[pypy-commit] pypy default: add missing file
arigo
pypy.commits at gmail.com
Tue Feb 9 17:24:11 EST 2016
Author: Armin Rigo <arigo at tunes.org>
Branch:
Changeset: r82135:675f24c75537
Date: 2016-02-09 23:23 +0100
http://bitbucket.org/pypy/pypy/changeset/675f24c75537/
Log: add missing file
diff --git a/lib_pypy/cffi/_embedding.h b/lib_pypy/cffi/_embedding.h
new file mode 100644
--- /dev/null
+++ b/lib_pypy/cffi/_embedding.h
@@ -0,0 +1,517 @@
+
+/***** Support code for embedding *****/
+
+#if defined(_MSC_VER)
+# define CFFI_DLLEXPORT __declspec(dllexport)
+#elif defined(__GNUC__)
+# define CFFI_DLLEXPORT __attribute__((visibility("default")))
+#else
+# define CFFI_DLLEXPORT /* nothing */
+#endif
+
+
+/* There are two global variables of type _cffi_call_python_fnptr:
+
+ * _cffi_call_python, which we declare just below, is the one called
+ by ``extern "Python"`` implementations.
+
+ * _cffi_call_python_org, which on CPython is actually part of the
+ _cffi_exports[] array, is the function pointer copied from
+ _cffi_backend.
+
+ After initialization is complete, both are equal. However, the
+ first one remains equal to &_cffi_start_and_call_python until the
+ very end of initialization, when we are (or should be) sure that
+ concurrent threads also see a completely initialized world, and
+ only then is it changed.
+*/
+#undef _cffi_call_python
+typedef void (*_cffi_call_python_fnptr)(struct _cffi_externpy_s *, char *);
+static void _cffi_start_and_call_python(struct _cffi_externpy_s *, char *);
+static _cffi_call_python_fnptr _cffi_call_python = &_cffi_start_and_call_python;
+
+
+#ifndef _MSC_VER
+ /* --- Assuming a GCC not infinitely old --- */
+# define cffi_compare_and_swap(l,o,n) __sync_bool_compare_and_swap(l,o,n)
+# define cffi_write_barrier() __sync_synchronize()
+# if !defined(__amd64__) && !defined(__x86_64__) && \
+ !defined(__i386__) && !defined(__i386)
+# define cffi_read_barrier() __sync_synchronize()
+# else
+# define cffi_read_barrier() (void)0
+# endif
+#else
+ /* --- Windows threads version --- */
+# include <Windows.h>
+# define cffi_compare_and_swap(l,o,n) \
+ (InterlockedCompareExchangePointer(l,n,o) == (o))
+# define cffi_write_barrier() InterlockedCompareExchange(&_cffi_dummy,0,0)
+# define cffi_read_barrier() (void)0
+static volatile LONG _cffi_dummy;
+#endif
+
+#ifdef WITH_THREAD
+# ifndef _MSC_VER
+# include <pthread.h>
+ static pthread_mutex_t _cffi_embed_startup_lock;
+# else
+ static CRITICAL_SECTION _cffi_embed_startup_lock;
+# endif
+ static char _cffi_embed_startup_lock_ready = 0;
+#endif
+
+static void _cffi_acquire_reentrant_mutex(void)
+{
+ static void *volatile lock = NULL;
+
+ while (!cffi_compare_and_swap(&lock, NULL, (void *)1)) {
+ /* should ideally do a spin loop instruction here, but
+ hard to do it portably and doesn't really matter I
+ think: pthread_mutex_init() should be very fast, and
+ this is only run at start-up anyway. */
+ }
+
+#ifdef WITH_THREAD
+ if (!_cffi_embed_startup_lock_ready) {
+# ifndef _MSC_VER
+ pthread_mutexattr_t attr;
+ pthread_mutexattr_init(&attr);
+ pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+ pthread_mutex_init(&_cffi_embed_startup_lock, &attr);
+# else
+ InitializeCriticalSection(&_cffi_embed_startup_lock);
+# endif
+ _cffi_embed_startup_lock_ready = 1;
+ }
+#endif
+
+ while (!cffi_compare_and_swap(&lock, (void *)1, NULL))
+ ;
+
+#ifndef _MSC_VER
+ pthread_mutex_lock(&_cffi_embed_startup_lock);
+#else
+ EnterCriticalSection(&_cffi_embed_startup_lock);
+#endif
+}
+
+static void _cffi_release_reentrant_mutex(void)
+{
+#ifndef _MSC_VER
+ pthread_mutex_unlock(&_cffi_embed_startup_lock);
+#else
+ LeaveCriticalSection(&_cffi_embed_startup_lock);
+#endif
+}
+
+
+/********** CPython-specific section **********/
+#ifndef PYPY_VERSION
+
+
+#define _cffi_call_python_org _cffi_exports[_CFFI_CPIDX]
+
+PyMODINIT_FUNC _CFFI_PYTHON_STARTUP_FUNC(void); /* forward */
+
+static void _cffi_py_initialize(void)
+{
+ /* XXX use initsigs=0, which "skips initialization registration of
+ signal handlers, which might be useful when Python is
+ embedded" according to the Python docs. But review and think
+ if it should be a user-controllable setting.
