Adding upstream version 14.2.upstream/14.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 320 insertions, 0 deletions

diff --git a/src/pulsecore/fdsem.c b/src/pulsecore/fdsem.c
new file mode 100644
index 0000000..a7fbf95
--- /dev/null
+++ b/src/pulsecore/fdsem.c
@@ -0,0 +1,320 @@
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2006 Lennart Poettering
+
+  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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef HAVE_SYS_SYSCALL_H
+#include <sys/syscall.h>
+#endif
+
+#include <unistd.h>
+#include <errno.h>
+
+#include <pulsecore/atomic.h>
+#include <pulsecore/log.h>
+#include <pulsecore/macro.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/core-error.h>
+#include <pulse/xmalloc.h>
+
+#ifndef HAVE_PIPE
+#include <pulsecore/pipe.h>
+#endif
+
+#ifdef HAVE_SYS_EVENTFD_H
+#include <sys/eventfd.h>
+#endif
+
+#include "fdsem.h"
+
+struct pa_fdsem {
+    int fds[2];
+#ifdef HAVE_SYS_EVENTFD_H
+    int efd;
+#endif
+    int write_type;
+    pa_fdsem_data *data;
+};
+
+pa_fdsem *pa_fdsem_new(void) {
+    pa_fdsem *f;
+
+    f = pa_xmalloc0(PA_ALIGN(sizeof(pa_fdsem)) + PA_ALIGN(sizeof(pa_fdsem_data)));
+
+#ifdef HAVE_SYS_EVENTFD_H
+    if ((f->efd = eventfd(0, EFD_CLOEXEC)) >= 0)
+        f->fds[0] = f->fds[1] = -1;
+    else
+#endif
+    {
+        if (pa_pipe_cloexec(f->fds) < 0) {
+            pa_xfree(f);
+            return NULL;
+        }
+    }
+
+    f->data = (pa_fdsem_data*) ((uint8_t*) f + PA_ALIGN(sizeof(pa_fdsem)));
+
+    pa_atomic_store(&f->data->waiting, 0);
+    pa_atomic_store(&f->data->signalled, 0);
+    pa_atomic_store(&f->data->in_pipe, 0);
+
+    return f;
+}
+
+pa_fdsem *pa_fdsem_open_shm(pa_fdsem_data *data, int event_fd) {
+    pa_fdsem *f = NULL;
+
+    pa_assert(data);
+    pa_assert(event_fd >= 0);
+
+#ifdef HAVE_SYS_EVENTFD_H
+    f = pa_xnew0(pa_fdsem, 1);
+
+    f->efd = event_fd;
+    pa_make_fd_cloexec(f->efd);
+    f->fds[0] = f->fds[1] = -1;
+    f->data = data;
+#endif
+
+    return f;
+}
+
+pa_fdsem *pa_fdsem_new_shm(pa_fdsem_data *data) {
+    pa_fdsem *f = NULL;
+
+    pa_assert(data);
+
+#ifdef HAVE_SYS_EVENTFD_H
+
+    f = pa_xnew0(pa_fdsem, 1);
+
+    if ((f->efd = eventfd(0, EFD_CLOEXEC)) < 0) {
+        pa_xfree(f);
+        return NULL;
+    }
+
+    f->fds[0] = f->fds[1] = -1;
+    f->data = data;
+
+    pa_atomic_store(&f->data->waiting, 0);
+    pa_atomic_store(&f->data->signalled, 0);
+    pa_atomic_store(&f->data->in_pipe, 0);
+
+#endif
+
+    return f;
+}
+
+void pa_fdsem_free(pa_fdsem *f) {
+    pa_assert(f);
+
+#ifdef HAVE_SYS_EVENTFD_H
+    if (f->efd >= 0)
+        pa_close(f->efd);
+#endif
+    pa_close_pipe(f->fds);
+
+    pa_xfree(f);
+}
+
+static void flush(pa_fdsem *f) {
+    ssize_t r;
+    pa_assert(f);
+
+    if (pa_atomic_load(&f->data->in_pipe) <= 0)
+        return;
+
+    do {
+        char x[10];
+
+#ifdef HAVE_SYS_EVENTFD_H
+        if (f->efd >= 0) {
+            uint64_t u;
+
+            if ((r = pa_read(f->efd, &u, sizeof(u), NULL)) != sizeof(u)) {
+
+                if (r >= 0 || errno != EINTR) {
+                    pa_log_error("Invalid read from eventfd: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
+                    pa_assert_not_reached();
+                }
+
+                continue;
+            }
+            r = (ssize_t) u;
+        } else
+#endif
+
+        if ((r = pa_read(f->fds[0], &x, sizeof(x), NULL)) <= 0) {
+
+            if (r >= 0 || errno != EINTR) {
+                pa_log_error("Invalid read from pipe: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
