Initial checkin of gRPC to third_party/

third_party/grpc/src/core/iomgr/tcp_posix.c

Index: third_party/grpc/src/core/iomgr/tcp_posix.c
diff --git a/third_party/grpc/src/core/iomgr/tcp_posix.c b/third_party/grpc/src/core/iomgr/tcp_posix.c
new file mode 100644
index 0000000000000000000000000000000000000000..f74eb3fe5115110de299526f808245a02c9ead10
--- /dev/null
+++ b/third_party/grpc/src/core/iomgr/tcp_posix.c
@@ -0,0 +1,493 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_POSIX_SOCKET
+
+#include "src/core/iomgr/tcp_posix.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/slice.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/time.h>
+
+#include "src/core/debug/trace.h"
+#include "src/core/iomgr/pollset_posix.h"
+#include "src/core/iomgr/pollset_set_posix.h"
+#include "src/core/profiling/timers.h"
+#include "src/core/support/string.h"
+
+#ifdef GPR_HAVE_MSG_NOSIGNAL
+#define SENDMSG_FLAGS MSG_NOSIGNAL
+#else
+#define SENDMSG_FLAGS 0
+#endif
+
+#ifdef GPR_MSG_IOVLEN_TYPE
+typedef GPR_MSG_IOVLEN_TYPE msg_iovlen_type;
+#else
+typedef size_t msg_iovlen_type;
+#endif
+
+int grpc_tcp_trace = 0;
+
+typedef struct {
+  grpc_endpoint base;
+  grpc_fd *em_fd;
+  int fd;
+  int finished_edge;
+  msg_iovlen_type iov_size; /* Number of slices to allocate per read attempt */
+  size_t slice_size;
+  gpr_refcount refcount;
+
+  /* garbage after the last read */
+  gpr_slice_buffer last_read_buffer;
+
+  gpr_slice_buffer *incoming_buffer;
+  gpr_slice_buffer *outgoing_buffer;
+  /** slice within outgoing_buffer to write next */
+  size_t outgoing_slice_idx;
+  /** byte within outgoing_buffer->slices[outgoing_slice_idx] to write next */
+  size_t outgoing_byte_idx;
+
+  grpc_closure *read_cb;
+  grpc_closure *write_cb;
+  grpc_closure *release_fd_cb;
+  int *release_fd;
+
+  grpc_closure read_closure;
+  grpc_closure write_closure;
+
+  char *peer_string;
+} grpc_tcp;
+
+static void tcp_handle_read(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
+                            bool success);
+static void tcp_handle_write(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
+                             bool success);
+
+static void tcp_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  grpc_fd_shutdown(exec_ctx, tcp->em_fd);
+}
+
+static void tcp_free(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
+  grpc_fd_orphan(exec_ctx, tcp->em_fd, tcp->release_fd_cb, tcp->release_fd,
+                 "tcp_unref_orphan");
+  gpr_slice_buffer_destroy(&tcp->last_read_buffer);
+  gpr_free(tcp->peer_string);
+  gpr_free(tcp);
+}
+
+/*#define GRPC_TCP_REFCOUNT_DEBUG*/
+#ifdef GRPC_TCP_REFCOUNT_DEBUG
+#define TCP_UNREF(cl, tcp, reason) \
+  tcp_unref((cl), (tcp), (reason), __FILE__, __LINE__)
+#define TCP_REF(tcp, reason) tcp_ref((tcp), (reason), __FILE__, __LINE__)
+static void tcp_unref(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp,
+                      const char *reason, const char *file, int line) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "TCP unref %p : %s %d -> %d", tcp,
+          reason, tcp->refcount.count, tcp->refcount.count - 1);
+  if (gpr_unref(&tcp->refcount)) {
+    tcp_free(exec_ctx, tcp);
+  }
+}
+
+static void tcp_ref(grpc_tcp *tcp, const char *reason, const char *file,
+                    int line) {
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "TCP   ref %p : %s %d -> %d", tcp,
+          reason, tcp->refcount.count, tcp->refcount.count + 1);
+  gpr_ref(&tcp->refcount);
+}
+#else
+#define TCP_UNREF(cl, tcp, reason) tcp_unref((cl), (tcp))
+#define TCP_REF(tcp, reason) tcp_ref((tcp))
+static void tcp_unref(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
