core: Proper poll() emulation to fix pacat and friends on Windows

Currently, Windows versions of pacat and friends fail because the current
poll emulation is not sufficient (it only works for socket fds).

Luckily Gnulib has a much better emulation that seems to work good enough.
The implementation has been largely copied (except a few bug fix
regarding timeout handling, to be pushed upstream) and works on pipes
and files as well. The copy has been obtained through their gnulib-tool utility,
which gives a LGPLv2.1+ licensed file.

This fixes the "Assertion (!e->dead) failed" error coming and lets pacat
and friends stream happily to/from a server (I didn't actually test parec).

1 files changed, 237 insertions, 0 deletions

diff --git a/src/pulsecore/poll-posix.c b/src/pulsecore/poll-posix.c
new file mode 100644
index 000000000..cd888b506
--- /dev/null
+++ b/src/pulsecore/poll-posix.c
@@ -0,0 +1,237 @@
+
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
+
+  PulseAudio 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.
+
+  PulseAudio 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with PulseAudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+/***
+   Based on work for the GNU C Library.
+   Copyright (C) 1994, 1996, 1997 Free Software Foundation, Inc.
+***/
+
+/* Poll the file descriptors described by the NFDS structures starting at
+   FDS.  If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
+   an event to occur; if TIMEOUT is -1, block until an event occurs.
+   Returns the number of file descriptors with events, zero if timed out,
+   or -1 for errors.  */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
+#include <pulsecore/socket.h>
+#include <pulsecore/core-util.h>
+#include <pulse/util.h>
+
+#include "poll.h"
+
+/* Mac OSX fails to implement poll() in a working way since 10.4. IOW, for
+ * several years. We need to enable a dirty workaround and emulate that call
+ * with select(), just like for Windows. sic! */
+
+#if !defined(HAVE_POLL_H) || defined(OS_IS_DARWIN)
+
+int pa_poll (struct pollfd *fds, unsigned long int nfds, int timeout) {
+    struct timeval tv;
+    fd_set rset, wset, xset;
+    struct pollfd *f;
+    int ready;
+    int maxfd = 0;
+#ifdef OS_IS_WIN32
+    char data[64];
+#endif
+
+    FD_ZERO (&rset);
+    FD_ZERO (&wset);
+    FD_ZERO (&xset);
+
+    if (nfds == 0) {
+        if (timeout >= 0) {
+            pa_msleep(timeout);
+            return 0;
+        }
+
+#ifdef OS_IS_WIN32
+        /*
+         * Windows does not support signals properly so waiting for them would
+         * mean a deadlock.
+         */
+        pa_msleep(100);
+        return 0;
+#else
+        return select(0, NULL, NULL, NULL, NULL);
+#endif
+    }
+
+    for (f = fds; f < &fds[nfds]; ++f) {
+        if (f->fd != -1) {
+            if (f->events & POLLIN)
+                FD_SET (f->fd, &rset);
+            if (f->events & POLLOUT)
+                FD_SET (f->fd, &wset);
+            if (f->events & POLLPRI)
+                FD_SET (f->fd, &xset);
+            if (f->fd > maxfd && (f->events & (POLLIN|POLLOUT|POLLPRI)))
+                maxfd = f->fd;
+        }
+    }
+
+    tv.tv_sec = timeout / 1000;
+    tv.tv_usec = (timeout % 1000) * 1000;
+
+    ready = select(maxfd + 1, &rset, &wset, &xset, (timeout == -1 ? NULL : &tv));
+
+    if ((ready == -1) && (errno == EBADF)) {
+        ready = 0;
+        maxfd = -1;
+
+#ifdef OS_IS_WIN32
+        /*
+         * Windows has no fcntl(), so we have to trick around with more
+         * select() calls to find out what went wrong
+         */
+
+        FD_ZERO (&rset);
+        FD_ZERO (&wset);
+        FD_ZERO (&xset);
+
+        for (f = fds; f < &fds[nfds]; ++f) {
+            if (f->fd != -1) {
+                fd_set sngl_rset, sngl_wset, sngl_xset;
+
+                FD_ZERO (&sngl_rset);
+                FD_ZERO (&sngl_wset);
+                FD_ZERO (&sngl_xset);
+
+                if (f->events & POLLIN)
