Commit 1e5a537a authored by Seppo Takalo's avatar Seppo Takalo Committed by Mahesh Mahadevan
Browse files

net: lib: coap_client: Remove unnecessary atomic variable 



In receiving thread, continuing the loops is based on
has_ongoing_exchanges() so it does not need atomic
coap_client_recv_active variable.

When idling, it wakes from semaphore. But there was potential
deadlock when coap_client_schedule_poll() would not signal the
semaphore, if atomic variable was already showing that it runs.
Removing the atomic variable removes this deadlock.

Signed-off-by: default avatarSeppo Takalo <seppo.takalo@nordicsemi.no>
parent 9c9dc9f7

subsys/net/lib/coap/coap_client.c

+1 −8
Original line number Diff line number Diff line
@@ -24,7 +24,6 @@ static K_MUTEX_DEFINE(coap_client_mutex); 
static struct coap_client *clients[CONFIG_COAP_CLIENT_MAX_INSTANCES];

static int num_clients;

static K_SEM_DEFINE(coap_client_recv_sem, 0, 1);

static atomic_t coap_client_recv_active;



static bool timeout_expired(struct coap_client_internal_request *internal_req);

static void cancel_requests_with(struct coap_client *client, int error);
@@ -82,10 +81,7 @@ static int coap_client_schedule_poll(struct coap_client *client, int sock, 
	memcpy(&internal_req->coap_request, req, sizeof(struct coap_client_request));

	internal_req->request_ongoing = true;



	if (!coap_client_recv_active) {

	k_sem_give(&coap_client_recv_sem);

	}

	atomic_set(&coap_client_recv_active, 1);



	return 0;

}
@@ -956,7 +952,6 @@ static void cancel_requests_with(struct coap_client *client, int error) 
			reset_internal_request(&client->requests[i]);

		}

	}

	atomic_clear(&coap_client_recv_active);

	k_mutex_unlock(&client->lock);



}
@@ -974,7 +969,6 @@ void coap_client_recv(void *coap_cl, void *a, void *b) 


	k_sem_take(&coap_client_recv_sem, K_FOREVER);

	while (true) {

		atomic_set(&coap_client_recv_active, 1);

		ret = handle_poll();

		if (ret < 0) {

			/* Error in polling */
@@ -987,7 +981,6 @@ void coap_client_recv(void *coap_cl, void *a, void *b) 
			continue;

		} else {

idle:

			atomic_set(&coap_client_recv_active, 0);

			k_sem_take(&coap_client_recv_sem, K_FOREVER);

		}

	}

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