diff options
Diffstat (limited to 'lib/select.c')
| -rw-r--r-- | lib/select.c | 38 |
1 files changed, 33 insertions, 5 deletions
diff --git a/lib/select.c b/lib/select.c index a31f90224..4f6acccd2 100644 --- a/lib/select.c +++ b/lib/select.c @@ -1,7 +1,7 @@ /* Emulation for select(2) Contributed by Paolo Bonzini. - Copyright 2008-2014 Free Software Foundation, Inc. + Copyright 2008-2016 Free Software Foundation, Inc. This file is part of gnulib. @@ -82,9 +82,11 @@ typedef DWORD (WINAPI *PNtQueryInformationFile) #define PIPE_BUF 512 #endif -/* Optimized test whether a HANDLE refers to a console. - See <http://lists.gnu.org/archive/html/bug-gnulib/2009-08/msg00065.html>. */ -#define IsConsoleHandle(h) (((intptr_t) (h) & 3) == 3) +static BOOL IsConsoleHandle (HANDLE h) +{ + DWORD mode; + return GetConsoleMode (h, &mode) != 0; +} static BOOL IsSocketHandle (HANDLE h) @@ -252,6 +254,7 @@ rpl_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds, DWORD ret, wait_timeout, nhandles, nsock, nbuffer; MSG msg; int i, fd, rc; + clock_t tend; if (nfds > FD_SETSIZE) nfds = FD_SETSIZE; @@ -388,6 +391,10 @@ rpl_select (int nfds, fd_set *rfds, fd_set *wfds, fd_set *xfds, /* Place a sentinel at the end of the array. */ handle_array[nhandles] = NULL; + /* When will the waiting period expire? */ + if (wait_timeout != INFINITE) + tend = clock () + wait_timeout; + restart: if (wait_timeout == 0 || nsock == 0) rc = 0; @@ -408,6 +415,16 @@ restart: wait_timeout = 0; } + /* How much is left to wait? */ + if (wait_timeout != INFINITE) + { + clock_t tnow = clock (); + if (tend >= tnow) + wait_timeout = tend - tnow; + else + wait_timeout = 0; + } + for (;;) { ret = MsgWaitForMultipleObjects (nhandles, handle_array, FALSE, @@ -453,7 +470,16 @@ restart: } } - if (rc == 0 && wait_timeout == INFINITE) + if (rc == 0 + && (wait_timeout == INFINITE + /* If NHANDLES > 1, but no bits are set, it means we've + been told incorrectly that some handle was signaled. + This happens with anonymous pipes, which always cause + MsgWaitForMultipleObjects to exit immediately, but no + data is found ready to be read by windows_poll_handle. + To avoid a total failure (whereby we return zero and + don't wait at all), let's poll in a more busy loop. */ + || (wait_timeout != 0 && nhandles > 1))) { /* Sleep 1 millisecond to avoid busy wait and retry with the original fd_sets. */ @@ -463,6 +489,8 @@ restart: SleepEx (1, TRUE); goto restart; } + if (timeout && wait_timeout == 0 && rc == 0) + timeout->tv_sec = timeout->tv_usec = 0; } /* Now fill in the results. */ |