+  if (gpr_unref(&tcp->refcount)) {
+    tcp_free(exec_ctx, tcp);
+  }
+}
+
+static void tcp_ref(grpc_tcp *tcp) { gpr_ref(&tcp->refcount); }
+#endif
+
+static void tcp_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  TCP_UNREF(exec_ctx, tcp, "destroy");
+}
+
+static void call_read_cb(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp, int success) {
+  grpc_closure *cb = tcp->read_cb;
+
+  if (grpc_tcp_trace) {
+    size_t i;
+    gpr_log(GPR_DEBUG, "read: success=%d", success);
+    for (i = 0; i < tcp->incoming_buffer->count; i++) {
+      char *dump = gpr_dump_slice(tcp->incoming_buffer->slices[i],
+                                  GPR_DUMP_HEX | GPR_DUMP_ASCII);
+      gpr_log(GPR_DEBUG, "READ %p: %s", tcp, dump);
+      gpr_free(dump);
+    }
+  }
+
+  tcp->read_cb = NULL;
+  tcp->incoming_buffer = NULL;
+  cb->cb(exec_ctx, cb->cb_arg, success);
+}
+
+#define MAX_READ_IOVEC 4
+static void tcp_continue_read(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
+  struct msghdr msg;
+  struct iovec iov[MAX_READ_IOVEC];
+  ssize_t read_bytes;
+  size_t i;
+
+  GPR_ASSERT(!tcp->finished_edge);
+  GPR_ASSERT(tcp->iov_size <= MAX_READ_IOVEC);
+  GPR_ASSERT(tcp->incoming_buffer->count <= MAX_READ_IOVEC);
+  GPR_TIMER_BEGIN("tcp_continue_read", 0);
+
+  while (tcp->incoming_buffer->count < (size_t)tcp->iov_size) {
+    gpr_slice_buffer_add_indexed(tcp->incoming_buffer,
+                                 gpr_slice_malloc(tcp->slice_size));
+  }
+  for (i = 0; i < tcp->incoming_buffer->count; i++) {
+    iov[i].iov_base = GPR_SLICE_START_PTR(tcp->incoming_buffer->slices[i]);
+    iov[i].iov_len = GPR_SLICE_LENGTH(tcp->incoming_buffer->slices[i]);
+  }
+
+  msg.msg_name = NULL;
+  msg.msg_namelen = 0;
+  msg.msg_iov = iov;
+  msg.msg_iovlen = tcp->iov_size;
+  msg.msg_control = NULL;
+  msg.msg_controllen = 0;
+  msg.msg_flags = 0;
+
+  GPR_TIMER_BEGIN("recvmsg", 1);
+  do {
+    read_bytes = recvmsg(tcp->fd, &msg, 0);
+  } while (read_bytes < 0 && errno == EINTR);
+  GPR_TIMER_END("recvmsg", 0);
+
+  if (read_bytes < 0) {
+    /* NB: After calling call_read_cb a parallel call of the read handler may
+     * be running. */
+    if (errno == EAGAIN) {
+      if (tcp->iov_size > 1) {
+        tcp->iov_size /= 2;
+      }
+      /* We've consumed the edge, request a new one */
+      grpc_fd_notify_on_read(exec_ctx, tcp->em_fd, &tcp->read_closure);
+    } else {
+      /* TODO(klempner): Log interesting errors */
+      gpr_slice_buffer_reset_and_unref(tcp->incoming_buffer);
+      call_read_cb(exec_ctx, tcp, 0);
+      TCP_UNREF(exec_ctx, tcp, "read");
+    }
+  } else if (read_bytes == 0) {
+    /* 0 read size ==> end of stream */
+    gpr_slice_buffer_reset_and_unref(tcp->incoming_buffer);
+    call_read_cb(exec_ctx, tcp, 0);
+    TCP_UNREF(exec_ctx, tcp, "read");
+  } else {
+    GPR_ASSERT((size_t)read_bytes <= tcp->incoming_buffer->length);
+    if ((size_t)read_bytes < tcp->incoming_buffer->length) {
+      gpr_slice_buffer_trim_end(
+          tcp->incoming_buffer,
+          tcp->incoming_buffer->length - (size_t)read_bytes,
+          &tcp->last_read_buffer);
+    } else if (tcp->iov_size < MAX_READ_IOVEC) {
+      ++tcp->iov_size;
+    }
+    GPR_ASSERT((size_t)read_bytes == tcp->incoming_buffer->length);
+    call_read_cb(exec_ctx, tcp, 1);
+    TCP_UNREF(exec_ctx, tcp, "read");
+  }
+
+  GPR_TIMER_END("tcp_continue_read", 0);
+}
+
+static void tcp_handle_read(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
+                            bool success) {
+  grpc_tcp *tcp = (grpc_tcp *)arg;
+  GPR_ASSERT(!tcp->finished_edge);
+
+  if (!success) {
+    gpr_slice_buffer_reset_and_unref(tcp->incoming_buffer);
