z_recv/z_try_recv without the need of z_check (#570)

* make z_recv/z_try_recv return z_result_t to allow differentiating between different cases without the need to call z_check on constructed object

* format

docs/examples.rst

@@ -123,7 +123,7 @@ Query
 
       z_get(z_loan(s), z_loan(key_expr), "", z_move(closure), NULL);
       z_owned_reply_t reply;
-      for (z_recv(z_loan(handler), &reply); z_check(reply); z_recv(z_loan(handler), &reply)) {
+      for (z_result_t res = z_recv(z_loan(handler), &reply); res == Z_OK; res = z_recv(z_loan(handler), &reply)) {
           if (z_reply_is_ok(&reply)) {
               const z_loaned_sample_t* sample = z_reply_ok(&reply);
               z_view_string_t key_string;

examples/z_get.c

@@ -71,7 +71,7 @@ int main(int argc, char **argv) {
           z_move(opts));  // here, the send is moved and will be dropped by zenoh when adequate
     z_owned_reply_t reply;
 
-    for (z_recv(z_loan(handler), &reply); z_check(reply); z_recv(z_loan(handler), &reply)) {
+    for (z_result_t res = z_recv(z_loan(handler), &reply); res == Z_OK; res = z_recv(z_loan(handler), &reply)) {
         if (z_reply_is_ok(z_loan(reply))) {
             const z_loaned_sample_t *sample = z_reply_ok(z_loan(reply));
 

examples/z_get_liveliness.c

@@ -53,7 +53,7 @@ int main(int argc, char **argv) {
     z_fifo_channel_reply_new(&closure, &handler, 16);
     zc_liveliness_get(z_loan(s), z_loan(keyexpr), z_move(closure), NULL);
     z_owned_reply_t reply;
-    for (z_recv(z_loan(handler), &reply); z_check(reply); z_recv(z_loan(handler), &reply)) {
+    for (z_result_t res = z_recv(z_loan(handler), &reply); res == Z_OK; res = z_recv(z_loan(handler), &reply)) {
         if (z_reply_is_ok(z_loan(reply))) {
             const z_loaned_sample_t *sample = z_reply_ok(z_loan(reply));
             z_view_string_t key_str;

examples/z_get_shm.c

@@ -109,7 +109,7 @@ int main(int argc, char** argv) {
           z_move(opts));  // here, the send is moved and will be dropped by zenoh when adequate
     z_owned_reply_t reply;
 
-    for (z_recv(z_loan(handler), &reply); z_check(reply); z_recv(z_loan(handler), &reply)) {
+    for (z_result_t res = z_recv(z_loan(handler), &reply); res == Z_OK; res = z_recv(z_loan(handler), &reply)) {
         if (z_reply_is_ok(z_loan(reply))) {
             const z_loaned_sample_t* sample = z_reply_ok(z_loan(reply));
 

examples/z_non_blocking_get.c

@@ -55,9 +55,9 @@ int main(int argc, char **argv) {
     z_get(z_loan(s), z_loan(keyexpr), "", z_move(closure),
           z_move(opts));  // here, the closure is moved and will be dropped by zenoh when adequate
     z_owned_reply_t reply;
-    for (bool has_more = z_try_recv(z_loan(handler), &reply); has_more;
-         has_more = z_try_recv(z_loan(handler), &reply)) {
-        if (!z_check(reply)) {
+    for (z_result_t res = z_try_recv(z_loan(handler), &reply); res != Z_CHANNEL_DISCONNECTED;
+         res = z_try_recv(z_loan(handler), &reply)) {
+        if (res != Z_OK) {
             z_sleep_ms(50);
             continue;
         }

examples/z_pub_cache.c

@@ -56,8 +56,8 @@ int main(int argc, char **argv) {
     ze_owned_publication_cache_t pub_cache;
     z_view_keyexpr_t ke;
     z_view_keyexpr_from_str(&ke, keyexpr);
-    ze_declare_publication_cache(&pub_cache, z_loan(s), z_loan(ke), &pub_cache_opts);
-    if (!z_check(pub_cache)) {
+
+    if (ze_declare_publication_cache(&pub_cache, z_loan(s), z_loan(ke), &pub_cache_opts) != Z_OK) {
         printf("Unable to declare publication cache for key expression!\n");
         exit(-1);
     }

