Merge github.com:grpc/grpc into newlines

21 files changed, 518 insertions, 2463 deletions

diff --git a/src/core/lib/iomgr/endpoint.c b/src/core/lib/iomgr/endpoint.c
index 74fa9c45df..2d300f4560 100644
--- a/src/core/lib/iomgr/endpoint.c
+++ b/src/core/lib/iomgr/endpoint.c
@@ -34,12 +34,12 @@
 #include "src/core/lib/iomgr/endpoint.h"
 
 void grpc_endpoint_read(grpc_exec_ctx* exec_ctx, grpc_endpoint* ep,
-                        gpr_slice_buffer* slices, grpc_closure* cb) {
+                        grpc_slice_buffer* slices, grpc_closure* cb) {
   ep->vtable->read(exec_ctx, ep, slices, cb);
 }
 
 void grpc_endpoint_write(grpc_exec_ctx* exec_ctx, grpc_endpoint* ep,
-                         gpr_slice_buffer* slices, grpc_closure* cb) {
+                         grpc_slice_buffer* slices, grpc_closure* cb) {
   ep->vtable->write(exec_ctx, ep, slices, cb);
 }
 
@@ -66,6 +66,8 @@ char* grpc_endpoint_get_peer(grpc_endpoint* ep) {
   return ep->vtable->get_peer(ep);
 }
 
+int grpc_endpoint_get_fd(grpc_endpoint* ep) { return ep->vtable->get_fd(ep); }
+
 grpc_workqueue* grpc_endpoint_get_workqueue(grpc_endpoint* ep) {
   return ep->vtable->get_workqueue(ep);
 }
diff --git a/src/core/lib/iomgr/endpoint.h b/src/core/lib/iomgr/endpoint.h
index 0ac5486ff5..1609b64f2b 100644
--- a/src/core/lib/iomgr/endpoint.h
+++ b/src/core/lib/iomgr/endpoint.h
@@ -34,8 +34,8 @@
 #ifndef GRPC_CORE_LIB_IOMGR_ENDPOINT_H
 #define GRPC_CORE_LIB_IOMGR_ENDPOINT_H
 
-#include <grpc/support/slice.h>
-#include <grpc/support/slice_buffer.h>
+#include <grpc/slice.h>
+#include <grpc/slice_buffer.h>
 #include <grpc/support/time.h>
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_set.h"
@@ -49,9 +49,9 @@ typedef struct grpc_endpoint_vtable grpc_endpoint_vtable;
 
 struct grpc_endpoint_vtable {
   void (*read)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-               gpr_slice_buffer *slices, grpc_closure *cb);
+               grpc_slice_buffer *slices, grpc_closure *cb);
   void (*write)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                gpr_slice_buffer *slices, grpc_closure *cb);
+                grpc_slice_buffer *slices, grpc_closure *cb);
   grpc_workqueue *(*get_workqueue)(grpc_endpoint *ep);
   void (*add_to_pollset)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
                          grpc_pollset *pollset);
@@ -61,6 +61,7 @@ struct grpc_endpoint_vtable {
   void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep);
   grpc_resource_user *(*get_resource_user)(grpc_endpoint *ep);
   char *(*get_peer)(grpc_endpoint *ep);
+  int (*get_fd)(grpc_endpoint *ep);
 };
 
 /* When data is available on the connection, calls the callback with slices.
@@ -69,10 +70,14 @@ struct grpc_endpoint_vtable {
    Valid slices may be placed into \a slices even when the callback is
    invoked with error != GRPC_ERROR_NONE. */
 void grpc_endpoint_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                        gpr_slice_buffer *slices, grpc_closure *cb);
+                        grpc_slice_buffer *slices, grpc_closure *cb);
 
 char *grpc_endpoint_get_peer(grpc_endpoint *ep);
 
+/* Get the file descriptor used by \a ep. Return -1 if \a ep is not using an fd.
+   */
+int grpc_endpoint_get_fd(grpc_endpoint *ep);
+
 /* Retrieve a reference to the workqueue associated with this endpoint */
 grpc_workqueue *grpc_endpoint_get_workqueue(grpc_endpoint *ep);
 
@@ -87,7 +92,7 @@ grpc_workqueue *grpc_endpoint_get_workqueue(grpc_endpoint *ep);
    it is a valid slice buffer.
    */
 void grpc_endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                         gpr_slice_buffer *slices, grpc_closure *cb);
+                         grpc_slice_buffer *slices, grpc_closure *cb);
 
 /* Causes any pending and future read/write callbacks to run immediately with
    success==0 */
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index db51ec4939..91041a7c28 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -163,7 +163,7 @@ static void fd_global_shutdown(void);
 #define PI_ADD_REF(p, r) pi_add_ref((p))
 #define PI_UNREF(exec_ctx, p, r) pi_unref((exec_ctx), (p))
 
-#endif /* !defined(GPRC_PI_REF_COUNT_DEBUG) */
+#endif /* !defined(GRPC_PI_REF_COUNT_DEBUG) */
 