+    call_read_cb(exec_ctx, tcp, 0);
+    TCP_UNREF(exec_ctx, tcp, "read");
+  } else {
+    tcp_continue_read(exec_ctx, tcp);
+  }
+}
+
+static void tcp_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                     gpr_slice_buffer *incoming_buffer, grpc_closure *cb) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  GPR_ASSERT(tcp->read_cb == NULL);
+  tcp->read_cb = cb;
+  tcp->incoming_buffer = incoming_buffer;
+  gpr_slice_buffer_reset_and_unref(incoming_buffer);
+  gpr_slice_buffer_swap(incoming_buffer, &tcp->last_read_buffer);
+  TCP_REF(tcp, "read");
+  if (tcp->finished_edge) {
+    tcp->finished_edge = 0;
+    grpc_fd_notify_on_read(exec_ctx, tcp->em_fd, &tcp->read_closure);
+  } else {
+    grpc_exec_ctx_enqueue(exec_ctx, &tcp->read_closure, true, NULL);
+  }
+}
+
+typedef enum { FLUSH_DONE, FLUSH_PENDING, FLUSH_ERROR } flush_result;
+
+#define MAX_WRITE_IOVEC 16
+static flush_result tcp_flush(grpc_tcp *tcp) {
+  struct msghdr msg;
+  struct iovec iov[MAX_WRITE_IOVEC];
+  msg_iovlen_type iov_size;
+  ssize_t sent_length;
+  size_t sending_length;
+  size_t trailing;
+  size_t unwind_slice_idx;
+  size_t unwind_byte_idx;
+
+  for (;;) {
+    sending_length = 0;
+    unwind_slice_idx = tcp->outgoing_slice_idx;
+    unwind_byte_idx = tcp->outgoing_byte_idx;
+    for (iov_size = 0; tcp->outgoing_slice_idx != tcp->outgoing_buffer->count &&
+                           iov_size != MAX_WRITE_IOVEC;
+         iov_size++) {
+      iov[iov_size].iov_base =
+          GPR_SLICE_START_PTR(
+              tcp->outgoing_buffer->slices[tcp->outgoing_slice_idx]) +
+          tcp->outgoing_byte_idx;
+      iov[iov_size].iov_len =
+          GPR_SLICE_LENGTH(
+              tcp->outgoing_buffer->slices[tcp->outgoing_slice_idx]) -
+          tcp->outgoing_byte_idx;
+      sending_length += iov[iov_size].iov_len;
+      tcp->outgoing_slice_idx++;
+      tcp->outgoing_byte_idx = 0;
+    }
+    GPR_ASSERT(iov_size > 0);
+
+    msg.msg_name = NULL;
+    msg.msg_namelen = 0;
+    msg.msg_iov = iov;
+    msg.msg_iovlen = iov_size;
+    msg.msg_control = NULL;
+    msg.msg_controllen = 0;
+    msg.msg_flags = 0;
+
+    GPR_TIMER_BEGIN("sendmsg", 1);
+    do {
+      /* TODO(klempner): Cork if this is a partial write */
+      sent_length = sendmsg(tcp->fd, &msg, SENDMSG_FLAGS);
+    } while (sent_length < 0 && errno == EINTR);
+    GPR_TIMER_END("sendmsg", 0);
+
+    if (sent_length < 0) {
+      if (errno == EAGAIN) {
+        tcp->outgoing_slice_idx = unwind_slice_idx;
+        tcp->outgoing_byte_idx = unwind_byte_idx;
+        return FLUSH_PENDING;
+      } else {
+        /* TODO(klempner): Log some of these */
+        return FLUSH_ERROR;
+      }
+    }
+
+    GPR_ASSERT(tcp->outgoing_byte_idx == 0);
+    trailing = sending_length - (size_t)sent_length;
+    while (trailing > 0) {
+      size_t slice_length;
+
+      tcp->outgoing_slice_idx--;
+      slice_length = GPR_SLICE_LENGTH(
+          tcp->outgoing_buffer->slices[tcp->outgoing_slice_idx]);
+      if (slice_length > trailing) {
+        tcp->outgoing_byte_idx = slice_length - trailing;
+        break;
+      } else {
+        trailing -= slice_length;
+      }
+    }
+
+    if (tcp->outgoing_slice_idx == tcp->outgoing_buffer->count) {
+      return FLUSH_DONE;
+    }
+  };
+}
+
+static void tcp_handle_write(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
+                             bool success) {
+  grpc_tcp *tcp = (grpc_tcp *)arg;
+  flush_result status;
+  grpc_closure *cb;
+
+  if (!success) {
+    cb = tcp->write_cb;
+    tcp->write_cb = NULL;
+    cb->cb(exec_ctx, cb->cb_arg, 0);
+    TCP_UNREF(exec_ctx, tcp, "write");
+    return;
