unix: Add "uselect" module, with poll() function.

Underlyingly, uses standard POSIX poll() for portability.

1 files changed, 190 insertions, 0 deletions

diff --git a/unix/moduselect.c b/unix/moduselect.c
new file mode 100644
index 0000000000..fbb78ab595
--- /dev/null
+++ b/unix/moduselect.c
@@ -0,0 +1,190 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014 Damien P. George
+ * Copyright (c) 2015 Paul Sokolovsky
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <poll.h>
+
+#include "py/nlr.h"
+#include "py/obj.h"
+#include "py/objlist.h"
+#include "py/objtuple.h"
+#include "py/mphal.h"
+
+/// \class Poll - poll class
+
+typedef struct _mp_obj_poll_t {
+    mp_obj_base_t base;
+    unsigned short alloc;
+    unsigned short len;
+    struct pollfd *entries;
+} mp_obj_poll_t;
+
+/// \method register(obj[, eventmask])
+STATIC mp_obj_t poll_register(uint n_args, const mp_obj_t *args) {
+    mp_obj_poll_t *self = args[0];
+    mp_uint_t flags;
+    if (n_args == 3) {
+        flags = mp_obj_get_int(args[2]);
+    } else {
+        flags = POLLIN | POLLOUT;
+    }
+
+    int i;
+    if (self->len < self->alloc) {
+        i = self->len++;
+    } else {
+        assert(0);
+    }
+
+    self->entries[i].fd = mp_obj_get_int(args[1]);
+    self->entries[i].events = flags;
+    self->entries[i].revents = 0;
+
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(poll_register_obj, 2, 3, poll_register);
+
+/// \method unregister(obj)
+STATIC mp_obj_t poll_unregister(mp_obj_t self_in, mp_obj_t obj_in) {
+    mp_obj_poll_t *self = self_in;
+    struct pollfd *entries = self->entries;
+    int fd = mp_obj_get_int(obj_in);
+    for (int i = self->len - 1; i >= 0; i--) {
+        if (entries->fd == fd) {
+            entries->fd = -1;
+            break;
+        }
+        entries++;
+    }
+
+    // TODO raise KeyError if obj didn't exist in map
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(poll_unregister_obj, poll_unregister);
+
+/// \method modify(obj, eventmask)
+STATIC mp_obj_t poll_modify(mp_obj_t self_in, mp_obj_t obj_in, mp_obj_t eventmask_in) {
+    mp_obj_poll_t *self = self_in;
+    struct pollfd *entries = self->entries;
+    int fd = mp_obj_get_int(obj_in);
+    for (int i = self->len - 1; i >= 0; i--) {
+        if (entries->fd == fd) {
+            entries->events = mp_obj_get_int(eventmask_in);
+            break;
+        }
+        entries++;
+    }
+
+    // TODO raise KeyError if obj didn't exist in map
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_3(poll_modify_obj, poll_modify);
+
+/// \method poll([timeout])
+/// Timeout is in milliseconds.
+STATIC mp_obj_t poll_poll(uint n_args, const mp_obj_t *args) {
+    mp_obj_poll_t *self = args[0];
+
+    // work out timeout (its given already in ms)
+    int timeout = -1;
+    if (n_args == 2) {
+        if (args[1] != mp_const_none) {
+            mp_int_t timeout_i = mp_obj_get_int(args[1]);
+            if (timeout_i >= 0) {
+                timeout = timeout_i;
+            }
+        }
+    }
+
+    int n_ready = poll(self->entries, self->len, timeout);
+    RAISE_ERRNO(n_ready, errno);
+    if (n_ready == 0) {
+        return mp_const_empty_tuple;
+    }
+
+    mp_obj_list_t *ret_list = mp_obj_new_list(n_ready, NULL);
+    int ret_i = 0;
+    struct pollfd *entries = self->entries;
+    for (int i = 0; i < self->len; i++) {
+        if (entries->revents != 0) {
+            mp_obj_tuple_t *t = mp_obj_new_tuple(2, NULL);
+            t->items[0] = MP_OBJ_NEW_SMALL_INT(entries->fd);
+            t->items[1] = MP_OBJ_NEW_SMALL_INT(entries->revents);
+            ret_list->items[ret_i++] = t;
+            entries++;
+        }
+    }
+
+    return ret_list;
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(poll_poll_obj, 1, 2, poll_poll);
+
+STATIC const mp_map_elem_t poll_locals_dict_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR_register), (mp_obj_t)&poll_register_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_unregister), (mp_obj_t)&poll_unregister_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_modify), (mp_obj_t)&poll_modify_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_poll), (mp_obj_t)&poll_poll_obj },
+};
+STATIC MP_DEFINE_CONST_DICT(poll_locals_dict, poll_locals_dict_table);
+
+STATIC const mp_obj_type_t mp_type_poll = {
+    { &mp_type_type },
+    .name = MP_QSTR_poll,
+    .locals_dict = (mp_obj_t)&poll_locals_dict,
+};
+
+STATIC mp_obj_t select_poll(mp_uint_t n_args, const mp_obj_t *args) {
+    int alloc = 4;
+    if (n_args > 0) {
+        alloc = mp_obj_get_int(args[0]);
+    }
+    mp_obj_poll_t *poll = m_new_obj(mp_obj_poll_t);
+    poll->base.type = &mp_type_poll;
+    poll->entries = m_new(struct pollfd, alloc);
+    poll->alloc = alloc;
+    poll->len = 0;
+    return poll;
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_select_poll_obj, 0, 1, select_poll);
+
+STATIC const mp_map_elem_t mp_module_select_globals_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_uselect) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_poll), (mp_obj_t)&mp_select_poll_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_POLLIN), MP_OBJ_NEW_SMALL_INT(POLLIN) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_POLLOUT), MP_OBJ_NEW_SMALL_INT(POLLOUT) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_POLLERR), MP_OBJ_NEW_SMALL_INT(POLLERR) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_POLLHUP), MP_OBJ_NEW_SMALL_INT(POLLHUP) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(mp_module_select_globals, mp_module_select_globals_table);
+
+const mp_obj_module_t mp_module_uselect = {
+    .base = { &mp_type_module },
+    .name = MP_QSTR_uselect,
+    .globals = (mp_obj_dict_t*)&mp_module_select_globals,
+};