From 11bea88b788aabb762b4e972a7f3fb2423fb32d8 Mon Sep 17 00:00:00 2001 From: Corinna Vinschen Date: Thu, 9 Sep 2021 11:35:54 +0200 Subject: [PATCH] Cygwin: pipes: always signal select_sem if any bytes are read or written Fold all code branches potentially having read or written data into a single if branch, so signalling select_sem catches all cases. Signed-off-by: Corinna Vinschen --- winsup/cygwin/fhandler_pipe.cc | 64 ++++++++++++---------------------- 1 file changed, 23 insertions(+), 41 deletions(-) diff --git a/winsup/cygwin/fhandler_pipe.cc b/winsup/cygwin/fhandler_pipe.cc index 488e14be8c2b..6994a5dceb84 100644 --- a/winsup/cygwin/fhandler_pipe.cc +++ b/winsup/cygwin/fhandler_pipe.cc @@ -303,20 +303,11 @@ fhandler_pipe::raw_read (void *ptr, size_t& len) waitret = WAIT_OBJECT_0; if (waitret == WAIT_CANCELED) - { - status = STATUS_THREAD_CANCELED; - break; - } + status = STATUS_THREAD_CANCELED; else if (waitret == WAIT_SIGNALED) - { - status = STATUS_THREAD_SIGNALED; - nbytes += io.Information; - if (select_sem && io.Information > 0) - ReleaseSemaphore (select_sem, - get_obj_handle_count (select_sem), NULL); - break; - } - status = io.Status; + status = STATUS_THREAD_SIGNALED; + else + status = io.Status; } if (isclosed ()) /* A signal handler might have closed the fd. */ { @@ -326,11 +317,17 @@ fhandler_pipe::raw_read (void *ptr, size_t& len) __seterrno (); nbytes = (size_t) -1; } - else if (NT_SUCCESS (status)) + else if (NT_SUCCESS (status) + || status == STATUS_BUFFER_OVERFLOW + || status == STATUS_THREAD_CANCELED + || status == STATUS_THREAD_SIGNALED) { nbytes_now = io.Information; ptr = ((char *) ptr) + nbytes_now; nbytes += nbytes_now; + if (select_sem && nbytes_now > 0) + ReleaseSemaphore (select_sem, + get_obj_handle_count (select_sem), NULL); } else { @@ -341,13 +338,6 @@ fhandler_pipe::raw_read (void *ptr, size_t& len) case STATUS_PIPE_BROKEN: /* This is really EOF. */ break; - case STATUS_MORE_ENTRIES: - case STATUS_BUFFER_OVERFLOW: - /* `io.Information' is supposedly valid. */ - nbytes_now = io.Information; - ptr = ((char *) ptr) + nbytes_now; - nbytes += nbytes_now; - break; case STATUS_PIPE_LISTENING: case STATUS_PIPE_EMPTY: if (nbytes != 0) @@ -366,10 +356,8 @@ fhandler_pipe::raw_read (void *ptr, size_t& len) } } - if (nbytes_now == 0) + if (nbytes_now == 0 || status == STATUS_BUFFER_OVERFLOW) break; - else if (select_sem) - ReleaseSemaphore (select_sem, get_obj_handle_count (select_sem), NULL); } ReleaseMutex (read_mtx); if (evt) @@ -467,20 +455,11 @@ fhandler_pipe_fifo::raw_write (const void *ptr, size_t len) waitret = WAIT_OBJECT_0; if (waitret == WAIT_CANCELED) - { - status = STATUS_THREAD_CANCELED; - break; - } + status = STATUS_THREAD_CANCELED; else if (waitret == WAIT_SIGNALED) - { - status = STATUS_THREAD_SIGNALED; - nbytes += io.Information; - if (select_sem && io.Information > 0) - ReleaseSemaphore (select_sem, - get_obj_handle_count (select_sem), NULL); - break; - } - status = io.Status; + status = STATUS_THREAD_SIGNALED; + else + status = io.Status; } if (isclosed ()) /* A signal handler might have closed the fd. */ { @@ -489,13 +468,18 @@ fhandler_pipe_fifo::raw_write (const void *ptr, size_t len) else __seterrno (); } - else if (NT_SUCCESS (status)) + else if (NT_SUCCESS (status) + || status == STATUS_THREAD_CANCELED + || status == STATUS_THREAD_SIGNALED) { nbytes_now = io.Information; ptr = ((char *) ptr) + nbytes_now; nbytes += nbytes_now; + if (select_sem && nbytes_now > 0) + ReleaseSemaphore (select_sem, + get_obj_handle_count (select_sem), NULL); /* 0 bytes returned? EAGAIN. See above. */ - if (nbytes == 0) + if (NT_SUCCESS (status) && nbytes == 0) set_errno (EAGAIN); } else if (STATUS_PIPE_IS_CLOSED (status)) @@ -508,8 +492,6 @@ fhandler_pipe_fifo::raw_write (const void *ptr, size_t len) if (nbytes_now == 0) break; - else if (select_sem) - ReleaseSemaphore (select_sem, get_obj_handle_count (select_sem), NULL); } if (evt) CloseHandle (evt); -- 2.31.1