poll-loop: Port to Windows.

[sliver-openvswitch.git] / lib / latch-windows.c

diff --git a/lib/latch-windows.c b/lib/latch-windows.c
new file mode 100644 (file)
index 0000000..34796d5
--- /dev/null
+++ b/lib/latch-windows.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2013 Nicira, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+
+#include "latch.h"
+#include <errno.h>
+#include <poll.h>
+#include <unistd.h>
+#include "poll-loop.h"
+#include "socket-util.h"
+
+/* Initializes 'latch' as initially unset. */
+void
+latch_init(struct latch *latch)
+{
+    latch->is_set = FALSE;
+    latch->wevent = CreateEvent(NULL, TRUE, FALSE, NULL);
+}
+
+/* Destroys 'latch'. */
+void
+latch_destroy(struct latch *latch)
+{
+    latch->is_set = FALSE;
+    CloseHandle(latch->wevent);
+}
+
+/* Resets 'latch' to the unset state.  Returns true if 'latch' was previously
+ * set, false otherwise. */
+bool
+latch_poll(struct latch *latch)
+{
+    bool is_set;
+
+    is_set = latch->is_set;
+    latch->is_set = FALSE;
+    ResetEvent(latch->wevent);
+    return is_set;
+}
+
+/* Sets 'latch'.
+ *
+ * Calls are not additive: a single latch_poll() clears out any number of
+ * latch_set(). */
+void
+latch_set(struct latch *latch)
+{
+    latch->is_set = TRUE;
+    SetEvent(latch->wevent);
+}
+
+/* Returns true if 'latch' is set, false otherwise.  Does not reset 'latch'
+ * to the unset state. */
+bool
+latch_is_set(const struct latch *latch)
+{
+    return latch->is_set;
+}
+
+/* Causes the next poll_block() to wake up when 'latch' is set.
+ *
+ * ('where' is used in debug logging.  Commonly one would use latch_wait() to
+ * automatically provide the caller's source file and line number for
+ * 'where'.) */
+void
+latch_wait_at(const struct latch *latch, const char *where)
+{
+    poll_fd_wait_at(0, latch->wevent, POLLIN, where);
+}