+  }
+
+  status = tcp_flush(tcp);
+  if (status == FLUSH_PENDING) {
+    grpc_fd_notify_on_write(exec_ctx, tcp->em_fd, &tcp->write_closure);
+  } else {
+    cb = tcp->write_cb;
+    tcp->write_cb = NULL;
+    GPR_TIMER_BEGIN("tcp_handle_write.cb", 0);
+    cb->cb(exec_ctx, cb->cb_arg, status == FLUSH_DONE);
+    GPR_TIMER_END("tcp_handle_write.cb", 0);
+    TCP_UNREF(exec_ctx, tcp, "write");
+  }
+}
+
+static void tcp_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                      gpr_slice_buffer *buf, grpc_closure *cb) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  flush_result status;
+
+  if (grpc_tcp_trace) {
+    size_t i;
+
+    for (i = 0; i < buf->count; i++) {
+      char *data =
+          gpr_dump_slice(buf->slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
+      gpr_log(GPR_DEBUG, "WRITE %p: %s", tcp, data);
+      gpr_free(data);
+    }
+  }
+
+  GPR_TIMER_BEGIN("tcp_write", 0);
+  GPR_ASSERT(tcp->write_cb == NULL);
+
+  if (buf->length == 0) {
+    GPR_TIMER_END("tcp_write", 0);
+    grpc_exec_ctx_enqueue(exec_ctx, cb, true, NULL);
+    return;
+  }
+  tcp->outgoing_buffer = buf;
+  tcp->outgoing_slice_idx = 0;
+  tcp->outgoing_byte_idx = 0;
+
+  status = tcp_flush(tcp);
+  if (status == FLUSH_PENDING) {
+    TCP_REF(tcp, "write");
+    tcp->write_cb = cb;
+    grpc_fd_notify_on_write(exec_ctx, tcp->em_fd, &tcp->write_closure);
+  } else {
+    grpc_exec_ctx_enqueue(exec_ctx, cb, status == FLUSH_DONE, NULL);
+  }
+
+  GPR_TIMER_END("tcp_write", 0);
+}
+
+static void tcp_add_to_pollset(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                               grpc_pollset *pollset) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  grpc_pollset_add_fd(exec_ctx, pollset, tcp->em_fd);
+}
+
+static void tcp_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                                   grpc_pollset_set *pollset_set) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  grpc_pollset_set_add_fd(exec_ctx, pollset_set, tcp->em_fd);
+}
+
+static char *tcp_get_peer(grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  return gpr_strdup(tcp->peer_string);
+}
+
+static const grpc_endpoint_vtable vtable = {
+    tcp_read, tcp_write, tcp_add_to_pollset, tcp_add_to_pollset_set,
+    tcp_shutdown, tcp_destroy, tcp_get_peer};
+
+grpc_endpoint *grpc_tcp_create(grpc_fd *em_fd, size_t slice_size,
+                               const char *peer_string) {
+  grpc_tcp *tcp = (grpc_tcp *)gpr_malloc(sizeof(grpc_tcp));
+  tcp->base.vtable = &vtable;
+  tcp->peer_string = gpr_strdup(peer_string);
+  tcp->fd = em_fd->fd;
+  tcp->read_cb = NULL;
+  tcp->write_cb = NULL;
+  tcp->release_fd_cb = NULL;
+  tcp->release_fd = NULL;
+  tcp->incoming_buffer = NULL;
+  tcp->slice_size = slice_size;
+  tcp->iov_size = 1;
+  tcp->finished_edge = 1;
+  /* paired with unref in grpc_tcp_destroy */
+  gpr_ref_init(&tcp->refcount, 1);
+  tcp->em_fd = em_fd;
+  tcp->read_closure.cb = tcp_handle_read;
+  tcp->read_closure.cb_arg = tcp;
+  tcp->write_closure.cb = tcp_handle_write;
+  tcp->write_closure.cb_arg = tcp;
+  gpr_slice_buffer_init(&tcp->last_read_buffer);
+
+  return &tcp->base;
+}
+
+int grpc_tcp_fd(grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  GPR_ASSERT(ep->vtable == &vtable);
+  return grpc_fd_wrapped_fd(tcp->em_fd);
+}
+
+void grpc_tcp_destroy_and_release_fd(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
+                                     int *fd, grpc_closure *done) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  GPR_ASSERT(ep->vtable == &vtable);
+  tcp->release_fd = fd;
+  tcp->release_fd_cb = done;
+  TCP_UNREF(exec_ctx, tcp, "destroy");
+}
+
+#endif