 /* This is also used as grpc_workqueue (by directly casing it) */
 typedef struct polling_island {
diff --git a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c b/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
deleted file mode 100644
index bf51404203..0000000000
--- a/src/core/lib/iomgr/ev_poll_and_epoll_posix.c
+++ /dev/null
@@ -1,2076 +0,0 @@
-/*
- *
- * 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.
- *
- */
-
-/* This file will be removed shortly: it's here to keep refactoring
- * steps simple and auditable.
- * It's the combination of the old files:
- *  - fd_posix.{h,c}
- *  - pollset_posix.{h,c}
- *  - pullset_multipoller_with_{poll,epoll}.{h,c}
- * The new version will be split into:
- *  - ev_poll_posix.{h,c}
- *  - ev_epoll_posix.{h,c}
- */
-
-#include "src/core/lib/iomgr/port.h"
-
-#ifdef GRPC_POSIX_SOCKET
-
-#include "src/core/lib/iomgr/ev_poll_and_epoll_posix.h"
-
-#include <assert.h>
-#include <errno.h>
-#include <poll.h>
-#include <string.h>
-#include <sys/socket.h>
-#include <unistd.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/string_util.h>
-#include <grpc/support/tls.h>
-#include <grpc/support/useful.h>
-
-#include "src/core/lib/iomgr/iomgr_internal.h"
-#include "src/core/lib/iomgr/wakeup_fd_posix.h"
-#include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/block_annotate.h"
-
-/*******************************************************************************
- * FD declarations
- */
-
-typedef struct grpc_fd_watcher {
-  struct grpc_fd_watcher *next;
-  struct grpc_fd_watcher *prev;
-  grpc_pollset *pollset;
-  grpc_pollset_worker *worker;
-  grpc_fd *fd;
-} grpc_fd_watcher;
-
-struct grpc_fd {
-  int fd;
-  /* refst format:
-     bit0:   1=active/0=orphaned
-     bit1-n: refcount
-     meaning that mostly we ref by two to avoid altering the orphaned bit,
-     and just unref by 1 when we're ready to flag the object as orphaned */
-  gpr_atm refst;
-
-  gpr_mu mu;
-  int shutdown;
-  int closed;
-  int released;
-
-  /* The watcher list.
-
-     The following watcher related fields are protected by watcher_mu.
-
-     An fd_watcher is an ephemeral object created when an fd wants to
-     begin polling, and destroyed after the poll.
-
-     It denotes the fd's interest in whether to read poll or write poll
-     or both or neither on this fd.
-
-     If a watcher is asked to poll for reads or writes, the read_watcher
-     or write_watcher fields are set respectively. A watcher may be asked
-     to poll for both, in which case both fields will be set.
-
-     read_watcher and write_watcher may be NULL if no watcher has been
-     asked to poll for reads or writes.
-
-     If an fd_watcher is not asked to poll for reads or writes, it's added
-     to a linked list of inactive watchers, rooted at inactive_watcher_root.
-     If at a later time there becomes need of a poller to poll, one of
-     the inactive pollers may be kicked out of their poll loops to take
-     that responsibility. */
-  grpc_fd_watcher inactive_watcher_root;
-  grpc_fd_watcher *read_watcher;
-  grpc_fd_watcher *write_watcher;
-
-  grpc_closure *read_closure;
-  grpc_closure *write_closure;
-
-  struct grpc_fd *freelist_next;
-
-  grpc_closure *on_done_closure;
-
-  grpc_iomgr_object iomgr_object;
-
-  /* The pollset that last noticed and notified that the fd is readable */
-  grpc_pollset *read_notifier_pollset;
-};
-
-/* Begin polling on an fd.
-   Registers that the given pollset is interested in this fd - so that if read
-   or writability interest changes, the pollset can be kicked to pick up that
-   new interest.
-   Return value is:
-     (fd_needs_read? read_mask : 0) | (fd_needs_write? write_mask : 0)
-   i.e. a combination of read_mask and write_mask determined by the fd's current
-   interest in said events.
-   Polling strategies that do not need to alter their behavior depending on the
-   fd's current interest (such as epoll) do not need to call this function.
-   MUST NOT be called with a pollset lock taken */
-static uint32_t fd_begin_poll(grpc_fd *fd, grpc_pollset *pollset,
-                              grpc_pollset_worker *worker, uint32_t read_mask,
-                              uint32_t write_mask, grpc_fd_watcher *rec);
-/* Complete polling previously started with fd_begin_poll
-   MUST NOT be called with a pollset lock taken
-   if got_read or got_write are 1, also does the become_{readable,writable} as
-   appropriate. */
-static void fd_end_poll(grpc_exec_ctx *exec_ctx, grpc_fd_watcher *rec,
-                        int got_read, int got_write,
-                        grpc_pollset *read_notifier_pollset);
-
-/* Return 1 if this fd is orphaned, 0 otherwise */
-static bool fd_is_orphaned(grpc_fd *fd);
-
-/* Reference counting for fds */
-/*#define GRPC_FD_REF_COUNT_DEBUG*/
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-static void fd_ref(grpc_fd *fd, const char *reason, const char *file, int line);
-static void fd_unref(grpc_fd *fd, const char *reason, const char *file,
-                     int line);
-#define GRPC_FD_REF(fd, reason) fd_ref(fd, reason, __FILE__, __LINE__)
-#define GRPC_FD_UNREF(fd, reason) fd_unref(fd, reason, __FILE__, __LINE__)
-#else
-static void fd_ref(grpc_fd *fd);
-static void fd_unref(grpc_fd *fd);
-#define GRPC_FD_REF(fd, reason) fd_ref(fd)
-#define GRPC_FD_UNREF(fd, reason) fd_unref(fd)
-#endif
-
-static void fd_global_init(void);
-static void fd_global_shutdown(void);
-
-#define CLOSURE_NOT_READY ((grpc_closure *)0)
-#define CLOSURE_READY ((grpc_closure *)1)
-
-/*******************************************************************************
- * pollset declarations
- */
-
-typedef struct grpc_pollset_vtable grpc_pollset_vtable;
-
-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);
-  grpc_error *(*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 */
-static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                           struct grpc_fd *fd);
-
-static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
-                               grpc_pollset_set *pollset_set, grpc_fd *fd);
-
-/* 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 */
-static int 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 pollset_kick, with an extended set of flags (defined above)
-   -- mostly for fd_posix's use. */
-static grpc_error *pollset_kick_ext(grpc_pollset *p,
-                                    grpc_pollset_worker *specific_worker,
-                                    uint32_t flags) GRPC_MUST_USE_RESULT;
-
-/* turn a pollset into a multipoller: platform specific */
-typedef void (*platform_become_multipoller_type)(grpc_exec_ctx *exec_ctx,
-                                                 grpc_pollset *pollset,
-                                                 struct grpc_fd **fds,
-                                                 size_t fd_count);
-static platform_become_multipoller_type platform_become_multipoller;
-
-/* Return 1 if the pollset has active threads in pollset_work (pollset must
- * be locked) */
-static int pollset_has_workers(grpc_pollset *pollset);
-
-static void remove_fd_from_all_epoll_sets(int fd);
-
-/*******************************************************************************
- * pollset_set definitions
- */
-
-struct grpc_pollset_set {
-  gpr_mu mu;
-
-  size_t pollset_count;
-  size_t pollset_capacity;
-  grpc_pollset **pollsets;
-
-  size_t pollset_set_count;
-  size_t pollset_set_capacity;
-  struct grpc_pollset_set **pollset_sets;
-
-  size_t fd_count;
-  size_t fd_capacity;
-  grpc_fd **fds;
-};
-
-/*******************************************************************************
- * fd_posix.c
- */
-
-/* We need to keep a freelist not because of any concerns of malloc performance
- * but instead so that implementations with multiple threads in (for example)
- * epoll_wait deal with the race between pollset removal and incoming poll
- * notifications.
- *
- * The problem is that the poller ultimately holds a reference to this
- * object, so it is very difficult to know when is safe to free it, at least
- * without some expensive synchronization.
- *
- * If we keep the object freelisted, in the worst case losing this race just
- * becomes a spurious read notification on a reused fd.
- */
-/* TODO(klempner): We could use some form of polling generation count to know
- * when these are safe to free. */
-/* TODO(klempner): Consider disabling freelisting if we don't have multiple
- * threads in poll on the same fd */
-/* TODO(klempner): Batch these allocations to reduce fragmentation */
-static grpc_fd *fd_freelist = NULL;
-static gpr_mu fd_freelist_mu;
-
-static void freelist_fd(grpc_fd *fd) {
-  gpr_mu_lock(&fd_freelist_mu);
-  fd->freelist_next = fd_freelist;
-  fd_freelist = fd;
-  grpc_iomgr_unregister_object(&fd->iomgr_object);
-  gpr_mu_unlock(&fd_freelist_mu);
-}
-
-static grpc_fd *alloc_fd(int fd) {
-  grpc_fd *r = NULL;
-  gpr_mu_lock(&fd_freelist_mu);
-  if (fd_freelist != NULL) {
-    r = fd_freelist;
-    fd_freelist = fd_freelist->freelist_next;
-  }
-  gpr_mu_unlock(&fd_freelist_mu);
-  if (r == NULL) {
-    r = gpr_malloc(sizeof(grpc_fd));
-    gpr_mu_init(&r->mu);
-  }
-
-  gpr_mu_lock(&r->mu);
-  gpr_atm_rel_store(&r->refst, 1);
-  r->shutdown = 0;
-  r->read_closure = CLOSURE_NOT_READY;
-  r->write_closure = CLOSURE_NOT_READY;
-  r->fd = fd;
-  r->inactive_watcher_root.next = r->inactive_watcher_root.prev =
-      &r->inactive_watcher_root;
-  r->freelist_next = NULL;
-  r->read_watcher = r->write_watcher = NULL;
-  r->on_done_closure = NULL;
-  r->closed = 0;
-  r->released = 0;
-  r->read_notifier_pollset = NULL;
-  gpr_mu_unlock(&r->mu);
-  return r;
-}
-
-static void destroy(grpc_fd *fd) {
-  gpr_mu_destroy(&fd->mu);
-  gpr_free(fd);
-}
-
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-#define REF_BY(fd, n, reason) ref_by(fd, n, reason, __FILE__, __LINE__)
-#define UNREF_BY(fd, n, reason) unref_by(fd, n, reason, __FILE__, __LINE__)
-static void ref_by(grpc_fd *fd, int n, const char *reason, const char *file,
-                   int line) {
-  gpr_log(GPR_DEBUG, "FD %d %p   ref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n,
-          gpr_atm_no_barrier_load(&fd->refst),
-          gpr_atm_no_barrier_load(&fd->refst) + n, reason, file, line);
-#else
-#define REF_BY(fd, n, reason) ref_by(fd, n)
-#define UNREF_BY(fd, n, reason) unref_by(fd, n)
-static void ref_by(grpc_fd *fd, int n) {
-#endif
-  GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&fd->refst, n) > 0);
-}
-
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-static void unref_by(grpc_fd *fd, int n, const char *reason, const char *file,
-                     int line) {
-  gpr_atm old;
-  gpr_log(GPR_DEBUG, "FD %d %p unref %d %d -> %d [%s; %s:%d]", fd->fd, fd, n,
-          gpr_atm_no_barrier_load(&fd->refst),
-          gpr_atm_no_barrier_load(&fd->refst) - n, reason, file, line);
-#else
-static void unref_by(grpc_fd *fd, int n) {
-  gpr_atm old;
-#endif
-  old = gpr_atm_full_fetch_add(&fd->refst, -n);
-  if (old == n) {
-    freelist_fd(fd);
-  } else {
-    GPR_ASSERT(old > n);
-  }
-}
-
-static void fd_global_init(void) { gpr_mu_init(&fd_freelist_mu); }
-
-static void fd_global_shutdown(void) {
-  gpr_mu_lock(&fd_freelist_mu);
-  gpr_mu_unlock(&fd_freelist_mu);
-  while (fd_freelist != NULL) {
-    grpc_fd *fd = fd_freelist;
-    fd_freelist = fd_freelist->freelist_next;
-    destroy(fd);
-  }
-  gpr_mu_destroy(&fd_freelist_mu);
-}
-
-static grpc_fd *fd_create(int fd, const char *name) {
-  grpc_fd *r = alloc_fd(fd);
-  char *name2;
-  gpr_asprintf(&name2, "%s fd=%d", name, fd);
-  grpc_iomgr_register_object(&r->iomgr_object, name2);
-  gpr_free(name2);
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-  gpr_log(GPR_DEBUG, "FD %d %p create %s", fd, r, name);
-#endif
-  return r;
-}
-
-static bool fd_is_orphaned(grpc_fd *fd) {
-  return (gpr_atm_acq_load(&fd->refst) & 1) == 0;
-}
-
-static grpc_error *pollset_kick_locked(grpc_fd_watcher *watcher) {
-  gpr_mu_lock(&watcher->pollset->mu);
-  GPR_ASSERT(watcher->worker);
-  grpc_error *err = pollset_kick_ext(watcher->pollset, watcher->worker,
-                                     GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP);
-  gpr_mu_unlock(&watcher->pollset->mu);
-  return err;
-}
-
-static void maybe_wake_one_watcher_locked(grpc_fd *fd) {
-  if (fd->inactive_watcher_root.next != &fd->inactive_watcher_root) {
-    pollset_kick_locked(fd->inactive_watcher_root.next);
-  } else if (fd->read_watcher) {
-    pollset_kick_locked(fd->read_watcher);
-  } else if (fd->write_watcher) {
-    pollset_kick_locked(fd->write_watcher);
-  }
-}
-
-static void wake_all_watchers_locked(grpc_fd *fd) {
-  grpc_fd_watcher *watcher;
-  for (watcher = fd->inactive_watcher_root.next;
-       watcher != &fd->inactive_watcher_root; watcher = watcher->next) {
-    pollset_kick_locked(watcher);
-  }
-  if (fd->read_watcher) {
-    pollset_kick_locked(fd->read_watcher);
-  }
-  if (fd->write_watcher && fd->write_watcher != fd->read_watcher) {
-    pollset_kick_locked(fd->write_watcher);
-  }
-}
-
-static int has_watchers(grpc_fd *fd) {
-  return fd->read_watcher != NULL || fd->write_watcher != NULL ||
-         fd->inactive_watcher_root.next != &fd->inactive_watcher_root;
-}
-
-static void close_fd_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  fd->closed = 1;
-  if (!fd->released) {
-    close(fd->fd);
-  } else {
-    remove_fd_from_all_epoll_sets(fd->fd);
-  }
-  grpc_exec_ctx_sched(exec_ctx, fd->on_done_closure, GRPC_ERROR_NONE, NULL);
-}
-
-static int fd_wrapped_fd(grpc_fd *fd) {
-  if (fd->released || fd->closed) {
-    return -1;
-  } else {
-    return fd->fd;
-  }
-}
-
-static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                      grpc_closure *on_done, int *release_fd,
-                      const char *reason) {
-  fd->on_done_closure = on_done;
-  fd->released = release_fd != NULL;
-  if (!fd->released) {
-    shutdown(fd->fd, SHUT_RDWR);
-  } else {
-    *release_fd = fd->fd;
-  }
-  gpr_mu_lock(&fd->mu);
-  REF_BY(fd, 1, reason); /* remove active status, but keep referenced */
-  if (!has_watchers(fd)) {
-    close_fd_locked(exec_ctx, fd);
-  } else {
-    wake_all_watchers_locked(fd);
-  }
-  gpr_mu_unlock(&fd->mu);
-  UNREF_BY(fd, 2, reason); /* drop the reference */
-}
-
-/* increment refcount by two to avoid changing the orphan bit */
-#ifdef GRPC_FD_REF_COUNT_DEBUG
-static void fd_ref(grpc_fd *fd, const char *reason, const char *file,
-                   int line) {
-  ref_by(fd, 2, reason, file, line);
-}
-
-static void fd_unref(grpc_fd *fd, const char *reason, const char *file,
-                     int line) {
-  unref_by(fd, 2, reason, file, line);
-}
-#else
-static void fd_ref(grpc_fd *fd) { ref_by(fd, 2); }
-
-static void fd_unref(grpc_fd *fd) { unref_by(fd, 2); }
-#endif
-
-static grpc_error *fd_shutdown_error(bool shutdown) {
-  if (!shutdown) {
-    return GRPC_ERROR_NONE;
-  } else {
-    return GRPC_ERROR_CREATE("FD shutdown");
-  }
-}
-
-static void notify_on_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                             grpc_closure **st, grpc_closure *closure) {
-  if (fd->shutdown) {
-    grpc_exec_ctx_sched(exec_ctx, closure, GRPC_ERROR_CREATE("FD shutdown"),
-                        NULL);
-  } else if (*st == CLOSURE_NOT_READY) {
-    /* not ready ==> switch to a waiting state by setting the closure */
-    *st = closure;
-  } else if (*st == CLOSURE_READY) {
-    /* already ready ==> queue the closure to run immediately */
-    *st = CLOSURE_NOT_READY;
-    grpc_exec_ctx_sched(exec_ctx, closure, fd_shutdown_error(fd->shutdown),
-                        NULL);
-    maybe_wake_one_watcher_locked(fd);
-  } else {
-    /* upcallptr was set to a different closure.  This is an error! */
-    gpr_log(GPR_ERROR,
-            "User called a notify_on function with a previous callback still "
-            "pending");
-    abort();
-  }
-}
-
-/* returns 1 if state becomes not ready */
-static int set_ready_locked(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                            grpc_closure **st) {
-  if (*st == CLOSURE_READY) {
-    /* duplicate ready ==> ignore */
-    return 0;
-  } else if (*st == CLOSURE_NOT_READY) {
-    /* not ready, and not waiting ==> flag ready */
-    *st = CLOSURE_READY;
-    return 0;
-  } else {
-    /* waiting ==> queue closure */
-    grpc_exec_ctx_sched(exec_ctx, *st, fd_shutdown_error(fd->shutdown), NULL);
-    *st = CLOSURE_NOT_READY;
-    return 1;
-  }
-}
-
-static void set_read_notifier_pollset_locked(
-    grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_pollset *read_notifier_pollset) {
-  fd->read_notifier_pollset = read_notifier_pollset;
-}
-
-static void fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  gpr_mu_lock(&fd->mu);
-  /* only shutdown once */
-  if (!fd->shutdown) {
-    fd->shutdown = 1;
-    /* signal read/write closed to OS so that future operations fail */
-    shutdown(fd->fd, SHUT_RDWR);
-    set_ready_locked(exec_ctx, fd, &fd->read_closure);
-    set_ready_locked(exec_ctx, fd, &fd->write_closure);
-  }
-  gpr_mu_unlock(&fd->mu);
-}
-
-static bool fd_is_shutdown(grpc_fd *fd) {
-  gpr_mu_lock(&fd->mu);
-  bool r = fd->shutdown;
-  gpr_mu_unlock(&fd->mu);
-  return r;
-}
-
-static void fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                              grpc_closure *closure) {
-  gpr_mu_lock(&fd->mu);
-  notify_on_locked(exec_ctx, fd, &fd->read_closure, closure);
-  gpr_mu_unlock(&fd->mu);
-}
-
-static void fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                               grpc_closure *closure) {
-  gpr_mu_lock(&fd->mu);
-  notify_on_locked(exec_ctx, fd, &fd->write_closure, closure);
-  gpr_mu_unlock(&fd->mu);
-}
-
-/* Return the read-notifier pollset */
-static grpc_pollset *fd_get_read_notifier_pollset(grpc_exec_ctx *exec_ctx,
-                                                  grpc_fd *fd) {
-  grpc_pollset *notifier = NULL;
-
-  gpr_mu_lock(&fd->mu);
-  notifier = fd->read_notifier_pollset;
-  gpr_mu_unlock(&fd->mu);
-
-  return notifier;
-}
-
-static uint32_t fd_begin_poll(grpc_fd *fd, grpc_pollset *pollset,
-                              grpc_pollset_worker *worker, uint32_t read_mask,
-                              uint32_t write_mask, grpc_fd_watcher *watcher) {
-  uint32_t mask = 0;
-  grpc_closure *cur;
-  int requested;
-  /* keep track of pollers that have requested our events, in case they change
-   */
-  GRPC_FD_REF(fd, "poll");
-
-  gpr_mu_lock(&fd->mu);
-
-  /* if we are shutdown, then don't add to the watcher set */
-  if (fd->shutdown) {
-    watcher->fd = NULL;
-    watcher->pollset = NULL;
-    watcher->worker = NULL;
-    gpr_mu_unlock(&fd->mu);
-    GRPC_FD_UNREF(fd, "poll");
-    return 0;
-  }
-
-  /* if there is nobody polling for read, but we need to, then start doing so */
-  cur = fd->read_closure;
-  requested = cur != CLOSURE_READY;
-  if (read_mask && fd->read_watcher == NULL && requested) {
-    fd->read_watcher = watcher;
-    mask |= read_mask;
-  }
-  /* if there is nobody polling for write, but we need to, then start doing so
-   */
-  cur = fd->write_closure;
-  requested = cur != CLOSURE_READY;
-  if (write_mask && fd->write_watcher == NULL && requested) {
-    fd->write_watcher = watcher;
-    mask |= write_mask;
-  }
-  /* if not polling, remember this watcher in case we need someone to later */
-  if (mask == 0 && worker != NULL) {
-    watcher->next = &fd->inactive_watcher_root;
-    watcher->prev = watcher->next->prev;
-    watcher->next->prev = watcher->prev->next = watcher;
-  }
-  watcher->pollset = pollset;
-  watcher->worker = worker;
-  watcher->fd = fd;
-  gpr_mu_unlock(&fd->mu);
-
-  return mask;
-}
-
-static void fd_end_poll(grpc_exec_ctx *exec_ctx, grpc_fd_watcher *watcher,
-                        int got_read, int got_write,
-                        grpc_pollset *read_notifier_pollset) {
-  int was_polling = 0;
-  int kick = 0;
-  grpc_fd *fd = watcher->fd;
-
-  if (fd == NULL) {
-    return;
-  }
-
-  gpr_mu_lock(&fd->mu);
-
-  if (watcher == fd->read_watcher) {
-    /* remove read watcher, kick if we still need a read */
-    was_polling = 1;
-    if (!got_read) {
-      kick = 1;
-    }
-    fd->read_watcher = NULL;
-  }
-  if (watcher == fd->write_watcher) {
-    /* remove write watcher, kick if we still need a write */
-    was_polling = 1;
-    if (!got_write) {
-      kick = 1;
-    }
-    fd->write_watcher = NULL;
-  }
-  if (!was_polling && watcher->worker != NULL) {
-    /* remove from inactive list */
-    watcher->next->prev = watcher->prev;
-    watcher->prev->next = watcher->next;
-  }
-  if (got_read) {
-    if (set_ready_locked(exec_ctx, fd, &fd->read_closure)) {
-      kick = 1;
-    }
-
-    if (read_notifier_pollset != NULL) {
-      set_read_notifier_pollset_locked(exec_ctx, fd, read_notifier_pollset);
-    }
-  }
-  if (got_write) {
-    if (set_ready_locked(exec_ctx, fd, &fd->write_closure)) {
-      kick = 1;
-    }
-  }
-  if (kick) {
-    maybe_wake_one_watcher_locked(fd);
-  }
-  if (fd_is_orphaned(fd) && !has_watchers(fd) && !fd->closed) {
-    close_fd_locked(exec_ctx, fd);
-  }
-  gpr_mu_unlock(&fd->mu);
-
-  GRPC_FD_UNREF(fd, "poll");
-}
-
-static grpc_workqueue *fd_get_workqueue(grpc_fd *fd) { return NULL; }
-
-/*******************************************************************************
- * pollset_posix.c
- */
-
-GPR_TLS_DECL(g_current_thread_poller);
-GPR_TLS_DECL(g_current_thread_worker);
-
-/** The alarm system needs to be able to wakeup 'some poller' sometimes
- *  (specifically when a new alarm needs to be triggered earlier than the next
- *  alarm 'epoch').
- *  This wakeup_fd gives us something to alert on when such a case occurs. */
-grpc_wakeup_fd grpc_global_wakeup_fd;
-
-static void remove_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
-  worker->prev->next = worker->next;
-  worker->next->prev = worker->prev;
-}
-
-static int pollset_has_workers(grpc_pollset *p) {
-  return p->root_worker.next != &p->root_worker;
-}
-
-static grpc_pollset_worker *pop_front_worker(grpc_pollset *p) {
-  if (pollset_has_workers(p)) {
-    grpc_pollset_worker *w = p->root_worker.next;
-    remove_worker(p, w);
-    return w;
-  } else {
-    return NULL;
-  }
-}
-
-static void push_back_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
-  worker->next = &p->root_worker;
-  worker->prev = worker->next->prev;
-  worker->prev->next = worker->next->prev = worker;
-}
-
-static void push_front_worker(grpc_pollset *p, grpc_pollset_worker *worker) {
-  worker->prev = &p->root_worker;
-  worker->next = worker->prev->next;
-  worker->prev->next = worker->next->prev = worker;
-}
-
-static void kick_append_error(grpc_error **composite, grpc_error *error) {
-  if (error == GRPC_ERROR_NONE) return;
-  if (*composite == GRPC_ERROR_NONE) {
-    *composite = GRPC_ERROR_CREATE("Kick Failure");
-  }
-  *composite = grpc_error_add_child(*composite, error);
-}
-
-static grpc_error *pollset_kick_ext(grpc_pollset *p,
-                                    grpc_pollset_worker *specific_worker,
-                                    uint32_t flags) {
-  GPR_TIMER_BEGIN("pollset_kick_ext", 0);
-  grpc_error *error = GRPC_ERROR_NONE;
-
