Merge pull request #16162 from yashykt/evengcleanup

Remove the notifier pollset from grpc event engine since it's not use…

5 files changed, 13 insertions, 101 deletions

diff --git a/src/core/lib/iomgr/ev_epoll1_linux.cc b/src/core/lib/iomgr/ev_epoll1_linux.cc
index 86a0243d2e..ecb7eadf85 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.cc
+++ b/src/core/lib/iomgr/ev_epoll1_linux.cc
@@ -140,10 +140,6 @@ struct grpc_fd {
 
   struct grpc_fd* freelist_next;
 
-  /* The pollset that last noticed that the fd is readable. The actual type
-   * stored in this is (grpc_pollset *) */
-  gpr_atm read_notifier_pollset;
-
   grpc_iomgr_object iomgr_object;
 };
 
@@ -293,7 +289,6 @@ static grpc_fd* fd_create(int fd, const char* name, bool track_err) {
   new_fd->read_closure->InitEvent();
   new_fd->write_closure->InitEvent();
   new_fd->error_closure->InitEvent();
-  gpr_atm_no_barrier_store(&new_fd->read_notifier_pollset, (gpr_atm)NULL);
 
   new_fd->freelist_next = nullptr;
 
@@ -376,11 +371,6 @@ static void fd_orphan(grpc_fd* fd, grpc_closure* on_done, int* release_fd,
   gpr_mu_unlock(&fd_freelist_mu);
 }
 
-static grpc_pollset* fd_get_read_notifier_pollset(grpc_fd* fd) {
-  gpr_atm notifier = gpr_atm_acq_load(&fd->read_notifier_pollset);
-  return (grpc_pollset*)notifier;
-}
-
 static bool fd_is_shutdown(grpc_fd* fd) {
   return fd->read_closure->IsShutdown();
 }
@@ -397,11 +387,7 @@ static void fd_notify_on_error(grpc_fd* fd, grpc_closure* closure) {
   fd->error_closure->NotifyOn(closure);
 }
 
-static void fd_become_readable(grpc_fd* fd, grpc_pollset* notifier) {
-  fd->read_closure->SetReady();
-  /* Use release store to match with acquire load in fd_get_read_notifier */
-  gpr_atm_rel_store(&fd->read_notifier_pollset, (gpr_atm)notifier);
-}
+static void fd_become_readable(grpc_fd* fd) { fd->read_closure->SetReady(); }
 
 static void fd_become_writable(grpc_fd* fd) { fd->write_closure->SetReady(); }
 
@@ -642,7 +628,7 @@ static grpc_error* process_epoll_events(grpc_pollset* pollset) {
       }
 
       if (read_ev || cancel || err_fallback) {
-        fd_become_readable(fd, pollset);
+        fd_become_readable(fd);
       }
 
       if (write_ev || cancel || err_fallback) {
@@ -1218,7 +1204,6 @@ static const grpc_event_engine_vtable vtable = {
     fd_notify_on_write,
     fd_notify_on_error,
     fd_is_shutdown,
-    fd_get_read_notifier_pollset,
 
     pollset_init,
     pollset_shutdown,
diff --git a/src/core/lib/iomgr/ev_epollex_linux.cc b/src/core/lib/iomgr/ev_epollex_linux.cc
index e1f3e43af7..6ec8267799 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.cc
+++ b/src/core/lib/iomgr/ev_epollex_linux.cc
@@ -220,10 +220,6 @@ struct grpc_fd {
   struct grpc_fd* freelist_next;
   grpc_closure* on_done_closure;
 
-  // The pollset that last noticed that the fd is readable. The actual type
-  // stored in this is (grpc_pollset *)
-  gpr_atm read_notifier_pollset;
-
   grpc_iomgr_object iomgr_object;
 