examples/z_pull.c

@@ -85,8 +85,8 @@ int main(int argc, char **argv) {
         if (c == -1) {
             z_sleep_s(1);
         } else {
-            z_try_recv(z_loan(handler), &sample);
-            if (z_check(sample)) {
+            z_result_t res = z_try_recv(z_loan(handler), &sample);
+            if (res == Z_OK) {
                 handle_sample(z_loan(sample));
                 z_drop(z_move(sample));
             }

examples/z_queryable_with_channels.c

@@ -62,7 +62,7 @@ int main(int argc, char **argv) {
 
     printf("^C to quit...\n");
     z_owned_query_t oquery;
-    for (z_recv(z_loan(handler), &oquery); z_check(oquery); z_recv(z_loan(handler), &oquery)) {
+    for (z_result_t res = z_recv(z_loan(handler), &oquery); res == Z_OK; res = z_recv(z_loan(handler), &oquery)) {
         const z_loaned_query_t *query = z_loan(oquery);
         z_view_string_t key_string;
         z_keyexpr_as_view_string(z_query_keyexpr(query), &key_string);

include/zenoh_commons.h

@@ -2364,19 +2364,21 @@ const struct z_loaned_fifo_handler_query_t *z_fifo_handler_query_loan(const stru
 ZENOHC_API void z_fifo_handler_query_null(struct z_owned_fifo_handler_query_t *this_);
 /**
  * Returns query from the fifo buffer. If there are no more pending queries will block until next query is received, or until
- * the channel is dropped (normally when Queryable is dropped). In the later case will return ``false`` and query will be
- * in the gravestone state.
+ * the channel is dropped (normally when Queryable is dropped).
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the query will be in the gravestone state),
+ * `Z_CHANNEL_NODATA` if the channel is still alive, but its buffer is empty (the query will be in the gravestone state).
  */
 ZENOHC_API
-bool z_fifo_handler_query_recv(const struct z_loaned_fifo_handler_query_t *this_,
-                               struct z_owned_query_t *query);
+z_result_t z_fifo_handler_query_recv(const struct z_loaned_fifo_handler_query_t *this_,
+                                     struct z_owned_query_t *query);
 /**
  * Returns query from the fifo buffer. If there are no more pending queries will return immediately (with query set to its gravestone state).
- * Will return false if the channel is dropped (normally when Queryable is dropped) and there are no more queries in the fifo.
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the query will be in the gravestone state),
+ * `Z_CHANNEL_NODATA` if the channel is still alive, but its buffer is empty (the query will be in the gravestone state).
  */
 ZENOHC_API
-bool z_fifo_handler_query_try_recv(const struct z_loaned_fifo_handler_query_t *this_,
-                                   struct z_owned_query_t *query);
+z_result_t z_fifo_handler_query_try_recv(const struct z_loaned_fifo_handler_query_t *this_,
+                                         struct z_owned_query_t *query);
 /**
  * Returns ``true`` if handler is valid, ``false`` if it is in gravestone state.
  */
@@ -2396,19 +2398,20 @@ const struct z_loaned_fifo_handler_reply_t *z_fifo_handler_reply_loan(const stru
 ZENOHC_API void z_fifo_handler_reply_null(struct z_owned_fifo_handler_reply_t *this_);
 /**
  * Returns reply from the fifo buffer. If there are no more pending replies will block until next reply is received, or until
- * the channel is dropped (normally when all replies are received). In the later case will return ``false`` and reply will be
- * in the gravestone state.
+ * the channel is dropped (normally when all replies are received).
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the reply will be in the gravestone state).
  */
 ZENOHC_API
-bool z_fifo_handler_reply_recv(const struct z_loaned_fifo_handler_reply_t *this_,
-                               struct z_owned_reply_t *reply);
+z_result_t z_fifo_handler_reply_recv(const struct z_loaned_fifo_handler_reply_t *this_,
+                                     struct z_owned_reply_t *reply);
 /**
  * Returns reply from the fifo buffer. If there are no more pending replies will return immediately (with reply set to its gravestone state).
- * Will return false if the channel is dropped (normally when all replies are received) and there are no more replies in the fifo.