-  /* pollset->mu already held */
-  if (specific_worker != NULL) {
-    if (specific_worker == GRPC_POLLSET_KICK_BROADCAST) {
-      GPR_TIMER_BEGIN("pollset_kick_ext.broadcast", 0);
-      GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0);
-      for (specific_worker = p->root_worker.next;
-           specific_worker != &p->root_worker;
-           specific_worker = specific_worker->next) {
-        kick_append_error(
-            &error, grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd));
-      }
-      p->kicked_without_pollers = true;
-      GPR_TIMER_END("pollset_kick_ext.broadcast", 0);
-    } else if (gpr_tls_get(&g_current_thread_worker) !=
-               (intptr_t)specific_worker) {
-      GPR_TIMER_MARK("different_thread_worker", 0);
-      if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) {
-        specific_worker->reevaluate_polling_on_wakeup = true;
-      }
-      specific_worker->kicked_specifically = true;
-      kick_append_error(&error,
-                        grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd));
-    } else if ((flags & GRPC_POLLSET_CAN_KICK_SELF) != 0) {
-      GPR_TIMER_MARK("kick_yoself", 0);
-      if ((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) != 0) {
-        specific_worker->reevaluate_polling_on_wakeup = true;
-      }
-      specific_worker->kicked_specifically = true;
-      kick_append_error(&error,
-                        grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd));
-    }
-  } else if (gpr_tls_get(&g_current_thread_poller) != (intptr_t)p) {
-    GPR_ASSERT((flags & GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) == 0);
-    GPR_TIMER_MARK("kick_anonymous", 0);
-    specific_worker = pop_front_worker(p);
-    if (specific_worker != NULL) {
-      if (gpr_tls_get(&g_current_thread_worker) == (intptr_t)specific_worker) {
-        GPR_TIMER_MARK("kick_anonymous_not_self", 0);
-        push_back_worker(p, specific_worker);
-        specific_worker = pop_front_worker(p);
-        if ((flags & GRPC_POLLSET_CAN_KICK_SELF) == 0 &&
-            gpr_tls_get(&g_current_thread_worker) ==
-                (intptr_t)specific_worker) {
-          push_back_worker(p, specific_worker);
-          specific_worker = NULL;
-        }
-      }
-      if (specific_worker != NULL) {
-        GPR_TIMER_MARK("finally_kick", 0);
-        push_back_worker(p, specific_worker);
-        kick_append_error(
-            &error, grpc_wakeup_fd_wakeup(&specific_worker->wakeup_fd->fd));
-      }
-    } else {
-      GPR_TIMER_MARK("kicked_no_pollers", 0);
-      p->kicked_without_pollers = true;
-    }
-  }
-
-  GPR_TIMER_END("pollset_kick_ext", 0);
-  return error;
-}
-
-static grpc_error *pollset_kick(grpc_pollset *p,
-                                grpc_pollset_worker *specific_worker) {
-  return pollset_kick_ext(p, specific_worker, 0);
-}
-
-/* global state management */
-
-static grpc_error *pollset_global_init(void) {
-  gpr_tls_init(&g_current_thread_poller);
-  gpr_tls_init(&g_current_thread_worker);
-  return grpc_wakeup_fd_init(&grpc_global_wakeup_fd);
-}
-
-static void pollset_global_shutdown(void) {
-  grpc_wakeup_fd_destroy(&grpc_global_wakeup_fd);
-  gpr_tls_destroy(&g_current_thread_poller);
-  gpr_tls_destroy(&g_current_thread_worker);
-}
-
-static grpc_error *kick_poller(void) {
-  return grpc_wakeup_fd_wakeup(&grpc_global_wakeup_fd);
-}
-
-/* main interface */
-
-static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null);
-
-static void pollset_init(grpc_pollset *pollset, gpr_mu **mu) {
-  gpr_mu_init(&pollset->mu);
-  *mu = &pollset->mu;
-  pollset->root_worker.next = pollset->root_worker.prev = &pollset->root_worker;
-  pollset->in_flight_cbs = 0;
-  pollset->shutting_down = 0;
-  pollset->called_shutdown = 0;
-  pollset->kicked_without_pollers = 0;
-  pollset->idle_jobs.head = pollset->idle_jobs.tail = NULL;
-  pollset->local_wakeup_cache = NULL;
-  pollset->kicked_without_pollers = 0;
-  become_basic_pollset(pollset, NULL);
-}
-
-static void pollset_destroy(grpc_pollset *pollset) {
-  GPR_ASSERT(pollset->in_flight_cbs == 0);
-  GPR_ASSERT(!pollset_has_workers(pollset));
-  GPR_ASSERT(pollset->idle_jobs.head == pollset->idle_jobs.tail);
-  pollset->vtable->destroy(pollset);
-  while (pollset->local_wakeup_cache) {
-    grpc_cached_wakeup_fd *next = pollset->local_wakeup_cache->next;
-    grpc_wakeup_fd_destroy(&pollset->local_wakeup_cache->fd);
-    gpr_free(pollset->local_wakeup_cache);
-    pollset->local_wakeup_cache = next;
-  }
-  gpr_mu_destroy(&pollset->mu);
-}
-
-static void pollset_reset(grpc_pollset *pollset) {
-  GPR_ASSERT(pollset->shutting_down);
-  GPR_ASSERT(pollset->in_flight_cbs == 0);
-  GPR_ASSERT(!pollset_has_workers(pollset));
-  GPR_ASSERT(pollset->idle_jobs.head == pollset->idle_jobs.tail);
-  pollset->vtable->destroy(pollset);
-  pollset->shutting_down = 0;
-  pollset->called_shutdown = 0;
-  pollset->kicked_without_pollers = 0;
-  become_basic_pollset(pollset, NULL);
-}
-
-static void pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                           grpc_fd *fd) {
-  gpr_mu_lock(&pollset->mu);
-  pollset->vtable->add_fd(exec_ctx, pollset, fd, 1);
-/* the following (enabled only in debug) will reacquire and then release
-   our lock - meaning that if the unlocking flag passed to add_fd above is
-   not respected, the code will deadlock (in a way that we have a chance of
-   debugging) */
-#ifndef NDEBUG
-  gpr_mu_lock(&pollset->mu);
-  gpr_mu_unlock(&pollset->mu);
-#endif
-}
-
-static void finish_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset) {
-  GPR_ASSERT(grpc_closure_list_empty(pollset->idle_jobs));
-  pollset->vtable->finish_shutdown(pollset);
-  grpc_exec_ctx_sched(exec_ctx, pollset->shutdown_done, GRPC_ERROR_NONE, NULL);
-}
-
-static void work_combine_error(grpc_error **composite, grpc_error *error) {
-  if (error == GRPC_ERROR_NONE) return;
-  if (*composite == GRPC_ERROR_NONE) {
-    *composite = GRPC_ERROR_CREATE("pollset_work");
-  }
-  *composite = grpc_error_add_child(*composite, error);
-}
-
-static grpc_error *pollset_work(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                                grpc_pollset_worker **worker_hdl,
-                                gpr_timespec now, gpr_timespec deadline) {
-  grpc_pollset_worker worker;
-  *worker_hdl = &worker;
-  grpc_error *error = GRPC_ERROR_NONE;
-
-  /* pollset->mu already held */
-  int added_worker = 0;
-  int locked = 1;
-  int queued_work = 0;
-  int keep_polling = 0;
-  GPR_TIMER_BEGIN("pollset_work", 0);
-  /* this must happen before we (potentially) drop pollset->mu */
-  worker.next = worker.prev = NULL;
-  worker.reevaluate_polling_on_wakeup = 0;
-  if (pollset->local_wakeup_cache != NULL) {
-    worker.wakeup_fd = pollset->local_wakeup_cache;
-    pollset->local_wakeup_cache = worker.wakeup_fd->next;
-  } else {
-    worker.wakeup_fd = gpr_malloc(sizeof(*worker.wakeup_fd));
-    error = grpc_wakeup_fd_init(&worker.wakeup_fd->fd);
-    if (error != GRPC_ERROR_NONE) {
-      return error;
-    }
-  }
-  worker.kicked_specifically = 0;
-  /* If there's work waiting for the pollset to be idle, and the
-     pollset is idle, then do that work */
-  if (!pollset_has_workers(pollset) &&
-      !grpc_closure_list_empty(pollset->idle_jobs)) {
-    GPR_TIMER_MARK("pollset_work.idle_jobs", 0);
-    grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
-    goto done;
-  }
-  /* If we're shutting down then we don't execute any extended work */
-  if (pollset->shutting_down) {
-    GPR_TIMER_MARK("pollset_work.shutting_down", 0);
-    goto done;
-  }
-  /* Give do_promote priority so we don't starve it out */
-  if (pollset->in_flight_cbs) {
-    GPR_TIMER_MARK("pollset_work.in_flight_cbs", 0);
-    gpr_mu_unlock(&pollset->mu);
-    locked = 0;
-    goto done;
-  }
-  /* Start polling, and keep doing so while we're being asked to
-     re-evaluate our pollers (this allows poll() based pollers to
-     ensure they don't miss wakeups) */
-  keep_polling = 1;
-  while (keep_polling) {
-    keep_polling = 0;
-    if (!pollset->kicked_without_pollers) {
-      if (!added_worker) {
-        push_front_worker(pollset, &worker);
-        added_worker = 1;
-        gpr_tls_set(&g_current_thread_worker, (intptr_t)&worker);
-      }
-      gpr_tls_set(&g_current_thread_poller, (intptr_t)pollset);
-      GPR_TIMER_BEGIN("maybe_work_and_unlock", 0);
-      work_combine_error(&error,
-                         pollset->vtable->maybe_work_and_unlock(
-                             exec_ctx, pollset, &worker, deadline, now));
-      GPR_TIMER_END("maybe_work_and_unlock", 0);
-      locked = 0;
-      gpr_tls_set(&g_current_thread_poller, 0);
-    } else {
-      GPR_TIMER_MARK("pollset_work.kicked_without_pollers", 0);
-      pollset->kicked_without_pollers = 0;
-    }
-  /* Finished execution - start cleaning up.
-     Note that we may arrive here from outside the enclosing while() loop.
-     In that case we won't loop though as we haven't added worker to the
-     worker list, which means nobody could ask us to re-evaluate polling). */
-  done:
-    if (!locked) {
-      queued_work |= grpc_exec_ctx_flush(exec_ctx);
-      gpr_mu_lock(&pollset->mu);
-      locked = 1;
-    }
-    /* If we're forced to re-evaluate polling (via pollset_kick with
-       GRPC_POLLSET_REEVALUATE_POLLING_ON_WAKEUP) then we land here and force
-       a loop */
-    if (worker.reevaluate_polling_on_wakeup) {
-      worker.reevaluate_polling_on_wakeup = 0;
-      pollset->kicked_without_pollers = 0;
-      if (queued_work || worker.kicked_specifically) {
-        /* If there's queued work on the list, then set the deadline to be
-           immediate so we get back out of the polling loop quickly */
-        deadline = gpr_inf_past(GPR_CLOCK_MONOTONIC);
-      }
-      keep_polling = 1;
-    }
-  }
-  if (added_worker) {
-    remove_worker(pollset, &worker);
-    gpr_tls_set(&g_current_thread_worker, 0);
-  }
-  /* release wakeup fd to the local pool */
-  worker.wakeup_fd->next = pollset->local_wakeup_cache;
-  pollset->local_wakeup_cache = worker.wakeup_fd;
-  /* check shutdown conditions */
-  if (pollset->shutting_down) {
-    if (pollset_has_workers(pollset)) {
-      pollset_kick(pollset, NULL);
-    } else if (!pollset->called_shutdown && pollset->in_flight_cbs == 0) {
-      pollset->called_shutdown = 1;
-      gpr_mu_unlock(&pollset->mu);
-      finish_shutdown(exec_ctx, pollset);
-      grpc_exec_ctx_flush(exec_ctx);
-      /* Continuing to access pollset here is safe -- it is the caller's
-       * responsibility to not destroy when it has outstanding calls to
-       * pollset_work.
-       * TODO(dklempner): Can we refactor the shutdown logic to avoid this? */
-      gpr_mu_lock(&pollset->mu);
-    } else if (!grpc_closure_list_empty(pollset->idle_jobs)) {
-      grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
-      gpr_mu_unlock(&pollset->mu);
-      grpc_exec_ctx_flush(exec_ctx);
-      gpr_mu_lock(&pollset->mu);
-    }
-  }
-  *worker_hdl = NULL;
-  GPR_TIMER_END("pollset_work", 0);
-  return error;
-}
-
-static void pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                             grpc_closure *closure) {
-  GPR_ASSERT(!pollset->shutting_down);
-  pollset->shutting_down = 1;
-  pollset->shutdown_done = closure;
-  pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST);
-  if (!pollset_has_workers(pollset)) {
-    grpc_exec_ctx_enqueue_list(exec_ctx, &pollset->idle_jobs, NULL);
-  }
-  if (!pollset->called_shutdown && pollset->in_flight_cbs == 0 &&
-      !pollset_has_workers(pollset)) {
-    pollset->called_shutdown = 1;
-    finish_shutdown(exec_ctx, pollset);
-  }
-}
-
-static int poll_deadline_to_millis_timeout(gpr_timespec deadline,
-                                           gpr_timespec now) {
-  gpr_timespec timeout;
-  static const int64_t max_spin_polling_us = 10;
-  if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
-    return -1;
-  }
-  if (gpr_time_cmp(deadline, gpr_time_add(now, gpr_time_from_micros(
-                                                   max_spin_polling_us,
-                                                   GPR_TIMESPAN))) <= 0) {
-    return 0;
-  }
-  timeout = gpr_time_sub(deadline, now);
-  return gpr_time_to_millis(gpr_time_add(
-      timeout, gpr_time_from_nanos(GPR_NS_PER_MS - 1, GPR_TIMESPAN)));
-}
-
-/*
- * basic_pollset - a vtable that provides polling for zero or one file
- *                 descriptor via poll()
- */
-
-typedef struct grpc_unary_promote_args {
-  const grpc_pollset_vtable *original_vtable;
-  grpc_pollset *pollset;
-  grpc_fd *fd;
-  grpc_closure promotion_closure;
-} grpc_unary_promote_args;
-
-static void basic_do_promote(grpc_exec_ctx *exec_ctx, void *args,
-                             grpc_error *error) {
-  grpc_unary_promote_args *up_args = args;
-  const grpc_pollset_vtable *original_vtable = up_args->original_vtable;
-  grpc_pollset *pollset = up_args->pollset;
-  grpc_fd *fd = up_args->fd;
-
-  /*
-   * This is quite tricky. There are a number of cases to keep in mind here:
-   * 1. fd may have been orphaned
-   * 2. The pollset may no longer be a unary poller (and we can't let case #1
-   * leak to other pollset types!)
-   * 3. pollset's fd (which may have changed) may have been orphaned
-   * 4. The pollset may be shutting down.
-   */
-
-  gpr_mu_lock(&pollset->mu);
-  /* First we need to ensure that nobody is polling concurrently */
-  GPR_ASSERT(!pollset_has_workers(pollset));
-
-  gpr_free(up_args);
-  /* At this point the pollset may no longer be a unary poller. In that case
-   * we should just call the right add function and be done. */
-  /* TODO(klempner): If we're not careful this could cause infinite recursion.
-   * That's not a problem for now because empty_pollset has a trivial poller
-   * and we don't have any mechanism to unbecome multipoller. */
-  pollset->in_flight_cbs--;
-  if (pollset->shutting_down) {
-    /* We don't care about this pollset anymore. */
-    if (pollset->in_flight_cbs == 0 && !pollset->called_shutdown) {
-      pollset->called_shutdown = 1;
-      finish_shutdown(exec_ctx, pollset);
-    }
-  } else if (fd_is_orphaned(fd)) {
-    /* Don't try to add it to anything, we'll drop our ref on it below */
-  } else if (pollset->vtable != original_vtable) {
-    pollset->vtable->add_fd(exec_ctx, pollset, fd, 0);
-  } else if (fd != pollset->data.ptr) {
-    grpc_fd *fds[2];
-    fds[0] = pollset->data.ptr;
-    fds[1] = fd;
-
-    if (fds[0] && !fd_is_orphaned(fds[0])) {
-      platform_become_multipoller(exec_ctx, pollset, fds, GPR_ARRAY_SIZE(fds));
-      GRPC_FD_UNREF(fds[0], "basicpoll");
-    } else {
-      /* old fd is orphaned and we haven't cleaned it up until now, so remain a
-       * unary poller */
-      /* Note that it is possible that fds[1] is also orphaned at this point.
-       * That's okay, we'll correct it at the next add or poll. */
-      if (fds[0]) GRPC_FD_UNREF(fds[0], "basicpoll");
-      pollset->data.ptr = fd;
-      GRPC_FD_REF(fd, "basicpoll");
-    }
-  }
-
-  gpr_mu_unlock(&pollset->mu);
-
-  /* Matching ref in basic_pollset_add_fd */
-  GRPC_FD_UNREF(fd, "basicpoll_add");
-}
-
-static void basic_pollset_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                                 grpc_fd *fd, int and_unlock_pollset) {
-  grpc_unary_promote_args *up_args;
-  GPR_ASSERT(fd);
-  if (fd == pollset->data.ptr) goto exit;
-
-  if (!pollset_has_workers(pollset)) {
-    /* Fast path -- no in flight cbs */
-    /* TODO(klempner): Comment this out and fix any test failures or establish
-     * they are due to timing issues */
-    grpc_fd *fds[2];
-    fds[0] = pollset->data.ptr;
-    fds[1] = fd;
-
-    if (fds[0] == NULL) {
-      pollset->data.ptr = fd;
-      GRPC_FD_REF(fd, "basicpoll");
-    } else if (!fd_is_orphaned(fds[0])) {
-      platform_become_multipoller(exec_ctx, pollset, fds, GPR_ARRAY_SIZE(fds));
-      GRPC_FD_UNREF(fds[0], "basicpoll");
-    } else {
-      /* old fd is orphaned and we haven't cleaned it up until now, so remain a
-       * unary poller */
-      GRPC_FD_UNREF(fds[0], "basicpoll");
-      pollset->data.ptr = fd;
-      GRPC_FD_REF(fd, "basicpoll");
-    }
-    goto exit;
-  }
-
-  /* Now we need to promote. This needs to happen when we're not polling. Since
-   * this may be called from poll, the wait needs to happen asynchronously. */
-  GRPC_FD_REF(fd, "basicpoll_add");
-  pollset->in_flight_cbs++;
-  up_args = gpr_malloc(sizeof(*up_args));
-  up_args->fd = fd;
-  up_args->original_vtable = pollset->vtable;
-  up_args->pollset = pollset;
-  up_args->promotion_closure.cb = basic_do_promote;
-  up_args->promotion_closure.cb_arg = up_args;
-
-  grpc_closure_list_append(&pollset->idle_jobs, &up_args->promotion_closure,
-                           GRPC_ERROR_NONE);
-  pollset_kick(pollset, GRPC_POLLSET_KICK_BROADCAST);
-
-exit:
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-  }
-}
-
-static grpc_error *basic_pollset_maybe_work_and_unlock(
-    grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker,
-    gpr_timespec deadline, gpr_timespec now) {
-#define POLLOUT_CHECK (POLLOUT | POLLHUP | POLLERR)
-#define POLLIN_CHECK (POLLIN | POLLHUP | POLLERR)
-
-  struct pollfd pfd[3];
-  grpc_fd *fd;
-  grpc_fd_watcher fd_watcher;
-  int timeout;
-  int r;
-  nfds_t nfds;
-  grpc_error *error = GRPC_ERROR_NONE;
-
-  fd = pollset->data.ptr;
-  if (fd && fd_is_orphaned(fd)) {
-    GRPC_FD_UNREF(fd, "basicpoll");
-    fd = pollset->data.ptr = NULL;
-  }
-  timeout = poll_deadline_to_millis_timeout(deadline, now);
-  pfd[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd);
-  pfd[0].events = POLLIN;
-  pfd[0].revents = 0;
-  pfd[1].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
-  pfd[1].events = POLLIN;
-  pfd[1].revents = 0;
-  nfds = 2;
-  if (fd) {
-    pfd[2].fd = fd->fd;
-    pfd[2].revents = 0;
-    GRPC_FD_REF(fd, "basicpoll_begin");
-    gpr_mu_unlock(&pollset->mu);
-    pfd[2].events =
-        (short)fd_begin_poll(fd, pollset, worker, POLLIN, POLLOUT, &fd_watcher);
-    if (pfd[2].events != 0) {
-      nfds++;
-    }
-  } else {
-    gpr_mu_unlock(&pollset->mu);
-  }
-
-  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
-     even going into the blocking annotation if possible */
-  /* poll fd count (argument 2) is shortened by one if we have no events
-     to poll on - such that it only includes the kicker */
-  GPR_TIMER_BEGIN("poll", 0);
-  GRPC_SCHEDULING_START_BLOCKING_REGION;
-  r = grpc_poll_function(pfd, nfds, timeout);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
-  GPR_TIMER_END("poll", 0);
-
-  if (r < 0) {
-    if (errno != EINTR) {
-      work_combine_error(&error, GRPC_OS_ERROR(errno, "poll"));
-    }
-    if (fd) {
-      fd_end_poll(exec_ctx, &fd_watcher, 0, 0, NULL);
-    }
-  } else if (r == 0) {
-    if (fd) {
-      fd_end_poll(exec_ctx, &fd_watcher, 0, 0, NULL);
-    }
-  } else {
-    if (pfd[0].revents & POLLIN_CHECK) {
-      work_combine_error(&error,
-                         grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd));
-    }
-    if (pfd[1].revents & POLLIN_CHECK) {
-      work_combine_error(&error,
-                         grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd));
-    }
-    if (nfds > 2) {
-      fd_end_poll(exec_ctx, &fd_watcher, pfd[2].revents & POLLIN_CHECK,
-                  pfd[2].revents & POLLOUT_CHECK, pollset);
-    } else if (fd) {
-      fd_end_poll(exec_ctx, &fd_watcher, 0, 0, NULL);
-    }
-  }
-
-  if (fd) {
-    GRPC_FD_UNREF(fd, "basicpoll_begin");
-  }
-
-  return error;
-}
-
-static void basic_pollset_destroy(grpc_pollset *pollset) {
-  if (pollset->data.ptr != NULL) {
-    GRPC_FD_UNREF(pollset->data.ptr, "basicpoll");
-    pollset->data.ptr = NULL;
-  }
-}
-
-static const grpc_pollset_vtable basic_pollset = {
-    basic_pollset_add_fd, basic_pollset_maybe_work_and_unlock,
-    basic_pollset_destroy, basic_pollset_destroy};
-
-static void become_basic_pollset(grpc_pollset *pollset, grpc_fd *fd_or_null) {
-  pollset->vtable = &basic_pollset;
-  pollset->data.ptr = fd_or_null;
-  if (fd_or_null != NULL) {
-    GRPC_FD_REF(fd_or_null, "basicpoll");
-  }
-}
-
-/*******************************************************************************
- * pollset_multipoller_with_poll_posix.c
- */
-
-#ifndef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
-
-typedef struct {
-  /* all polled fds */
-  size_t fd_count;
-  size_t fd_capacity;
-  grpc_fd **fds;
-  /* fds that have been removed from the pollset explicitly */
-  size_t del_count;
-  size_t del_capacity;
-  grpc_fd **dels;
-} poll_hdr;
-
-static void multipoll_with_poll_pollset_add_fd(grpc_exec_ctx *exec_ctx,
-                                               grpc_pollset *pollset,
-                                               grpc_fd *fd,
-                                               int and_unlock_pollset) {
-  size_t i;
-  poll_hdr *h = pollset->data.ptr;
-  /* TODO(ctiller): this is O(num_fds^2); maybe switch to a hash set here */
-  for (i = 0; i < h->fd_count; i++) {
-    if (h->fds[i] == fd) goto exit;
-  }
-  if (h->fd_count == h->fd_capacity) {
-    h->fd_capacity = GPR_MAX(h->fd_capacity + 8, h->fd_count * 3 / 2);
-    h->fds = gpr_realloc(h->fds, sizeof(grpc_fd *) * h->fd_capacity);
-  }
-  h->fds[h->fd_count++] = fd;
-  GRPC_FD_REF(fd, "multipoller");
-exit:
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-  }
-}
-
-static grpc_error *multipoll_with_poll_pollset_maybe_work_and_unlock(
-    grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker,
-    gpr_timespec deadline, gpr_timespec now) {
-#define POLLOUT_CHECK (POLLOUT | POLLHUP | POLLERR)
-#define POLLIN_CHECK (POLLIN | POLLHUP | POLLERR)
-
-  int timeout;
-  int r;
-  size_t i, j, fd_count;
-  nfds_t pfd_count;
-  poll_hdr *h;
-  /* TODO(ctiller): inline some elements to avoid an allocation */
-  grpc_fd_watcher *watchers;
-  struct pollfd *pfds;
-  grpc_error *error = GRPC_ERROR_NONE;
-
-  h = pollset->data.ptr;
-  timeout = poll_deadline_to_millis_timeout(deadline, now);
-  /* TODO(ctiller): perform just one malloc here if we exceed the inline case */
-  pfds = gpr_malloc(sizeof(*pfds) * (h->fd_count + 2));
-  watchers = gpr_malloc(sizeof(*watchers) * (h->fd_count + 2));
-  fd_count = 0;
-  pfd_count = 2;
-  pfds[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd);
-  pfds[0].events = POLLIN;
-  pfds[0].revents = 0;
-  pfds[1].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
-  pfds[1].events = POLLIN;
-  pfds[1].revents = 0;
-  for (i = 0; i < h->fd_count; i++) {
-    int remove = fd_is_orphaned(h->fds[i]);
-    for (j = 0; !remove && j < h->del_count; j++) {
-      if (h->fds[i] == h->dels[j]) remove = 1;
-    }
-    if (remove) {
-      GRPC_FD_UNREF(h->fds[i], "multipoller");
-    } else {
-      h->fds[fd_count++] = h->fds[i];
-      watchers[pfd_count].fd = h->fds[i];
-      GRPC_FD_REF(watchers[pfd_count].fd, "multipoller_start");
-      pfds[pfd_count].fd = h->fds[i]->fd;
-      pfds[pfd_count].revents = 0;
-      pfd_count++;
-    }
-  }
-  for (j = 0; j < h->del_count; j++) {
-    GRPC_FD_UNREF(h->dels[j], "multipoller_del");
-  }
-  h->del_count = 0;
-  h->fd_count = fd_count;
-  gpr_mu_unlock(&pollset->mu);