+
+ XXX we should also give a way to write errors to a buffer
+ instead of to stderr.
+
+ XXX if importing 'site' fails, CPython (any version) calls
+ exit(). Should we try to work around this behavior here?
+ */
+ Py_InitializeEx(0);
+}
+
+static int _cffi_initialize_python(void)
+{
+ /* This initializes Python, imports _cffi_backend, and then the
+ present .dll/.so is set up as a CPython C extension module.
+ */
+ int result;
+ PyGILState_STATE state;
+ PyObject *pycode=NULL, *global_dict=NULL, *x;
+
+#if PY_MAJOR_VERSION >= 3
+ /* see comments in _cffi_carefully_make_gil() about the
+ Python2/Python3 difference
+ */
+#else
+ /* Acquire the GIL. We have no threadstate here. If Python is
+ already initialized, it is possible that there is already one
+ existing for this thread, but it is not made current now.
+ */
+ PyEval_AcquireLock();
+
+ _cffi_py_initialize();
+
+ /* The Py_InitializeEx() sometimes made a threadstate for us, but
+ not always. Indeed Py_InitializeEx() could be called and do
+ nothing. So do we have a threadstate, or not? We don't know,
+ but we can replace it with NULL in all cases.
+ */
+ (void)PyThreadState_Swap(NULL);
+
+ /* Now we can release the GIL and re-acquire immediately using the
+ logic of PyGILState(), which handles making or installing the
+ correct threadstate.
+ */
+ PyEval_ReleaseLock();
+#endif
+ state = PyGILState_Ensure();
+
+ /* Call the initxxx() function from the present module. It will
+ create and initialize us as a CPython extension module, instead
+ of letting the startup Python code do it---it might reimport
+ the same .dll/.so and get maybe confused on some platforms.
+ It might also have troubles locating the .dll/.so again for all
+ I know.
+ */
+ (void)_CFFI_PYTHON_STARTUP_FUNC();
+ if (PyErr_Occurred())
+ goto error;
+
+ /* Now run the Python code provided to ffi.embedding_init_code().
+ */
+ pycode = Py_CompileString(_CFFI_PYTHON_STARTUP_CODE,
+ "<init code for '" _CFFI_MODULE_NAME "'>",
+ Py_file_input);
+ if (pycode == NULL)
+ goto error;
+ global_dict = PyDict_New();
+ if (global_dict == NULL)
+ goto error;
+ if (PyDict_SetItemString(global_dict, "__builtins__",
+ PyThreadState_GET()->interp->builtins) < 0)
+ goto error;
+ x = PyEval_EvalCode(
+#if PY_MAJOR_VERSION < 3
+ (PyCodeObject *)
+#endif
+ pycode, global_dict, global_dict);
+ if (x == NULL)
+ goto error;
+ Py_DECREF(x);
+
+ /* Done! Now if we've been called from
+ _cffi_start_and_call_python() in an ``extern "Python"``, we can
+ only hope that the Python code did correctly set up the
+ corresponding @ffi.def_extern() function. Otherwise, the
+ general logic of ``extern "Python"`` functions (inside the
+ _cffi_backend module) will find that the reference is still
+ missing and print an error.
+ */
+ result = 0;
+ done:
+ Py_XDECREF(pycode);
+ Py_XDECREF(global_dict);
+ PyGILState_Release(state);
+ return result;
+
+ error:;
+ {
+ /* Print as much information as potentially useful.