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the reply will be in the gravestone state),
+ * `Z_CHANNEL_NODATA` if the channel is still alive, but its buffer is empty (the reply will be in the gravestone state).
  */
 ZENOHC_API
-bool z_fifo_handler_reply_try_recv(const struct z_loaned_fifo_handler_reply_t *this_,
-                                   struct z_owned_reply_t *reply);
+z_result_t z_fifo_handler_reply_try_recv(const struct z_loaned_fifo_handler_reply_t *this_,
+                                         struct z_owned_reply_t *reply);
 /**
  * Returns ``true`` if handler is valid, ``false`` if it is in gravestone state.
  */
@@ -2428,19 +2431,21 @@ const struct z_loaned_fifo_handler_sample_t *z_fifo_handler_sample_loan(const st
 ZENOHC_API void z_fifo_handler_sample_null(struct z_owned_fifo_handler_sample_t *this_);
 /**
  * Returns sample from the fifo buffer. If there are no more pending replies will block until next sample is received, or until
- * the channel is dropped (normally when there are no more samples to receive). In the later case will return ``false`` and sample will be
- * in the gravestone state.
+ * the channel is dropped (normally when there are no more samples to receive).
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the sample will be in the gravestone state).
  */
 ZENOHC_API
-bool z_fifo_handler_sample_recv(const struct z_loaned_fifo_handler_sample_t *this_,
-                                struct z_owned_sample_t *sample);
+z_result_t z_fifo_handler_sample_recv(const struct z_loaned_fifo_handler_sample_t *this_,
+                                      struct z_owned_sample_t *sample);
 /**
- * Returns sample from the fifo buffer. If there are no more pending replies will return immediately (with sample set to its gravestone state).
- * Will return false if the channel is dropped (normally when there are no more samples to receive) and there are no more replies in the fifo.
+ * Returns sample from the fifo buffer.
+ * If there are no more pending replies will return immediately (with sample set to its gravestone state).
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the sample will be in the gravestone state),
+ * `Z_CHANNEL_NODATA` if the channel is still alive, but its buffer is empty (the sample will be in the gravestone state).
  */
 ZENOHC_API
-bool z_fifo_handler_sample_try_recv(const struct z_loaned_fifo_handler_sample_t *this_,
-                                    struct z_owned_sample_t *sample);
+z_result_t z_fifo_handler_sample_try_recv(const struct z_loaned_fifo_handler_sample_t *this_,
+                                          struct z_owned_sample_t *sample);
 /**
  * Query data from the matching queryables in the system.
  * Replies are provided through a callback function.
@@ -3187,19 +3192,20 @@ const struct z_loaned_ring_handler_query_t *z_ring_handler_query_loan(const stru
 ZENOHC_API void z_ring_handler_query_null(struct z_owned_ring_handler_query_t *this_);
 /**
  * Returns query from the ring buffer. If there are no more pending queries will block until next query is received, or until
- * the channel is dropped (normally when Queryable is dropped). In the later case will return ``false`` and query will be
- * in the gravestone state.
+ * the channel is dropped (normally when Queryable is dropped).
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the query will be in the gravestone state).
  */
 ZENOHC_API
-bool z_ring_handler_query_recv(const struct z_loaned_ring_handler_query_t *this_,
-                               struct z_owned_query_t *query);
+z_result_t z_ring_handler_query_recv(const struct z_loaned_ring_handler_query_t *this_,
+                                     struct z_owned_query_t *query);
 /**
  * Returns query from the ring buffer. If there are no more pending queries will return immediately (with query set to its gravestone state).
- * Will return false if the channel is dropped (normally when Queryable is dropped) and there are no more queries in the fifo.
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the query will be in the gravestone state),
+ * Z_CHANNEL_NODATA if the channel is still alive, but its buffer is empty (the query will be in the gravestone state).
  */
 ZENOHC_API
