Changeset 01900b6 in mainline for uspace/lib/c/generic/task.c

Timestamp:

2020-01-21T15:10:26Z (5 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

51da086

Parents:

f8fb03b

Message:

Use an optional output argument instead of errno to propagate the error

The use of errno is troublesome in all other than top-level library
functions since the value in errno might get overwritten by subsequent
inner calls on the error path (e.g. cleanup, deallocation, etc.). The
optional output argument makes it possible to explicitly ignore the
error code if it is not needed, but still to pass it reliably back to
the original caller.

This change affecs async_connect_me_to(),
async_connect_me_to_blocking(), async_connect_kbox(), service_connect(),
service_connect_blocking() and loader_connect().

File:

• uspace/lib/c/generic/task.c (modified) (5 diffs)

uspace/lib/c/generic/task.c

@@ -181 +181 @@
 
         /* Connect to a program loader. */
-        loader_t *ldr = loader_connect();
+        errno_t rc;
+        loader_t *ldr = loader_connect(&rc);
         if (ldr == NULL)
-                return EREFUSED;
+                return rc;
 
         bool wait_initialized = false;
@@ -189 +190 @@
         /* Get task ID. */
         task_id_t task_id;
-        errno_t rc = loader_get_task_id(ldr, &task_id);
+        rc = loader_get_task_id(ldr, &task_id);
         if (rc != EOK)
                 goto error;
@@ -250 +251 @@
         /* Start a debug session if requested */
         if (rsess != NULL) {
-                ksess = async_connect_kbox(task_id);
+                ksess = async_connect_kbox(task_id, &rc);
                 if (ksess == NULL) {
                         /* Most likely debugging support is not compiled in */
-                        rc = ENOTSUP;
                         goto error;
                 }
@@ -402 +402 @@
 errno_t task_setup_wait(task_id_t id, task_wait_t *wait)
 {
-        async_sess_t *sess_ns = ns_session_get();
+        errno_t rc;
+        async_sess_t *sess_ns = ns_session_get(&rc);
         if (sess_ns == NULL)
-                return EIO;
+                return rc;
 
         async_exch_t *exch = async_exchange_begin(sess_ns);
@@ -484 +485 @@
 errno_t task_retval(int val)
 {
-        async_sess_t *sess_ns = ns_session_get();
+        errno_t rc;
+        async_sess_t *sess_ns = ns_session_get(&rc);
         if (sess_ns == NULL)
-                return EIO;
+                return rc;
 
         async_exch_t *exch = async_exchange_begin(sess_ns);
-        errno_t rc = (errno_t) async_req_1_0(exch, NS_RETVAL, val);
+        rc = (errno_t) async_req_1_0(exch, NS_RETVAL, val);
         async_exchange_end(exch);