-
-  for (i = 2; i < pfd_count; i++) {
-    grpc_fd *fd = watchers[i].fd;
-    pfds[i].events = (short)fd_begin_poll(fd, pollset, worker, POLLIN, POLLOUT,
-                                          &watchers[i]);
-    GRPC_FD_UNREF(fd, "multipoller_start");
-  }
-
-  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
-     even going into the blocking annotation if possible */
-  GRPC_SCHEDULING_START_BLOCKING_REGION;
-  r = grpc_poll_function(pfds, pfd_count, timeout);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
-
-  if (r < 0) {
-    if (errno != EINTR) {
-      work_combine_error(&error, GRPC_OS_ERROR(errno, "poll"));
-    }
-    for (i = 2; i < pfd_count; i++) {
-      fd_end_poll(exec_ctx, &watchers[i], 0, 0, NULL);
-    }
-  } else if (r == 0) {
-    for (i = 2; i < pfd_count; i++) {
-      fd_end_poll(exec_ctx, &watchers[i], 0, 0, NULL);
-    }
-  } else {
-    if (pfds[0].revents & POLLIN_CHECK) {
-      work_combine_error(&error,
-                         grpc_wakeup_fd_consume_wakeup(&grpc_global_wakeup_fd));
-    }
-    if (pfds[1].revents & POLLIN_CHECK) {
-      work_combine_error(&error,
-                         grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd));
-    }
-    for (i = 2; i < pfd_count; i++) {
-      if (watchers[i].fd == NULL) {
-        fd_end_poll(exec_ctx, &watchers[i], 0, 0, NULL);
-        continue;
-      }
-      fd_end_poll(exec_ctx, &watchers[i], pfds[i].revents & POLLIN_CHECK,
-                  pfds[i].revents & POLLOUT_CHECK, pollset);
-    }
-  }
-
-  gpr_free(pfds);
-  gpr_free(watchers);
-
-  return error;
-}
-
-static void multipoll_with_poll_pollset_finish_shutdown(grpc_pollset *pollset) {
-  size_t i;
-  poll_hdr *h = pollset->data.ptr;
-  for (i = 0; i < h->fd_count; i++) {
-    GRPC_FD_UNREF(h->fds[i], "multipoller");
-  }
-  for (i = 0; i < h->del_count; i++) {
-    GRPC_FD_UNREF(h->dels[i], "multipoller_del");
-  }
-  h->fd_count = 0;
-  h->del_count = 0;
-}
-
-static void multipoll_with_poll_pollset_destroy(grpc_pollset *pollset) {
-  poll_hdr *h = pollset->data.ptr;
-  multipoll_with_poll_pollset_finish_shutdown(pollset);
-  gpr_free(h->fds);
-  gpr_free(h->dels);
-  gpr_free(h);
-}
-
-static const grpc_pollset_vtable multipoll_with_poll_pollset = {
-    multipoll_with_poll_pollset_add_fd,
-    multipoll_with_poll_pollset_maybe_work_and_unlock,
-    multipoll_with_poll_pollset_finish_shutdown,
-    multipoll_with_poll_pollset_destroy};
-
-static void poll_become_multipoller(grpc_exec_ctx *exec_ctx,
-                                    grpc_pollset *pollset, grpc_fd **fds,
-                                    size_t nfds) {
-  size_t i;
-  poll_hdr *h = gpr_malloc(sizeof(poll_hdr));
-  pollset->vtable = &multipoll_with_poll_pollset;
-  pollset->data.ptr = h;
-  h->fd_count = nfds;
-  h->fd_capacity = nfds;
-  h->fds = gpr_malloc(nfds * sizeof(grpc_fd *));
-  h->del_count = 0;
-  h->del_capacity = 0;
-  h->dels = NULL;
-  for (i = 0; i < nfds; i++) {
-    h->fds[i] = fds[i];
-    GRPC_FD_REF(fds[i], "multipoller");
-  }
-}
-
-#endif /* !GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
-
-/*******************************************************************************
- * pollset_multipoller_with_epoll_posix.c
- */
-
-#ifdef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
-
-#include <errno.h>
-#include <poll.h>
-#include <string.h>
-#include <sys/epoll.h>
-#include <unistd.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-#include <grpc/support/useful.h>
-
-#include "src/core/lib/iomgr/ev_posix.h"
-#include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/support/block_annotate.h"
-
-static void set_ready(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure **st,
-                      grpc_pollset *read_notifier_pollset) {
-  /* only one set_ready can be active at once (but there may be a racing
-     notify_on) */
-  gpr_mu_lock(&fd->mu);
-  set_ready_locked(exec_ctx, fd, st);
-
-  /* A non-NULL read_notifier_pollset means that the fd is readable. */
-  if (read_notifier_pollset != NULL) {
-    /* Note: Since the fd might be a part of multiple pollsets, this might be
-     * called multiple times (for each time the fd becomes readable) and it is
-     * okay to set the fd's read-notifier pollset to anyone of these pollsets */
-    set_read_notifier_pollset_locked(exec_ctx, fd, read_notifier_pollset);
-  }
-
-  gpr_mu_unlock(&fd->mu);
-}
-
-static void fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
-                               grpc_pollset *notifier_pollset) {
-  set_ready(exec_ctx, fd, &fd->read_closure, notifier_pollset);
-}
-
-static void fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd) {
-  set_ready(exec_ctx, fd, &fd->write_closure, NULL);
-}
-
-struct epoll_fd_list {
-  int *epoll_fds;
-  size_t count;
-  size_t capacity;
-};
-
-static struct epoll_fd_list epoll_fd_global_list;
-static gpr_once init_epoll_fd_list_mu = GPR_ONCE_INIT;
-static gpr_mu epoll_fd_list_mu;
-
-static void init_mu(void) { gpr_mu_init(&epoll_fd_list_mu); }
-
-static void add_epoll_fd_to_global_list(int epoll_fd) {
-  gpr_once_init(&init_epoll_fd_list_mu, init_mu);
-
-  gpr_mu_lock(&epoll_fd_list_mu);
-  if (epoll_fd_global_list.count == epoll_fd_global_list.capacity) {
-    epoll_fd_global_list.capacity =
-        GPR_MAX((size_t)8, epoll_fd_global_list.capacity * 2);
-    epoll_fd_global_list.epoll_fds =
-        gpr_realloc(epoll_fd_global_list.epoll_fds,
-                    epoll_fd_global_list.capacity * sizeof(int));
-  }
-  epoll_fd_global_list.epoll_fds[epoll_fd_global_list.count++] = epoll_fd;
-  gpr_mu_unlock(&epoll_fd_list_mu);
-}
-
-static void remove_epoll_fd_from_global_list(int epoll_fd) {
-  gpr_mu_lock(&epoll_fd_list_mu);
-  GPR_ASSERT(epoll_fd_global_list.count > 0);
-  for (size_t i = 0; i < epoll_fd_global_list.count; i++) {
-    if (epoll_fd == epoll_fd_global_list.epoll_fds[i]) {
-      epoll_fd_global_list.epoll_fds[i] =
-          epoll_fd_global_list.epoll_fds[--(epoll_fd_global_list.count)];
-      break;
-    }
-  }
-  gpr_mu_unlock(&epoll_fd_list_mu);
-}
-
-static void remove_fd_from_all_epoll_sets(int fd) {
-  int err;
-  gpr_once_init(&init_epoll_fd_list_mu, init_mu);
-  gpr_mu_lock(&epoll_fd_list_mu);
-  if (epoll_fd_global_list.count == 0) {
-    gpr_mu_unlock(&epoll_fd_list_mu);
-    return;
-  }
-  for (size_t i = 0; i < epoll_fd_global_list.count; i++) {
-    err = epoll_ctl(epoll_fd_global_list.epoll_fds[i], EPOLL_CTL_DEL, fd, NULL);
-    if (err < 0 && errno != ENOENT) {
-      gpr_log(GPR_ERROR, "epoll_ctl del for %d failed: %s", fd,
-              strerror(errno));
-    }
-  }
-  gpr_mu_unlock(&epoll_fd_list_mu);
-}
-
-typedef struct {
-  grpc_pollset *pollset;
-  grpc_fd *fd;
-  grpc_closure closure;
-} delayed_add;
-
-typedef struct { int epoll_fd; } epoll_hdr;
-
-static void finally_add_fd(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
-                           grpc_fd *fd) {
-  epoll_hdr *h = pollset->data.ptr;
-  struct epoll_event ev;
-  int err;
-  grpc_fd_watcher watcher;
-
-  /* We pretend to be polling whilst adding an fd to keep the fd from being
-     closed during the add. This may result in a spurious wakeup being assigned
-     to this pollset whilst adding, but that should be benign. */
-  GPR_ASSERT(fd_begin_poll(fd, pollset, NULL, 0, 0, &watcher) == 0);
-  if (watcher.fd != NULL) {
-    ev.events = (uint32_t)(EPOLLIN | EPOLLOUT | EPOLLET);
-    ev.data.ptr = fd;
-    err = epoll_ctl(h->epoll_fd, EPOLL_CTL_ADD, fd->fd, &ev);
-    if (err < 0) {
-      /* FDs may be added to a pollset multiple times, so EEXIST is normal. */
-      if (errno != EEXIST) {
-        gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s", fd->fd,
-                strerror(errno));
-      }
-    }
-  }
-  fd_end_poll(exec_ctx, &watcher, 0, 0, NULL);
-}
-
-static void perform_delayed_add(grpc_exec_ctx *exec_ctx, void *arg,
-                                grpc_error *error) {
-  delayed_add *da = arg;
-
-  if (!fd_is_orphaned(da->fd)) {
-    finally_add_fd(exec_ctx, da->pollset, da->fd);
-  }
-
-  gpr_mu_lock(&da->pollset->mu);
-  da->pollset->in_flight_cbs--;
-  if (da->pollset->shutting_down) {
-    /* We don't care about this pollset anymore. */
-    if (da->pollset->in_flight_cbs == 0 && !da->pollset->called_shutdown) {
-      da->pollset->called_shutdown = 1;
-      grpc_exec_ctx_sched(exec_ctx, da->pollset->shutdown_done, GRPC_ERROR_NONE,
-                          NULL);
-    }
-  }
-  gpr_mu_unlock(&da->pollset->mu);
-
-  GRPC_FD_UNREF(da->fd, "delayed_add");
-
-  gpr_free(da);
-}
-
-static void multipoll_with_epoll_pollset_add_fd(grpc_exec_ctx *exec_ctx,
-                                                grpc_pollset *pollset,
-                                                grpc_fd *fd,
-                                                int and_unlock_pollset) {
-  if (and_unlock_pollset) {
-    gpr_mu_unlock(&pollset->mu);
-    finally_add_fd(exec_ctx, pollset, fd);
-  } else {
-    delayed_add *da = gpr_malloc(sizeof(*da));
-    da->pollset = pollset;
-    da->fd = fd;
-    GRPC_FD_REF(fd, "delayed_add");
-    grpc_closure_init(&da->closure, perform_delayed_add, da);
-    pollset->in_flight_cbs++;
-    grpc_exec_ctx_sched(exec_ctx, &da->closure, GRPC_ERROR_NONE, NULL);
-  }
-}
-
-/* TODO(klempner): We probably want to turn this down a bit */
-#define GRPC_EPOLL_MAX_EVENTS 1000
-
-static grpc_error *multipoll_with_epoll_pollset_maybe_work_and_unlock(
-    grpc_exec_ctx *exec_ctx, grpc_pollset *pollset, grpc_pollset_worker *worker,
-    gpr_timespec deadline, gpr_timespec now) {
-  struct epoll_event ep_ev[GRPC_EPOLL_MAX_EVENTS];
-  int ep_rv;
-  int poll_rv;
-  epoll_hdr *h = pollset->data.ptr;
-  int timeout_ms;
-  struct pollfd pfds[2];
-  grpc_error *error = GRPC_ERROR_NONE;
-
-  /* If you want to ignore epoll's ability to sanely handle parallel pollers,
-   * for a more apples-to-apples performance comparison with poll, add a
-   * if (pollset->counter != 0) { return 0; }
-   * here.
-   */
-
-  gpr_mu_unlock(&pollset->mu);
-
-  timeout_ms = poll_deadline_to_millis_timeout(deadline, now);
-
-  pfds[0].fd = GRPC_WAKEUP_FD_GET_READ_FD(&worker->wakeup_fd->fd);
-  pfds[0].events = POLLIN;
-  pfds[0].revents = 0;
-  pfds[1].fd = h->epoll_fd;
-  pfds[1].events = POLLIN;
-  pfds[1].revents = 0;
-
-  /* TODO(vpai): Consider first doing a 0 timeout poll here to avoid
-     even going into the blocking annotation if possible */
-  GPR_TIMER_BEGIN("poll", 0);
-  GRPC_SCHEDULING_START_BLOCKING_REGION;
-  poll_rv = grpc_poll_function(pfds, 2, timeout_ms);
-  GRPC_SCHEDULING_END_BLOCKING_REGION;
-  GPR_TIMER_END("poll", 0);
-
-  if (poll_rv < 0) {
-    if (errno != EINTR) {
-      work_combine_error(&error, GRPC_OS_ERROR(errno, "poll"));
-    }
-  } else if (poll_rv == 0) {
-    /* do nothing */
-  } else {
-    if (pfds[0].revents) {
-      work_combine_error(&error,
-                         grpc_wakeup_fd_consume_wakeup(&worker->wakeup_fd->fd));
-    }
-    if (pfds[1].revents) {
-      do {
-        /* The following epoll_wait never blocks; it has a timeout of 0 */
-        ep_rv = epoll_wait(h->epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0);
-        if (ep_rv < 0) {
-          if (errno != EINTR) {
-            work_combine_error(&error, GRPC_OS_ERROR(errno, "epoll_wait"));
-          }
-        } else {
-          int i;
-          for (i = 0; i < ep_rv; ++i) {
-            grpc_fd *fd = ep_ev[i].data.ptr;
-            /* TODO(klempner): We might want to consider making err and pri
-             * separate events */
-            int cancel = ep_ev[i].events & (EPOLLERR | EPOLLHUP);
-            int read_ev = ep_ev[i].events & (EPOLLIN | EPOLLPRI);
-            int write_ev = ep_ev[i].events & EPOLLOUT;
-            if (fd == NULL) {
-              work_combine_error(&error, grpc_wakeup_fd_consume_wakeup(
-                                             &grpc_global_wakeup_fd));
-            } else {
-              if (read_ev || cancel) {
-                fd_become_readable(exec_ctx, fd, pollset);
-              }
-              if (write_ev || cancel) {
-                fd_become_writable(exec_ctx, fd);
-              }
-            }
-          }
-        }
-      } while (ep_rv == GRPC_EPOLL_MAX_EVENTS);
-    }
-  }
-  return error;
-}
-
-static void multipoll_with_epoll_pollset_finish_shutdown(
-    grpc_pollset *pollset) {}
-
-static void multipoll_with_epoll_pollset_destroy(grpc_pollset *pollset) {
-  epoll_hdr *h = pollset->data.ptr;
-  close(h->epoll_fd);
-  remove_epoll_fd_from_global_list(h->epoll_fd);
-  gpr_free(h);
-}
-
-static const grpc_pollset_vtable multipoll_with_epoll_pollset = {
-    multipoll_with_epoll_pollset_add_fd,
-    multipoll_with_epoll_pollset_maybe_work_and_unlock,
-    multipoll_with_epoll_pollset_finish_shutdown,
-    multipoll_with_epoll_pollset_destroy};
-
-static void epoll_become_multipoller(grpc_exec_ctx *exec_ctx,
-                                     grpc_pollset *pollset, grpc_fd **fds,
-                                     size_t nfds) {
-  size_t i;
-  epoll_hdr *h = gpr_malloc(sizeof(epoll_hdr));
-  struct epoll_event ev;
-  int err;
-
-  pollset->vtable = &multipoll_with_epoll_pollset;
-  pollset->data.ptr = h;
-  h->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
-  if (h->epoll_fd < 0) {
-    /* TODO(klempner): Fall back to poll here, especially on ENOSYS */
-    gpr_log(GPR_ERROR, "epoll_create1 failed: %s", strerror(errno));
-    abort();
-  }
-  add_epoll_fd_to_global_list(h->epoll_fd);
-
-  ev.events = (uint32_t)(EPOLLIN | EPOLLET);
-  ev.data.ptr = NULL;
-  err = epoll_ctl(h->epoll_fd, EPOLL_CTL_ADD,
-                  GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd), &ev);
-  if (err < 0) {
-    gpr_log(GPR_ERROR, "epoll_ctl add for %d failed: %s",
-            GRPC_WAKEUP_FD_GET_READ_FD(&grpc_global_wakeup_fd),
-            strerror(errno));
-  }
-
-  for (i = 0; i < nfds; i++) {
-    multipoll_with_epoll_pollset_add_fd(exec_ctx, pollset, fds[i], 0);
-  }
-}
-
-#else /* GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
-
-static void remove_fd_from_all_epoll_sets(int fd) {}
-
-#endif /* GRPC_LINUX_MULTIPOLL_WITH_EPOLL */
-
-/*******************************************************************************
- * pollset_set_posix.c
- */
-
-static grpc_pollset_set *pollset_set_create(void) {
-  grpc_pollset_set *pollset_set = gpr_malloc(sizeof(*pollset_set));
-  memset(pollset_set, 0, sizeof(*pollset_set));
-  gpr_mu_init(&pollset_set->mu);
-  return pollset_set;
-}
-
-static void pollset_set_destroy(grpc_pollset_set *pollset_set) {
-  size_t i;
-  gpr_mu_destroy(&pollset_set->mu);
-  for (i = 0; i < pollset_set->fd_count; i++) {
-    GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
-  }
-  gpr_free(pollset_set->pollsets);
-  gpr_free(pollset_set->pollset_sets);
-  gpr_free(pollset_set->fds);
-  gpr_free(pollset_set);
-}
-
-static void pollset_set_add_pollset(grpc_exec_ctx *exec_ctx,
-                                    grpc_pollset_set *pollset_set,
-                                    grpc_pollset *pollset) {
-  size_t i, j;
-  gpr_mu_lock(&pollset_set->mu);
-  if (pollset_set->pollset_count == pollset_set->pollset_capacity) {
-    pollset_set->pollset_capacity =
-        GPR_MAX(8, 2 * pollset_set->pollset_capacity);
-    pollset_set->pollsets =
-        gpr_realloc(pollset_set->pollsets, pollset_set->pollset_capacity *
-                                               sizeof(*pollset_set->pollsets));
-  }
-  pollset_set->pollsets[pollset_set->pollset_count++] = pollset;
-  for (i = 0, j = 0; i < pollset_set->fd_count; i++) {
-    if (fd_is_orphaned(pollset_set->fds[i])) {
-      GRPC_FD_UNREF(pollset_set->fds[i], "pollset_set");
-    } else {
-      pollset_add_fd(exec_ctx, pollset, pollset_set->fds[i]);
-      pollset_set->fds[j++] = pollset_set->fds[i];
-    }
-  }
-  pollset_set->fd_count = j;
-  gpr_mu_unlock(&pollset_set->mu);
-}
-
-static void pollset_set_del_pollset(grpc_exec_ctx *exec_ctx,
-                                    grpc_pollset_set *pollset_set,
-                                    grpc_pollset *pollset) {
-  size_t i;
-  gpr_mu_lock(&pollset_set->mu);
-  for (i = 0; i < pollset_set->pollset_count; i++) {
-    if (pollset_set->pollsets[i] == pollset) {
-      pollset_set->pollset_count--;
-      GPR_SWAP(grpc_pollset *, pollset_set->pollsets[i],
-               pollset_set->pollsets[pollset_set->pollset_count]);
-      break;
-    }
-  }
-  gpr_mu_unlock(&pollset_set->mu);
-}
-
-static void pollset_set_add_pollset_set(grpc_exec_ctx *exec_ctx,
-                                        grpc_pollset_set *bag,
-                                        grpc_pollset_set *item) {
-  size_t i, j;
-  gpr_mu_lock(&bag->mu);
-  if (bag->pollset_set_count == bag->pollset_set_capacity) {
-    bag->pollset_set_capacity = GPR_MAX(8, 2 * bag->pollset_set_capacity);
-    bag->pollset_sets =
-        gpr_realloc(bag->pollset_sets,
-                    bag->pollset_set_capacity * sizeof(*bag->pollset_sets));
-  }
-  bag->pollset_sets[bag->pollset_set_count++] = item;
-  for (i = 0, j = 0; i < bag->fd_count; i++) {
-    if (fd_is_orphaned(bag->fds[i])) {
-      GRPC_FD_UNREF(bag->fds[i], "pollset_set");
-    } else {
-      pollset_set_add_fd(exec_ctx, item, bag->fds[i]);
-      bag->fds[j++] = bag->fds[i];
-    }
-  }
-  bag->fd_count = j;
-  gpr_mu_unlock(&bag->mu);
-}
-
-static void pollset_set_del_pollset_set(grpc_exec_ctx *exec_ctx,
-                                        grpc_pollset_set *bag,
-                                        grpc_pollset_set *item) {
-  size_t i;
-  gpr_mu_lock(&bag->mu);
-  for (i = 0; i < bag->pollset_set_count; i++) {
-    if (bag->pollset_sets[i] == item) {
-      bag->pollset_set_count--;
-      GPR_SWAP(grpc_pollset_set *, bag->pollset_sets[i],
-               bag->pollset_sets[bag->pollset_set_count]);
-      break;
-    }
-  }
-  gpr_mu_unlock(&bag->mu);
-}
-
-static void pollset_set_add_fd(grpc_exec_ctx *exec_ctx,
-                               grpc_pollset_set *pollset_set, grpc_fd *fd) {
-  size_t i;
-  gpr_mu_lock(&pollset_set->mu);
-  if (pollset_set->fd_count == pollset_set->fd_capacity) {
-    pollset_set->fd_capacity = GPR_MAX(8, 2 * pollset_set->fd_capacity);
-    pollset_set->fds = gpr_realloc(
-        pollset_set->fds, pollset_set->fd_capacity * sizeof(*pollset_set->fds));
-  }
-  GRPC_FD_REF(fd, "pollset_set");
-  pollset_set->fds[pollset_set->fd_count++] = fd;
-  for (i = 0; i < pollset_set->pollset_count; i++) {
-    pollset_add_fd(exec_ctx, pollset_set->pollsets[i], fd);
-  }
-  for (i = 0; i < pollset_set->pollset_set_count; i++) {
-    pollset_set_add_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
-  }
-  gpr_mu_unlock(&pollset_set->mu);
-}
-
-static void pollset_set_del_fd(grpc_exec_ctx *exec_ctx,
-                               grpc_pollset_set *pollset_set, grpc_fd *fd) {
-  size_t i;
-  gpr_mu_lock(&pollset_set->mu);
-  for (i = 0; i < pollset_set->fd_count; i++) {
-    if (pollset_set->fds[i] == fd) {
-      pollset_set->fd_count--;
-      GPR_SWAP(grpc_fd *, pollset_set->fds[i],
-               pollset_set->fds[pollset_set->fd_count]);
-      GRPC_FD_UNREF(fd, "pollset_set");
-      break;
-    }
-  }
-  for (i = 0; i < pollset_set->pollset_set_count; i++) {
-    pollset_set_del_fd(exec_ctx, pollset_set->pollset_sets[i], fd);
-  }
-  gpr_mu_unlock(&pollset_set->mu);
-}
-
-/*******************************************************************************
- * workqueue stubs
- */
-
-#ifdef GRPC_WORKQUEUE_REFCOUNT_DEBUG
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue,
-                                     const char *file, int line,
-                                     const char *reason) {
-  return workqueue;
-}
-static void workqueue_unref(grpc_exec_ctx *exec_ctx, grpc_workqueue *workqueue,
-                            const char *file, int line, const char *reason) {}
-#else
-static grpc_workqueue *workqueue_ref(grpc_workqueue *workqueue) {
-  return workqueue;
-}
-static void workqueue_unref(grpc_exec_ctx *exec_ctx,
-                            grpc_workqueue *workqueue) {}
-#endif
-
-static void workqueue_enqueue(grpc_exec_ctx *exec_ctx,
-                              grpc_workqueue *workqueue, grpc_closure *closure,
-                              grpc_error *error) {
-  grpc_exec_ctx_sched(exec_ctx, closure, error, NULL);
-}
-
-/*******************************************************************************
- * event engine binding
- */
-
-static void shutdown_engine(void) {
-  fd_global_shutdown();
-  pollset_global_shutdown();
-}
-
-static const grpc_event_engine_vtable vtable = {
-    .pollset_size = sizeof(grpc_pollset),
-
-    .fd_create = fd_create,
-    .fd_wrapped_fd = fd_wrapped_fd,
-    .fd_orphan = fd_orphan,
-    .fd_shutdown = fd_shutdown,
-    .fd_is_shutdown = fd_is_shutdown,
-    .fd_notify_on_read = fd_notify_on_read,
-    .fd_notify_on_write = fd_notify_on_write,
-    .fd_get_read_notifier_pollset = fd_get_read_notifier_pollset,
-    .fd_get_workqueue = fd_get_workqueue,
-
-    .pollset_init = pollset_init,
-    .pollset_shutdown = pollset_shutdown,
-    .pollset_reset = pollset_reset,
-    .pollset_destroy = pollset_destroy,
-    .pollset_work = pollset_work,
-    .pollset_kick = pollset_kick,
-    .pollset_add_fd = pollset_add_fd,
-
-    .pollset_set_create = pollset_set_create,
-    .pollset_set_destroy = pollset_set_destroy,
-    .pollset_set_add_pollset = pollset_set_add_pollset,
-    .pollset_set_del_pollset = pollset_set_del_pollset,
-    .pollset_set_add_pollset_set = pollset_set_add_pollset_set,
-    .pollset_set_del_pollset_set = pollset_set_del_pollset_set,
-    .pollset_set_add_fd = pollset_set_add_fd,
-    .pollset_set_del_fd = pollset_set_del_fd,
-
-    .kick_poller = kick_poller,
-
-    .workqueue_ref = workqueue_ref,
-    .workqueue_unref = workqueue_unref,
-    .workqueue_enqueue = workqueue_enqueue,
-
-    .shutdown_engine = shutdown_engine,
-};
-
-const grpc_event_engine_vtable *grpc_init_poll_and_epoll_posix(void) {
-#ifdef GRPC_LINUX_MULTIPOLL_WITH_EPOLL
-  platform_become_multipoller = epoll_become_multipoller;
-#else
-  platform_become_multipoller = poll_become_multipoller;
-#endif
-  fd_global_init();
-  pollset_global_init();
-  return &vtable;
-}
-
-#endif
diff --git a/src/core/lib/iomgr/ev_poll_and_epoll_posix.h b/src/core/lib/iomgr/ev_poll_and_epoll_posix.h
deleted file mode 100644
index 06d6dbf29d..0000000000
--- a/src/core/lib/iomgr/ev_poll_and_epoll_posix.h
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- *
- * 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_CORE_LIB_IOMGR_EV_POLL_AND_EPOLL_POSIX_H
-#define GRPC_CORE_LIB_IOMGR_EV_POLL_AND_EPOLL_POSIX_H
-
-#include "src/core/lib/iomgr/ev_posix.h"
-
-const grpc_event_engine_vtable *grpc_init_poll_and_epoll_posix(void);
-
-#endif /* GRPC_CORE_LIB_IOMGR_EV_POLL_AND_EPOLL_POSIX_H */
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index ef36ba89b2..ab139895fd 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -45,7 +45,6 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/iomgr/ev_epoll_linux.h"
-#include "src/core/lib/iomgr/ev_poll_and_epoll_posix.h"
 #include "src/core/lib/iomgr/ev_poll_posix.h"
 #include "src/core/lib/support/env.h"
 
