Fix some kicking bugs
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.c b/src/core/lib/iomgr/ev_epoll1_linux.c
index 0f067b5..64eef09 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.c
+++ b/src/core/lib/iomgr/ev_epoll1_linux.c
@@ -95,6 +95,7 @@
struct grpc_pollset_worker {
kick_state kick_state;
+ int kick_state_mutator; // which line of code last changed kick state
bool initialized_cv;
grpc_pollset_worker *next;
grpc_pollset_worker *prev;
@@ -102,6 +103,12 @@
grpc_closure_list schedule_on_end_work;
};
+#define SET_KICK_STATE(worker, state) \
+ do { \
+ (worker)->kick_state = (state); \
+ (worker)->kick_state_mutator = __LINE__; \
+ } while (false)
+
#define MAX_NEIGHBOURHOODS 1024
typedef struct pollset_neighbourhood {
@@ -431,13 +438,20 @@
if (pollset->root_worker != NULL) {
grpc_pollset_worker *worker = pollset->root_worker;
do {
- if (worker->initialized_cv) {
- worker->kick_state = KICKED;
- gpr_cv_signal(&worker->cv);
- } else {
- worker->kick_state = KICKED;
- append_error(&error, grpc_wakeup_fd_wakeup(&global_wakeup_fd),
- "pollset_shutdown");
+ switch (worker->kick_state) {
+ case KICKED:
+ break;
+ case UNKICKED:
+ SET_KICK_STATE(worker, KICKED);
+ if (worker->initialized_cv) {
+ gpr_cv_signal(&worker->cv);
+ }
+ break;
+ case DESIGNATED_POLLER:
+ SET_KICK_STATE(worker, KICKED);
+ append_error(&error, grpc_wakeup_fd_wakeup(&global_wakeup_fd),
+ "pollset_shutdown");
+ break;
}
worker = worker->next;
@@ -534,7 +548,7 @@
gpr_timespec deadline) {
if (worker_hdl != NULL) *worker_hdl = worker;
worker->initialized_cv = false;
- worker->kick_state = UNKICKED;
+ SET_KICK_STATE(worker, UNKICKED);
worker->schedule_on_end_work = (grpc_closure_list)GRPC_CLOSURE_LIST_INIT;
pollset->begin_refs++;
@@ -563,8 +577,9 @@
pollset->seen_inactive = false;
if (neighbourhood->active_root == NULL) {
neighbourhood->active_root = pollset->next = pollset->prev = pollset;
- if (gpr_atm_no_barrier_cas(&g_active_poller, 0, (gpr_atm)worker)) {
- worker->kick_state = DESIGNATED_POLLER;
+ if (worker->kick_state == UNKICKED &&
+ gpr_atm_no_barrier_cas(&g_active_poller, 0, (gpr_atm)worker)) {
+ SET_KICK_STATE(worker, DESIGNATED_POLLER);
}
} else {
pollset->next = neighbourhood->active_root;
@@ -588,7 +603,7 @@
pollset->shutdown_closure == NULL) {
if (gpr_cv_wait(&worker->cv, &pollset->mu, deadline) &&
worker->kick_state == UNKICKED) {
- worker->kick_state = KICKED;
+ SET_KICK_STATE(worker, KICKED);
}
}
*now = gpr_now(now->clock_type);
@@ -615,7 +630,7 @@
case UNKICKED:
if (gpr_atm_no_barrier_cas(&g_active_poller, 0,
(gpr_atm)inspect_worker)) {
- inspect_worker->kick_state = DESIGNATED_POLLER;
+ SET_KICK_STATE(inspect_worker, DESIGNATED_POLLER);
if (inspect_worker->initialized_cv) {
gpr_cv_signal(&inspect_worker->cv);
}
@@ -652,14 +667,14 @@
grpc_pollset_worker *worker,
grpc_pollset_worker **worker_hdl) {
if (worker_hdl != NULL) *worker_hdl = NULL;
- worker->kick_state = KICKED;
