Merge pull request grpc#96 from dklempner/pollset_kick

Factor out the pollset kicking mechanism and eliminate sharding
soon · Jan 17, 2015 · 55c3b27 · 55c3b27
2 parents beddbda + 7f3ed1e
commit 55c3b27
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Showing 11 changed files with 479 additions and 71 deletions.
diff --git a/Makefile b/Makefile
diff --git a/build.json b/build.json
@@ -38,6 +38,7 @@
         "src/core/iomgr/fd_posix.c",
         "src/core/iomgr/iomgr.c",
         "src/core/iomgr/iomgr_posix.c",
+	"src/core/iomgr/pollset_kick_posix.c",
         "src/core/iomgr/pollset_multipoller_with_poll_posix.c",
         "src/core/iomgr/pollset_posix.c",
         "src/core/iomgr/resolve_address_posix.c",
@@ -126,6 +127,8 @@
         "src/core/iomgr/iomgr.h",
         "src/core/iomgr/iomgr_internal.h",
         "src/core/iomgr/iomgr_posix.h",
+	"src/core/iomgr/pollset_kick.h",
+	"src/core/iomgr/pollset_kick_posix.h",
         "src/core/iomgr/pollset.h",
         "src/core/iomgr/pollset_posix.h",
         "src/core/iomgr/resolve_address.h",
@@ -1497,6 +1500,19 @@
         "gpr_test_util",
         "gpr"
       ]
+    },
+    {
+      "name": "poll_kick_test",
+      "build": "test",
+      "src": [
+	"test/core/iomgr/poll_kick_test.c"
+      ],
+      "deps": [
+	"grpc_test_util",
+	"grpc",
+	"gpr_test_util",
+	"gpr"
+      ]
     }
   ]
 }
diff --git a/src/core/iomgr/pollset_kick.h b/src/core/iomgr/pollset_kick.h
@@ -0,0 +1,68 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef __GRPC_INTERNAL_IOMGR_POLLSET_KICK_H_
+#define __GRPC_INTERNAL_IOMGR_POLLSET_KICK_H_
+
+#include <grpc/support/port_platform.h>
+
+/* This is an abstraction around the typical pipe mechanism for waking up a
+   thread sitting in a poll() style call. */
+
+#ifdef GPR_POSIX_SOCKET
+#include "src/core/iomgr/pollset_kick_posix.h"
+#else
+#error "No pollset kick support on platform"
+#endif
+
+void grpc_pollset_kick_global_init(void);
+void grpc_pollset_kick_global_destroy(void);
+
+void grpc_pollset_kick_init(grpc_pollset_kick_state *kick_state);
+void grpc_pollset_kick_destroy(grpc_pollset_kick_state *kick_state);
+
+/* Must be called before entering poll(). If return value is -1, this consumed
+   an existing kick. Otherwise the return value is an FD to add to the poll set.
+ */
+int grpc_pollset_kick_pre_poll(grpc_pollset_kick_state *kick_state);
+
+/* Consume an existing kick. Must be called after poll returns that the fd was
+   readable, and before calling kick_post_poll. */
+void grpc_pollset_kick_consume(grpc_pollset_kick_state *kick_state);
+
+/* Must be called after pre_poll, and after consume if applicable */
+void grpc_pollset_kick_post_poll(grpc_pollset_kick_state *kick_state);
+
+void grpc_pollset_kick_kick(grpc_pollset_kick_state *kick_state);
+
+#endif /* __GRPC_INTERNAL_IOMGR_POLLSET_KICK_H_ */
diff --git a/src/core/iomgr/pollset_kick_posix.c 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);
+}
diff --git a/src/core/iomgr/pollset_kick_posix.h b/src/core/iomgr/pollset_kick_posix.h
@@ -0,0 +1,47 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef __GRPC_INTERNAL_IOMGR_POLLSET_KICK_POSIX_H_
+#define __GRPC_INTERNAL_IOMGR_POLLSET_KICK_POSIX_H_
+
+#include <grpc/support/sync.h>
+
+struct grpc_kick_pipe_info;
+
+typedef struct grpc_pollset_kick_state {
+  gpr_mu mu;
+  int kicked;
+  struct grpc_kick_pipe_info *pipe_info;
+} grpc_pollset_kick_state;
+
+#endif /* __GRPC_INTERNAL_IOMGR_POLLSET_KICK_POSIX_H_ */
diff --git a/src/core/iomgr/pollset_multipoller_with_poll_posix.c b/src/core/iomgr/pollset_multipoller_with_poll_posix.c
@@ -131,7 +131,11 @@ static int multipoll_with_poll_pollset_maybe_work(
   }
   nf = 0;
   np = 1;
-  h->pfds[0].fd = grpc_kick_read_fd(pollset);
+  h->pfds[0].fd = grpc_pollset_kick_pre_poll(&pollset->kick_state);
+  if (h->pfds[0].fd < 0) {
+    /* Already kicked */
+    return 1;
+  }
   h->pfds[0].events = POLLIN;
   h->pfds[0].revents = POLLOUT;
   for (i = 0; i < h->fd_count; i++) {
@@ -173,7 +177,7 @@ static int multipoll_with_poll_pollset_maybe_work(
     /* do nothing */
   } else {
     if (h->pfds[0].revents & POLLIN) {
-      grpc_kick_drain(pollset);
+      grpc_pollset_kick_consume(&pollset->kick_state);
     }
     for (i = 1; i < np; i++) {
       if (h->pfds[i].revents & POLLIN) {
@@ -184,6 +188,7 @@ static int multipoll_with_poll_pollset_maybe_work(
       }
     }
   }
+  grpc_pollset_kick_post_poll(&pollset->kick_state);
   end_polling(pollset);
 
   gpr_mu_lock(&pollset->mu);