@@ -67,7 +66,6 @@ static const event_engine_factory g_factories[] = {
     {"epoll", grpc_init_epoll_linux},
     {"poll", grpc_init_poll_posix},
     {"poll-cv", grpc_init_poll_cv_posix},
-    {"legacy", grpc_init_poll_and_epoll_posix},
 };
 
 static void add(const char *beg, const char *end, char ***ss, size_t *ns) {
diff --git a/src/core/lib/iomgr/load_file.c b/src/core/lib/iomgr/load_file.c
index b62ecbc534..217bc5da59 100644
--- a/src/core/lib/iomgr/load_file.c
+++ b/src/core/lib/iomgr/load_file.c
@@ -44,10 +44,10 @@
 #include "src/core/lib/support/string.h"
 
 grpc_error *grpc_load_file(const char *filename, int add_null_terminator,
-                           gpr_slice *output) {
+                           grpc_slice *output) {
   unsigned char *contents = NULL;
   size_t contents_size = 0;
-  gpr_slice result = gpr_empty_slice();
+  grpc_slice result = gpr_empty_slice();
   FILE *file;
   size_t bytes_read = 0;
   grpc_error *error = GRPC_ERROR_NONE;
@@ -72,7 +72,7 @@ grpc_error *grpc_load_file(const char *filename, int add_null_terminator,
   if (add_null_terminator) {
     contents[contents_size++] = 0;
   }
-  result = gpr_slice_new(contents, contents_size, gpr_free);
+  result = grpc_slice_new(contents, contents_size, gpr_free);
 
 end:
   *output = result;
diff --git a/src/core/lib/iomgr/load_file.h b/src/core/lib/iomgr/load_file.h
index 9aac2225d1..73ee8c3abf 100644
--- a/src/core/lib/iomgr/load_file.h
+++ b/src/core/lib/iomgr/load_file.h
@@ -36,7 +36,7 @@
 
 #include <stdio.h>
 
-#include <grpc/support/slice.h>
+#include <grpc/slice.h>
 
 #include "src/core/lib/iomgr/error.h"
 
@@ -47,7 +47,7 @@ extern "C" {
 /* Loads the content of a file into a slice. add_null_terminator will add
    a NULL terminator if non-zero. */
 grpc_error *grpc_load_file(const char *filename, int add_null_terminator,
-                           gpr_slice *slice);
+                           grpc_slice *slice);
 
 #ifdef __cplusplus
 }
diff --git a/src/core/lib/iomgr/resource_quota.c b/src/core/lib/iomgr/resource_quota.c
index 8a06443d58..051a30baa3 100644
--- a/src/core/lib/iomgr/resource_quota.c
+++ b/src/core/lib/iomgr/resource_quota.c
@@ -44,6 +44,81 @@
 
 int grpc_resource_quota_trace = 0;
 
+/* Internal linked list pointers for a resource user */
+typedef struct {
+  grpc_resource_user *next;
+  grpc_resource_user *prev;
+} grpc_resource_user_link;
+
+/* Resource users are kept in (potentially) several intrusive linked lists
+   at once. These are the list names. */
+typedef enum {
+  /* Resource users that are waiting for an allocation */
+  GRPC_RULIST_AWAITING_ALLOCATION,
+  /* Resource users that have free memory available for internal reclamation */
+  GRPC_RULIST_NON_EMPTY_FREE_POOL,
+  /* Resource users that have published a benign reclamation is available */
+  GRPC_RULIST_RECLAIMER_BENIGN,
+  /* Resource users that have published a destructive reclamation is
+     available */
+  GRPC_RULIST_RECLAIMER_DESTRUCTIVE,
+  /* Number of lists: must be last */
+  GRPC_RULIST_COUNT
+} grpc_rulist;
+
+struct grpc_resource_user {
+  /* The quota this resource user consumes from */
+  grpc_resource_quota *resource_quota;
+
+  /* Closure to schedule an allocation under the resource quota combiner lock */
+  grpc_closure allocate_closure;
+  /* Closure to publish a non empty free pool under the resource quota combiner
+     lock */
+  grpc_closure add_to_free_pool_closure;
+
+  /* one ref for each ref call (released by grpc_resource_user_unref), and one
+     ref for each byte allocated (released by grpc_resource_user_free) */
+  gpr_atm refs;
+  /* is this resource user unlocked? starts at 0, increases for each shutdown
+     call */
+  gpr_atm shutdown;
+
+  gpr_mu mu;
+  /* The amount of memory (in bytes) this user has cached for its own use: to
+     avoid quota contention, each resource user can keep some memory in
+     addition to what it is immediately using (e.g., for caching), and the quota
+     can pull it back under memory pressure.
+     This value can become negative if more memory has been requested than
+     existed in the free pool, at which point the quota is consulted to bring
+     this value non-negative (asynchronously). */
+  int64_t free_pool;
+  /* A list of closures to call once free_pool becomes non-negative - ie when
+     all outstanding allocations have been granted. */
+  grpc_closure_list on_allocated;
+  /* True if we are currently trying to allocate from the quota, false if not */
+  bool allocating;
+  /* True if we are currently trying to add ourselves to the non-free quota
+     list, false otherwise */
+  bool added_to_free_pool;
+
+  /* Reclaimers: index 0 is the benign reclaimer, 1 is the destructive reclaimer
+   */
+  grpc_closure *reclaimers[2];
+  /* Trampoline closures to finish reclamation and re-enter the quota combiner
+     lock */
+  grpc_closure post_reclaimer_closure[2];
+
+  /* Closure to execute under the quota combiner to de-register and shutdown the
+     resource user */
+  grpc_closure destroy_closure;
+
+  /* Links in the various grpc_rulist lists */
+  grpc_resource_user_link links[GRPC_RULIST_COUNT];
+
+  /* The name of this resource user, for debugging/tracing */
+  char *name;
+};
+
 struct grpc_resource_quota {
   /* refcount */
   gpr_refcount refs;
@@ -272,7 +347,7 @@ static bool rq_reclaim(grpc_exec_ctx *exec_ctx,
  */
 
 typedef struct {
-  gpr_slice_refcount base;
+  grpc_slice_refcount base;
   gpr_refcount refs;
   grpc_resource_user *resource_user;
   size_t size;
@@ -289,7 +364,7 @@ static void ru_slice_unref(void *p) {
     /* TODO(ctiller): this is dangerous, but I think safe for now:
        we have no guarantee here that we're at a safe point for creating an
        execution context, but we have no way of writing this code otherwise.
-       In the future: consider lifting gpr_slice to grpc, and offering an
+       In the future: consider lifting grpc_slice to grpc, and offering an
        internal_{ref,unref} pair that is execution context aware.
        Alternatively,
        make exec_ctx be thread local and 'do the right thing' (whatever that
@@ -302,15 +377,15 @@ static void ru_slice_unref(void *p) {
   }
 }
 
-static gpr_slice ru_slice_create(grpc_resource_user *resource_user,
-                                 size_t size) {
+static grpc_slice ru_slice_create(grpc_resource_user *resource_user,
+                                  size_t size) {
   ru_slice_refcount *rc = gpr_malloc(sizeof(ru_slice_refcount) + size);
   rc->base.ref = ru_slice_ref;
   rc->base.unref = ru_slice_unref;
   gpr_ref_init(&rc->refs, 1);
   rc->resource_user = resource_user;
   rc->size = size;
-  gpr_slice slice;
+  grpc_slice slice;
   slice.refcount = &rc->base;
   slice.data.refcounted.bytes = (uint8_t *)(rc + 1);
   slice.data.refcounted.length = size;
@@ -373,9 +448,19 @@ static void ru_post_destructive_reclaimer(grpc_exec_ctx *exec_ctx, void *ru,
   rulist_add_tail(resource_user, GRPC_RULIST_RECLAIMER_DESTRUCTIVE);
 }
 
+static void ru_shutdown(grpc_exec_ctx *exec_ctx, void *ru, grpc_error *error) {
+  grpc_resource_user *resource_user = ru;
+  grpc_exec_ctx_sched(exec_ctx, resource_user->reclaimers[0],
+                      GRPC_ERROR_CANCELLED, NULL);
+  grpc_exec_ctx_sched(exec_ctx, resource_user->reclaimers[1],
+                      GRPC_ERROR_CANCELLED, NULL);
+  resource_user->reclaimers[0] = NULL;
+  resource_user->reclaimers[1] = NULL;
+}
+
 static void ru_destroy(grpc_exec_ctx *exec_ctx, void *ru, grpc_error *error) {
   grpc_resource_user *resource_user = ru;
-  GPR_ASSERT(resource_user->allocated == 0);
+  GPR_ASSERT(gpr_atm_no_barrier_load(&resource_user->refs) == 0);
   for (int i = 0; i < GRPC_RULIST_COUNT; i++) {
     rulist_remove(resource_user, (grpc_rulist)i);
   }
@@ -383,13 +468,14 @@ static void ru_destroy(grpc_exec_ctx *exec_ctx, void *ru, grpc_error *error) {
                       GRPC_ERROR_CANCELLED, NULL);
   grpc_exec_ctx_sched(exec_ctx, resource_user->reclaimers[1],
                       GRPC_ERROR_CANCELLED, NULL);
-  grpc_exec_ctx_sched(exec_ctx, (grpc_closure *)gpr_atm_no_barrier_load(
-                                    &resource_user->on_done_destroy_closure),
-                      GRPC_ERROR_NONE, NULL);
   if (resource_user->free_pool != 0) {
     resource_user->resource_quota->free_pool += resource_user->free_pool;
     rq_step_sched(exec_ctx, resource_user->resource_quota);
   }
+  grpc_resource_quota_internal_unref(exec_ctx, resource_user->resource_quota);
+  gpr_mu_destroy(&resource_user->mu);
+  gpr_free(resource_user->name);
+  gpr_free(resource_user);
 }
 
 static void ru_allocated_slices(grpc_exec_ctx *exec_ctx, void *arg,
@@ -397,7 +483,7 @@ static void ru_allocated_slices(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_resource_user_slice_allocator *slice_allocator = arg;
   if (error == GRPC_ERROR_NONE) {
     for (size_t i = 0; i < slice_allocator->count; i++) {
-      gpr_slice_buffer_add_indexed(
+      grpc_slice_buffer_add_indexed(
           slice_allocator->dest, ru_slice_create(slice_allocator->resource_user,
                                                  slice_allocator->length));
     }
@@ -539,9 +625,9 @@ const grpc_arg_pointer_vtable *grpc_resource_quota_arg_vtable(void) {
  * grpc_resource_user api
  */
 
-void grpc_resource_user_init(grpc_resource_user *resource_user,
-                             grpc_resource_quota *resource_quota,
-                             const char *name) {
+grpc_resource_user *grpc_resource_user_create(
+    grpc_resource_quota *resource_quota, const char *name) {
+  grpc_resource_user *resource_user = gpr_malloc(sizeof(*resource_user));
   resource_user->resource_quota =
       grpc_resource_quota_internal_ref(resource_quota);
   grpc_closure_init(&resource_user->allocate_closure, &ru_allocate,
@@ -555,12 +641,12 @@ void grpc_resource_user_init(grpc_resource_user *resource_user,
   grpc_closure_init(&resource_user->destroy_closure, &ru_destroy,
                     resource_user);
   gpr_mu_init(&resource_user->mu);
-  resource_user->allocated = 0;
+  gpr_atm_rel_store(&resource_user->refs, 1);
+  gpr_atm_rel_store(&resource_user->shutdown, 0);
   resource_user->free_pool = 0;
   grpc_closure_list_init(&resource_user->on_allocated);
   resource_user->allocating = false;
   resource_user->added_to_free_pool = false;
-  gpr_atm_no_barrier_store(&resource_user->on_done_destroy_closure, 0);
   resource_user->reclaimers[0] = NULL;
   resource_user->reclaimers[1] = NULL;
   for (int i = 0; i < GRPC_RULIST_COUNT; i++) {
@@ -572,56 +658,54 @@ void grpc_resource_user_init(grpc_resource_user *resource_user,
     gpr_asprintf(&resource_user->name, "anonymous_resource_user_%" PRIxPTR,
                  (intptr_t)resource_user);
   }
+  return resource_user;
 }
 
-void grpc_resource_user_shutdown(grpc_exec_ctx *exec_ctx,
-                                 grpc_resource_user *resource_user,
-                                 grpc_closure *on_done) {
-  gpr_mu_lock(&resource_user->mu);
-  GPR_ASSERT(gpr_atm_no_barrier_load(&resource_user->on_done_destroy_closure) ==
-             0);
-  gpr_atm_no_barrier_store(&resource_user->on_done_destroy_closure,
-                           (gpr_atm)on_done);
-  if (resource_user->allocated == 0) {
+static void ru_ref_by(grpc_resource_user *resource_user, gpr_atm amount) {
+  GPR_ASSERT(amount > 0);
+  GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&resource_user->refs, amount) != 0);
+}
+
+static void ru_unref_by(grpc_exec_ctx *exec_ctx,
+                        grpc_resource_user *resource_user, gpr_atm amount) {
+  GPR_ASSERT(amount > 0);
+  gpr_atm old = gpr_atm_full_fetch_add(&resource_user->refs, -amount);
+  GPR_ASSERT(old >= amount);
+  if (old == amount) {
     grpc_combiner_execute(exec_ctx, resource_user->resource_quota->combiner,
                           &resource_user->destroy_closure, GRPC_ERROR_NONE,
                           false);
   }
-  gpr_mu_unlock(&resource_user->mu);
 }
 
