1 files changed, 161 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..d16e49e459
--- /dev/null
+++ b/src/core/iomgr/pollset_kick_posix.c
@@ -0,0 +1,161 @@
+/*
+ *
+ * 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 "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 <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+/* This implementation is based on a freelist of pipes. */
+
+typedef struct grpc_kick_pipe_info {
+  int pipe_read_fd;
+  int pipe_write_fd;
+  struct grpc_kick_pipe_info *next;
+} grpc_kick_pipe_info;
+
+static grpc_kick_pipe_info *pipe_freelist = NULL;
+static gpr_mu pipe_freelist_mu;
+
+static grpc_kick_pipe_info *allocate_pipe() {
+  grpc_kick_pipe_info *info;
+  gpr_mu_lock(&pipe_freelist_mu);
+  if (pipe_freelist != NULL) {
+    info = pipe_freelist;
+    pipe_freelist = pipe_freelist->next;
+  } else {
+    int pipefd[2];
+    /* TODO(klempner): Make this nonfatal */
+    GPR_ASSERT(0 == pipe(pipefd));
+    GPR_ASSERT(grpc_set_socket_nonblocking(pipefd[0], 1));
+    GPR_ASSERT(grpc_set_socket_nonblocking(pipefd[1], 1));
+    info = gpr_malloc(sizeof(*info));
+    info->pipe_read_fd = pipefd[0];
+    info->pipe_write_fd = pipefd[1];
+    info->next = NULL;
+  }
+  gpr_mu_unlock(&pipe_freelist_mu);
+  return info;
+}
+
+static void free_pipe(grpc_kick_pipe_info *pipe_info) {
+  /* TODO(klempner): Start closing pipes if the free list gets too large */
+  gpr_mu_lock(&pipe_freelist_mu);
+  pipe_info->next = pipe_freelist;
+  pipe_freelist = pipe_info;
+  gpr_mu_unlock(&pipe_freelist_mu);
+}
+
+void grpc_pollset_kick_global_init() {
+  pipe_freelist = NULL;
+  gpr_mu_init(&pipe_freelist_mu);
+}
+
+void grpc_pollset_kick_global_destroy() {
+  while (pipe_freelist != NULL) {
+    grpc_kick_pipe_info *current = pipe_freelist;
+    pipe_freelist = pipe_freelist->next;
+    close(current->pipe_read_fd);
+    close(current->pipe_write_fd);
+    gpr_free(current);
+  }
+  gpr_mu_destroy(&pipe_freelist_mu);
+}
+
+void grpc_pollset_kick_init(grpc_pollset_kick_state *kick_state) {
+  gpr_mu_init(&kick_state->mu);
+  kick_state->kicked = 0;
+  kick_state->pipe_info = NULL;
+}
+
+void grpc_pollset_kick_destroy(grpc_pollset_kick_state *kick_state) {
+  gpr_mu_destroy(&kick_state->mu);
+  GPR_ASSERT(kick_state->pipe_info == NULL);
+}
+
+int grpc_pollset_kick_pre_poll(grpc_pollset_kick_state *kick_state) {
+  gpr_mu_lock(&kick_state->mu);
+  if (kick_state->kicked) {
+    kick_state->kicked = 0;
+    gpr_mu_unlock(&kick_state->mu);
+    return -1;
+  }
+  kick_state->pipe_info = allocate_pipe();
+  gpr_mu_unlock(&kick_state->mu);
+  return kick_state->pipe_info->pipe_read_fd;
+}
+
+void grpc_pollset_kick_consume(grpc_pollset_kick_state *kick_state) {
+  char buf[128];
+  int r;
+
+  for (;;) {
+    r = read(kick_state->pipe_info->pipe_read_fd, buf, sizeof(buf));
+    if (r > 0) continue;
+    if (r == 0) return;
+    switch (errno) {
+      case EAGAIN:
+        return;
+      case EINTR:
+        continue;
+      default:
+        gpr_log(GPR_ERROR, "error reading pipe: %s", strerror(errno));
+        return;
+    }
+  }
+}
+
+void grpc_pollset_kick_post_poll(grpc_pollset_kick_state *kick_state) {
+  gpr_mu_lock(&kick_state->mu);
+  free_pipe(kick_state->pipe_info);
+  kick_state->pipe_info = NULL;
+  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->pipe_info != NULL) {
+    char c = 0;
+    while (write(kick_state->pipe_info->pipe_write_fd, &c, 1) != 1 &&
+           errno == EINTR)
+      ;
+  } else {
+    kick_state->kicked = 1;
+  }
+  gpr_mu_unlock(&kick_state->mu);
+}