Initial checkin of gRPC to third_party/

third_party/grpc/src/core/iomgr/pollset.h

+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_IOMGR_POLLSET_H
+#define GRPC_INTERNAL_CORE_IOMGR_POLLSET_H
+
+#include <grpc/support/port_platform.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/time.h>
+
+#include "src/core/iomgr/exec_ctx.h"
+
+#define GRPC_POLLSET_KICK_BROADCAST ((grpc_pollset_worker *)1)
+
+/* A grpc_pollset is a set of file descriptors that a higher level item is
+   interested in. For example:
+    - a server will typically keep a pollset containing all connected channels,
+      so that it can find new calls to service
+    - a completion queue might keep a pollset with an entry for each transport
+      that is servicing a call that it's tracking */
+
+typedef struct grpc_pollset grpc_pollset;
+typedef struct grpc_pollset_worker grpc_pollset_worker;
+
+size_t grpc_pollset_size(void);
+void grpc_pollset_init(grpc_pollset *pollset, gpr_mu **mu);
+/* Begin shutting down the pollset, and call closure when done.
+ * GRPC_POLLSET_MU(pollset) must be held */
+void grpc_pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                           grpc_closure *closure);
+/** Reset the pollset to its initial state (perhaps with some cached objects);
+ *  must have been previously shutdown */
+void grpc_pollset_reset(grpc_pollset *pollset);
+void grpc_pollset_destroy(grpc_pollset *pollset);
+
+/* Do some work on a pollset.
+   May involve invoking asynchronous callbacks, or actually polling file
+   descriptors.
+   Requires GRPC_POLLSET_MU(pollset) locked.
+   May unlock GRPC_POLLSET_MU(pollset) during its execution.
+
+   worker is a (platform-specific) handle that can be used to wake up
+   from grpc_pollset_work before any events are received and before the timeout
+   has expired. It is both initialized and destroyed by grpc_pollset_work.
+   Initialization of worker is guaranteed to occur BEFORE the
+   GRPC_POLLSET_MU(pollset) is released for the first time by
+   grpc_pollset_work, and it is guaranteed that GRPC_POLLSET_MU(pollset) will
+   not be released by grpc_pollset_work AFTER worker has been destroyed.
+
+   Tries not to block past deadline.
+   May call grpc_closure_list_run on grpc_closure_list, without holding the
+   pollset
+   lock */
+void grpc_pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                       grpc_pollset_worker **worker, gpr_timespec now,
+                       gpr_timespec deadline);
+
+/* Break one polling thread out of polling work for this pollset.
+   If specific_worker is GRPC_POLLSET_KICK_BROADCAST, kick ALL the workers.
+   Otherwise, if specific_worker is non-NULL, then kick that worker. */
+void grpc_pollset_kick(grpc_pollset *pollset,
+                       grpc_pollset_worker *specific_worker);
+
+#endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_H */