-void grpc_resource_user_destroy(grpc_exec_ctx *exec_ctx,
-                                grpc_resource_user *resource_user) {
-  grpc_resource_quota_internal_unref(exec_ctx, resource_user->resource_quota);
-  gpr_mu_destroy(&resource_user->mu);
-  gpr_free(resource_user->name);
+void grpc_resource_user_ref(grpc_resource_user *resource_user) {
+  ru_ref_by(resource_user, 1);
+}
+
+void grpc_resource_user_unref(grpc_exec_ctx *exec_ctx,
+                              grpc_resource_user *resource_user) {
+  ru_unref_by(exec_ctx, resource_user, 1);
+}
+
+void grpc_resource_user_shutdown(grpc_exec_ctx *exec_ctx,
+                                 grpc_resource_user *resource_user) {
+  if (gpr_atm_full_fetch_add(&resource_user->shutdown, 1) == 0) {
+    grpc_combiner_execute(exec_ctx, resource_user->resource_quota->combiner,
+                          grpc_closure_create(ru_shutdown, resource_user),
+                          GRPC_ERROR_NONE, false);
+  }
 }
 
 void grpc_resource_user_alloc(grpc_exec_ctx *exec_ctx,
                               grpc_resource_user *resource_user, size_t size,
                               grpc_closure *optional_on_done) {
   gpr_mu_lock(&resource_user->mu);
-  grpc_closure *on_done_destroy = (grpc_closure *)gpr_atm_no_barrier_load(
-      &resource_user->on_done_destroy_closure);
-  if (on_done_destroy != NULL) {
-    /* already shutdown */
-    if (grpc_resource_quota_trace) {
-      gpr_log(GPR_DEBUG, "RQ %s %s: alloc %" PRIdPTR " after shutdown",
-              resource_user->resource_quota->name, resource_user->name, size);
-    }
-    grpc_exec_ctx_sched(
-        exec_ctx, optional_on_done,
-        GRPC_ERROR_CREATE("Buffer pool user is already shutdown"), NULL);
-    gpr_mu_unlock(&resource_user->mu);
-    return;
-  }
-  resource_user->allocated += (int64_t)size;
+  ru_ref_by(resource_user, (gpr_atm)size);
   resource_user->free_pool -= (int64_t)size;
   if (grpc_resource_quota_trace) {
-    gpr_log(GPR_DEBUG, "RQ %s %s: alloc %" PRIdPTR "; allocated -> %" PRId64
-                       ", free_pool -> %" PRId64,
+    gpr_log(GPR_DEBUG, "RQ %s %s: alloc %" PRIdPTR "; free_pool -> %" PRId64,
             resource_user->resource_quota->name, resource_user->name, size,
-            resource_user->allocated, resource_user->free_pool);
+            resource_user->free_pool);
   }
   if (resource_user->free_pool < 0) {
     grpc_closure_list_append(&resource_user->on_allocated, optional_on_done,
@@ -641,15 +725,12 @@ void grpc_resource_user_alloc(grpc_exec_ctx *exec_ctx,
 void grpc_resource_user_free(grpc_exec_ctx *exec_ctx,
                              grpc_resource_user *resource_user, size_t size) {
   gpr_mu_lock(&resource_user->mu);
-  GPR_ASSERT(resource_user->allocated >= (int64_t)size);
   bool was_zero_or_negative = resource_user->free_pool <= 0;
   resource_user->free_pool += (int64_t)size;
-  resource_user->allocated -= (int64_t)size;
   if (grpc_resource_quota_trace) {
-    gpr_log(GPR_DEBUG, "RQ %s %s: free %" PRIdPTR "; allocated -> %" PRId64
-                       ", free_pool -> %" PRId64,
+    gpr_log(GPR_DEBUG, "RQ %s %s: free %" PRIdPTR "; free_pool -> %" PRId64,
             resource_user->resource_quota->name, resource_user->name, size,
-            resource_user->allocated, resource_user->free_pool);
+            resource_user->free_pool);
   }
   bool is_bigger_than_zero = resource_user->free_pool > 0;
   if (is_bigger_than_zero && was_zero_or_negative &&
@@ -659,29 +740,23 @@ void grpc_resource_user_free(grpc_exec_ctx *exec_ctx,
                           &resource_user->add_to_free_pool_closure,
                           GRPC_ERROR_NONE, false);
   }
-  grpc_closure *on_done_destroy = (grpc_closure *)gpr_atm_no_barrier_load(
-      &resource_user->on_done_destroy_closure);
-  if (on_done_destroy != NULL && resource_user->allocated == 0) {
-    grpc_combiner_execute(exec_ctx, resource_user->resource_quota->combiner,
-                          &resource_user->destroy_closure, GRPC_ERROR_NONE,
-                          false);
-  }
   gpr_mu_unlock(&resource_user->mu);
+  ru_unref_by(exec_ctx, resource_user, (gpr_atm)size);
 }
 
 void grpc_resource_user_post_reclaimer(grpc_exec_ctx *exec_ctx,
                                        grpc_resource_user *resource_user,
                                        bool destructive,
                                        grpc_closure *closure) {
-  if (gpr_atm_acq_load(&resource_user->on_done_destroy_closure) == 0) {
-    GPR_ASSERT(resource_user->reclaimers[destructive] == NULL);
-    resource_user->reclaimers[destructive] = closure;
-    grpc_combiner_execute(exec_ctx, resource_user->resource_quota->combiner,
-                          &resource_user->post_reclaimer_closure[destructive],
-                          GRPC_ERROR_NONE, false);
-  } else {
+  GPR_ASSERT(resource_user->reclaimers[destructive] == NULL);
+  if (gpr_atm_acq_load(&resource_user->shutdown) > 0) {
     grpc_exec_ctx_sched(exec_ctx, closure, GRPC_ERROR_CANCELLED, NULL);
+    return;
   }
+  resource_user->reclaimers[destructive] = closure;
+  grpc_combiner_execute(exec_ctx, resource_user->resource_quota->combiner,
+                        &resource_user->post_reclaimer_closure[destructive],
+                        GRPC_ERROR_NONE, false);
 }
 
 void grpc_resource_user_finish_reclamation(grpc_exec_ctx *exec_ctx,
@@ -708,7 +783,7 @@ void grpc_resource_user_slice_allocator_init(
 void grpc_resource_user_alloc_slices(
     grpc_exec_ctx *exec_ctx,
     grpc_resource_user_slice_allocator *slice_allocator, size_t length,
-    size_t count, gpr_slice_buffer *dest) {
+    size_t count, grpc_slice_buffer *dest) {
   slice_allocator->length = length;
   slice_allocator->count = count;
   slice_allocator->dest = dest;
@@ -716,9 +791,9 @@ void grpc_resource_user_alloc_slices(
                            count * length, &slice_allocator->on_allocated);
 }
 
-gpr_slice grpc_resource_user_slice_malloc(grpc_exec_ctx *exec_ctx,
-                                          grpc_resource_user *resource_user,
-                                          size_t size) {
+grpc_slice grpc_resource_user_slice_malloc(grpc_exec_ctx *exec_ctx,
+                                           grpc_resource_user *resource_user,
+                                           size_t size) {
   grpc_resource_user_alloc(exec_ctx, resource_user, size, NULL);
   return ru_slice_create(resource_user, size);
 }
diff --git a/src/core/lib/iomgr/resource_quota.h b/src/core/lib/iomgr/resource_quota.h
index da68f21a2c..0181fd978b 100644
--- a/src/core/lib/iomgr/resource_quota.h
+++ b/src/core/lib/iomgr/resource_quota.h
@@ -84,91 +84,15 @@ void grpc_resource_quota_internal_unref(grpc_exec_ctx *exec_ctx,
 grpc_resource_quota *grpc_resource_quota_from_channel_args(
     const grpc_channel_args *channel_args);
 
-/* Resource users are kept in (potentially) several intrusive linked lists
-   at once. These are the list names. */
-typedef enum {
-  /* Resource users that are waiting for an allocation */
-  GRPC_RULIST_AWAITING_ALLOCATION,
-  /* Resource users that have free memory available for internal reclamation */
-  GRPC_RULIST_NON_EMPTY_FREE_POOL,
-  /* Resource users that have published a benign reclamation is available */
-  GRPC_RULIST_RECLAIMER_BENIGN,
-  /* Resource users that have published a destructive reclamation is
-     available */
-  GRPC_RULIST_RECLAIMER_DESTRUCTIVE,
-  /* Number of lists: must be last */
-  GRPC_RULIST_COUNT
-} grpc_rulist;
-
 typedef struct grpc_resource_user grpc_resource_user;
 
-/* Internal linked list pointers for a resource user */
-typedef struct {
-  grpc_resource_user *next;
-  grpc_resource_user *prev;
-} grpc_resource_user_link;
-
-struct grpc_resource_user {
-  /* The quota this resource user consumes from */
-  grpc_resource_quota *resource_quota;
-
-  /* Closure to schedule an allocation under the resource quota combiner lock */
-  grpc_closure allocate_closure;
-  /* Closure to publish a non empty free pool under the resource quota combiner
-     lock */
-  grpc_closure add_to_free_pool_closure;
-
-  gpr_mu mu;
-  /* Total allocated memory outstanding by this resource user in bytes;
-     always positive */
-  int64_t allocated;
-  /* The amount of memory (in bytes) this user has cached for its own use: to
-     avoid quota contention, each resource user can keep some memory in
-     addition to what it is immediately using (e.g., for caching), and the quota
-     can pull it back under memory pressure.
-     This value can become negative if more memory has been requested than
-     existed in the free pool, at which point the quota is consulted to bring
-     this value non-negative (asynchronously). */
-  int64_t free_pool;
-  /* A list of closures to call once free_pool becomes non-negative - ie when
-     all outstanding allocations have been granted. */
-  grpc_closure_list on_allocated;
-  /* True if we are currently trying to allocate from the quota, false if not */
-  bool allocating;
-  /* True if we are currently trying to add ourselves to the non-free quota
-     list, false otherwise */
-  bool added_to_free_pool;
-
-  /* Reclaimers: index 0 is the benign reclaimer, 1 is the destructive reclaimer
-   */
-  grpc_closure *reclaimers[2];
-  /* Trampoline closures to finish reclamation and re-enter the quota combiner
-     lock */
-  grpc_closure post_reclaimer_closure[2];
-
-  /* Closure to execute under the quota combiner to de-register and shutdown the
-     resource user */
-  grpc_closure destroy_closure;
-  /* User supplied closure to call once the user has finished shutting down AND
-     all outstanding allocations have been freed. Real type is grpc_closure*,
-     but it's stored as an atomic to avoid a mutex on some fast paths. */
-  gpr_atm on_done_destroy_closure;
-
-  /* Links in the various grpc_rulist lists */
-  grpc_resource_user_link links[GRPC_RULIST_COUNT];
-
-  /* The name of this resource user, for debugging/tracing */
-  char *name;
-};
-
-void grpc_resource_user_init(grpc_resource_user *resource_user,
-                             grpc_resource_quota *resource_quota,
-                             const char *name);
+grpc_resource_user *grpc_resource_user_create(
+    grpc_resource_quota *resource_quota, const char *name);
+void grpc_resource_user_ref(grpc_resource_user *resource_user);
+void grpc_resource_user_unref(grpc_exec_ctx *exec_ctx,
+                              grpc_resource_user *resource_user);
 void grpc_resource_user_shutdown(grpc_exec_ctx *exec_ctx,
-                                 grpc_resource_user *resource_user,
-                                 grpc_closure *on_done);
-void grpc_resource_user_destroy(grpc_exec_ctx *exec_ctx,
-                                grpc_resource_user *resource_user);
+                                 grpc_resource_user *resource_user);
 
 /* Allocate from the resource user (and its quota).
    If optional_on_done is NULL, then allocate immediately. This may push the
@@ -203,7 +127,7 @@ typedef struct grpc_resource_user_slice_allocator {
   /* Number of slices to allocate on the current request */
   size_t count;
   /* Destination for slices to allocate on the current request */
-  gpr_slice_buffer *dest;
+  grpc_slice_buffer *dest;
   /* Parent resource user */
   grpc_resource_user *resource_user;
 } grpc_resource_user_slice_allocator;
@@ -219,11 +143,11 @@ void grpc_resource_user_slice_allocator_init(
 void grpc_resource_user_alloc_slices(
     grpc_exec_ctx *exec_ctx,
     grpc_resource_user_slice_allocator *slice_allocator, size_t length,
-    size_t count, gpr_slice_buffer *dest);
+    size_t count, grpc_slice_buffer *dest);
 
 /* Allocate one slice of length \a size synchronously. */
-gpr_slice grpc_resource_user_slice_malloc(grpc_exec_ctx *exec_ctx,
-                                          grpc_resource_user *resource_user,
-                                          size_t size);
+grpc_slice grpc_resource_user_slice_malloc(grpc_exec_ctx *exec_ctx,
+                                           grpc_resource_user *resource_user,
+                                           size_t size);
 
 #endif /* GRPC_CORE_LIB_IOMGR_RESOURCE_QUOTA_H */
diff --git a/src/core/lib/iomgr/socket_mutator.c b/src/core/lib/iomgr/socket_mutator.c
new file mode 100644
index 0000000000..8b1efb6bab
--- /dev/null
+++ b/src/core/lib/iomgr/socket_mutator.c
@@ -0,0 +1,98 @@
+/*
+ *
+ * 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/lib/iomgr/socket_mutator.h"
+
+#include <grpc/impl/codegen/grpc_types.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/useful.h>
+
+void grpc_socket_mutator_init(grpc_socket_mutator *mutator,
+                              const grpc_socket_mutator_vtable *vtable) {
+  mutator->vtable = vtable;
+  gpr_ref_init(&mutator->refcount, 1);
+}
+
+grpc_socket_mutator *grpc_socket_mutator_ref(grpc_socket_mutator *mutator) {
+  gpr_ref(&mutator->refcount);
+  return mutator;
+}
+
+bool grpc_socket_mutator_mutate_fd(grpc_socket_mutator *mutator, int fd) {
+  return mutator->vtable->mutate_fd(fd, mutator);
+}
+
+int grpc_socket_mutator_compare(grpc_socket_mutator *a,
+                                grpc_socket_mutator *b) {
+  int c = GPR_ICMP(a, b);
+  if (c != 0) {
+    grpc_socket_mutator *sma = a;
+    grpc_socket_mutator *smb = b;
+    c = GPR_ICMP(sma->vtable, smb->vtable);
+    if (c == 0) {
+      c = sma->vtable->compare(sma, smb);
+    }
+  }
+  return c;
+}
+
+void grpc_socket_mutator_unref(grpc_socket_mutator *mutator) {
+  if (gpr_unref(&mutator->refcount)) {
+    mutator->vtable->destory(mutator);
+  }
+}
+
+static void *socket_mutator_arg_copy(void *p) {
+  return grpc_socket_mutator_ref(p);
+}
+
+static void socket_mutator_arg_destroy(void *p) {
+  grpc_socket_mutator_unref(p);
+}
+
+static int socket_mutator_cmp(void *a, void *b) {
+  return grpc_socket_mutator_compare((grpc_socket_mutator *)a,
+                                     (grpc_socket_mutator *)b);
+}
+
+static const grpc_arg_pointer_vtable socket_mutator_arg_vtable = {
+    socket_mutator_arg_copy, socket_mutator_arg_destroy, socket_mutator_cmp};
+
+grpc_arg grpc_socket_mutator_to_arg(grpc_socket_mutator *mutator) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_POINTER;
+  arg.key = GRPC_ARG_SOCKET_MUTATOR;
+  arg.value.pointer.vtable = &socket_mutator_arg_vtable;
+  arg.value.pointer.p = mutator;
+  return arg;
+}
diff --git a/src/core/lib/iomgr/socket_mutator.h b/src/core/lib/iomgr/socket_mutator.h
new file mode 100644
index 0000000000..2f5b6c248e
--- /dev/null
+++ b/src/core/lib/iomgr/socket_mutator.h
@@ -0,0 +1,80 @@
+/*
+ *
+ * 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_CORE_LIB_IOMGR_SOCKET_MUTATOR_H
+#define GRPC_CORE_LIB_IOMGR_SOCKET_MUTATOR_H
+
+#include <grpc/impl/codegen/grpc_types.h>
+#include <grpc/support/sync.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** The virtual table of grpc_socket_mutator */
+typedef struct {
+  /** Mutates the socket opitons of \a fd */
+  bool (*mutate_fd)(int fd, grpc_socket_mutator *mutator);
+  /** Compare socket mutator \a a and \a b */
+  int (*compare)(grpc_socket_mutator *a, grpc_socket_mutator *b);
+  /** Destroys the socket mutator instance */
+  void (*destory)(grpc_socket_mutator *mutator);
+} grpc_socket_mutator_vtable;
+
+/** The Socket Mutator interface allows changes on socket options */
+struct grpc_socket_mutator {
+  const grpc_socket_mutator_vtable *vtable;
+  gpr_refcount refcount;
+};
+
+/** called by concrete implementations to initialize the base struct */
+void grpc_socket_mutator_init(grpc_socket_mutator *mutator,
+                              const grpc_socket_mutator_vtable *vtable);
+
+/** Wrap \a mutator as a grpc_arg */
+grpc_arg grpc_socket_mutator_to_arg(grpc_socket_mutator *mutator);
+
+/** Perform the file descriptor mutation operation of \a mutator on \a fd */
+bool grpc_socket_mutator_mutate_fd(grpc_socket_mutator *mutator, int fd);
+
+/** Compare if \a a and \a b are the same mutator or have same settings */
+int grpc_socket_mutator_compare(grpc_socket_mutator *a, grpc_socket_mutator *b);
+
+grpc_socket_mutator *grpc_socket_mutator_ref(grpc_socket_mutator *mutator);
+void grpc_socket_mutator_unref(grpc_socket_mutator *mutator);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GRPC_CORE_LIB_IOMGR_SOCKET_MUTATOR_H */
diff --git a/src/core/lib/iomgr/socket_utils_common_posix.c b/src/core/lib/iomgr/socket_utils_common_posix.c
index bc28bbe316..88e9ade253 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.c
+++ b/src/core/lib/iomgr/socket_utils_common_posix.c
@@ -209,6 +209,15 @@ grpc_error *grpc_set_socket_low_latency(int fd, int low_latency) {
   return GRPC_ERROR_NONE;
 }
 
+/* set a socket using a grpc_socket_mutator */
+grpc_error *grpc_set_socket_with_mutator(int fd, grpc_socket_mutator *mutator) {
+  GPR_ASSERT(mutator);
+  if (!grpc_socket_mutator_mutate_fd(mutator, fd)) {
+    return GRPC_ERROR_CREATE("grpc_socket_mutator failed.");
+  }
+  return GRPC_ERROR_NONE;
+}
+
 static gpr_once g_probe_ipv6_once = GPR_ONCE_INIT;
 static int g_ipv6_loopback_available;
 
diff --git a/src/core/lib/iomgr/socket_utils_posix.h b/src/core/lib/iomgr/socket_utils_posix.h
index 175fb2b717..e84d3781a1 100644
--- a/src/core/lib/iomgr/socket_utils_posix.h
+++ b/src/core/lib/iomgr/socket_utils_posix.h
@@ -39,7 +39,9 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
+#include <grpc/impl/codegen/grpc_types.h>
 #include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/iomgr/socket_mutator.h"
 
 /* a wrapper for accept or accept4 */
 int grpc_accept4(int sockfd, grpc_resolved_address *resolved_addr, int nonblock,
@@ -88,6 +90,9 @@ grpc_error *grpc_set_socket_sndbuf(int fd, int buffer_size_bytes);
 /* Tries to set the socket's receive buffer to given size. */
 grpc_error *grpc_set_socket_rcvbuf(int fd, int buffer_size_bytes);
 
+/* Tries to set the socket using a grpc_socket_mutator */
+grpc_error *grpc_set_socket_with_mutator(int fd, grpc_socket_mutator *mutator);
+
 /* An enum to keep track of IPv4/IPv6 socket modes.
 
