implement device reservation scheme

1 files changed, 158 insertions, 0 deletions

diff --git a/src/modules/reserve-wrap.c b/src/modules/reserve-wrap.c
new file mode 100644
index 00000000..df2861f5
--- /dev/null
+++ b/src/modules/reserve-wrap.c
@@ -0,0 +1,158 @@
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2009 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 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.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <pulse/xmalloc.h>
+#include <pulse/i18n.h>
+
+#include <pulsecore/core-error.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/shared.h>
+
+#include <modules/dbus-util.h>
+
+#include "reserve.h"
+#include "reserve-wrap.h"
+
+struct pa_reserve_wrapper {
+    PA_REFCNT_DECLARE;
+    pa_core *core;
+    pa_dbus_connection *connection;
+    pa_hook hook;
+    struct rd_device *device;
+    char *shared_name;
+};
+
+static void reserve_wrapper_free(pa_reserve_wrapper *r) {
+    pa_assert(r);
+
+    if (r->device)
+        rd_release(r->device);
+
+    pa_hook_done(&r->hook);
+
+    if (r->connection)
+        pa_dbus_connection_unref(r->connection);
+
+    if (r->shared_name) {
+        pa_assert_se(pa_shared_remove(r->core, r->shared_name) >= 0);
+        pa_xfree(r->shared_name);
+    }
+
+    pa_xfree(r);
+}
+
+static int request_cb(rd_device *d, int forced) {
+    pa_reserve_wrapper *r;
+    int k;
+
+    pa_assert(d);
+    pa_assert_se(r = rd_get_userdata(d));
+    pa_assert(PA_REFCNT_VALUE(r) >= 1);
+
+    PA_REFCNT_INC(r);
+
+    k = pa_hook_fire(&r->hook, PA_INT_TO_PTR(forced));
+    pa_log_debug("Device unlock has been requested and %s.", k < 0 ? "failed" : "succeeded");
+
+    pa_reserve_wrapper_unref(r);
+
+    return k < 0 ? -1 : 1;
+}
+
+pa_reserve_wrapper* pa_reserve_wrapper_get(pa_core *c, const char *device_name) {
+    pa_reserve_wrapper *r;
+    DBusError error;
+    int k;
+    char *t;
+
+    dbus_error_init(&error);
+
+    pa_assert(c);
+    pa_assert(device_name);
+
+    t = pa_sprintf_malloc("reserve-wrapper@%s", device_name);
+
+    if ((r = pa_shared_get(c, t))) {
+        pa_xfree(t);
+
+        pa_assert(PA_REFCNT_VALUE(r) >= 1);
+        PA_REFCNT_INC(r);
+
+        return r;
+    }
+
+    r = pa_xnew0(pa_reserve_wrapper, 1);
+    PA_REFCNT_INIT(r);
+    r->core = c;
+    pa_hook_init(&r->hook, r);
+    r->shared_name = t;
+
+    pa_assert_se(pa_shared_set(c, r->shared_name, r) >= 0);
+
+    if (!(r->connection = pa_dbus_bus_get(c, DBUS_BUS_SESSION, &error)) || dbus_error_is_set(&error)) {
+        pa_log_error("Unable to contact D-Bus session bus: %s: %s", error.name, error.message);
+        goto fail;
+    }
+
+    if ((k = rd_acquire(
+                 &r->device,
+                 pa_dbus_connection_get(r->connection),
+                 device_name,
+                 _("PulseAudio Sound Server"),
+                 0,
+                 request_cb,
+                 &error)) < 0) {
+
+        pa_log_error("Failed to acquire reservation lock on device '%s': %s", device_name, pa_cstrerror(-k));
+        goto fail;
+    }
+
+    pa_log_debug("Successfully acquired reservation lock on device '%s'", device_name);
+
+    rd_set_userdata(r->device, r);
+
+    return r;
+
+fail:
+    reserve_wrapper_free(r);
+    return NULL;
+}
+
+void pa_reserve_wrapper_unref(pa_reserve_wrapper *r) {
+    pa_assert(r);
+    pa_assert(PA_REFCNT_VALUE(r) >= 1);
+
+    if (PA_REFCNT_DEC(r) > 0)
+        return;
+
+    reserve_wrapper_free(r);
+}
+
+pa_hook* pa_reserve_wrapper_hook(pa_reserve_wrapper *r) {
+    pa_assert(r);
+    pa_assert(PA_REFCNT_VALUE(r) >= 1);
+
+    return &r->hook;
+}