TCP: Allow delay for sends

This is not at all optimal for applications that already buffer their
data but can have a huge impact on those that don't. Applications that
don't wish to use this should disable this for their socket.

5 files changed, 25 insertions, 8 deletions

diff --git a/kernel/drivers/pit.c b/kernel/drivers/pit.c
index 9161885..b875449 100644
--- a/kernel/drivers/pit.c
+++ b/kernel/drivers/pit.c
@@ -51,7 +51,8 @@ void int_clock(reg_t *regs) {
   timer_current_uptime = tsc_calculate_ms(current_tsc);
   random_add_entropy_fast((u8 *)&current_tsc, sizeof(current_tsc));
   switch_counter++;
-  if (timer_current_uptime - last_flush > 50) {
+  if (timer_current_uptime - last_flush > 5) {
+    tcp_flush_buffers();
     tcp_flush_acks();
     last_flush = timer_current_uptime;
   }
diff --git a/kernel/network/tcp.c b/kernel/network/tcp.c
index acdbdb3..6bec93e 100644
--- a/kernel/network/tcp.c
+++ b/kernel/network/tcp.c
@@ -288,7 +288,7 @@ void handle_tcp(ipv4_t src_ip, ipv4_t dst_ip, const u8 *payload,
     }
     if (tcp_payload_length > 0) {
       if (tcp_payload_length > ringbuffer_unused(&con->incoming_buffer)) {
-        return;
+        break;
       }
       int rc = ringbuffer_write(&con->incoming_buffer, tcp_payload,
                                 tcp_payload_length);
diff --git a/kernel/socket.c b/kernel/socket.c
index bab80c5..82e8140 100644
--- a/kernel/socket.c
+++ b/kernel/socket.c
@@ -69,6 +69,24 @@ struct TcpConnection *tcp_find_connection(ipv4_t src_ip, u16 src_port,
   return NULL;
 }
 
+int tcp_sync_buffer(struct TcpConnection *con);
+void tcp_flush_buffers(void) {
+  for (int i = 0;; i++) {
+    struct TcpConnection *c;
+    int end;
+    if (!relist_get(&open_tcp_connections, i, (void **)&c, &end)) {
+      if (end) {
+        break;
+      }
+      continue;
+    }
+    if (TCP_STATE_CLOSED == c->state) {
+      continue;
+    }
+    tcp_sync_buffer(c);
+  }
+}
+
 void tcp_flush_acks(void) {
   for (int i = 0;; i++) {
     struct TcpConnection *c;
@@ -127,9 +145,7 @@ struct UdpConnection *udp_find_connection(ipv4_t src_ip, u16 src_port,
   return NULL;
 }
 
-int tcp_sync_buffer(vfs_fd_t *fd) {
-  struct TcpConnection *con = fd->inode->internal_object;
-  assert(con);
+int tcp_sync_buffer(struct TcpConnection *con) {
   if (TCP_STATE_CLOSED == con->state) {
     return 0;
   }
@@ -156,7 +172,7 @@ int tcp_sync_buffer(vfs_fd_t *fd) {
 void tcp_close(vfs_fd_t *fd) {
   struct TcpConnection *con = fd->inode->internal_object;
   assert(con);
-  tcp_sync_buffer(fd);
+  tcp_sync_buffer(con);
 
   tcp_close_connection(con);
 }
@@ -214,7 +230,7 @@ int tcp_write(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
 
   struct ringbuffer *rb = &con->outgoing_buffer;
   if (ringbuffer_unused(rb) < len) {
-    if (!tcp_sync_buffer(fd)) {
+    if (!tcp_sync_buffer(con)) {
       return 0;
     }
     if (!send_tcp_packet(con, buffer, len)) {
diff --git a/kernel/socket.h b/kernel/socket.h
index e0cf92f..5ea71f5 100644
--- a/kernel/socket.h
+++ b/kernel/socket.h
@@ -144,4 +144,5 @@ int setsockopt(int socket, int level, int option_name, const void *option_value,
                socklen_t option_len);
 void tcp_remove_connection(struct TcpConnection *con);
 void tcp_flush_acks(void);
+void tcp_flush_buffers(void);
 #endif
diff --git a/kernel/timer.c b/kernel/timer.c
index 2121462..21020b0 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -19,7 +19,6 @@ void timer_start_init(void) {
   enable_interrupts();
   cmos_init();
   cmos_start_call(1, &has_unix_time, &start_unix_time);
-  enable_interrupts();
 }
 
 void timer_wait_for_init(void) {