diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
index c37ead2318253d0311d8e762007b05b753a535f4..97d50a91be58ce68c92680e1ed453b88472b925c 100644
--- a/src/core/lib/surface/call.c
+++ b/src/core/lib/surface/call.c
@@ -145,16 +145,28 @@ typedef struct batch_control {
grpc_transport_stream_op_batch op;
} batch_control;
+typedef struct {
+ gpr_mu child_list_mu;
+ grpc_call *first_child;
+} parent_call;
+
+typedef struct {
+ grpc_call *parent;
+ /** siblings: children of the same parent form a list, and this list is
+ protected under
+ parent->mu */
+ grpc_call *sibling_next;
+ grpc_call *sibling_prev;
+} child_call;
+
struct grpc_call {
gpr_arena *arena;
grpc_completion_queue *cq;
grpc_polling_entity pollent;
grpc_channel *channel;
- grpc_call *parent;
- grpc_call *first_child;
gpr_timespec start_time;
- /* protects first_child, and child next/prev links */
- gpr_mu child_list_mu;
+ /* parent_call* */ gpr_atm parent_call_atm;
+ child_call *child_call;
/* client or server call */
bool is_client;
@@ -206,12 +218,6 @@ struct grpc_call {
int send_extra_metadata_count;
gpr_timespec send_deadline;
- /** siblings: children of the same parent form a list, and this list is
- protected under
- parent->mu */
- grpc_call *sibling_next;
- grpc_call *sibling_prev;
-
grpc_slice_buffer_stream sending_stream;
grpc_byte_stream *receiving_stream;
@@ -276,6 +282,23 @@ static void add_init_error(grpc_error **composite, grpc_error *new) {
*composite = grpc_error_add_child(*composite, new);
}
+static parent_call *get_or_create_parent_call(grpc_call *call) {
+ parent_call *p = (parent_call *)gpr_atm_acq_load(&call->parent_call_atm);
+ if (p == NULL) {
+ p = gpr_arena_alloc(call->arena, sizeof(*p));
+ gpr_mu_init(&p->child_list_mu);
+ if (!gpr_atm_rel_cas(&call->parent_call_atm, (gpr_atm)NULL, (gpr_atm)p)) {
+ gpr_mu_destroy(&p->child_list_mu);
+ p = (parent_call *)gpr_atm_acq_load(&call->parent_call_atm);
+ }
+ }
+ return p;
+}
+
+static parent_call *get_parent_call(grpc_call *call) {
+ return (parent_call *)gpr_atm_acq_load(&call->parent_call_atm);
+}
+
grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
const grpc_call_create_args *args,
grpc_call **out_call) {
@@ -291,10 +314,8 @@ grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
sizeof(grpc_call) + channel_stack->call_stack_size);
call->arena = arena;
*out_call = call;
- gpr_mu_init(&call->child_list_mu);
call->channel = args->channel;
call->cq = args->cq;
- call->parent = args->parent_call;
call->start_time = gpr_now(GPR_CLOCK_MONOTONIC);
/* Always support no compression */
GPR_BITSET(&call->encodings_accepted_by_peer, GRPC_COMPRESS_NONE);
@@ -326,11 +347,17 @@ grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
gpr_convert_clock_type(args->send_deadline, GPR_CLOCK_MONOTONIC);
if (args->parent_call != NULL) {
+ child_call *cc = call->child_call =
+ gpr_arena_alloc(arena, sizeof(child_call));
+ call->child_call->parent = args->parent_call;
+
GRPC_CALL_INTERNAL_REF(args->parent_call, "child");
GPR_ASSERT(call->is_client);
GPR_ASSERT(!args->parent_call->is_client);
- gpr_mu_lock(&args->parent_call->child_list_mu);
+ parent_call *pc = get_or_create_parent_call(args->parent_call);
+
+ gpr_mu_lock(&pc->child_list_mu);
if (args->propagation_mask & GRPC_PROPAGATE_DEADLINE) {
send_deadline = gpr_time_min(
@@ -364,17 +391,17 @@ grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
}
}
- if (args->parent_call->first_child == NULL) {
- args->parent_call->first_child = call;
- call->sibling_next = call->sibling_prev = call;
+ if (pc->first_child == NULL) {
+ pc->first_child = call;
+ cc->sibling_next = cc->sibling_prev = call;
} else {
- call->sibling_next = args->parent_call->first_child;
- call->sibling_prev = args->parent_call->first_child->sibling_prev;
- call->sibling_next->sibling_prev = call->sibling_prev->sibling_next =
- call;
+ cc->sibling_next = pc->first_child;
+ cc->sibling_prev = pc->first_child->child_call->sibling_prev;
