Drop addr-based send in sendBufMsg

async_postgres/pg_client.nim

@@ -2564,8 +2564,7 @@ proc executeImpl(
     # chronos drains the send Future in the background while we descend into
     # the receive loop. The outer try/except below owns sendFut's lifetime:
     # it drains sendFut on the normal path (propagating any stored write
-    # error) and cancels it on any abnormal exit so the Future never leaks
-    # and `conn.sendBuf` is never mutated while a write still borrows it.
+    # error) and cancels it on any abnormal exit so the Future never leaks.
     var sendFut = conn.sendBufMsg()
   else:
     await conn.sendBufMsg()
@@ -2692,14 +2691,12 @@ proc executeImpl(
         await conn.fillRecvBuf(timeout)
 
     when hasChronos:
-      # Normal path: drain sendFut to propagate any stored write error and
-      # release the borrow on conn.sendBuf.
+      # Normal path: drain sendFut to propagate any stored write error.
       await sendFut
   except CatchableError as e:
     when hasChronos:
       # Abnormal path (recv error, cancellation, failed stored write):
-      # ensure sendFut never escapes as an unhandled Future and that no
-      # in-flight write still holds addr conn.sendBuf[0].
+      # ensure sendFut never escapes as an unhandled Future.
       if not sendFut.finished:
         try:
           await cancelAndWait(sendFut)
@@ -2945,8 +2942,7 @@ proc executeIsolatedImpl(
       await sendFut
   except CatchableError as e:
     when hasChronos:
-      # Abnormal path: cancel or drain sendFut so the Future never leaks
-      # and no in-flight write still borrows conn.sendBuf.
+      # Abnormal path: cancel or drain sendFut so the Future never leaks.
       if not sendFut.finished:
         try:
           await cancelAndWait(sendFut)

async_postgres/pg_connection.nim

@@ -905,14 +905,15 @@ proc sendMsg*(conn: PgConnection, data: seq[byte]): Future[void] {.async.} =
       await conn.socket.sendRawBytes(data)
 
 proc sendBufMsg*(conn: PgConnection): Future[void] {.async.} =
-  ## Send conn.sendBuf to the server without copying the seq.
-  ## Safe because conn.state == csBusy prevents concurrent access to sendBuf.
+  ## Send conn.sendBuf to the server.
+  ## The transport receives its own copy of the buffer, so conn.sendBuf is safe
+  ## to mutate while the returned Future is still pending.
   when hasChronos:
     if conn.sendBuf.len > 0:
-      await conn.writer.write(addr conn.sendBuf[0], conn.sendBuf.len)
+      await conn.writer.write(conn.sendBuf)
   elif hasAsyncDispatch:
     if conn.sendBuf.len > 0:
-      await conn.socket.sendRawData(addr conn.sendBuf[0], conn.sendBuf.len)
+      await conn.socket.sendRawBytes(conn.sendBuf)
 
 proc closeTransport(conn: PgConnection) {.async.} =
   ## Close transport resources without sending Terminate.