-bool z_ring_handler_query_try_recv(const struct z_loaned_ring_handler_query_t *this_,
-                                   struct z_owned_query_t *query);
+z_result_t z_ring_handler_query_try_recv(const struct z_loaned_ring_handler_query_t *this_,
+                                         struct z_owned_query_t *query);
 /**
  * Returns ``true`` if handler is valid, ``false`` if it is in gravestone state.
  */
@@ -3219,19 +3225,20 @@ const struct z_loaned_ring_handler_reply_t *z_ring_handler_reply_loan(const stru
 ZENOHC_API void z_ring_handler_reply_null(struct z_owned_ring_handler_reply_t *this_);
 /**
  * Returns reply from the ring buffer. If there are no more pending replies will block until next reply is received, or until
- * the channel is dropped (normally when all replies are received). In the later case will return ``false`` and reply will be
- * in the gravestone state.
+ * the channel is dropped (normally when all replies are received).
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the reply will be in the gravestone state).
  */
 ZENOHC_API
-bool z_ring_handler_reply_recv(const struct z_loaned_ring_handler_reply_t *this_,
-                               struct z_owned_reply_t *reply);
+z_result_t z_ring_handler_reply_recv(const struct z_loaned_ring_handler_reply_t *this_,
+                                     struct z_owned_reply_t *reply);
 /**
  * Returns reply from the ring buffer. If there are no more pending replies will return immediately (with reply set to its gravestone state).
- * Will return false if the channel is dropped (normally when all replies are received) and there are no more replies in the fifo.
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the reply will be in the gravestone state),
+ * `Z_CHANNEL_NODATA` if the channel is still alive, but its buffer is empty (the reply will be in the gravestone state).
  */
 ZENOHC_API
-bool z_ring_handler_reply_try_recv(const struct z_loaned_ring_handler_reply_t *this_,
-                                   struct z_owned_reply_t *reply);
+z_result_t z_ring_handler_reply_try_recv(const struct z_loaned_ring_handler_reply_t *this_,
+                                         struct z_owned_reply_t *reply);
 /**
  * Returns ``true`` if handler is valid, ``false`` if it is in gravestone state.
  */
@@ -3251,19 +3258,20 @@ const struct z_loaned_ring_handler_sample_t *z_ring_handler_sample_loan(const st
 ZENOHC_API void z_ring_handler_sample_null(struct z_owned_ring_handler_sample_t *this_);
 /**
  * Returns sample from the ring buffer. If there are no more pending replies will block until next sample is received, or until
- * the channel is dropped (normally when there are no more samples to receive). In the later case will return ``false`` and sample will be
- * in the gravestone state.
+ * the channel is dropped (normally when there are no more replies to receive).
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the sample will be in the gravestone state).
  */
 ZENOHC_API
-bool z_ring_handler_sample_recv(const struct z_loaned_ring_handler_sample_t *this_,
-                                struct z_owned_sample_t *sample);
+z_result_t z_ring_handler_sample_recv(const struct z_loaned_ring_handler_sample_t *this_,
+                                      struct z_owned_sample_t *sample);
 /**
  * Returns sample from the ring buffer. If there are no more pending replies will return immediately (with sample set to its gravestone state).
- * Will return false if the channel is dropped (normally when there are no more samples to receive) and there are no more replies in the fifo.
+ * @return 0 in case of success, `Z_CHANNEL_DISCONNECTED` if channel was dropped (the sample will be in the gravestone state),
+ * `Z_CHANNEL_NODATA` if the channel is still alive, but its buffer is empty (the sample will be in the gravestone state).
  */
 ZENOHC_API
-bool z_ring_handler_sample_try_recv(const struct z_loaned_ring_handler_sample_t *this_,
-                                    struct z_owned_sample_t *sample);
+z_result_t z_ring_handler_sample_try_recv(const struct z_loaned_ring_handler_sample_t *this_,
+                                          struct z_owned_sample_t *sample);
 /**
  * Returns sample attachment.
  *

