cpython/Modules/_multiprocessing/connection.h

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/*
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* Definition of a `Connection` type.
* Used by `socket_connection.c` and `pipe_connection.c`.
*
* connection.h
*
* Copyright (c) 2006-2008, R Oudkerk --- see COPYING.txt
*/
#ifndef CONNECTION_H
#define CONNECTION_H
/*
* Read/write flags
*/
#define READABLE 1
#define WRITABLE 2
#define CHECK_READABLE(self) \
if (!(self->flags & READABLE)) { \
PyErr_SetString(PyExc_IOError, "connection is write-only"); \
return NULL; \
}
#define CHECK_WRITABLE(self) \
if (!(self->flags & WRITABLE)) { \
PyErr_SetString(PyExc_IOError, "connection is read-only"); \
return NULL; \
}
/*
* Allocation and deallocation
*/
static PyObject *
connection_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
ConnectionObject *self;
HANDLE handle;
BOOL readable = TRUE, writable = TRUE;
static char *kwlist[] = {"handle", "readable", "writable", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kwds, F_HANDLE "|ii", kwlist,
&handle, &readable, &writable))
return NULL;
if (handle == INVALID_HANDLE_VALUE || (Py_ssize_t)handle < 0) {
PyErr_Format(PyExc_IOError, "invalid handle %zd",
(Py_ssize_t)handle);
return NULL;
}
if (!readable && !writable) {
PyErr_SetString(PyExc_ValueError,
"either readable or writable must be true");
return NULL;
}
self = PyObject_New(ConnectionObject, type);
if (self == NULL)
return NULL;
self->weakreflist = NULL;
self->handle = handle;
self->flags = 0;
if (readable)
self->flags |= READABLE;
if (writable)
self->flags |= WRITABLE;
assert(self->flags >= 1 && self->flags <= 3);
return (PyObject*)self;
}
static void
connection_dealloc(ConnectionObject* self)
{
if (self->weakreflist != NULL)
PyObject_ClearWeakRefs((PyObject*)self);
if (self->handle != INVALID_HANDLE_VALUE) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
}
PyObject_Del(self);
}
/*
* Functions for transferring buffers
*/
static PyObject *
connection_sendbytes(ConnectionObject *self, PyObject *args)
{
char *buffer;
Py_ssize_t length, offset=0, size=PY_SSIZE_T_MIN;
int res;
if (!PyArg_ParseTuple(args, F_RBUFFER "#|" F_PY_SSIZE_T F_PY_SSIZE_T,
&buffer, &length, &offset, &size))
return NULL;
CHECK_WRITABLE(self);
if (offset < 0) {
PyErr_SetString(PyExc_ValueError, "offset is negative");
return NULL;
}
if (length < offset) {
PyErr_SetString(PyExc_ValueError, "buffer length < offset");
return NULL;
}
if (size == PY_SSIZE_T_MIN) {
size = length - offset;
} else {
if (size < 0) {
PyErr_SetString(PyExc_ValueError, "size is negative");
return NULL;
}
if (offset + size > length) {
PyErr_SetString(PyExc_ValueError,
"buffer length < offset + size");
return NULL;
}
}
res = conn_send_string(self, buffer + offset, size);
if (res < 0) {
if (PyErr_Occurred())
return NULL;
else
return mp_SetError(PyExc_IOError, res);
}
Py_RETURN_NONE;
}
static PyObject *
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connection_recvbytes(ConnectionObject *self, PyObject *args)
{
char *freeme = NULL;
Py_ssize_t res, maxlength = PY_SSIZE_T_MAX;
PyObject *result = NULL;
if (!PyArg_ParseTuple(args, "|" F_PY_SSIZE_T, &maxlength))
return NULL;
CHECK_READABLE(self);
if (maxlength < 0) {
PyErr_SetString(PyExc_ValueError, "maxlength < 0");
return NULL;
}
res = conn_recv_string(self, self->buffer, CONNECTION_BUFFER_SIZE,
&freeme, maxlength);
if (res < 0) {
if (res == MP_BAD_MESSAGE_LENGTH) {
if ((self->flags & WRITABLE) == 0) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
self->handle = INVALID_HANDLE_VALUE;
} else {
self->flags = WRITABLE;
}
}
mp_SetError(PyExc_IOError, res);
} else {
if (freeme == NULL) {
