2 * Copyright (c) 2013 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
23 #include "poll-loop.h"
24 #include "socket-util.h"
26 /* Initializes 'latch' as initially unset. */
28 latch_init(struct latch *latch)
30 latch->is_set = FALSE;
31 latch->wevent = CreateEvent(NULL, TRUE, FALSE, NULL);
34 /* Destroys 'latch'. */
36 latch_destroy(struct latch *latch)
38 latch->is_set = FALSE;
39 CloseHandle(latch->wevent);
42 /* Resets 'latch' to the unset state. Returns true if 'latch' was previously
43 * set, false otherwise. */
45 latch_poll(struct latch *latch)
49 is_set = latch->is_set;
50 latch->is_set = FALSE;
51 ResetEvent(latch->wevent);
57 * Calls are not additive: a single latch_poll() clears out any number of
60 latch_set(struct latch *latch)
63 SetEvent(latch->wevent);
66 /* Returns true if 'latch' is set, false otherwise. Does not reset 'latch'
67 * to the unset state. */
69 latch_is_set(const struct latch *latch)
74 /* Causes the next poll_block() to wake up when 'latch' is set.
76 * ('where' is used in debug logging. Commonly one would use latch_wait() to
77 * automatically provide the caller's source file and line number for
80 latch_wait_at(const struct latch *latch, const char *where)
82 poll_fd_wait_at(0, latch->wevent, POLLIN, where);