Initial checkin of gRPC to third_party/

third_party/grpc/src/core/iomgr/pollset_posix.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_POSIX_H
+#define GRPC_INTERNAL_CORE_IOMGR_POLLSET_POSIX_H
+
+#include <poll.h>
+
+#include <grpc/support/sync.h>
+
+#include "src/core/iomgr/exec_ctx.h"
+#include "src/core/iomgr/iomgr.h"
+#include "src/core/iomgr/pollset.h"
+#include "src/core/iomgr/wakeup_fd_posix.h"
+
+typedef struct grpc_pollset_vtable grpc_pollset_vtable;
+
+/* forward declare only in this file to avoid leaking impl details via
+   pollset.h; real users of grpc_fd should always include 'fd_posix.h' and not
+   use the struct tag */
+struct grpc_fd;
+
+typedef struct grpc_cached_wakeup_fd {
+  grpc_wakeup_fd fd;
+  struct grpc_cached_wakeup_fd *next;
+} grpc_cached_wakeup_fd;
+
+struct grpc_pollset_worker {
+  grpc_cached_wakeup_fd *wakeup_fd;
+  int reevaluate_polling_on_wakeup;
+  int kicked_specifically;
+  struct grpc_pollset_worker *next;
+  struct grpc_pollset_worker *prev;
+};
+
+struct grpc_pollset {
+  /* pollsets under posix can mutate representation as fds are added and
+     removed.
+     For example, we may choose a poll() based implementation on linux for
+     few fds, and an epoll() based implementation for many fds */
+  const grpc_pollset_vtable *vtable;
+  gpr_mu mu;
+  grpc_pollset_worker root_worker;
+  int in_flight_cbs;
+  int shutting_down;
+  int called_shutdown;
+  int kicked_without_pollers;
+  grpc_closure *shutdown_done;
+  grpc_closure_list idle_jobs;
+  union {
+    int fd;
+    void *ptr;
+  } data;
+  /* Local cache of eventfds for workers */
+  grpc_cached_wakeup_fd *local_wakeup_cache;
+};
+
+struct grpc_pollset_vtable {
+  void (*add_fd)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                 struct grpc_fd *fd, int and_unlock_pollset);
+  void (*maybe_work_and_unlock)(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                                grpc_pollset_worker *worker,
+                                gpr_timespec deadline, gpr_timespec now);
+  void (*finish_shutdown)(grpc_pollset *pollset);
+  void (*destroy)(grpc_pollset *pollset);
+};
+
+/* Add an fd to a pollset */
+void grpc_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
+                         struct grpc_fd *fd);
+
+/* Returns the fd to listen on for kicks */
+int grpc_kick_read_fd(grpc_pollset *p);
+/* Call after polling has been kicked to leave the kicked state */
+void grpc_kick_drain(grpc_pollset *p);
+
+/* Convert a timespec to milliseconds:
+   - very small or negative poll times are clamped to zero to do a
+     non-blocking poll (which becomes spin polling)
+   - other small values are rounded up to one millisecond
+   - longer than a millisecond polls are rounded up to the next nearest
+     millisecond to avoid spinning
+   - infinite timeouts are converted to -1 */
+int grpc_poll_deadline_to_millis_timeout(gpr_timespec deadline,
+                                         gpr_timespec now);
+
+/* Allow kick to wakeup the currently polling worker */
+#define GRPC_POLLSET_CAN_KICK_SELF 1
+/* Force the wakee to repoll when awoken */
+#define GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP 2
+/* As per grpc_pollset_kick, with an extended set of flags (defined above)
+   -- mostly for fd_posix's use. */
+void grpc_pollset_kick_ext(grpc_pollset *p,
+                           grpc_pollset_worker *specific_worker,
+                           uint32_t flags);
+
+/* turn a pollset into a multipoller: platform specific */
+typedef void (*grpc_platform_become_multipoller_type)(grpc_exec_ctx *exec_ctx,
+                                                      grpc_pollset *pollset,
+                                                      struct grpc_fd **fds,
+                                                      size_t fd_count);
+extern grpc_platform_become_multipoller_type grpc_platform_become_multipoller;
+
+void grpc_poll_become_multipoller(grpc_exec_ctx *exec_ctx,
+                                  grpc_pollset *pollset, struct grpc_fd **fds,
+                                  size_t fd_count);
+
+/* Return 1 if the pollset has active threads in grpc_pollset_work (pollset must
+ * be locked) */
+int grpc_pollset_has_workers(grpc_pollset *pollset);
+
+void grpc_remove_fd_from_all_epoll_sets(int fd);
+
+/* override to allow tests to hook poll() usage */
+/* NOTE: Any changes to grpc_poll_function must take place when the gRPC
+   is certainly not doing any polling anywhere.
+   Otherwise, there might be a race between changing the variable and actually
+   doing a polling operation */
+typedef int (*grpc_poll_function_type)(struct pollfd *, nfds_t, int);
+extern grpc_poll_function_type grpc_poll_function;
+extern grpc_wakeup_fd grpc_global_wakeup_fd;
+
+#endif /* GRPC_INTERNAL_CORE_IOMGR_POLLSET_POSIX_H */