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-rw-r--r--libc/sysdeps/linux/common/pselect.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/common/pselect.c b/libc/sysdeps/linux/common/pselect.c
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index 000000000..93a85a622
--- /dev/null
+++ b/libc/sysdeps/linux/common/pselect.c
@@ -0,0 +1,66 @@
+/* Copyright (C) 1996-1998,2001,2002,2003,2006 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <errno.h>
+#include <signal.h>
+#include <stddef.h> /* For NULL. */
+#include <sys/time.h>
+#include <sys/select.h>
+
+libc_hidden_proto(sigprocmask)
+libc_hidden_proto(select)
+
+
+/* Check the first NFDS descriptors each in READFDS (if not NULL) for read
+ readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
+ (if not NULL) for exceptional conditions. If TIMEOUT is not NULL, time out
+ after waiting the interval specified therein. Additionally set the sigmask
+ SIGMASK for this call. Returns the number of ready descriptors, or -1 for
+ errors. */
+int
+pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+ const struct timespec *timeout, const sigset_t *sigmask)
+{
+ struct timeval tval;
+ int retval;
+ sigset_t savemask;
+
+ /* Change nanosecond number to microseconds. This might mean losing
+ precision and therefore the `pselect` should be available. But
+ for now it is hardly found. */
+ if (timeout != NULL)
+ TIMESPEC_TO_TIMEVAL (&tval, timeout);
+
+ /* The setting and restoring of the signal mask and the select call
+ should be an atomic operation. This can't be done without kernel
+ help. */
+ if (sigmask != NULL)
+ sigprocmask (SIG_SETMASK, sigmask, &savemask);
+
+ /* Note the pselect() is a cancellation point. But since we call
+ select() which itself is a cancellation point we do not have
+ to do anything here. */
+ retval = select (nfds, readfds, writefds, exceptfds,
+ timeout != NULL ? &tval : NULL);
+
+ if (sigmask != NULL)
+ sigprocmask (SIG_SETMASK, &savemask, NULL);
+
+ return retval;
+}