+ SET_KICK_STATE(worker, KICKED);
grpc_closure_list_move(&worker->schedule_on_end_work,
&exec_ctx->closure_list);
if (gpr_atm_no_barrier_load(&g_active_poller) == (gpr_atm)worker) {
if (worker->next != worker && worker->next->kick_state == UNKICKED) {
GPR_ASSERT(worker->next->initialized_cv);
gpr_atm_no_barrier_store(&g_active_poller, (gpr_atm)worker->next);
- worker->next->kick_state = DESIGNATED_POLLER;
+ SET_KICK_STATE(worker->next, DESIGNATED_POLLER);
gpr_cv_signal(&worker->next->cv);
if (grpc_exec_ctx_has_work(exec_ctx)) {
gpr_mu_unlock(&pollset->mu);
@@ -752,38 +767,53 @@
return GRPC_ERROR_NONE;
}
grpc_pollset_worker *next_worker = root_worker->next;
- if (root_worker == next_worker &&
+ if (root_worker == next_worker && // only try and wake up a poller if
+ // there is no next worker
root_worker == (grpc_pollset_worker *)gpr_atm_no_barrier_load(
&g_active_poller)) {
- root_worker->kick_state = KICKED;
+ SET_KICK_STATE(root_worker, KICKED);
return grpc_wakeup_fd_wakeup(&global_wakeup_fd);
} else if (next_worker->kick_state == UNKICKED) {
GPR_ASSERT(next_worker->initialized_cv);
- next_worker->kick_state = KICKED;
+ SET_KICK_STATE(next_worker, KICKED);
gpr_cv_signal(&next_worker->cv);
return GRPC_ERROR_NONE;
+ } else if (next_worker->kick_state == DESIGNATED_POLLER) {
+ if (root_worker->kick_state != DESIGNATED_POLLER) {
+ SET_KICK_STATE(root_worker, KICKED);
+ if (root_worker->initialized_cv) {
+ gpr_cv_signal(&root_worker->cv);
+ }
+ return GRPC_ERROR_NONE;
+ } else {
+ SET_KICK_STATE(next_worker, KICKED);
+ return grpc_wakeup_fd_wakeup(&global_wakeup_fd);
+ }
} else {
+ GPR_ASSERT(next_worker->kick_state == KICKED);
+ SET_KICK_STATE(next_worker, KICKED);
return GRPC_ERROR_NONE;
}
} else {
+ GPR_ASSERT(false);
return GRPC_ERROR_NONE;
}
} else if (specific_worker->kick_state == KICKED) {
return GRPC_ERROR_NONE;
} else if (gpr_tls_get(&g_current_thread_worker) ==
(intptr_t)specific_worker) {
- specific_worker->kick_state = KICKED;
+ SET_KICK_STATE(specific_worker, KICKED);
return GRPC_ERROR_NONE;
} else if (specific_worker ==
(grpc_pollset_worker *)gpr_atm_no_barrier_load(&g_active_poller)) {
- specific_worker->kick_state = KICKED;
+ SET_KICK_STATE(specific_worker, KICKED);
return grpc_wakeup_fd_wakeup(&global_wakeup_fd);
} else if (specific_worker->initialized_cv) {
- specific_worker->kick_state = KICKED;
+ SET_KICK_STATE(specific_worker, KICKED);
gpr_cv_signal(&specific_worker->cv);
return GRPC_ERROR_NONE;
} else {
- specific_worker->kick_state = KICKED;
+ SET_KICK_STATE(specific_worker, KICKED);
return GRPC_ERROR_NONE;
}
}
@@ -830,7 +860,7 @@
grpc_pollset_worker *inspect_worker = inspect->root_worker;
do {
if (inspect_worker->kick_state == UNKICKED) {
- inspect_worker->kick_state = KICKED;
+ SET_KICK_STATE(inspect_worker, KICKED);
grpc_closure_list_append(
&inspect_worker->schedule_on_end_work, closure, error);
if (inspect_worker->initialized_cv) {