    Currently, this information is only used when a socket is first created, but
diff --git a/src/core/lib/iomgr/tcp_client.h b/src/core/lib/iomgr/tcp_client.h
index 18e6e60ebc..0485661316 100644
--- a/src/core/lib/iomgr/tcp_client.h
+++ b/src/core/lib/iomgr/tcp_client.h
@@ -34,6 +34,7 @@
 #ifndef GRPC_CORE_LIB_IOMGR_TCP_CLIENT_H
 #define GRPC_CORE_LIB_IOMGR_TCP_CLIENT_H
 
+#include <grpc/impl/codegen/grpc_types.h>
 #include <grpc/support/time.h>
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/pollset_set.h"
diff --git a/src/core/lib/iomgr/tcp_client_posix.c b/src/core/lib/iomgr/tcp_client_posix.c
index bc08c94ee0..13347735df 100644
--- a/src/core/lib/iomgr/tcp_client_posix.c
+++ b/src/core/lib/iomgr/tcp_client_posix.c
@@ -51,6 +51,7 @@
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_posix.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
+#include "src/core/lib/iomgr/socket_mutator.h"
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 #include "src/core/lib/iomgr/tcp_posix.h"
 #include "src/core/lib/iomgr/timer.h"
@@ -73,7 +74,8 @@ typedef struct {
   grpc_channel_args *channel_args;
 } async_connect;
 
-static grpc_error *prepare_socket(const grpc_resolved_address *addr, int fd) {
+static grpc_error *prepare_socket(const grpc_resolved_address *addr, int fd,
+                                  const grpc_channel_args *channel_args) {
   grpc_error *err = GRPC_ERROR_NONE;
 
   GPR_ASSERT(fd >= 0);
@@ -88,6 +90,16 @@ static grpc_error *prepare_socket(const grpc_resolved_address *addr, int fd) {
   }
   err = grpc_set_socket_no_sigpipe_if_possible(fd);
   if (err != GRPC_ERROR_NONE) goto error;
+  if (channel_args) {
+    for (size_t i = 0; i < channel_args->num_args; i++) {
+      if (0 == strcmp(channel_args->args[i].key, GRPC_ARG_SOCKET_MUTATOR)) {
+        GPR_ASSERT(channel_args->args[i].type == GRPC_ARG_POINTER);
+        grpc_socket_mutator *mutator = channel_args->args[i].value.pointer.p;
+        err = grpc_set_socket_with_mutator(fd, mutator);
+        if (err != GRPC_ERROR_NONE) goto error;
+      }
+    }
+  }
   goto done;
 
 error:
@@ -287,7 +299,7 @@ static void tcp_client_connect_impl(grpc_exec_ctx *exec_ctx,
     GPR_ASSERT(grpc_sockaddr_is_v4mapped(addr, &addr4_copy));
     addr = &addr4_copy;
   }
-  if ((error = prepare_socket(addr, fd)) != GRPC_ERROR_NONE) {
+  if ((error = prepare_socket(addr, fd, channel_args)) != GRPC_ERROR_NONE) {
     grpc_exec_ctx_sched(exec_ctx, closure, error, NULL);
     return;
   }
diff --git a/src/core/lib/iomgr/tcp_client_windows.c b/src/core/lib/iomgr/tcp_client_windows.c
index 30f7c66f15..4d1e809872 100644
--- a/src/core/lib/iomgr/tcp_client_windows.c
+++ b/src/core/lib/iomgr/tcp_client_windows.c
@@ -37,10 +37,10 @@
 
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 
+#include <grpc/slice_buffer.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/log_windows.h>
-#include <grpc/support/slice_buffer.h>
 #include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index 880af93ee1..12a4797e6f 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -46,9 +46,9 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <grpc/slice.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>
@@ -56,6 +56,7 @@
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 
 #ifdef GRPC_HAVE_MSG_NOSIGNAL
@@ -83,10 +84,10 @@ typedef struct {
   gpr_atm shutdown_count;
 
   /* garbage after the last read */
-  gpr_slice_buffer last_read_buffer;
+  grpc_slice_buffer last_read_buffer;
 
-  gpr_slice_buffer *incoming_buffer;
-  gpr_slice_buffer *outgoing_buffer;
+  grpc_slice_buffer *incoming_buffer;
+  grpc_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 */
@@ -102,7 +103,7 @@ typedef struct {
 
   char *peer_string;
 
-  grpc_resource_user resource_user;
+  grpc_resource_user *resource_user;
   grpc_resource_user_slice_allocator slice_allocator;
 } grpc_tcp;
 
@@ -110,28 +111,18 @@ static void tcp_handle_read(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
                             grpc_error *error);
 static void tcp_handle_write(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
                              grpc_error *error);
-static void tcp_unref_closure(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
-                              grpc_error *error);
-
-static void tcp_maybe_shutdown_resource_user(grpc_exec_ctx *exec_ctx,
-                                             grpc_tcp *tcp) {
-  if (gpr_atm_full_fetch_add(&tcp->shutdown_count, 1) == 0) {
-    grpc_resource_user_shutdown(exec_ctx, &tcp->resource_user,
-                                grpc_closure_create(tcp_unref_closure, tcp));
-  }
-}
 
 static void tcp_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
-  tcp_maybe_shutdown_resource_user(exec_ctx, tcp);
   grpc_fd_shutdown(exec_ctx, tcp->em_fd);
+  grpc_resource_user_shutdown(exec_ctx, tcp->resource_user);
 }
 
 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);
-  grpc_resource_user_destroy(exec_ctx, &tcp->resource_user);
+  grpc_slice_buffer_destroy(&tcp->last_read_buffer);
+  grpc_resource_user_unref(exec_ctx, tcp->resource_user);
   gpr_free(tcp->peer_string);
   gpr_free(tcp);
 }
@@ -168,16 +159,10 @@ static void tcp_unref(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
 static void tcp_ref(grpc_tcp *tcp) { gpr_ref(&tcp->refcount); }
 #endif
 
-static void tcp_unref_closure(grpc_exec_ctx *exec_ctx, void *arg,
-                              grpc_error *error) {
-  TCP_UNREF(exec_ctx, arg, "resource_user");
-}
-
 static void tcp_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_network_status_unregister_endpoint(ep);
   grpc_tcp *tcp = (grpc_tcp *)ep;
-  tcp_maybe_shutdown_resource_user(exec_ctx, tcp);
-  gpr_slice_buffer_reset_and_unref(&tcp->last_read_buffer);
+  grpc_slice_buffer_reset_and_unref(&tcp->last_read_buffer);
   TCP_UNREF(exec_ctx, tcp, "destroy");
 }
 
@@ -191,8 +176,8 @@ static void call_read_cb(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp,
     gpr_log(GPR_DEBUG, "read: error=%s", str);
     grpc_error_free_string(str);
     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);
+      char *dump = grpc_dump_slice(tcp->incoming_buffer->slices[i],
+                                   GPR_DUMP_HEX | GPR_DUMP_ASCII);
       gpr_log(GPR_DEBUG, "READ %p (peer=%s): %s", tcp, tcp->peer_string, dump);
       gpr_free(dump);
     }
@@ -216,8 +201,8 @@ static void tcp_do_read(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
   GPR_TIMER_BEGIN("tcp_continue_read", 0);
 
   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]);
+    iov[i].iov_base = GRPC_SLICE_START_PTR(tcp->incoming_buffer->slices[i]);
+    iov[i].iov_len = GRPC_SLICE_LENGTH(tcp->incoming_buffer->slices[i]);
   }
 
   msg.msg_name = NULL;
@@ -244,19 +229,19 @@ static void tcp_do_read(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
       /* We've consumed the edge, request a new one */
       grpc_fd_notify_on_read(exec_ctx, tcp->em_fd, &tcp->read_closure);
     } else {
-      gpr_slice_buffer_reset_and_unref(tcp->incoming_buffer);
+      grpc_slice_buffer_reset_and_unref(tcp->incoming_buffer);
       call_read_cb(exec_ctx, tcp, GRPC_OS_ERROR(errno, "recvmsg"));
       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);
+    grpc_slice_buffer_reset_and_unref(tcp->incoming_buffer);
     call_read_cb(exec_ctx, tcp, GRPC_ERROR_CREATE("Socket closed"));
     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(
+      grpc_slice_buffer_trim_end(
           tcp->incoming_buffer,
           tcp->incoming_buffer->length - (size_t)read_bytes,
           &tcp->last_read_buffer);
@@ -275,8 +260,8 @@ static void tcp_read_allocation_done(grpc_exec_ctx *exec_ctx, void *tcpp,
                                      grpc_error *error) {
   grpc_tcp *tcp = tcpp;
   if (error != GRPC_ERROR_NONE) {
-    gpr_slice_buffer_reset_and_unref(tcp->incoming_buffer);
-    gpr_slice_buffer_reset_and_unref(&tcp->last_read_buffer);
+    grpc_slice_buffer_reset_and_unref(tcp->incoming_buffer);
+    grpc_slice_buffer_reset_and_unref(&tcp->last_read_buffer);
     call_read_cb(exec_ctx, tcp, GRPC_ERROR_REF(error));
     TCP_UNREF(exec_ctx, tcp, "read");
   } else {
@@ -301,8 +286,8 @@ static void tcp_handle_read(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
   GPR_ASSERT(!tcp->finished_edge);
 
   if (error != GRPC_ERROR_NONE) {
-    gpr_slice_buffer_reset_and_unref(tcp->incoming_buffer);
-    gpr_slice_buffer_reset_and_unref(&tcp->last_read_buffer);
+    grpc_slice_buffer_reset_and_unref(tcp->incoming_buffer);
+    grpc_slice_buffer_reset_and_unref(&tcp->last_read_buffer);
     call_read_cb(exec_ctx, tcp, GRPC_ERROR_REF(error));
     TCP_UNREF(exec_ctx, tcp, "read");
   } else {
@@ -311,13 +296,13 @@ static void tcp_handle_read(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
 }
 
 static void tcp_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                     gpr_slice_buffer *incoming_buffer, grpc_closure *cb) {
+                     grpc_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);
+  grpc_slice_buffer_reset_and_unref(incoming_buffer);
+  grpc_slice_buffer_swap(incoming_buffer, &tcp->last_read_buffer);
   TCP_REF(tcp, "read");
   if (tcp->finished_edge) {
     tcp->finished_edge = false;
@@ -347,11 +332,11 @@ static bool tcp_flush(grpc_tcp *tcp, grpc_error **error) {
                        iov_size != MAX_WRITE_IOVEC;
          iov_size++) {
       iov[iov_size].iov_base =
-          GPR_SLICE_START_PTR(
+          GRPC_SLICE_START_PTR(
               tcp->outgoing_buffer->slices[tcp->outgoing_slice_idx]) +
           tcp->outgoing_byte_idx;
       iov[iov_size].iov_len =
-          GPR_SLICE_LENGTH(
+          GRPC_SLICE_LENGTH(
               tcp->outgoing_buffer->slices[tcp->outgoing_slice_idx]) -
           tcp->outgoing_byte_idx;
       sending_length += iov[iov_size].iov_len;
@@ -392,7 +377,7 @@ static bool tcp_flush(grpc_tcp *tcp, grpc_error **error) {
       size_t slice_length;
 
       tcp->outgoing_slice_idx--;
-      slice_length = GPR_SLICE_LENGTH(
+      slice_length = GRPC_SLICE_LENGTH(
           tcp->outgoing_buffer->slices[tcp->outgoing_slice_idx]);
       if (slice_length > trailing) {
         tcp->outgoing_byte_idx = slice_length - trailing;
@@ -442,7 +427,7 @@ static void tcp_handle_write(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
 }
 
 static void tcp_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                      gpr_slice_buffer *buf, grpc_closure *cb) {
+                      grpc_slice_buffer *buf, grpc_closure *cb) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   grpc_error *error = GRPC_ERROR_NONE;
 
@@ -451,7 +436,7 @@ static void tcp_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
     for (i = 0; i < buf->count; i++) {
       char *data =
-          gpr_dump_slice(buf->slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
+          grpc_dump_slice(buf->slices[i], GPR_DUMP_HEX | GPR_DUMP_ASCII);
       gpr_log(GPR_DEBUG, "WRITE %p (peer=%s): %s", tcp, tcp->peer_string, data);
       gpr_free(data);
     }
@@ -508,6 +493,11 @@ static char *tcp_get_peer(grpc_endpoint *ep) {
   return gpr_strdup(tcp->peer_string);
 }
 
+static int tcp_get_fd(grpc_endpoint *ep) {
+  grpc_tcp *tcp = (grpc_tcp *)ep;
+  return tcp->fd;
+}
+
 static grpc_workqueue *tcp_get_workqueue(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   return grpc_fd_get_workqueue(tcp->em_fd);
@@ -515,7 +505,7 @@ static grpc_workqueue *tcp_get_workqueue(grpc_endpoint *ep) {
 
 static grpc_resource_user *tcp_get_resource_user(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
-  return &tcp->resource_user;
+  return tcp->resource_user;
 }
 
 static const grpc_endpoint_vtable vtable = {tcp_read,
@@ -526,7 +516,8 @@ static const grpc_endpoint_vtable vtable = {tcp_read,
                                             tcp_shutdown,
                                             tcp_destroy,
                                             tcp_get_resource_user,
-                                            tcp_get_peer};
+                                            tcp_get_peer,
+                                            tcp_get_fd};
 
 grpc_endpoint *grpc_tcp_create(grpc_fd *em_fd,
                                grpc_resource_quota *resource_quota,
@@ -543,20 +534,18 @@ grpc_endpoint *grpc_tcp_create(grpc_fd *em_fd,
   tcp->slice_size = slice_size;
   tcp->iov_size = 1;
   tcp->finished_edge = true;
-  /* paired with unref in grpc_tcp_destroy, and with the shutdown for our
-   * resource_user */
-  gpr_ref_init(&tcp->refcount, 2);
+  /* paired with unref in grpc_tcp_destroy */
+  gpr_ref_init(&tcp->refcount, 1);
   gpr_atm_no_barrier_store(&tcp->shutdown_count, 0);
   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);
-  grpc_resource_user_init(&tcp->resource_user, resource_quota, peer_string);
-  grpc_resource_user_slice_allocator_init(&tcp->slice_allocator,
-                                          &tcp->resource_user,
-                                          tcp_read_allocation_done, tcp);
+  grpc_slice_buffer_init(&tcp->last_read_buffer);
+  tcp->resource_user = grpc_resource_user_create(resource_quota, peer_string);
+  grpc_resource_user_slice_allocator_init(
+      &tcp->slice_allocator, tcp->resource_user, tcp_read_allocation_done, tcp);
   /* Tell network status tracker about new endpoint */
   grpc_network_status_register_endpoint(&tcp->base);
 
@@ -576,8 +565,7 @@ void grpc_tcp_destroy_and_release_fd(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   GPR_ASSERT(ep->vtable == &vtable);
   tcp->release_fd = fd;
   tcp->release_fd_cb = done;
-  tcp_maybe_shutdown_resource_user(exec_ctx, tcp);
-  gpr_slice_buffer_reset_and_unref(&tcp->last_read_buffer);
+  grpc_slice_buffer_reset_and_unref(&tcp->last_read_buffer);
   TCP_UNREF(exec_ctx, tcp, "destroy");
 }
 
diff --git a/src/core/lib/iomgr/tcp_uv.c b/src/core/lib/iomgr/tcp_uv.c
index 8e74c9e863..6e2ad1dbe9 100644
--- a/src/core/lib/iomgr/tcp_uv.c
+++ b/src/core/lib/iomgr/tcp_uv.c
@@ -38,14 +38,17 @@
 #include <limits.h>
 #include <string.h>
 
+#include <grpc/slice_buffer.h>
+
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/slice_buffer.h>
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/network_status_tracker.h"
+#include "src/core/lib/iomgr/resource_quota.h"
 #include "src/core/lib/iomgr/tcp_uv.h"
+#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 
 int grpc_tcp_trace = 0;
@@ -62,15 +65,14 @@ typedef struct {
   grpc_closure *read_cb;
   grpc_closure *write_cb;
 
-  gpr_slice read_slice;
-  gpr_slice_buffer *read_slices;
-  gpr_slice_buffer *write_slices;
+  grpc_slice read_slice;
+  grpc_slice_buffer *read_slices;
+  grpc_slice_buffer *write_slices;
   uv_buf_t *write_buffers;
 
-  grpc_resource_user resource_user;
+  grpc_resource_user *resource_user;
 
   bool shutting_down;
-  bool resource_user_shutting_down;
 
   char *peer_string;
   grpc_pollset *pollset;
@@ -78,23 +80,23 @@ typedef struct {
 
 static void uv_close_callback(uv_handle_t *handle) { gpr_free(handle); }
 
-static void tcp_free(grpc_tcp *tcp) {
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_resource_user_destroy(&exec_ctx, &tcp->resource_user);
+static void tcp_free(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
+  grpc_resource_user_unref(exec_ctx, tcp->resource_user);
   gpr_free(tcp);
-  grpc_exec_ctx_finish(&exec_ctx);
 }
 
 /*#define GRPC_TCP_REFCOUNT_DEBUG*/
 #ifdef GRPC_TCP_REFCOUNT_DEBUG
-#define TCP_UNREF(tcp, reason) tcp_unref((tcp), (reason), __FILE__, __LINE__)
-#define TCP_REF(tcp, reason) tcp_ref((tcp), (reason), __FILE__, __LINE__)
-static void tcp_unref(grpc_tcp *tcp, const char *reason, const char *file,
-                      int line) {
+#define TCP_UNREF(exec_ctx, tcp, reason) \
+  tcp_unref((exec_ctx), (tcp), (reason), __FILE__, __LINE__)
+#define TCP_REF(tcp, reason) \
+  tcp_ref((exec_ctx), (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(tcp);
+    tcp_free(exec_ctx, tcp);
   }
 }
 
@@ -105,11 +107,11 @@ static void tcp_ref(grpc_tcp *tcp, const char *reason, const char *file,
   gpr_ref(&tcp->refcount);
 }
 #else
-#define TCP_UNREF(tcp, reason) tcp_unref((tcp))
+#define TCP_UNREF(exec_ctx, tcp, reason) tcp_unref((exec_ctx), (tcp))
 #define TCP_REF(tcp, reason) tcp_ref((tcp))
-static void tcp_unref(grpc_tcp *tcp) {
+static void tcp_unref(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
   if (gpr_unref(&tcp->refcount)) {
-    tcp_free(tcp);
+    tcp_free(exec_ctx, tcp);
   }
 }
 