include/zenoh_concrete.h

@@ -22,6 +22,8 @@
 #include <stdint.h>
 #include <stdlib.h>
 #define DEFAULT_SCOUTING_TIMEOUT 1000
+#define Z_CHANNEL_DISCONNECTED 1
+#define Z_CHANNEL_NODATA 2
 #define Z_OK 0
 #define Z_EINVAL -1
 #define Z_EPARSE -2

include/zenoh_macros.h

@@ -421,42 +421,42 @@ inline void z_closure(
 };
 
 
-inline bool z_try_recv(const z_loaned_fifo_handler_query_t* this_, z_owned_query_t* query) {
+inline z_result_t z_try_recv(const z_loaned_fifo_handler_query_t* this_, z_owned_query_t* query) {
     return z_fifo_handler_query_try_recv(this_, query);
 };
-inline bool z_try_recv(const z_loaned_fifo_handler_reply_t* this_, z_owned_reply_t* reply) {
+inline z_result_t z_try_recv(const z_loaned_fifo_handler_reply_t* this_, z_owned_reply_t* reply) {
     return z_fifo_handler_reply_try_recv(this_, reply);
 };
-inline bool z_try_recv(const z_loaned_fifo_handler_sample_t* this_, z_owned_sample_t* sample) {
+inline z_result_t z_try_recv(const z_loaned_fifo_handler_sample_t* this_, z_owned_sample_t* sample) {
     return z_fifo_handler_sample_try_recv(this_, sample);
 };
-inline bool z_try_recv(const z_loaned_ring_handler_query_t* this_, z_owned_query_t* query) {
+inline z_result_t z_try_recv(const z_loaned_ring_handler_query_t* this_, z_owned_query_t* query) {
     return z_ring_handler_query_try_recv(this_, query);
 };
-inline bool z_try_recv(const z_loaned_ring_handler_reply_t* this_, z_owned_reply_t* reply) {
+inline z_result_t z_try_recv(const z_loaned_ring_handler_reply_t* this_, z_owned_reply_t* reply) {
     return z_ring_handler_reply_try_recv(this_, reply);
 };
-inline bool z_try_recv(const z_loaned_ring_handler_sample_t* this_, z_owned_sample_t* sample) {
+inline z_result_t z_try_recv(const z_loaned_ring_handler_sample_t* this_, z_owned_sample_t* sample) {
     return z_ring_handler_sample_try_recv(this_, sample);
 };
 
 
-inline bool z_recv(const z_loaned_fifo_handler_query_t* this_, z_owned_query_t* query) {
+inline z_result_t z_recv(const z_loaned_fifo_handler_query_t* this_, z_owned_query_t* query) {
     return z_fifo_handler_query_recv(this_, query);
 };
-inline bool z_recv(const z_loaned_fifo_handler_reply_t* this_, z_owned_reply_t* reply) {
+inline z_result_t z_recv(const z_loaned_fifo_handler_reply_t* this_, z_owned_reply_t* reply) {
     return z_fifo_handler_reply_recv(this_, reply);
 };
-inline bool z_recv(const z_loaned_fifo_handler_sample_t* this_, z_owned_sample_t* sample) {
+inline z_result_t z_recv(const z_loaned_fifo_handler_sample_t* this_, z_owned_sample_t* sample) {
     return z_fifo_handler_sample_recv(this_, sample);
 };
-inline bool z_recv(const z_loaned_ring_handler_query_t* this_, z_owned_query_t* query) {
+inline z_result_t z_recv(const z_loaned_ring_handler_query_t* this_, z_owned_query_t* query) {
     return z_ring_handler_query_recv(this_, query);
 };
-inline bool z_recv(const z_loaned_ring_handler_reply_t* this_, z_owned_reply_t* reply) {
+inline z_result_t z_recv(const z_loaned_ring_handler_reply_t* this_, z_owned_reply_t* reply) {
     return z_ring_handler_reply_recv(this_, reply);
 };
-inline bool z_recv(const z_loaned_ring_handler_sample_t* this_, z_owned_sample_t* sample) {
+inline z_result_t z_recv(const z_loaned_ring_handler_sample_t* this_, z_owned_sample_t* sample) {
     return z_ring_handler_sample_recv(this_, sample);
 };