result = PyString_FromStringAndSize(self->buffer, res);
} else {
result = PyString_FromStringAndSize(freeme, res);
PyMem_Free(freeme);
}
}
return result;
}
static PyObject *
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connection_recvbytes_into(ConnectionObject *self, PyObject *args)
{
char *freeme = NULL, *buffer = NULL;
Py_ssize_t res, length, offset = 0;
PyObject *result = NULL;
Py_buffer pbuf;
CHECK_READABLE(self);
if (!PyArg_ParseTuple(args, "w*|" F_PY_SSIZE_T,
&pbuf, &offset))
return NULL;
buffer = pbuf.buf;
length = pbuf.len;
if (offset < 0) {
PyErr_SetString(PyExc_ValueError, "negative offset");
goto _error;
}
if (offset > length) {
PyErr_SetString(PyExc_ValueError, "offset too large");
goto _error;
}
res = conn_recv_string(self, buffer+offset, length-offset,
&freeme, PY_SSIZE_T_MAX);
if (res < 0) {
if (res == MP_BAD_MESSAGE_LENGTH) {
if ((self->flags & WRITABLE) == 0) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
self->handle = INVALID_HANDLE_VALUE;
} else {
self->flags = WRITABLE;
}
}
mp_SetError(PyExc_IOError, res);
} else {
if (freeme == NULL) {
result = PyInt_FromSsize_t(res);
} else {
result = PyObject_CallFunction(BufferTooShort,
F_RBUFFER "#",
freeme, res);
PyMem_Free(freeme);
if (result) {
PyErr_SetObject(BufferTooShort, result);
Py_DECREF(result);
}
goto _error;
}
}
_cleanup:
PyBuffer_Release(&pbuf);
return result;
_error:
result = NULL;
goto _cleanup;
}
/*
* Functions for transferring objects
*/
static PyObject *
connection_send_obj(ConnectionObject *self, PyObject *obj)
{
char *buffer;
int res;
Py_ssize_t length;
PyObject *pickled_string = NULL;
CHECK_WRITABLE(self);
pickled_string = PyObject_CallFunctionObjArgs(pickle_dumps, obj,
pickle_protocol, NULL);
if (!pickled_string)
goto failure;
if (PyString_AsStringAndSize(pickled_string, &buffer, &length) < 0)
goto failure;
res = conn_send_string(self, buffer, (int)length);
if (res < 0) {
mp_SetError(PyExc_IOError, res);
goto failure;
}
Py_XDECREF(pickled_string);
Py_RETURN_NONE;
failure:
Py_XDECREF(pickled_string);
return NULL;
}
static PyObject *
connection_recv_obj(ConnectionObject *self)
{
char *freeme = NULL;
Py_ssize_t res;
PyObject *temp = NULL, *result = NULL;
CHECK_READABLE(self);
res = conn_recv_string(self, self->buffer, CONNECTION_BUFFER_SIZE,
&freeme, PY_SSIZE_T_MAX);
if (res < 0) {
if (res == MP_BAD_MESSAGE_LENGTH) {
if ((self->flags & WRITABLE) == 0) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
self->handle = INVALID_HANDLE_VALUE;
} else {
self->flags = WRITABLE;
}
}
mp_SetError(PyExc_IOError, res);
} else {
if (freeme == NULL) {
temp = PyString_FromStringAndSize(self->buffer, res);
} else {
temp = PyString_FromStringAndSize(freeme, res);
PyMem_Free(freeme);
}
}
if (temp)
result = PyObject_CallFunctionObjArgs(pickle_loads,
temp, NULL);
Py_XDECREF(temp);
return result;
}
/*
* Other functions
*/
static PyObject *
connection_poll(ConnectionObject *self, PyObject *args)
{
PyObject *timeout_obj = NULL;
double timeout = 0.0;
int res;
CHECK_READABLE(self);
if (!PyArg_ParseTuple(args, "|O", &timeout_obj))
return NULL;
if (timeout_obj == NULL) {
timeout = 0.0;
} else if (timeout_obj == Py_None) {
timeout = -1.0; /* block forever */
} else {
timeout = PyFloat_AsDouble(timeout_obj);
if (PyErr_Occurred())
return NULL;
if (timeout < 0.0)
timeout = 0.0;
}
Py_BEGIN_ALLOW_THREADS
res = conn_poll(self, timeout, _save);
Py_END_ALLOW_THREADS
switch (res) {
case TRUE:
Py_RETURN_TRUE;
case FALSE:
Py_RETURN_FALSE;
default:
return mp_SetError(PyExc_IOError, res);
}
}
static PyObject *
connection_fileno(ConnectionObject* self)
{
if (self->handle == INVALID_HANDLE_VALUE) {