   // Do we need to track EPOLLERR events separately?
@@ -353,7 +349,6 @@ static void invalidate_fd(grpc_fd* fd) {
   memset(&fd->pollable_mu, -1, sizeof(fd->pollable_mu));
   fd->pollable_obj = nullptr;
   fd->on_done_closure = nullptr;
-  gpr_atm_no_barrier_store(&fd->read_notifier_pollset, 0);
   memset(&fd->iomgr_object, -1, sizeof(fd->iomgr_object));
   fd->track_err = false;
 }
@@ -445,7 +440,6 @@ static grpc_fd* fd_create(int fd, const char* name, bool track_err) {
   new_fd->error_closure->InitEvent();
   new_fd->freelist_next = nullptr;
   new_fd->on_done_closure = nullptr;
-  gpr_atm_no_barrier_store(&new_fd->read_notifier_pollset, (gpr_atm)NULL);
 
   char* fd_name;
   gpr_asprintf(&fd_name, "%s fd=%d", name, fd);
@@ -514,11 +508,6 @@ static void fd_orphan(grpc_fd* fd, grpc_closure* on_done, int* release_fd,
   UNREF_BY(fd, 2, reason); /* Drop the reference */
 }
 
-static grpc_pollset* fd_get_read_notifier_pollset(grpc_fd* fd) {
-  gpr_atm notifier = gpr_atm_acq_load(&fd->read_notifier_pollset);
-  return (grpc_pollset*)notifier;
-}
-
 static bool fd_is_shutdown(grpc_fd* fd) {
   return fd->read_closure->IsShutdown();
 }
@@ -875,17 +864,7 @@ static int poll_deadline_to_millis_timeout(grpc_millis millis) {
     return static_cast<int>(delta);
 }
 
-static void fd_become_readable(grpc_fd* fd, grpc_pollset* notifier) {
-  fd->read_closure->SetReady();
-
-  /* Note, it is possible that fd_become_readable might be called twice with
-     different 'notifier's when an fd becomes readable and it is in two epoll
-     sets (This can happen briefly during polling island merges). In such cases
-     it does not really matter which notifer is set as the read_notifier_pollset
-     (They would both point to the same polling island anyway) */
-  /* Use release store to match with acquire load in fd_get_read_notifier */
-  gpr_atm_rel_store(&fd->read_notifier_pollset, (gpr_atm)notifier);
-}
+static void fd_become_readable(grpc_fd* fd) { fd->read_closure->SetReady(); }
 
 static void fd_become_writable(grpc_fd* fd) { fd->write_closure->SetReady(); }
 
@@ -983,7 +962,7 @@ static grpc_error* pollable_process_events(grpc_pollset* pollset,
         fd_has_errors(fd);
       }
       if (read_ev || cancel || err_fallback) {
-        fd_become_readable(fd, pollset);
+        fd_become_readable(fd);
       }
       if (write_ev || cancel || err_fallback) {
         fd_become_writable(fd);
@@ -1637,7 +1616,6 @@ static const grpc_event_engine_vtable vtable = {
     fd_notify_on_write,
     fd_notify_on_error,
     fd_is_shutdown,
-    fd_get_read_notifier_pollset,
 
     pollset_init,
     pollset_shutdown,
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.cc b/src/core/lib/iomgr/ev_epollsig_linux.cc
index 2189801c18..28656b0666 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.cc
+++ b/src/core/lib/iomgr/ev_epollsig_linux.cc
@@ -137,10 +137,6 @@ struct grpc_fd {
   struct grpc_fd* freelist_next;
   grpc_closure* on_done_closure;
 
-  /* The pollset that last noticed that the fd is readable. The actual type
-   * stored in this is (grpc_pollset *) */
-  gpr_atm read_notifier_pollset;
-
   grpc_iomgr_object iomgr_object;
 
   /* Do we need to track EPOLLERR events separately? */
@@ -845,7 +841,6 @@ static grpc_fd* fd_create(int fd, const char* name, bool track_err) {
   new_fd->write_closure->InitEvent();
   new_fd->error_closure->InitEvent();
   new_fd->track_err = track_err;
-  gpr_atm_no_barrier_store(&new_fd->read_notifier_pollset, (gpr_atm)NULL);
 
   new_fd->freelist_next = nullptr;
   new_fd->on_done_closure = nullptr;
@@ -927,11 +922,6 @@ static void fd_orphan(grpc_fd* fd, grpc_closure* on_done, int* release_fd,
   GRPC_ERROR_UNREF(error);
 }
 
-static grpc_pollset* fd_get_read_notifier_pollset(grpc_fd* fd) {
-  gpr_atm notifier = gpr_atm_acq_load(&fd->read_notifier_pollset);
-  return (grpc_pollset*)notifier;
-}
-
 static bool fd_is_shutdown(grpc_fd* fd) {
   return fd->read_closure->IsShutdown();
 }
@@ -1115,17 +1105,7 @@ static int poll_deadline_to_millis_timeout(grpc_millis millis) {
     return static_cast<int>(delta);
 }
 
