1 files changed, 168 insertions, 0 deletions
diff --git a/src/core/iomgr/pollset_kick_posix.c b/src/core/iomgr/pollset_kick_posix.c
new file mode 100644
index 0000000000..51021784f2
--- /dev/null
+++ b/src/core/iomgr/pollset_kick_posix.c
@@ -0,0 +1,168 @@
+/*
+ *
+ * Copyright 2015, 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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_POSIX_SOCKET
+#include "src/core/iomgr/pollset_kick_posix.h"
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "src/core/iomgr/socket_utils_posix.h"
+#include "src/core/iomgr/wakeup_fd_posix.h"
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+/* This implementation is based on a freelist of wakeup fds, with extra logic to
+ * handle kicks while there is no attached fd. */
+
+/* TODO(klempner): Autosize this, and consider providing a way to disable the
+ * cap entirely on systems with large fd limits */
+#define GRPC_MAX_CACHED_WFDS 50
+
+static grpc_kick_fd_info *fd_freelist = NULL;
+static int fd_freelist_count = 0;
+static gpr_mu fd_freelist_mu;
+
+static grpc_kick_fd_info *allocate_wfd(void) {
+  grpc_kick_fd_info *info = NULL;
+  gpr_mu_lock(&fd_freelist_mu);
+  if (fd_freelist != NULL) {
+    info = fd_freelist;
+    fd_freelist = fd_freelist->next;
+    --fd_freelist_count;
+  }
+  gpr_mu_unlock(&fd_freelist_mu);
+  if (info == NULL) {
+    info = gpr_malloc(sizeof(*info));
+    grpc_wakeup_fd_create(&info->wakeup_fd);
+    info->next = NULL;
+  }
+  return info;
+}
+
+static void destroy_wfd(grpc_kick_fd_info *wfd) {
+  grpc_wakeup_fd_destroy(&wfd->wakeup_fd);
+  gpr_free(wfd);
+}
+
+static void free_wfd(grpc_kick_fd_info *fd_info) {
+  gpr_mu_lock(&fd_freelist_mu);
+  if (fd_freelist_count < GRPC_MAX_CACHED_WFDS) {
+    fd_info->next = fd_freelist;
+    fd_freelist = fd_info;
+    fd_freelist_count++;
+    fd_info = NULL;
+  }
+  gpr_mu_unlock(&fd_freelist_mu);
+
+  if (fd_info) {
+    destroy_wfd(fd_info);
+  }
+}
+
+void grpc_pollset_kick_init(grpc_pollset_kick_state *kick_state) {
+  gpr_mu_init(&kick_state->mu);
+  kick_state->kicked = 0;
+  kick_state->fd_list.next = kick_state->fd_list.prev = &kick_state->fd_list;
+}
+
+void grpc_pollset_kick_destroy(grpc_pollset_kick_state *kick_state) {
+  gpr_mu_destroy(&kick_state->mu);
+  GPR_ASSERT(kick_state->fd_list.next == &kick_state->fd_list);
+}
+
+grpc_kick_fd_info *grpc_pollset_kick_pre_poll(
+    grpc_pollset_kick_state *kick_state) {
+  grpc_kick_fd_info *fd_info;
+  gpr_mu_lock(&kick_state->mu);
+  if (kick_state->kicked) {
+    kick_state->kicked = 0;
+    gpr_mu_unlock(&kick_state->mu);
+    return NULL;
+  }
+  fd_info = allocate_wfd();
+  fd_info->next = &kick_state->fd_list;
+  fd_info->prev = fd_info->next->prev;
+  fd_info->next->prev = fd_info->prev->next = fd_info;
+  gpr_mu_unlock(&kick_state->mu);
+  return fd_info;
+}
+
+void grpc_pollset_kick_consume(grpc_pollset_kick_state *kick_state,
+                               grpc_kick_fd_info *fd_info) {
+  grpc_wakeup_fd_consume_wakeup(&fd_info->wakeup_fd);
+}
+
+void grpc_pollset_kick_post_poll(grpc_pollset_kick_state *kick_state,
+                                 grpc_kick_fd_info *fd_info) {
+  gpr_mu_lock(&kick_state->mu);
+  fd_info->next->prev = fd_info->prev;
+  fd_info->prev->next = fd_info->next;
+  free_wfd(fd_info);
+  gpr_mu_unlock(&kick_state->mu);
+}
+
+void grpc_pollset_kick_kick(grpc_pollset_kick_state *kick_state) {
+  gpr_mu_lock(&kick_state->mu);
+  if (kick_state->fd_list.next != &kick_state->fd_list) {
+    grpc_wakeup_fd_wakeup(&kick_state->fd_list.next->wakeup_fd);
+  } else {
+    kick_state->kicked = 1;
+  }
+  gpr_mu_unlock(&kick_state->mu);
+}
+
+void grpc_pollset_kick_global_init_fallback_fd(void) {
+  gpr_mu_init(&fd_freelist_mu);
+  grpc_wakeup_fd_global_init_force_fallback();
+}
+
+void grpc_pollset_kick_global_init(void) {
+  gpr_mu_init(&fd_freelist_mu);
+  grpc_wakeup_fd_global_init();
+}
+
+void grpc_pollset_kick_global_destroy(void) {
+  while (fd_freelist != NULL) {
+    grpc_kick_fd_info *current = fd_freelist;
+    fd_freelist = fd_freelist->next;
+    destroy_wfd(current);
+  }
+  grpc_wakeup_fd_global_destroy();
+  gpr_mu_destroy(&fd_freelist_mu);
+}
+
+#endif /* GPR_POSIX_SOCKET */