EmbeddedPkg: Extend NvVarStoreFormattedLib LIBRARY_CLASS

[mirror_edk2.git] / AppPkg / Applications / Python / Python-2.7.10 / Python / pystate.c

\r
/* Thread and interpreter state structures and their interfaces */\r
\r
#include "Python.h"\r
\r
/* --------------------------------------------------------------------------\r
CAUTION\r
\r
Always use malloc() and free() directly in this file.  A number of these\r
functions are advertised as safe to call when the GIL isn't held, and in\r
a debug build Python redirects (e.g.) PyMem_NEW (etc) to Python's debugging\r
obmalloc functions.  Those aren't thread-safe (they rely on the GIL to avoid\r
the expense of doing their own locking).\r
-------------------------------------------------------------------------- */\r
\r
#ifdef HAVE_DLOPEN\r
#ifdef HAVE_DLFCN_H\r
#include <dlfcn.h>\r
#endif\r
#ifndef RTLD_LAZY\r
#define RTLD_LAZY 1\r
#endif\r
#endif\r
\r
#ifdef __cplusplus\r
extern "C" {\r
#endif\r
\r
#ifdef WITH_THREAD\r
#include "pythread.h"\r
static PyThread_type_lock head_mutex = NULL; /* Protects interp->tstate_head */\r
#define HEAD_INIT() (void)(head_mutex || (head_mutex = PyThread_allocate_lock()))\r
#define HEAD_LOCK() PyThread_acquire_lock(head_mutex, WAIT_LOCK)\r
#define HEAD_UNLOCK() PyThread_release_lock(head_mutex)\r
\r
/* The single PyInterpreterState used by this process'\r
   GILState implementation\r
*/\r
static PyInterpreterState *autoInterpreterState = NULL;\r
static int autoTLSkey = 0;\r
#else\r
#define HEAD_INIT() /* Nothing */\r
#define HEAD_LOCK() /* Nothing */\r
#define HEAD_UNLOCK() /* Nothing */\r
#endif\r
\r
static PyInterpreterState *interp_head = NULL;\r
\r
PyThreadState *_PyThreadState_Current = NULL;\r
PyThreadFrameGetter _PyThreadState_GetFrame = NULL;\r
\r
#ifdef WITH_THREAD\r
static void _PyGILState_NoteThreadState(PyThreadState* tstate);\r
#endif\r
\r
\r
PyInterpreterState *\r
PyInterpreterState_New(void)\r
{\r
    PyInterpreterState *interp = (PyInterpreterState *)\r
                                 malloc(sizeof(PyInterpreterState));\r
\r
    if (interp != NULL) {\r
        HEAD_INIT();\r
#ifdef WITH_THREAD\r
        if (head_mutex == NULL)\r
            Py_FatalError("Can't initialize threads for interpreter");\r
#endif\r
        interp->modules = NULL;\r
        interp->modules_reloading = NULL;\r
        interp->sysdict = NULL;\r
        interp->builtins = NULL;\r
        interp->tstate_head = NULL;\r
        interp->codec_search_path = NULL;\r
        interp->codec_search_cache = NULL;\r
        interp->codec_error_registry = NULL;\r
#ifdef HAVE_DLOPEN\r
#ifdef RTLD_NOW\r
        interp->dlopenflags = RTLD_NOW;\r
#else\r
        interp->dlopenflags = RTLD_LAZY;\r
#endif\r
#endif\r
#ifdef WITH_TSC\r
        interp->tscdump = 0;\r
#endif\r
\r
        HEAD_LOCK();\r
        interp->next = interp_head;\r
        interp_head = interp;\r
        HEAD_UNLOCK();\r
    }\r
\r
    return interp;\r
}\r
\r
\r
void\r
PyInterpreterState_Clear(PyInterpreterState *interp)\r
{\r
    PyThreadState *p;\r
    HEAD_LOCK();\r
    for (p = interp->tstate_head; p != NULL; p = p->next)\r
        PyThreadState_Clear(p);\r
    HEAD_UNLOCK();\r
    Py_CLEAR(interp->codec_search_path);\r
    Py_CLEAR(interp->codec_search_cache);\r
    Py_CLEAR(interp->codec_error_registry);\r
    Py_CLEAR(interp->modules);\r
    Py_CLEAR(interp->modules_reloading);\r
    Py_CLEAR(interp->sysdict);\r
    Py_CLEAR(interp->builtins);\r
}\r
\r
\r
static void\r
zapthreads(PyInterpreterState *interp)\r
{\r
    PyThreadState *p;\r