+ cc->sibling_next->child_call->sibling_prev =
+ cc->sibling_prev->child_call->sibling_next = call;
}
- gpr_mu_unlock(&args->parent_call->child_list_mu);
+ gpr_mu_unlock(&pc->child_list_mu);
}
call->send_deadline = send_deadline;
@@ -469,7 +496,10 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call,
if (c->receiving_stream != NULL) {
grpc_byte_stream_destroy(exec_ctx, c->receiving_stream);
}
- gpr_mu_destroy(&c->child_list_mu);
+ parent_call *pc = get_parent_call(c);
+ if (pc != NULL) {
+ gpr_mu_destroy(&pc->child_list_mu);
+ }
for (ii = 0; ii < c->send_extra_metadata_count; ii++) {
GRPC_MDELEM_UNREF(exec_ctx, c->send_extra_metadata[ii].md);
}
@@ -499,31 +529,31 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call,
}
void grpc_call_destroy(grpc_call *c) {
- int cancel;
- grpc_call *parent = c->parent;
+ child_call *cc = c->child_call;
grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
GPR_TIMER_BEGIN("grpc_call_destroy", 0);
GRPC_API_TRACE("grpc_call_destroy(c=%p)", 1, (c));
- if (parent) {
- gpr_mu_lock(&parent->child_list_mu);
- if (c == parent->first_child) {
- parent->first_child = c->sibling_next;
- if (c == parent->first_child) {
- parent->first_child = NULL;
+ if (cc) {
+ parent_call *pc = get_parent_call(cc->parent);
+ gpr_mu_lock(&pc->child_list_mu);
+ if (c == pc->first_child) {
+ pc->first_child = cc->sibling_next;
+ if (c == pc->first_child) {
+ pc->first_child = NULL;
}
}
- c->sibling_prev->sibling_next = c->sibling_next;
- c->sibling_next->sibling_prev = c->sibling_prev;
- gpr_mu_unlock(&parent->child_list_mu);
- GRPC_CALL_INTERNAL_UNREF(&exec_ctx, parent, "child");
+ cc->sibling_prev->child_call->sibling_next = cc->sibling_next;
+ cc->sibling_next->child_call->sibling_prev = cc->sibling_prev;
+ gpr_mu_unlock(&pc->child_list_mu);
+ GRPC_CALL_INTERNAL_UNREF(&exec_ctx, cc->parent, "child");
}
GPR_ASSERT(!c->destroy_called);
c->destroy_called = 1;
- cancel = gpr_atm_acq_load(&c->any_ops_sent_atm) &&
- !gpr_atm_acq_load(&c->received_final_op_atm);
+ bool cancel = gpr_atm_acq_load(&c->any_ops_sent_atm) != 0 &&
+ gpr_atm_acq_load(&c->received_final_op_atm) == 0;
if (cancel) {
cancel_with_error(&exec_ctx, c, STATUS_FROM_API_OVERRIDE,
GRPC_ERROR_CANCELLED);
@@ -1079,7 +1109,6 @@ static grpc_error *consolidate_batch_errors(batch_control *bctl) {
static void post_batch_completion(grpc_exec_ctx *exec_ctx,
batch_control *bctl) {
- grpc_call *child_call;
grpc_call *next_child_call;
grpc_call *call = bctl->call;
grpc_error *error = consolidate_batch_errors(bctl);
@@ -1104,21 +1133,25 @@ static void post_batch_completion(grpc_exec_ctx *exec_ctx,
/* propagate cancellation to any interested children */
gpr_atm_rel_store(&call->received_final_op_atm, 1);
- gpr_mu_lock(&call->child_list_mu);
- child_call = call->first_child;
- if (child_call != NULL) {
- do {
- next_child_call = child_call->sibling_next;
- if (child_call->cancellation_is_inherited) {
- GRPC_CALL_INTERNAL_REF(child_call, "propagate_cancel");
- cancel_with_error(exec_ctx, child_call, STATUS_FROM_API_OVERRIDE,
- GRPC_ERROR_CANCELLED);
- GRPC_CALL_INTERNAL_UNREF(exec_ctx, child_call, "propagate_cancel");
- }
- child_call = next_child_call;
- } while (child_call != call->first_child);
+ parent_call *pc = get_parent_call(call);
+ if (pc != NULL) {
+ grpc_call *child;
+ gpr_mu_lock(&pc->child_list_mu);
+ child = pc->first_child;
+ if (child != NULL) {
+ do {
+ next_child_call = child->child_call->sibling_next;
+ if (child->cancellation_is_inherited) {
+ GRPC_CALL_INTERNAL_REF(child, "propagate_cancel");
+ cancel_with_error(exec_ctx, child, STATUS_FROM_API_OVERRIDE,
+ GRPC_ERROR_CANCELLED);
+ GRPC_CALL_INTERNAL_UNREF(exec_ctx, child, "propagate_cancel");
+ }
+ child = next_child_call;
+ } while (child != pc->first_child);
+ }
+ gpr_mu_unlock(&pc->child_list_mu);
}
- gpr_mu_unlock(&call->child_list_mu);
if (call->is_client) {
get_final_status(call, set_status_value_directly,