PyErr_SetString(PyExc_IOError, "handle is invalid");
return NULL;
}
return PyInt_FromLong((long)self->handle);
}
static PyObject *
connection_close(ConnectionObject *self)
{
if (self->handle != INVALID_HANDLE_VALUE) {
Py_BEGIN_ALLOW_THREADS
CLOSE(self->handle);
Py_END_ALLOW_THREADS
self->handle = INVALID_HANDLE_VALUE;
}
Py_RETURN_NONE;
}
static PyObject *
connection_repr(ConnectionObject *self)
{
static char *conn_type[] = {"read-only", "write-only", "read-write"};
assert(self->flags >= 1 && self->flags <= 3);
return FROM_FORMAT("<%s %s, handle %zd>",
conn_type[self->flags - 1],
CONNECTION_NAME, (Py_ssize_t)self->handle);
}
/*
* Getters and setters
*/
static PyObject *
connection_closed(ConnectionObject *self, void *closure)
{
return PyBool_FromLong((long)(self->handle == INVALID_HANDLE_VALUE));
}
static PyObject *
connection_readable(ConnectionObject *self, void *closure)
{
return PyBool_FromLong((long)(self->flags & READABLE));
}
static PyObject *
connection_writable(ConnectionObject *self, void *closure)
{
return PyBool_FromLong((long)(self->flags & WRITABLE));
}
/*
* Tables
*/
static PyMethodDef connection_methods[] = {
{"send_bytes", (PyCFunction)connection_sendbytes, METH_VARARGS,
"send the byte data from a readable buffer-like object"},
{"recv_bytes", (PyCFunction)connection_recvbytes, METH_VARARGS,
"receive byte data as a string"},
{"recv_bytes_into",(PyCFunction)connection_recvbytes_into,METH_VARARGS,
"receive byte data into a writeable buffer-like object\n"
"returns the number of bytes read"},
{"send", (PyCFunction)connection_send_obj, METH_O,
"send a (picklable) object"},
{"recv", (PyCFunction)connection_recv_obj, METH_NOARGS,
"receive a (picklable) object"},
{"poll", (PyCFunction)connection_poll, METH_VARARGS,
"whether there is any input available to be read"},
{"fileno", (PyCFunction)connection_fileno, METH_NOARGS,
"file descriptor or handle of the connection"},
{"close", (PyCFunction)connection_close, METH_NOARGS,
"close the connection"},
{NULL} /* Sentinel */
};
static PyGetSetDef connection_getset[] = {
{"closed", (getter)connection_closed, NULL,
"True if the connection is closed", NULL},
{"readable", (getter)connection_readable, NULL,
"True if the connection is readable", NULL},
{"writable", (getter)connection_writable, NULL,
"True if the connection is writable", NULL},
{NULL}
};
/*
* Connection type
*/
PyDoc_STRVAR(connection_doc,
"Connection type whose constructor signature is\n\n"
" Connection(handle, readable=True, writable=True).\n\n"
"The constructor does *not* duplicate the handle.");
PyTypeObject CONNECTION_TYPE = {
PyVarObject_HEAD_INIT(NULL, 0)
/* tp_name */ "_multiprocessing." CONNECTION_NAME,
/* tp_basicsize */ sizeof(ConnectionObject),
/* tp_itemsize */ 0,
/* tp_dealloc */ (destructor)connection_dealloc,
/* tp_print */ 0,
/* tp_getattr */ 0,
/* tp_setattr */ 0,
/* tp_compare */ 0,
/* tp_repr */ (reprfunc)connection_repr,
/* tp_as_number */ 0,
/* tp_as_sequence */ 0,
/* tp_as_mapping */ 0,
/* tp_hash */ 0,
/* tp_call */ 0,
/* tp_str */ 0,
/* tp_getattro */ 0,
/* tp_setattro */ 0,
/* tp_as_buffer */ 0,
/* tp_flags */ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
Py_TPFLAGS_HAVE_WEAKREFS,
/* tp_doc */ connection_doc,
/* tp_traverse */ 0,
/* tp_clear */ 0,
/* tp_richcompare */ 0,
/* tp_weaklistoffset */ offsetof(ConnectionObject, weakreflist),
/* tp_iter */ 0,
/* tp_iternext */ 0,
/* tp_methods */ connection_methods,
/* tp_members */ 0,
/* tp_getset */ connection_getset,
/* tp_base */ 0,
/* tp_dict */ 0,
/* tp_descr_get */ 0,
/* tp_descr_set */ 0,
/* tp_dictoffset */ 0,
/* tp_init */ 0,
/* tp_alloc */ 0,
/* tp_new */ connection_new,
};
#endif /* CONNECTION_H */