-static void fd_become_readable(grpc_fd* fd, grpc_pollset* notifier) {
-  fd->read_closure->SetReady();
-
-  /* Note, it is possible that fd_become_readable might be called twice with
-     different 'notifier's when an fd becomes readable and it is in two epoll
-     sets (This can happen briefly during polling island merges). In such cases
-     it does not really matter which notifer is set as the read_notifier_pollset
-     (They would both point to the same polling island anyway) */
-  /* Use release store to match with acquire load in fd_get_read_notifier */
-  gpr_atm_rel_store(&fd->read_notifier_pollset, (gpr_atm)notifier);
-}
+static void fd_become_readable(grpc_fd* fd) { fd->read_closure->SetReady(); }
 
 static void fd_become_writable(grpc_fd* fd) { fd->write_closure->SetReady(); }
 
@@ -1283,7 +1263,7 @@ static void pollset_work_and_unlock(grpc_pollset* pollset,
         fd_has_errors(fd);
       }
       if (read_ev || cancel || err_fallback) {
-        fd_become_readable(fd, pollset);
+        fd_become_readable(fd);
       }
       if (write_ev || cancel || err_fallback) {
         fd_become_writable(fd);
@@ -1668,7 +1648,6 @@ static const grpc_event_engine_vtable vtable = {
     fd_notify_on_write,
     fd_notify_on_error,
     fd_is_shutdown,
-    fd_get_read_notifier_pollset,
 
     pollset_init,
     pollset_shutdown,
diff --git a/src/core/lib/iomgr/ev_poll_posix.cc b/src/core/lib/iomgr/ev_poll_posix.cc
index c9c09881a2..ff4888eeb8 100644
--- a/src/core/lib/iomgr/ev_poll_posix.cc
+++ b/src/core/lib/iomgr/ev_poll_posix.cc
@@ -108,9 +108,6 @@ struct grpc_fd {
   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.
@@ -131,8 +128,7 @@ static uint32_t fd_begin_poll(grpc_fd* fd, grpc_pollset* pollset,
    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_fd_watcher* rec, int got_read, int got_write,
-                        grpc_pollset* read_notifier_pollset);
+static void fd_end_poll(grpc_fd_watcher* rec, int got_read, int got_write);
 
 /* Return 1 if this fd is orphaned, 0 otherwise */
 static bool fd_is_orphaned(grpc_fd* fd);
@@ -346,7 +342,6 @@ static grpc_fd* fd_create(int fd, const char* name, bool track_err) {
   r->closed = 0;
   r->released = 0;
   gpr_atm_no_barrier_store(&r->pollhup, 0);
-  r->read_notifier_pollset = nullptr;
 
   char* name2;
   gpr_asprintf(&name2, "%s fd=%d", name, fd);
@@ -359,17 +354,6 @@ static bool fd_is_orphaned(grpc_fd* fd) {
   return (gpr_atm_acq_load(&fd->refst) & 1) == 0;
 }
 
-/* Return the read-notifier pollset */
-static grpc_pollset* fd_get_read_notifier_pollset(grpc_fd* fd) {
-  grpc_pollset* notifier = nullptr;
-
-  gpr_mu_lock(&fd->mu);
-  notifier = fd->read_notifier_pollset;
-  gpr_mu_unlock(&fd->mu);
-
-  return notifier;
-}
-
 static grpc_error* pollset_kick_locked(grpc_fd_watcher* watcher) {
   gpr_mu_lock(&watcher->pollset->mu);
   GPR_ASSERT(watcher->worker);
@@ -512,11 +496,6 @@ static int set_ready_locked(grpc_fd* fd, grpc_closure** st) {
   }
 }
 
-static void set_read_notifier_pollset_locked(
-    grpc_fd* fd, grpc_pollset* read_notifier_pollset) {
-  fd->read_notifier_pollset = read_notifier_pollset;
-}
-
 static void fd_shutdown(grpc_fd* fd, grpc_error* why) {
   gpr_mu_lock(&fd->mu);
   /* only shutdown once */
@@ -608,8 +587,7 @@ static uint32_t fd_begin_poll(grpc_fd* fd, grpc_pollset* pollset,
   return mask;
 }
 