    /* No need to lock the mutex here because this should only happen\r
       when the threads are all really dead (XXX famous last words). */\r
    while ((p = interp->tstate_head) != NULL) {\r
        PyThreadState_Delete(p);\r
    }\r
}\r
\r
\r
void\r
PyInterpreterState_Delete(PyInterpreterState *interp)\r
{\r
    PyInterpreterState **p;\r
    zapthreads(interp);\r
    HEAD_LOCK();\r
    for (p = &interp_head; ; p = &(*p)->next) {\r
        if (*p == NULL)\r
            Py_FatalError(\r
                "PyInterpreterState_Delete: invalid interp");\r
        if (*p == interp)\r
            break;\r
    }\r
    if (interp->tstate_head != NULL)\r
        Py_FatalError("PyInterpreterState_Delete: remaining threads");\r
    *p = interp->next;\r
    HEAD_UNLOCK();\r
    free(interp);\r
}\r
\r
\r
/* Default implementation for _PyThreadState_GetFrame */\r
static struct _frame *\r
threadstate_getframe(PyThreadState *self)\r
{\r
    return self->frame;\r
}\r
\r
static PyThreadState *\r
new_threadstate(PyInterpreterState *interp, int init)\r
{\r
    PyThreadState *tstate = (PyThreadState *)malloc(sizeof(PyThreadState));\r
\r
    if (_PyThreadState_GetFrame == NULL)\r
        _PyThreadState_GetFrame = threadstate_getframe;\r
\r
    if (tstate != NULL) {\r
        tstate->interp = interp;\r
\r
        tstate->frame = NULL;\r
        tstate->recursion_depth = 0;\r
        tstate->tracing = 0;\r
        tstate->use_tracing = 0;\r
        tstate->tick_counter = 0;\r
        tstate->gilstate_counter = 0;\r
        tstate->async_exc = NULL;\r
#ifdef WITH_THREAD\r
        tstate->thread_id = PyThread_get_thread_ident();\r
#else\r
        tstate->thread_id = 0;\r
#endif\r
\r
        tstate->dict = NULL;\r
\r
        tstate->curexc_type = NULL;\r
        tstate->curexc_value = NULL;\r
        tstate->curexc_traceback = NULL;\r
\r
        tstate->exc_type = NULL;\r
        tstate->exc_value = NULL;\r
        tstate->exc_traceback = NULL;\r
\r
        tstate->c_profilefunc = NULL;\r
        tstate->c_tracefunc = NULL;\r
        tstate->c_profileobj = NULL;\r
        tstate->c_traceobj = NULL;\r
\r
        tstate->trash_delete_nesting = 0;\r
        tstate->trash_delete_later = NULL;\r
\r
        if (init)\r
            _PyThreadState_Init(tstate);\r
\r
        HEAD_LOCK();\r
        tstate->next = interp->tstate_head;\r
        interp->tstate_head = tstate;\r
        HEAD_UNLOCK();\r
    }\r
\r
    return tstate;\r
}\r
\r
PyThreadState *\r
PyThreadState_New(PyInterpreterState *interp)\r
{\r
    return new_threadstate(interp, 1);\r
}\r
\r
PyThreadState *\r
_PyThreadState_Prealloc(PyInterpreterState *interp)\r
{\r
    return new_threadstate(interp, 0);\r
}\r
\r
void\r
_PyThreadState_Init(PyThreadState *tstate)\r
{\r
#ifdef WITH_THREAD\r
    _PyGILState_NoteThreadState(tstate);\r
#endif\r
}\r
\r
void\r
PyThreadState_Clear(PyThreadState *tstate)\r
{\r
    if (Py_VerboseFlag && tstate->frame != NULL)\r
        fprintf(stderr,\r
          "PyThreadState_Clear: warning: thread still has a frame\n");\r
\r
    Py_CLEAR(tstate->frame);\r
\r
    Py_CLEAR(tstate->dict);\r
    Py_CLEAR(tstate->async_exc);\r
\r
    Py_CLEAR(tstate->curexc_type);\r
    Py_CLEAR(tstate->curexc_value);\r
    Py_CLEAR(tstate->curexc_traceback);\r
\r
    Py_CLEAR(tstate->exc_type);\r
    Py_CLEAR(tstate->exc_value);\r
    Py_CLEAR(tstate->exc_traceback);\r
\r
    tstate->c_profilefunc = NULL;\r
    tstate->c_tracefunc = NULL;\r
    Py_CLEAR(tstate->c_profileobj);\r
    Py_CLEAR(tstate->c_traceobj);\r
}\r
\r