+ Debugging load-time failures with embedding is not fun
+ */
+ PyObject *exception, *v, *tb, *f, *modules, *mod;
+ PyErr_Fetch(&exception, &v, &tb);
+ if (exception != NULL) {
+ PyErr_NormalizeException(&exception, &v, &tb);
+ PyErr_Display(exception, v, tb);
+ }
+ Py_XDECREF(exception);
+ Py_XDECREF(v);
+ Py_XDECREF(tb);
+
+ f = PySys_GetObject((char *)"stderr");
+ if (f != NULL && f != Py_None) {
+ PyFile_WriteString("\nFrom: " _CFFI_MODULE_NAME
+ "\ncompiled with cffi version: 1.5.1"
+ "\n_cffi_backend module: ", f);
+ modules = PyImport_GetModuleDict();
+ mod = PyDict_GetItemString(modules, "_cffi_backend");
+ if (mod == NULL) {
+ PyFile_WriteString("not loaded", f);
+ }
+ else {
+ v = PyObject_GetAttrString(mod, "__file__");
+ PyFile_WriteObject(v, f, 0);
+ Py_XDECREF(v);
+ }
+ PyFile_WriteString("\nsys.path: ", f);
+ PyFile_WriteObject(PySys_GetObject((char *)"path"), f, 0);
+ PyFile_WriteString("\n\n", f);
+ }
+ }
+ result = -1;
+ goto done;
+}
+
+PyAPI_DATA(char *) _PyParser_TokenNames[]; /* from CPython */
+
+static int _cffi_carefully_make_gil(void)
+{
+ /* This does the basic initialization of Python. It can be called
+ completely concurrently from unrelated threads. It assumes
+ that we don't hold the GIL before (if it exists), and we don't
+ hold it afterwards.
+
+ What it really does is completely different in Python 2 and
+ Python 3.
+
+ Python 2
+ ========
+
+ Initialize the GIL, without initializing the rest of Python,
+ by calling PyEval_InitThreads().
+
+ PyEval_InitThreads() must not be called concurrently at all.
+ So we use a global variable as a simple spin lock. This global
+ variable must be from 'libpythonX.Y.so', not from this
+ cffi-based extension module, because it must be shared from
+ different cffi-based extension modules. We choose
+ _PyParser_TokenNames[0] as a completely arbitrary pointer value
+ that is never written to. The default is to point to the
+ string "ENDMARKER". We change it temporarily to point to the
+ next character in that string. (Yes, I know it's REALLY
+ obscure.)
+
+ Python 3
+ ========
+
+ In Python 3, PyEval_InitThreads() cannot be called before
+ Py_InitializeEx() any more. So this function calls
+ Py_InitializeEx() first. It uses the same obscure logic to
+ make sure we never call it concurrently.
+
+ Arguably, this is less good on the spinlock, because
+ Py_InitializeEx() takes much longer to run than
+ PyEval_InitThreads(). But I didn't find a way around it.
+ */
+
+#ifdef WITH_THREAD
+ char *volatile *lock = (char *volatile *)_PyParser_TokenNames;
+ char *old_value;
+
+ while (1) { /* spin loop */
+ old_value = *lock;
+ if (old_value[0] == 'E') {
+ assert(old_value[1] == 'N');
+ if (cffi_compare_and_swap(lock, old_value, old_value + 1))
+ break;
+ }
+ else {
+ assert(old_value[0] == 'N');
+ /* should ideally do a spin loop instruction here, but
+ hard to do it portably and doesn't really matter I
+ think: PyEval_InitThreads() should be very fast, and
+ this is only run at start-up anyway. */
+ }
+ }
+#endif
+
+#if PY_MAJOR_VERSION >= 3
+ /* Python 3: call Py_InitializeEx() */
+ {
+ PyGILState_STATE state = PyGILState_UNLOCKED;
+ if (!Py_IsInitialized())
+ _cffi_py_initialize();
+ else
+ state = PyGILState_Ensure();
+
+ PyEval_InitThreads();
+ PyGILState_Release(state);
+ }
+#else
+ /* Python 2: call PyEval_InitThreads() */
+# ifdef WITH_THREAD
+ if (!PyEval_ThreadsInitialized()) {
+ PyEval_InitThreads(); /* makes the GIL */
+ PyEval_ReleaseLock(); /* then release it */
+ }
+ /* else: there is already a GIL, but we still needed to do the
+ spinlock dance to make sure that we see it as fully ready */
+# endif
+#endif
+
+#ifdef WITH_THREAD
+ /* release the lock */
+ while (!cffi_compare_and_swap(lock, old_value + 1, old_value))
+ ;
+#endif
+
+ return 0;
+}
+
+/********** end CPython-specific section **********/
+
+
+#else
+
+
+/********** PyPy-specific section **********/
+
+PyMODINIT_FUNC _CFFI_PYTHON_STARTUP_FUNC(const void *[]); /* forward */
+
+static struct _cffi_pypy_init_s {
+ const char *name;
+ void (*func)(const void *[]);
+ const char *code;
+} _cffi_pypy_init = {
+ _CFFI_MODULE_NAME,
+ _CFFI_PYTHON_STARTUP_FUNC,
+ _CFFI_PYTHON_STARTUP_CODE,
+};
+
+extern int pypy_carefully_make_gil(const char *);
+extern int pypy_init_embedded_cffi_module(int, struct _cffi_pypy_init_s *);
+
+static int _cffi_carefully_make_gil(void)
+{
+ return pypy_carefully_make_gil(_CFFI_MODULE_NAME);
+}
+
+static int _cffi_initialize_python(void)
+{
+ return pypy_init_embedded_cffi_module(0xB011, &_cffi_pypy_init);
+}
+
+/********** end PyPy-specific section **********/
+
+
+#endif
+
+
+#ifdef __GNUC__
+__attribute__((noinline))
+#endif
+static _cffi_call_python_fnptr _cffi_start_python(void)
+{
+ /* Delicate logic to initialize Python. This function can be
+ called multiple times concurrently, e.g. when the process calls
+ its first ``extern "Python"`` functions in multiple threads at
+ once. It can also be called recursively, in which case we must
+ ignore it. We also have to consider what occurs if several
+ different cffi-based extensions reach this code in parallel
+ threads---it is a different copy of the code, then, and we
+ can't have any shared global variable unless it comes from
+ 'libpythonX.Y.so'.