-static void fd_end_poll(grpc_fd_watcher* watcher, int got_read, int got_write,
-                        grpc_pollset* read_notifier_pollset) {
+static void fd_end_poll(grpc_fd_watcher* watcher, int got_read, int got_write) {
   int was_polling = 0;
   int kick = 0;
   grpc_fd* fd = watcher->fd;
@@ -645,9 +623,6 @@ static void fd_end_poll(grpc_fd_watcher* watcher, int got_read, int got_write,
     if (set_ready_locked(fd, &fd->read_closure)) {
       kick = 1;
     }
-    if (read_notifier_pollset != nullptr) {
-      set_read_notifier_pollset_locked(fd, read_notifier_pollset);
-    }
   }
   if (got_write) {
     if (set_ready_locked(fd, &fd->write_closure)) {
@@ -997,16 +972,16 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
 
         for (i = 1; i < pfd_count; i++) {
           if (watchers[i].fd == nullptr) {
-            fd_end_poll(&watchers[i], 0, 0, nullptr);
+            fd_end_poll(&watchers[i], 0, 0);
           } else {
             // Wake up all the file descriptors, if we have an invalid one
             // we can identify it on the next pollset_work()
-            fd_end_poll(&watchers[i], 1, 1, pollset);
+            fd_end_poll(&watchers[i], 1, 1);
           }
         }
       } else if (r == 0) {
         for (i = 1; i < pfd_count; i++) {
-          fd_end_poll(&watchers[i], 0, 0, nullptr);
+          fd_end_poll(&watchers[i], 0, 0);
         }
       } else {
         if (pfds[0].revents & POLLIN_CHECK) {
@@ -1018,7 +993,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
         }
         for (i = 1; i < pfd_count; i++) {
           if (watchers[i].fd == nullptr) {
-            fd_end_poll(&watchers[i], 0, 0, nullptr);
+            fd_end_poll(&watchers[i], 0, 0);
           } else {
             if (grpc_polling_trace.enabled()) {
               gpr_log(GPR_INFO, "%p got_event: %d r:%d w:%d [%d]", pollset,
@@ -1032,7 +1007,7 @@ static grpc_error* pollset_work(grpc_pollset* pollset,
               gpr_atm_no_barrier_store(&watchers[i].fd->pollhup, 1);
             }
             fd_end_poll(&watchers[i], pfds[i].revents & POLLIN_CHECK,
-                        pfds[i].revents & POLLOUT_CHECK, pollset);
+                        pfds[i].revents & POLLOUT_CHECK);
           }
         }
       }
@@ -1724,7 +1699,6 @@ static const grpc_event_engine_vtable vtable = {
     fd_notify_on_write,
     fd_notify_on_error,
     fd_is_shutdown,
-    fd_get_read_notifier_pollset,
 
     pollset_init,
     pollset_shutdown,
diff --git a/src/core/lib/iomgr/ev_posix.h b/src/core/lib/iomgr/ev_posix.h
index b4c17fc80d..393c3dd05e 100644
--- a/src/core/lib/iomgr/ev_posix.h
+++ b/src/core/lib/iomgr/ev_posix.h
@@ -52,7 +52,6 @@ typedef struct grpc_event_engine_vtable {
   void (*fd_notify_on_write)(grpc_fd* fd, grpc_closure* closure);
   void (*fd_notify_on_error)(grpc_fd* fd, grpc_closure* closure);
   bool (*fd_is_shutdown)(grpc_fd* fd);
-  grpc_pollset* (*fd_get_read_notifier_pollset)(grpc_fd* fd);
 
   void (*pollset_init)(grpc_pollset* pollset, gpr_mu** mu);
   void (*pollset_shutdown)(grpc_pollset* pollset, grpc_closure* closure);
@@ -142,9 +141,6 @@ void grpc_fd_notify_on_write(grpc_fd* fd, grpc_closure* closure);
  * needs to have been set on grpc_fd_create */
 void grpc_fd_notify_on_error(grpc_fd* fd, grpc_closure* closure);
 
-/* Return the read notifier pollset from the fd */
-grpc_pollset* grpc_fd_get_read_notifier_pollset(grpc_fd* fd);
-
 /* pollset_posix functions */
 
 /* Add an fd to a pollset */