\r
/* Common code for PyThreadState_Delete() and PyThreadState_DeleteCurrent() */\r
static void\r
tstate_delete_common(PyThreadState *tstate)\r
{\r
    PyInterpreterState *interp;\r
    PyThreadState **p;\r
    PyThreadState *prev_p = NULL;\r
    if (tstate == NULL)\r
        Py_FatalError("PyThreadState_Delete: NULL tstate");\r
    interp = tstate->interp;\r
    if (interp == NULL)\r
        Py_FatalError("PyThreadState_Delete: NULL interp");\r
    HEAD_LOCK();\r
    for (p = &interp->tstate_head; ; p = &(*p)->next) {\r
        if (*p == NULL)\r
            Py_FatalError(\r
                "PyThreadState_Delete: invalid tstate");\r
        if (*p == tstate)\r
            break;\r
        /* Sanity check.  These states should never happen but if\r
         * they do we must abort.  Otherwise we'll end up spinning in\r
         * in a tight loop with the lock held.  A similar check is done\r
         * in thread.c find_key().  */\r
        if (*p == prev_p)\r
            Py_FatalError(\r
                "PyThreadState_Delete: small circular list(!)"\r
                " and tstate not found.");\r
        prev_p = *p;\r
        if ((*p)->next == interp->tstate_head)\r
            Py_FatalError(\r
                "PyThreadState_Delete: circular list(!) and"\r
                " tstate not found.");\r
    }\r
    *p = tstate->next;\r
    HEAD_UNLOCK();\r
    free(tstate);\r
}\r
\r
\r
void\r
PyThreadState_Delete(PyThreadState *tstate)\r
{\r
    if (tstate == _PyThreadState_Current)\r
        Py_FatalError("PyThreadState_Delete: tstate is still current");\r
    tstate_delete_common(tstate);\r
#ifdef WITH_THREAD\r
    if (autoInterpreterState && PyThread_get_key_value(autoTLSkey) == tstate)\r
        PyThread_delete_key_value(autoTLSkey);\r
#endif /* WITH_THREAD */\r
}\r
\r
\r
#ifdef WITH_THREAD\r
void\r
PyThreadState_DeleteCurrent()\r
{\r
    PyThreadState *tstate = _PyThreadState_Current;\r
    if (tstate == NULL)\r
        Py_FatalError(\r
            "PyThreadState_DeleteCurrent: no current tstate");\r
    _PyThreadState_Current = NULL;\r
    if (autoInterpreterState && PyThread_get_key_value(autoTLSkey) == tstate)\r
        PyThread_delete_key_value(autoTLSkey);\r
    tstate_delete_common(tstate);\r
    PyEval_ReleaseLock();\r
}\r
#endif /* WITH_THREAD */\r
\r
\r
PyThreadState *\r
PyThreadState_Get(void)\r
{\r
    if (_PyThreadState_Current == NULL)\r
        Py_FatalError("PyThreadState_Get: no current thread");\r
\r
    return _PyThreadState_Current;\r
}\r
\r
\r
PyThreadState *\r
PyThreadState_Swap(PyThreadState *newts)\r
{\r
    PyThreadState *oldts = _PyThreadState_Current;\r
\r
    _PyThreadState_Current = newts;\r
    /* It should not be possible for more than one thread state\r
       to be used for a thread.  Check this the best we can in debug\r
       builds.\r
    */\r
#if defined(Py_DEBUG) && defined(WITH_THREAD)\r
    if (newts) {\r
        /* This can be called from PyEval_RestoreThread(). Similar\r
           to it, we need to ensure errno doesn't change.\r
        */\r
        int err = errno;\r
        PyThreadState *check = PyGILState_GetThisThreadState();\r
        if (check && check->interp == newts->interp && check != newts)\r
            Py_FatalError("Invalid thread state for this thread");\r
        errno = err;\r
    }\r
#endif\r
    return oldts;\r
}\r
\r
/* An extension mechanism to store arbitrary additional per-thread state.\r
   PyThreadState_GetDict() returns a dictionary that can be used to hold such\r