+
+ Idea:
+
+ * _cffi_carefully_make_gil(): "carefully" call
+ PyEval_InitThreads() (possibly with Py_InitializeEx() first).
+
+ * then we use a (local) custom lock to make sure that a call to this
+ cffi-based extension will wait if another call to the *same*
+ extension is running the initialization in another thread.
+ It is reentrant, so that a recursive call will not block, but
+ only one from a different thread.
+
+ * then we grab the GIL and (Python 2) we call Py_InitializeEx().
+ At this point, concurrent calls to Py_InitializeEx() are not
+ possible: we have the GIL.
+
+ * do the rest of the specific initialization, which may
+ temporarily release the GIL but not the custom lock.
+ Only release the custom lock when we are done.
+ */
+ static char called = 0;
+
+ if (_cffi_carefully_make_gil() != 0)
+ return NULL;
+
+ _cffi_acquire_reentrant_mutex();
+
+ /* Here the GIL exists, but we don't have it. We're only protected
+ from concurrency by the reentrant mutex. */
+
+ /* This file only initializes the embedded module once, the first
+ time this is called, even if there are subinterpreters. */
+ if (!called) {
+ called = 1; /* invoke _cffi_initialize_python() only once,
+ but don't set '_cffi_call_python' right now,
+ otherwise concurrent threads won't call
+ this function at all (we need them to wait) */
+ if (_cffi_initialize_python() == 0) {
+ /* now initialization is finished. Switch to the fast-path. */
+
+ /* We would like nobody to see the new value of
+ '_cffi_call_python' without also seeing the rest of the
+ data initialized. However, this is not possible. But
+ the new value of '_cffi_call_python' is the function
+ 'cffi_call_python()' from _cffi_backend. So: */
+ cffi_write_barrier();
+ /* ^^^ we put a write barrier here, and a corresponding
+ read barrier at the start of cffi_call_python(). This
+ ensures that after that read barrier, we see everything
+ done here before the write barrier.
+ */
+
+ assert(_cffi_call_python_org != NULL);
+ _cffi_call_python = (_cffi_call_python_fnptr)_cffi_call_python_org;
+ }
+ else {
+ /* initialization failed. Reset this to NULL, even if it was
+ already set to some other value. Future calls to
+ _cffi_start_python() are still forced to occur, and will
+ always return NULL from now on. */
+ _cffi_call_python_org = NULL;
+ }
+ }
+
+ _cffi_release_reentrant_mutex();
+
+ return (_cffi_call_python_fnptr)_cffi_call_python_org;
+}
+
+static
+void _cffi_start_and_call_python(struct _cffi_externpy_s *externpy, char *args)
+{
+ _cffi_call_python_fnptr fnptr;
+ int current_err = errno;
+#ifdef _MSC_VER
+ int current_lasterr = GetLastError();
+#endif
+ fnptr = _cffi_start_python();
+ if (fnptr == NULL) {
+ fprintf(stderr, "function %s() called, but initialization code "
+ "failed. Returning 0.\n", externpy->name);
+ memset(args, 0, externpy->size_of_result);
+ }
+#ifdef _MSC_VER
+ SetLastError(current_lasterr);
+#endif
+ errno = current_err;
+
+ if (fnptr != NULL)
+ fnptr(externpy, args);
+}
+
+
+/* The cffi_start_python() function makes sure Python is initialized
+ and our cffi module is set up. It can be called manually from the
+ user C code. The same effect is obtained automatically from any
+ dll-exported ``extern "Python"`` function. This function returns
+ -1 if initialization failed, 0 if all is OK. */
+_CFFI_UNUSED_FN
+static int cffi_start_python(void)
+{
+ if (_cffi_call_python == &_cffi_start_and_call_python) {
+ if (_cffi_start_python() == NULL)
+ return -1;
+ }
+ cffi_read_barrier();
+ return 0;
+}
+
+#undef cffi_compare_and_swap
+#undef cffi_write_barrier
+#undef cffi_read_barrier
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