@@ -122,15 +124,15 @@ static void alloc_uv_buf(uv_handle_t *handle, size_t suggested_size,
   grpc_tcp *tcp = handle->data;
   (void)suggested_size;
   tcp->read_slice = grpc_resource_user_slice_malloc(
-      &exec_ctx, &tcp->resource_user, GRPC_TCP_DEFAULT_READ_SLICE_SIZE);
-  buf->base = (char *)GPR_SLICE_START_PTR(tcp->read_slice);
-  buf->len = GPR_SLICE_LENGTH(tcp->read_slice);
+      &exec_ctx, tcp->resource_user, GRPC_TCP_DEFAULT_READ_SLICE_SIZE);
+  buf->base = (char *)GRPC_SLICE_START_PTR(tcp->read_slice);
+  buf->len = GRPC_SLICE_LENGTH(tcp->read_slice);
   grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void read_callback(uv_stream_t *stream, ssize_t nread,
                           const uv_buf_t *buf) {
-  gpr_slice sub;
+  grpc_slice sub;
   grpc_error *error;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_tcp *tcp = stream->data;
@@ -139,7 +141,7 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
     // Nothing happened. Wait for the next callback
     return;
   }
-  TCP_UNREF(tcp, "read");
+  TCP_UNREF(&exec_ctx, tcp, "read");
   tcp->read_cb = NULL;
   // TODO(murgatroid99): figure out what the return value here means
   uv_read_stop(stream);
@@ -147,8 +149,8 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
     error = GRPC_ERROR_CREATE("EOF");
   } else if (nread > 0) {
     // Successful read
-    sub = gpr_slice_sub_no_ref(tcp->read_slice, 0, (size_t)nread);
-    gpr_slice_buffer_add(tcp->read_slices, sub);
+    sub = grpc_slice_sub_no_ref(tcp->read_slice, 0, (size_t)nread);
+    grpc_slice_buffer_add(tcp->read_slices, sub);
     error = GRPC_ERROR_NONE;
     if (grpc_tcp_trace) {
       size_t i;
@@ -156,8 +158,8 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
       gpr_log(GPR_DEBUG, "read: error=%s", str);
       grpc_error_free_string(str);
       for (i = 0; i < tcp->read_slices->count; i++) {
-        char *dump = gpr_dump_slice(tcp->read_slices->slices[i],
-                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
+        char *dump = grpc_dump_slice(tcp->read_slices->slices[i],
+                                     GPR_DUMP_HEX | GPR_DUMP_ASCII);
         gpr_log(GPR_DEBUG, "READ %p (peer=%s): %s", tcp, tcp->peer_string,
                 dump);
         gpr_free(dump);
@@ -172,14 +174,14 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
 }
 
 static void uv_endpoint_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                             gpr_slice_buffer *read_slices, grpc_closure *cb) {
+                             grpc_slice_buffer *read_slices, grpc_closure *cb) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   int status;
   grpc_error *error = GRPC_ERROR_NONE;
   GPR_ASSERT(tcp->read_cb == NULL);
   tcp->read_cb = cb;
   tcp->read_slices = read_slices;
-  gpr_slice_buffer_reset_and_unref(read_slices);
+  grpc_slice_buffer_reset_and_unref(read_slices);
   TCP_REF(tcp, "read");
   // TODO(murgatroid99): figure out what the return value here means
   status =
@@ -202,7 +204,7 @@ static void write_callback(uv_write_t *req, int status) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_closure *cb = tcp->write_cb;
   tcp->write_cb = NULL;
-  TCP_UNREF(tcp, "write");
+  TCP_UNREF(&exec_ctx, tcp, "write");
   if (status == 0) {
     error = GRPC_ERROR_NONE;
   } else {
@@ -213,28 +215,28 @@ static void write_callback(uv_write_t *req, int status) {
     gpr_log(GPR_DEBUG, "write complete on %p: error=%s", tcp, str);
   }
   gpr_free(tcp->write_buffers);
-  grpc_resource_user_free(&exec_ctx, &tcp->resource_user,
+  grpc_resource_user_free(&exec_ctx, tcp->resource_user,
                           sizeof(uv_buf_t) * tcp->write_slices->count);
   grpc_exec_ctx_sched(&exec_ctx, cb, error, NULL);
   grpc_exec_ctx_finish(&exec_ctx);
 }
 
 static void uv_endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                              gpr_slice_buffer *write_slices,
+                              grpc_slice_buffer *write_slices,
                               grpc_closure *cb) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   uv_buf_t *buffers;
   unsigned int buffer_count;
   unsigned int i;
-  gpr_slice *slice;
+  grpc_slice *slice;
   uv_write_t *write_req;
 
   if (grpc_tcp_trace) {
     size_t j;
 
     for (j = 0; j < write_slices->count; j++) {
-      char *data = gpr_dump_slice(write_slices->slices[j],
-                                  GPR_DUMP_HEX | GPR_DUMP_ASCII);
+      char *data = grpc_dump_slice(write_slices->slices[j],
+                                   GPR_DUMP_HEX | GPR_DUMP_ASCII);
       gpr_log(GPR_DEBUG, "WRITE %p (peer=%s): %s", tcp, tcp->peer_string, data);
       gpr_free(data);
     }
@@ -259,12 +261,12 @@ static void uv_endpoint_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   tcp->write_cb = cb;
   buffer_count = (unsigned int)tcp->write_slices->count;
   buffers = gpr_malloc(sizeof(uv_buf_t) * buffer_count);
-  grpc_resource_user_alloc(exec_ctx, &tcp->resource_user,
+  grpc_resource_user_alloc(exec_ctx, tcp->resource_user,
                            sizeof(uv_buf_t) * buffer_count, NULL);
   for (i = 0; i < buffer_count; i++) {
     slice = &tcp->write_slices->slices[i];
-    buffers[i].base = (char *)GPR_SLICE_START_PTR(*slice);
-    buffers[i].len = GPR_SLICE_LENGTH(*slice);
+    buffers[i].base = (char *)GRPC_SLICE_START_PTR(*slice);
+    buffers[i].len = GRPC_SLICE_LENGTH(*slice);
   }
   tcp->write_buffers = buffers;
   write_req = &tcp->write_req;
@@ -295,22 +297,6 @@ static void uv_add_to_pollset_set(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
 static void shutdown_callback(uv_shutdown_t *req, int status) {}
 
-static void resource_user_shutdown_done(grpc_exec_ctx *exec_ctx, void *arg,
-                                        grpc_error *error) {
-  TCP_UNREF(arg, "resource_user");
-}
-
-static void uv_resource_user_maybe_shutdown(grpc_exec_ctx *exec_ctx,
-                                            grpc_tcp *tcp) {
-  if (!tcp->resource_user_shutting_down) {
-    tcp->resource_user_shutting_down = true;
-    TCP_REF(tcp, "resource_user");
-    grpc_resource_user_shutdown(
-        exec_ctx, &tcp->resource_user,
-        grpc_closure_create(resource_user_shutdown_done, tcp));
-  }
-}
-
 static void uv_endpoint_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   if (!tcp->shutting_down) {
@@ -324,8 +310,7 @@ static void uv_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_network_status_unregister_endpoint(ep);
   grpc_tcp *tcp = (grpc_tcp *)ep;
   uv_close((uv_handle_t *)tcp->handle, uv_close_callback);
-  uv_resource_user_maybe_shutdown(exec_ctx, tcp);
-  TCP_UNREF(tcp, "destroy");
+  TCP_UNREF(exec_ctx, tcp, "destroy");
 }
 
 static char *uv_get_peer(grpc_endpoint *ep) {
@@ -335,15 +320,18 @@ static char *uv_get_peer(grpc_endpoint *ep) {
 
 static grpc_resource_user *uv_get_resource_user(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
-  return &tcp->resource_user;
+  return tcp->resource_user;
 }
 
 static grpc_workqueue *uv_get_workqueue(grpc_endpoint *ep) { return NULL; }
 
+static int uv_get_fd(grpc_endpoint *ep) { return -1; }
+
 static grpc_endpoint_vtable vtable = {
     uv_endpoint_read,  uv_endpoint_write,     uv_get_workqueue,
     uv_add_to_pollset, uv_add_to_pollset_set, uv_endpoint_shutdown,
-    uv_destroy,        uv_get_resource_user,  uv_get_peer};
+    uv_destroy,        uv_get_resource_user,  uv_get_peer,
+    uv_get_fd};
 
 grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle,
                                grpc_resource_quota *resource_quota,
@@ -364,8 +352,7 @@ grpc_endpoint *grpc_tcp_create(uv_tcp_t *handle,
   gpr_ref_init(&tcp->refcount, 1);
   tcp->peer_string = gpr_strdup(peer_string);
   tcp->shutting_down = false;
-  tcp->resource_user_shutting_down = false;
-  grpc_resource_user_init(&tcp->resource_user, resource_quota, peer_string);
+  tcp->resource_user = grpc_resource_user_create(resource_quota, peer_string);
   /* Tell network status tracking code about the new endpoint */
   grpc_network_status_register_endpoint(&tcp->base);
 
diff --git a/src/core/lib/iomgr/tcp_windows.c b/src/core/lib/iomgr/tcp_windows.c
index 46f0491d10..62afbcef51 100644
--- a/src/core/lib/iomgr/tcp_windows.c
+++ b/src/core/lib/iomgr/tcp_windows.c
@@ -40,10 +40,10 @@
 #include "src/core/lib/iomgr/network_status_tracker.h"
 #include "src/core/lib/iomgr/sockaddr_windows.h"
 
+#include <grpc/slice_buffer.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/log_windows.h>
-#include <grpc/support/slice_buffer.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
 
@@ -105,50 +105,39 @@ typedef struct grpc_tcp {
 
   grpc_closure *read_cb;
   grpc_closure *write_cb;
-  gpr_slice read_slice;
-  gpr_slice_buffer *write_slices;
-  gpr_slice_buffer *read_slices;
+  grpc_slice read_slice;
+  grpc_slice_buffer *write_slices;
+  grpc_slice_buffer *read_slices;
 
-  grpc_resource_user resource_user;
+  grpc_resource_user *resource_user;
 
   /* The IO Completion Port runs from another thread. We need some mechanism
      to protect ourselves when requesting a shutdown. */
   gpr_mu mu;
   int shutting_down;
 
-  gpr_atm resource_user_shutdown_count;
-
   char *peer_string;
 } grpc_tcp;
 
-static void win_unref_closure(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
-                              grpc_error *error);
-
-static void win_maybe_shutdown_resource_user(grpc_exec_ctx *exec_ctx,
-                                             grpc_tcp *tcp) {
-  if (gpr_atm_full_fetch_add(&tcp->resource_user_shutdown_count, 1) == 0) {
-    grpc_resource_user_shutdown(exec_ctx, &tcp->resource_user,
-                                grpc_closure_create(win_unref_closure, tcp));
-  }
-}
-
-static void tcp_free(grpc_tcp *tcp) {
+static void tcp_free(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
   grpc_winsocket_destroy(tcp->socket);
   gpr_mu_destroy(&tcp->mu);
   gpr_free(tcp->peer_string);
+  grpc_resource_user_unref(exec_ctx, tcp->resource_user);
   gpr_free(tcp);
 }
 
 /*#define GRPC_TCP_REFCOUNT_DEBUG*/
 #ifdef GRPC_TCP_REFCOUNT_DEBUG
-#define TCP_UNREF(tcp, reason) tcp_unref((tcp), (reason), __FILE__, __LINE__)
+#define TCP_UNREF(exec_ctx, tcp, reason) \
+  tcp_unref((exec_ctx), (tcp), (reason), __FILE__, __LINE__)
 #define TCP_REF(tcp, reason) tcp_ref((tcp), (reason), __FILE__, __LINE__)
-static void tcp_unref(grpc_tcp *tcp, const char *reason, const char *file,
-                      int 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(tcp);
+    tcp_free(exec_ctx, tcp);
   }
 }
 
@@ -159,28 +148,23 @@ static void tcp_ref(grpc_tcp *tcp, const char *reason, const char *file,
   gpr_ref(&tcp->refcount);
 }
 #else
-#define TCP_UNREF(tcp, reason) tcp_unref((tcp))
+#define TCP_UNREF(exec_ctx, tcp, reason) tcp_unref((exec_ctx), (tcp))
 #define TCP_REF(tcp, reason) tcp_ref((tcp))
-static void tcp_unref(grpc_tcp *tcp) {
+static void tcp_unref(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp) {
   if (gpr_unref(&tcp->refcount)) {
-    tcp_free(tcp);
+    tcp_free(exec_ctx, tcp);
   }
 }
 
 static void tcp_ref(grpc_tcp *tcp) { gpr_ref(&tcp->refcount); }
 #endif
 
-static void win_unref_closure(grpc_exec_ctx *exec_ctx, void *arg,
-                              grpc_error *error) {
-  TCP_UNREF(arg, "resource_user");
-}
-
 /* Asynchronous callback from the IOCP, or the background thread. */
 static void on_read(grpc_exec_ctx *exec_ctx, void *tcpp, grpc_error *error) {
   grpc_tcp *tcp = tcpp;
   grpc_closure *cb = tcp->read_cb;
   grpc_winsocket *socket = tcp->socket;
-  gpr_slice sub;
+  grpc_slice sub;
   grpc_winsocket_callback_info *info = &socket->read_info;
 
   GRPC_ERROR_REF(error);
@@ -190,25 +174,25 @@ static void on_read(grpc_exec_ctx *exec_ctx, void *tcpp, grpc_error *error) {
       char *utf8_message = gpr_format_message(info->wsa_error);
       error = GRPC_ERROR_CREATE(utf8_message);
       gpr_free(utf8_message);
-      gpr_slice_unref(tcp->read_slice);
+      grpc_slice_unref(tcp->read_slice);
     } else {
       if (info->bytes_transfered != 0 && !tcp->shutting_down) {
-        sub = gpr_slice_sub_no_ref(tcp->read_slice, 0, info->bytes_transfered);
-        gpr_slice_buffer_add(tcp->read_slices, sub);
+        sub = grpc_slice_sub_no_ref(tcp->read_slice, 0, info->bytes_transfered);
+        grpc_slice_buffer_add(tcp->read_slices, sub);
       } else {
-        gpr_slice_unref(tcp->read_slice);
+        grpc_slice_unref(tcp->read_slice);
         error = GRPC_ERROR_CREATE("End of TCP stream");
       }
     }
   }
 
   tcp->read_cb = NULL;
-  TCP_UNREF(tcp, "read");
+  TCP_UNREF(exec_ctx, tcp, "read");
   grpc_exec_ctx_sched(exec_ctx, cb, error, NULL);
 }
 
 static void win_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                     gpr_slice_buffer *read_slices, grpc_closure *cb) {
+                     grpc_slice_buffer *read_slices, grpc_closure *cb) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   grpc_winsocket *handle = tcp->socket;
   grpc_winsocket_callback_info *info = &handle->read_info;
@@ -225,13 +209,13 @@ static void win_read(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
 
   tcp->read_cb = cb;
   tcp->read_slices = read_slices;
-  gpr_slice_buffer_reset_and_unref(read_slices);
+  grpc_slice_buffer_reset_and_unref(read_slices);
 
-  tcp->read_slice = gpr_slice_malloc(8192);
+  tcp->read_slice = grpc_slice_malloc(8192);
 
-  buffer.len = (ULONG)GPR_SLICE_LENGTH(
+  buffer.len = (ULONG)GRPC_SLICE_LENGTH(
       tcp->read_slice);  // we know slice size fits in 32bit.
-  buffer.buf = (char *)GPR_SLICE_START_PTR(tcp->read_slice);
+  buffer.buf = (char *)GRPC_SLICE_START_PTR(tcp->read_slice);
 
   TCP_REF(tcp, "read");
 
@@ -287,13 +271,13 @@ static void on_write(grpc_exec_ctx *exec_ctx, void *tcpp, grpc_error *error) {
     }
   }
 
-  TCP_UNREF(tcp, "write");
+  TCP_UNREF(exec_ctx, tcp, "write");
   grpc_exec_ctx_sched(exec_ctx, cb, error, NULL);
 }
 
 /* Initiates a write. */
 static void win_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
-                      gpr_slice_buffer *slices, grpc_closure *cb) {
+                      grpc_slice_buffer *slices, grpc_closure *cb) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
   grpc_winsocket *socket = tcp->socket;
   grpc_winsocket_callback_info *info = &socket->write_info;
@@ -320,10 +304,10 @@ static void win_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   }
 
   for (i = 0; i < tcp->write_slices->count; i++) {
-    len = GPR_SLICE_LENGTH(tcp->write_slices->slices[i]);
+    len = GRPC_SLICE_LENGTH(tcp->write_slices->slices[i]);
     GPR_ASSERT(len <= ULONG_MAX);
     buffers[i].len = (ULONG)len;
-    buffers[i].buf = (char *)GPR_SLICE_START_PTR(tcp->write_slices->slices[i]);
+    buffers[i].buf = (char *)GRPC_SLICE_START_PTR(tcp->write_slices->slices[i]);
   }
 
   /* First, let's try a synchronous, non-blocking write. */
@@ -355,7 +339,7 @@ static void win_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
   if (status != 0) {
     int wsa_error = WSAGetLastError();
     if (wsa_error != WSA_IO_PENDING) {
-      TCP_UNREF(tcp, "write");
+      TCP_UNREF(exec_ctx, tcp, "write");
       grpc_exec_ctx_sched(exec_ctx, cb, GRPC_WSA_ERROR(wsa_error, "WSASend"),
                           NULL);
       return;
@@ -396,15 +380,14 @@ static void win_shutdown(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
      callback. See the comments in on_read and on_write. */
   tcp->shutting_down = 1;
   grpc_winsocket_shutdown(tcp->socket);
-  win_maybe_shutdown_resource_user(exec_ctx, tcp);
   gpr_mu_unlock(&tcp->mu);
+  grpc_resource_user_shutdown(exec_ctx, tcp->resource_user);
 }
 
 static void win_destroy(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep) {
   grpc_network_status_unregister_endpoint(ep);
   grpc_tcp *tcp = (grpc_tcp *)ep;
-  win_maybe_shutdown_resource_user(exec_ctx, tcp);
-  TCP_UNREF(tcp, "destroy");
+  TCP_UNREF(exec_ctx, tcp, "destroy");
 }
 
 static char *win_get_peer(grpc_endpoint *ep) {
@@ -416,9 +399,11 @@ static grpc_workqueue *win_get_workqueue(grpc_endpoint *ep) { return NULL; }
 
 static grpc_resource_user *win_get_resource_user(grpc_endpoint *ep) {
   grpc_tcp *tcp = (grpc_tcp *)ep;
-  return &tcp->resource_user;
+  return tcp->resource_user;
 }
 
+static int win_get_fd(grpc_endpoint *ep) { return -1; }
+
 static grpc_endpoint_vtable vtable = {win_read,
                                       win_write,
                                       win_get_workqueue,
@@ -427,7 +412,8 @@ static grpc_endpoint_vtable vtable = {win_read,
                                       win_shutdown,
                                       win_destroy,
                                       win_get_resource_user,
-                                      win_get_peer};
+                                      win_get_peer,
+                                      win_get_fd};
 
 grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket,
                                grpc_resource_quota *resource_quota,
@@ -441,7 +427,7 @@ grpc_endpoint *grpc_tcp_create(grpc_winsocket *socket,
   grpc_closure_init(&tcp->on_read, on_read, tcp);
   grpc_closure_init(&tcp->on_write, on_write, tcp);
   tcp->peer_string = gpr_strdup(peer_string);
-  grpc_resource_user_init(&tcp->resource_user, resource_quota, peer_string);
+  tcp->resource_user = grpc_resource_user_create(resource_quota, peer_string);
   /* Tell network status tracking code about the new endpoint */
   grpc_network_status_register_endpoint(&tcp->base);
 
diff --git a/src/core/lib/iomgr/wakeup_fd_pipe.c b/src/core/lib/iomgr/wakeup_fd_pipe.c
index 183f0eb930..e186d63683 100644
--- a/src/core/lib/iomgr/wakeup_fd_pipe.c
+++ b/src/core/lib/iomgr/wakeup_fd_pipe.c
@@ -95,6 +95,8 @@ static void pipe_destroy(grpc_wakeup_fd* fd_info) {
 
 static int pipe_check_availability(void) {
   grpc_wakeup_fd fd;
+  fd.read_fd = fd.write_fd = -1;
+
   if (pipe_init(&fd) == GRPC_ERROR_NONE) {
     pipe_destroy(&fd);
     return 1;