   state; the caller should pick a unique key and store its state there.  If\r
   PyThreadState_GetDict() returns NULL, an exception has *not* been raised\r
   and the caller should assume no per-thread state is available. */\r
\r
PyObject *\r
PyThreadState_GetDict(void)\r
{\r
    if (_PyThreadState_Current == NULL)\r
        return NULL;\r
\r
    if (_PyThreadState_Current->dict == NULL) {\r
        PyObject *d;\r
        _PyThreadState_Current->dict = d = PyDict_New();\r
        if (d == NULL)\r
            PyErr_Clear();\r
    }\r
    return _PyThreadState_Current->dict;\r
}\r
\r
\r
/* Asynchronously raise an exception in a thread.\r
   Requested by Just van Rossum and Alex Martelli.\r
   To prevent naive misuse, you must write your own extension\r
   to call this, or use ctypes.  Must be called with the GIL held.\r
   Returns the number of tstates modified (normally 1, but 0 if `id` didn't\r
   match any known thread id).  Can be called with exc=NULL to clear an\r
   existing async exception.  This raises no exceptions. */\r
\r
int\r
PyThreadState_SetAsyncExc(long id, PyObject *exc) {\r
    PyThreadState *tstate = PyThreadState_GET();\r
    PyInterpreterState *interp = tstate->interp;\r
    PyThreadState *p;\r
\r
    /* Although the GIL is held, a few C API functions can be called\r
     * without the GIL held, and in particular some that create and\r
     * destroy thread and interpreter states.  Those can mutate the\r
     * list of thread states we're traversing, so to prevent that we lock\r
     * head_mutex for the duration.\r
     */\r
    HEAD_LOCK();\r
    for (p = interp->tstate_head; p != NULL; p = p->next) {\r
        if (p->thread_id == id) {\r
            /* Tricky:  we need to decref the current value\r
             * (if any) in p->async_exc, but that can in turn\r
             * allow arbitrary Python code to run, including\r
             * perhaps calls to this function.  To prevent\r
             * deadlock, we need to release head_mutex before\r
             * the decref.\r
             */\r
            PyObject *old_exc = p->async_exc;\r
            Py_XINCREF(exc);\r
            p->async_exc = exc;\r
            HEAD_UNLOCK();\r
            Py_XDECREF(old_exc);\r
            return 1;\r
        }\r
    }\r
    HEAD_UNLOCK();\r
    return 0;\r
}\r
\r
\r
/* Routines for advanced debuggers, requested by David Beazley.\r
   Don't use unless you know what you are doing! */\r
\r
PyInterpreterState *\r
PyInterpreterState_Head(void)\r
{\r
    return interp_head;\r
}\r
\r
PyInterpreterState *\r
PyInterpreterState_Next(PyInterpreterState *interp) {\r
    return interp->next;\r
}\r
\r
PyThreadState *\r
PyInterpreterState_ThreadHead(PyInterpreterState *interp) {\r
    return interp->tstate_head;\r
}\r
\r
PyThreadState *\r
PyThreadState_Next(PyThreadState *tstate) {\r
    return tstate->next;\r
}\r
\r
/* The implementation of sys._current_frames().  This is intended to be\r
   called with the GIL held, as it will be when called via\r
   sys._current_frames().  It's possible it would work fine even without\r
   the GIL held, but haven't thought enough about that.\r
*/\r
PyObject *\r
_PyThread_CurrentFrames(void)\r
{\r
    PyObject *result;\r
    PyInterpreterState *i;\r
\r
    result = PyDict_New();\r
    if (result == NULL)\r
        return NULL;\r
\r
    /* for i in all interpreters:\r
     *     for t in all of i's thread states:\r
     *          if t's frame isn't NULL, map t's id to its frame\r
     * Because these lists can mutate even when the GIL is held, we\r
