From 6c622490a5004b06b8d714c7fbb73b2caa4fee7a Mon Sep 17 00:00:00 2001 From: Takashi Yano Date: Sat, 5 Mar 2022 08:39:05 +0900 Subject: [PATCH] Cygwin: pty: Add several further comments to the pty code. --- winsup/cygwin/fhandler_tty.cc | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc index 0c762d75e..c2e612580 100644 --- a/winsup/cygwin/fhandler_tty.cc +++ b/winsup/cygwin/fhandler_tty.cc @@ -76,6 +76,13 @@ void release_attach_mutex (void) inline static bool process_alive (DWORD pid); +/* This functions looks for a process which attached to the same console + with current process and is matched to given conditions: + match: If true, return given pid if the process pid attaches to the + same console, otherwise, return 0. If false, return pid except + for given pid. + cygwin: return only process's pid which has cygwin pid. + stub_only: return only stub process's pid of non-cygwin process. */ DWORD fhandler_pty_common::get_console_process_id (DWORD pid, bool match, bool cygwin, bool stub_only) @@ -158,6 +165,7 @@ set_switch_to_nat_pipe (HANDLE *in, HANDLE *out, HANDLE *err) *err = replace_err->get_output_handle_nat (); } +/* Determine if the given path is cygwin binary. */ static bool path_iscygexec_a_w (LPCSTR na, LPSTR ca, LPCWSTR nw, LPWSTR cw) { @@ -3860,6 +3868,7 @@ fhandler_pty_slave::transfer_input (tty::xfer_dir dir, HANDLE from, tty *ttyp, if (dir == tty::to_cyg && ttyp->pcon_activated) { /* from handle is console handle */ + /* Reaches here for nat->cyg case with pcon activated. */ INPUT_RECORD r[INREC_SIZE]; DWORD n; while (PeekConsoleInputA (from, r, INREC_SIZE, &n) && n) @@ -3931,7 +3940,8 @@ fhandler_pty_slave::transfer_input (tty::xfer_dir dir, HANDLE from, tty *ttyp, } } else - { + { /* Reaches here when both cyg->nat and nat->cyg cases with + pcon not activated or cyg->nat case with pcon activated. */ DWORD bytes_in_pipe; while (::bytes_available (bytes_in_pipe, from) && bytes_in_pipe) { @@ -3964,9 +3974,11 @@ fhandler_pty_slave::transfer_input (tty::xfer_dir dir, HANDLE from, tty *ttyp, } } - if (dir == tty::to_nat) + /* Fix input_available_event which indicates availability in cyg pipe. */ + if (dir == tty::to_nat) /* all data is transfered to nat pipe, + so no data available in cyg pipe. */ ResetEvent (input_available_event); - else if (transfered) + else if (transfered) /* There is data transfered to cyg pipe. */ SetEvent (input_available_event); ttyp->pty_input_state = dir; ttyp->discard_input = false;