Changeset 5d50c419 in mainline for uspace/lib/c/generic/io/chardev.c

Timestamp:

2017-11-19T21:14:19Z (8 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

c657bd7

Parents:

75fcf9b

Message:

Chardev API should separate error code from number of bytes transferred. This is cleaner, allows the code to be more independent of Exxx sign and allows for partial success (some bytes successfully transferred and then an error occurred.)

File:

• uspace/lib/c/generic/io/chardev.c (modified) (4 diffs)

uspace/lib/c/generic/io/chardev.c

@@ -40 +40 @@
 #include <io/chardev.h>
 #include <ipc/chardev.h>
+#include <stddef.h>
 #include <stdlib.h>
 
@@ -76 +77 @@
 }
 
-ssize_t chardev_read(chardev_t *chardev, void *data, size_t size)
+int chardev_read(chardev_t *chardev, void *data, size_t size, size_t *nread)
 {
         if (size > 4 * sizeof(sysarg_t))
@@ -88 +89 @@
         if (ret > 0 && (size_t)ret <= size)
                 memcpy(data, message, size);
-        return ret;
+
+        if (ret < 0) {
+                *nread = 0;
+                return ret;
+        }
+
+        *nread = ret;
+        return EOK;
 }
 
-ssize_t chardev_write(chardev_t *chardev, const void *data, size_t size)
+int chardev_write(chardev_t *chardev, const void *data, size_t size,
+    size_t *nwritten)
 {
         int ret;
@@ -104 +113 @@
             message[0], message[1], message[2]);
         async_exchange_end(exch);
-        return ret;
+
+        if (ret < 0) {
+                *nwritten = 0;
+                return ret;
+        }
+
+        *nwritten = ret;
+        return EOK;
 }