of regrtest still passes outside of tsan.
I've implemented part of the C1x atomic types so that we can explicitly mark
variables that are used across threads, and get defined behavior as compilers
advance.
I've added tsan's client header and implementation to the codebase in
dynamic_annotations.{h,c} (docs at
http://code.google.com/p/data-race-test/wiki/DynamicAnnotations).
Unfortunately, I haven't been able to get helgrind and drd to give sensible
error messages, even when I use their client annotations, so I'm not supporting
them.
Victor Stinner
Victor Stinner
Eric Snow
Benjamin Peterson
Victor Stinner
Serhiy Storchaka
Kristján Valur Jónsson
Antoine Pitrou
Jeffrey Yasskin