diff --git a/Misc/NEWS b/Misc/NEWS index 4763598d3ae..80f7dc79333 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -12,6 +12,12 @@ What's New in Python 2.5 alpha 1? Core and builtins ----------------- +- SF bug #1163563: the original fix for bug #1010677 ("thread Module + Breaks PyGILState_Ensure()") broke badly in the case of multiple + interpreter states; back out that fix and do a better job (see + http://mail.python.org/pipermail/python-dev/2005-June/054258.html + for a longer write-up of the problem). + - SF patch #1180995: marshal now uses a binary format by default when serializing floats. diff --git a/Modules/threadmodule.c b/Modules/threadmodule.c index 098a78490d1..3025595df1b 100644 --- a/Modules/threadmodule.c +++ b/Modules/threadmodule.c @@ -413,10 +413,12 @@ static void t_bootstrap(void *boot_raw) { struct bootstate *boot = (struct bootstate *) boot_raw; - PyGILState_STATE gstate; + PyThreadState *tstate; PyObject *res; - gstate = PyGILState_Ensure(); + tstate = PyThreadState_New(boot->interp); + + PyEval_AcquireThread(tstate); res = PyEval_CallObjectWithKeywords( boot->func, boot->args, boot->keyw); if (res == NULL) { @@ -441,7 +443,8 @@ t_bootstrap(void *boot_raw) Py_DECREF(boot->args); Py_XDECREF(boot->keyw); PyMem_DEL(boot_raw); - PyGILState_Release(gstate); + PyThreadState_Clear(tstate); + PyThreadState_DeleteCurrent(); PyThread_exit_thread(); } diff --git a/Python/pystate.c b/Python/pystate.c index e2cf7c564d5..3ac799ce886 100644 --- a/Python/pystate.c +++ b/Python/pystate.c @@ -36,6 +36,12 @@ static PyThread_type_lock head_mutex = NULL; /* Protects interp->tstate_head */ #define HEAD_INIT() (void)(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) + +/* The single PyInterpreterState used by this process' + GILState implementation +*/ +static PyInterpreterState *autoInterpreterState = NULL; +static int autoTLSkey = 0; #else #define HEAD_INIT() /* Nothing */ #define HEAD_LOCK() /* Nothing */ @@ -47,6 +53,8 @@ static PyInterpreterState *interp_head = NULL; PyThreadState *_PyThreadState_Current = NULL; PyThreadFrameGetter _PyThreadState_GetFrame = NULL; +static void _PyGILState_NoteThreadState(PyThreadState* tstate); + PyInterpreterState * PyInterpreterState_New(void) @@ -180,6 +188,8 @@ PyThreadState_New(PyInterpreterState *interp) tstate->c_profileobj = NULL; tstate->c_traceobj = NULL; + _PyGILState_NoteThreadState(tstate); + HEAD_LOCK(); tstate->next = interp->tstate_head; interp->tstate_head = tstate; @@ -261,6 +271,8 @@ PyThreadState_DeleteCurrent() "PyThreadState_DeleteCurrent: no current tstate"); _PyThreadState_Current = NULL; tstate_delete_common(tstate); + if (autoTLSkey && PyThread_get_key_value(autoTLSkey) == tstate) + PyThread_delete_key_value(autoTLSkey); PyEval_ReleaseLock(); } #endif /* WITH_THREAD */ @@ -393,12 +405,6 @@ PyThreadState_IsCurrent(PyThreadState *tstate) return tstate == _PyThreadState_Current; } -/* The single PyInterpreterState used by this process' - GILState implementation -*/ -static PyInterpreterState *autoInterpreterState = NULL; -static int autoTLSkey = 0; - /* Internal initialization/finalization functions called by Py_Initialize/Py_Finalize */ @@ -408,12 +414,10 @@ _PyGILState_Init(PyInterpreterState *i, PyThreadState *t) assert(i && t); /* must init with valid states */ autoTLSkey = PyThread_create_key(); autoInterpreterState = i; - /* Now stash the thread state for this thread in TLS */ assert(PyThread_get_key_value(autoTLSkey) == NULL); - if (PyThread_set_key_value(autoTLSkey, (void *)t) < 0) - Py_FatalError("Couldn't create autoTLSkey mapping"); - assert(t->gilstate_counter == 0); /* must be a new thread state */ - t->gilstate_counter = 1; + assert(t->gilstate_counter == 0); + + _PyGILState_NoteThreadState(t); } void @@ -424,6 +428,41 @@ _PyGILState_Fini(void) autoInterpreterState = NULL;; } +/* When a thread state is created for a thread by some mechanism other than + PyGILState_Ensure, it's important that the GILState machinery knows about + it so it doesn't try to create another thread state for the thread (this is + a better fix for SF bug #1010677 than the first one attempted). +*/ +void +_PyGILState_NoteThreadState(PyThreadState* tstate) +{ + /* If autoTLSkey is 0, this must be the very first threadstate created + in Py_Initialize(). Don't do anything for now (we'll be back here + when _PyGILState_Init is called). */ + if (!autoTLSkey) + return; + + /* Stick the thread state for this thread in thread local storage. + + The only situation where you can legitimately have more than one + thread state for an OS level thread is when there are multiple + interpreters, when: + + a) You shouldn't really be using the PyGILState_ APIs anyway, + and: + + b) The slightly odd way PyThread_set_key_value works (see + comments by its implementation) means that the first thread + state created for that given OS level thread will "win", + which seems reasonable behaviour. + */ + if (PyThread_set_key_value(autoTLSkey, (void *)tstate) < 0) + Py_FatalError("Couldn't create autoTLSkey mapping"); + + /* PyGILState_Release must not try to delete this thread state. */ + tstate->gilstate_counter = 1; +} + /* The public functions */ PyThreadState * PyGILState_GetThisThreadState(void) @@ -450,8 +489,9 @@ PyGILState_Ensure(void) tcur = PyThreadState_New(autoInterpreterState); if (tcur == NULL) Py_FatalError("Couldn't create thread-state for new thread"); - if (PyThread_set_key_value(autoTLSkey, (void *)tcur) < 0) - Py_FatalError("Couldn't create autoTLSkey mapping"); + /* This is our thread state! We'll need to delete it in the + matching call to PyGILState_Release(). */ + tcur->gilstate_counter = 0; current = 0; /* new thread state is never current */ } else @@ -498,8 +538,6 @@ PyGILState_Release(PyGILState_STATE oldstate) * habit of coming back). */ PyThreadState_DeleteCurrent(); - /* Delete this thread from our TLS. */ - PyThread_delete_key_value(autoTLSkey); } /* Release the lock if necessary */ else if (oldstate == PyGILState_UNLOCKED)