Changeset bbf159a in mainline for uspace/srv/net/tl/tcp/ucall.c

Timestamp:

2011-12-13T17:06:25Z (12 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

7a8c1c4e

Parents:

0d29e0cd

Message:

Eliminate busy waiting when TCP send buffer is full.

File:

• uspace/srv/net/tl/tcp/ucall.c (modified) (2 diffs)

uspace/srv/net/tl/tcp/ucall.c

@@ -121 +121 @@
         }
 
-        if (conn->snd_buf_fin)
+        fibril_mutex_lock(&conn->snd_buf_lock);
+
+        if (conn->snd_buf_fin) {
+                fibril_mutex_unlock(&conn->snd_buf_lock);
                 return TCP_ECLOSING;
+        }
 
         while (size > 0) {
                 buf_free = conn->snd_buf_size - conn->snd_buf_used;
                 while (buf_free == 0 && !conn->reset) {
-                        tcp_tqueue_new_data(conn);
+                        log_msg(LVL_DEBUG, "%s: buf_free == 0, waiting.",
+                            conn->name);
+                        fibril_condvar_wait(&conn->snd_buf_cv,
+                            &conn->snd_buf_lock);
                         buf_free = conn->snd_buf_size - conn->snd_buf_used;
                 }
 
-                if (conn->reset)
+                if (conn->reset) {
+                        fibril_mutex_unlock(&conn->snd_buf_lock);
                         return TCP_ERESET;
+                }
 
                 xfer_size = min(size, buf_free);
@@ -141 +150 @@
                 conn->snd_buf_used += xfer_size;
                 size -= xfer_size;
-        }
-
+
+                fibril_mutex_unlock(&conn->snd_buf_lock);
+                tcp_tqueue_new_data(conn);
+                fibril_mutex_lock(&conn->snd_buf_lock);
+        }
+
+        fibril_mutex_unlock(&conn->snd_buf_lock);
         tcp_tqueue_new_data(conn);