+                    FD_SET (f->fd, &sngl_rset);
+                if (f->events & POLLOUT)
+                    FD_SET (f->fd, &sngl_wset);
+                if (f->events & POLLPRI)
+                    FD_SET (f->fd, &sngl_xset);
+                if (f->events & (POLLIN|POLLOUT|POLLPRI)) {
+                    struct timeval singl_tv;
+
+                    singl_tv.tv_sec = 0;
+                    singl_tv.tv_usec = 0;
+
+                    if (select(f->fd, &rset, &wset, &xset, &singl_tv) != -1) {
+                        if (f->events & POLLIN)
+                            FD_SET (f->fd, &rset);
+                        if (f->events & POLLOUT)
+                            FD_SET (f->fd, &wset);
+                        if (f->events & POLLPRI)
+                            FD_SET (f->fd, &xset);
+                        if (f->fd > maxfd && (f->events & (POLLIN|POLLOUT|POLLPRI)))
+                            maxfd = f->fd;
+                        ++ready;
+                    } else if (errno == EBADF)
+                        f->revents |= POLLNVAL;
+                }
+            }
+        }
+
+#else /* !OS_IS_WIN32 */
+
+        for (f = fds; f < &fds[nfds]; f++)
+            if (f->fd != -1) {
+                /* use fcntl() to find out whether the descriptor is valid */
+                if (fcntl(f->fd, F_GETFL) != -1) {
+                    if (f->fd > maxfd && (f->events & (POLLIN|POLLOUT|POLLPRI))) {
+                        maxfd = f->fd;
+                        ready++;
+                    }
+                } else {
+                    FD_CLR(f->fd, &rset);
+                    FD_CLR(f->fd, &wset);
+                    FD_CLR(f->fd, &xset);
+                }
+            }
+
+#endif
+
+        if (ready) {
+        /* Linux alters the tv struct... but it shouldn't matter here ...
+         * as we're going to be a little bit out anyway as we've just eaten
+         * more than a couple of cpu cycles above */
+            ready = select(maxfd + 1, &rset, &wset, &xset, (timeout == -1 ? NULL : &tv));
+        }
+    }
+
+#ifdef OS_IS_WIN32
+    errno = WSAGetLastError();
+#endif
+
+    if (ready > 0) {
+        ready = 0;
+        for (f = fds; f < &fds[nfds]; ++f) {
+            f->revents = 0;
+            if (f->fd != -1) {
+                if (FD_ISSET (f->fd, &rset)) {
+                    /* support for POLLHUP.  An hung up descriptor does not
+                       increase the return value! */
+#ifdef OS_IS_DARWIN
+                    /* There is a bug in Mac OS X that causes it to ignore MSG_PEEK
+                     * for some kinds of descriptors.  Detect if this descriptor is a
+                     * connected socket, a server socket, or something else using a
+                     * 0-byte recv, and use ioctl(2) to detect POLLHUP.  */
+                    int r = recv(f->fd, NULL, 0, MSG_PEEK);
+                    if (r == 0 || (r < 0 && errno == ENOTSOCK))
+                        ioctl(f->fd, FIONREAD, &r);
+
+                    if (r == 0)
+                        f->revents |= POLLHUP;
+#else /* !OS_IS_DARWIN */
+                    if (recv (f->fd, data, 64, MSG_PEEK) == -1) {
+                        if (errno == ESHUTDOWN || errno == ECONNRESET ||
+                            errno == ECONNABORTED || errno == ENETRESET) {
+                            fprintf(stderr, "Hangup\n");
+                            f->revents |= POLLHUP;
+                        }
+                    }
+#endif
+
+                    if (f->revents == 0)
+                        f->revents |= POLLIN;
+                }
+                if (FD_ISSET (f->fd, &wset))
+                    f->revents |= POLLOUT;
+                if (FD_ISSET (f->fd, &xset))
+                    f->revents |= POLLPRI;
+            }
+            if (f->revents)
+                ready++;
+        }
+    }
+
+    return ready;
+}
+
+#endif /* HAVE_SYS_POLL_H */