     * need to grab head_mutex for the duration.\r
     */\r
    HEAD_LOCK();\r
    for (i = interp_head; i != NULL; i = i->next) {\r
        PyThreadState *t;\r
        for (t = i->tstate_head; t != NULL; t = t->next) {\r
            PyObject *id;\r
            int stat;\r
            struct _frame *frame = t->frame;\r
            if (frame == NULL)\r
                continue;\r
            id = PyInt_FromLong(t->thread_id);\r
            if (id == NULL)\r
                goto Fail;\r
            stat = PyDict_SetItem(result, id, (PyObject *)frame);\r
            Py_DECREF(id);\r
            if (stat < 0)\r
                goto Fail;\r
        }\r
    }\r
    HEAD_UNLOCK();\r
    return result;\r
\r
 Fail:\r
    HEAD_UNLOCK();\r
    Py_DECREF(result);\r
    return NULL;\r
}\r
\r
/* Python "auto thread state" API. */\r
#ifdef WITH_THREAD\r
\r
/* Keep this as a static, as it is not reliable!  It can only\r
   ever be compared to the state for the *current* thread.\r
   * If not equal, then it doesn't matter that the actual\r
     value may change immediately after comparison, as it can't\r
     possibly change to the current thread's state.\r
   * If equal, then the current thread holds the lock, so the value can't\r
     change until we yield the lock.\r
*/\r
static int\r
PyThreadState_IsCurrent(PyThreadState *tstate)\r
{\r
    /* Must be the tstate for this thread */\r
    assert(PyGILState_GetThisThreadState()==tstate);\r
    /* On Windows at least, simple reads and writes to 32 bit values\r
       are atomic.\r
    */\r
    return tstate == _PyThreadState_Current;\r
}\r
\r
/* Internal initialization/finalization functions called by\r
   Py_Initialize/Py_Finalize\r
*/\r
void\r
_PyGILState_Init(PyInterpreterState *i, PyThreadState *t)\r
{\r
    assert(i && t); /* must init with valid states */\r
    autoTLSkey = PyThread_create_key();\r
    autoInterpreterState = i;\r
    assert(PyThread_get_key_value(autoTLSkey) == NULL);\r
    assert(t->gilstate_counter == 0);\r
\r
    _PyGILState_NoteThreadState(t);\r
}\r
\r
void\r
_PyGILState_Fini(void)\r
{\r
    PyThread_delete_key(autoTLSkey);\r
    autoInterpreterState = NULL;\r
}\r
\r
/* When a thread state is created for a thread by some mechanism other than\r
   PyGILState_Ensure, it's important that the GILState machinery knows about\r
   it so it doesn't try to create another thread state for the thread (this is\r
   a better fix for SF bug #1010677 than the first one attempted).\r
*/\r
static void\r
_PyGILState_NoteThreadState(PyThreadState* tstate)\r
{\r
    /* If autoTLSkey isn't initialized, this must be the very first\r
       threadstate created in Py_Initialize().  Don't do anything for now\r
       (we'll be back here when _PyGILState_Init is called). */\r
    if (!autoInterpreterState)\r
        return;\r
\r
    /* Stick the thread state for this thread in thread local storage.\r
\r
       The only situation where you can legitimately have more than one\r
       thread state for an OS level thread is when there are multiple\r
       interpreters, when:\r
\r
           a) You shouldn't really be using the PyGILState_ APIs anyway,\r
          and:\r
\r
           b) The slightly odd way PyThread_set_key_value works (see\r
          comments by its implementation) means that the first thread\r
          state created for that given OS level thread will "win",\r
          which seems reasonable behaviour.\r
    */\r
    if (PyThread_set_key_value(autoTLSkey, (void *)tstate) < 0)\r