+                pa_assert_not_reached();
+            }
+
+            continue;
+        }
+
+    } while (pa_atomic_sub(&f->data->in_pipe, (int) r) > (int) r);
+}
+
+void pa_fdsem_post(pa_fdsem *f) {
+    pa_assert(f);
+
+    if (pa_atomic_cmpxchg(&f->data->signalled, 0, 1)) {
+
+        if (pa_atomic_load(&f->data->waiting)) {
+            ssize_t r;
+            char x = 'x';
+
+            pa_atomic_inc(&f->data->in_pipe);
+
+            for (;;) {
+
+#ifdef HAVE_SYS_EVENTFD_H
+                if (f->efd >= 0) {
+                    uint64_t u = 1;
+
+                    if ((r = pa_write(f->efd, &u, sizeof(u), &f->write_type)) != sizeof(u)) {
+                        if (r >= 0 || errno != EINTR) {
+                            pa_log_error("Invalid write to eventfd: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
+                            pa_assert_not_reached();
+                        }
+
+                        continue;
+                    }
+                } else
+#endif
+
+                if ((r = pa_write(f->fds[1], &x, 1, &f->write_type)) != 1) {
+                    if (r >= 0 || errno != EINTR) {
+                        pa_log_error("Invalid write to pipe: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
+                        pa_assert_not_reached();
+                    }
+
+                    continue;
+                }
+
+                break;
+            }
+        }
+    }
+}
+
+void pa_fdsem_wait(pa_fdsem *f) {
+    pa_assert(f);
+
+    flush(f);
+
+    if (pa_atomic_cmpxchg(&f->data->signalled, 1, 0))
+        return;
+
+    pa_atomic_inc(&f->data->waiting);
+
+    while (!pa_atomic_cmpxchg(&f->data->signalled, 1, 0)) {
+        char x[10];
+        ssize_t r;
+
+#ifdef HAVE_SYS_EVENTFD_H
+        if (f->efd >= 0) {
+            uint64_t u;
+
+            if ((r = pa_read(f->efd, &u, sizeof(u), NULL)) != sizeof(u)) {
+
+                if (r >= 0 || errno != EINTR) {
+                    pa_log_error("Invalid read from eventfd: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
+                    pa_assert_not_reached();
+                }
+
+                continue;
+            }
+
+            r = (ssize_t) u;
+        } else
+#endif
+
+        if ((r = pa_read(f->fds[0], &x, sizeof(x), NULL)) <= 0) {
+
+            if (r >= 0 || errno != EINTR) {
+                pa_log_error("Invalid read from pipe: %s", r < 0 ? pa_cstrerror(errno) : "EOF");
+                pa_assert_not_reached();
+            }
+
+            continue;
+        }
+
+        pa_atomic_sub(&f->data->in_pipe, (int) r);
+    }
+
+    pa_assert_se(pa_atomic_dec(&f->data->waiting) >= 1);
+}
+
+int pa_fdsem_try(pa_fdsem *f) {
+    pa_assert(f);
+
+    flush(f);
+
+    if (pa_atomic_cmpxchg(&f->data->signalled, 1, 0))
+        return 1;
+
+    return 0;
+}
+
+int pa_fdsem_get(pa_fdsem *f) {
+    pa_assert(f);
+
+#ifdef HAVE_SYS_EVENTFD_H
+    if (f->efd >= 0)
+        return f->efd;
+#endif
+
+    return f->fds[0];
+}
+
+int pa_fdsem_before_poll(pa_fdsem *f) {
+    pa_assert(f);
+
+    flush(f);
+
+    if (pa_atomic_cmpxchg(&f->data->signalled, 1, 0))
+        return -1;
+
+    pa_atomic_inc(&f->data->waiting);
+
+    if (pa_atomic_cmpxchg(&f->data->signalled, 1, 0)) {
+        pa_assert_se(pa_atomic_dec(&f->data->waiting) >= 1);
+        return -1;
+    }
+    return 0;
+}
+
+int pa_fdsem_after_poll(pa_fdsem *f) {
+    pa_assert(f);
+
+    pa_assert_se(pa_atomic_dec(&f->data->waiting) >= 1);
+
+    flush(f);
+
+    if (pa_atomic_cmpxchg(&f->data->signalled, 1, 0))
+        return 1;
+
+    return 0;
+}