        Py_FatalError("Couldn't create autoTLSkey mapping");\r
\r
    /* PyGILState_Release must not try to delete this thread state. */\r
    tstate->gilstate_counter = 1;\r
}\r
\r
/* The public functions */\r
PyThreadState *\r
PyGILState_GetThisThreadState(void)\r
{\r
    if (autoInterpreterState == NULL)\r
        return NULL;\r
    return (PyThreadState *)PyThread_get_key_value(autoTLSkey);\r
}\r
\r
PyGILState_STATE\r
PyGILState_Ensure(void)\r
{\r
    int current;\r
    PyThreadState *tcur;\r
    /* Note that we do not auto-init Python here - apart from\r
       potential races with 2 threads auto-initializing, pep-311\r
       spells out other issues.  Embedders are expected to have\r
       called Py_Initialize() and usually PyEval_InitThreads().\r
    */\r
    assert(autoInterpreterState); /* Py_Initialize() hasn't been called! */\r
    tcur = (PyThreadState *)PyThread_get_key_value(autoTLSkey);\r
    if (tcur == NULL) {\r
        /* Create a new thread state for this thread */\r
        tcur = PyThreadState_New(autoInterpreterState);\r
        if (tcur == NULL)\r
            Py_FatalError("Couldn't create thread-state for new thread");\r
        /* This is our thread state!  We'll need to delete it in the\r
           matching call to PyGILState_Release(). */\r
        tcur->gilstate_counter = 0;\r
        current = 0; /* new thread state is never current */\r
    }\r
    else\r
        current = PyThreadState_IsCurrent(tcur);\r
    if (current == 0)\r
        PyEval_RestoreThread(tcur);\r
    /* Update our counter in the thread-state - no need for locks:\r
       - tcur will remain valid as we hold the GIL.\r
       - the counter is safe as we are the only thread "allowed"\r
         to modify this value\r
    */\r
    ++tcur->gilstate_counter;\r
    return current ? PyGILState_LOCKED : PyGILState_UNLOCKED;\r
}\r
\r
void\r
PyGILState_Release(PyGILState_STATE oldstate)\r
{\r
    PyThreadState *tcur = (PyThreadState *)PyThread_get_key_value(\r
                                                            autoTLSkey);\r
    if (tcur == NULL)\r
        Py_FatalError("auto-releasing thread-state, "\r
                      "but no thread-state for this thread");\r
    /* We must hold the GIL and have our thread state current */\r
    /* XXX - remove the check - the assert should be fine,\r
       but while this is very new (April 2003), the extra check\r
       by release-only users can't hurt.\r
    */\r
    if (! PyThreadState_IsCurrent(tcur))\r
        Py_FatalError("This thread state must be current when releasing");\r
    assert(PyThreadState_IsCurrent(tcur));\r
    --tcur->gilstate_counter;\r
    assert(tcur->gilstate_counter >= 0); /* illegal counter value */\r
\r
    /* If we're going to destroy this thread-state, we must\r
     * clear it while the GIL is held, as destructors may run.\r
     */\r
    if (tcur->gilstate_counter == 0) {\r
        /* can't have been locked when we created it */\r
        assert(oldstate == PyGILState_UNLOCKED);\r
        PyThreadState_Clear(tcur);\r
        /* Delete the thread-state.  Note this releases the GIL too!\r
         * It's vital that the GIL be held here, to avoid shutdown\r
         * races; see bugs 225673 and 1061968 (that nasty bug has a\r
         * habit of coming back).\r
         */\r
        PyThreadState_DeleteCurrent();\r
    }\r
    /* Release the lock if necessary */\r
    else if (oldstate == PyGILState_UNLOCKED)\r
        PyEval_SaveThread();\r
}\r
\r
#endif /* WITH_THREAD */\r
\r
#ifdef __cplusplus\r
}\r
#endif\r
\r
\r