[aravis/realtime] gv_stream: WIP for realtime support

[Emmanuel Pacaud <emmanuel src gnome org>]

commit ae14e320a45b94c68870be6da0470bae972427df
Author: Emmanuel Pacaud <emmanuel gnome org>
Date:   Tue Mar 18 17:05:43 2014 +0100

    gv_stream: WIP for realtime support

 src/arvmisc.c     |   81 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/arvmisc.h     |    2 +
 tests/.gitignore  |    1 +
 tests/Makefile.am |    5 ++-
 tests/dbus.c      |   68 ++++++++++++++++++++++++++++++++++++++++++++
 tests/misc.c      |    9 ++++++
 6 files changed, 165 insertions(+), 1 deletions(-)
---
diff --git a/src/arvmisc.c b/src/arvmisc.c
index 2e555a7..cd9ee15 100644
--- a/src/arvmisc.c
+++ b/src/arvmisc.c
@@ -26,6 +26,87 @@
 #include <math.h>
 #include <stdio.h>
 #include <zlib.h>
+#include <errno.h>
+#include <gio/gio.h>
+
+#ifdef __linux__
+
+#include <linux/sched.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+
+gboolean
+arv_make_realtime (void)
+{
+       struct sched_param p;
+
+       memset (&p, 0, sizeof(p));
+       p.sched_priority = 3;
+
+       if (sched_setscheduler (0, SCHED_RR|SCHED_RESET_ON_FORK, &p) < 0 && errno == EPERM) {
+               GDBusProxy *proxy;
+               GVariant *answer;
+               pid_t thread_id;
+               GError *error = NULL;
+               gint32 priority = p.sched_priority;
+
+               thread_id = syscall(SYS_gettid);
+               
+               proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
+                                                      G_DBUS_PROXY_FLAGS_NONE,
+                                                      NULL,
+                                                      "org.freedesktop.RealtimeKit1",
+                                                      "/org/freedesktop/RealtimeKit1",
+                                                      "org.freedesktop.RealtimeKit1",
+                                                      NULL, &error);
+
+               if (error != NULL) {
+                       g_warning ("[::make_realtime] Failed to create dbus proxy (%s)",
+                                  error->message);
+                       g_clear_pointer (&error, g_error_free);
+               }
+
+               answer = g_dbus_proxy_get_cached_property (proxy, "MaxRealtimePriority");
+
+               if (answer == NULL) {
+                       g_warning ("[::make_realtime] Failed to get MaxRealtimePriority");
+               } else {
+                       g_variant_unref (answer);
+               }
+               
+               priority = g_variant_get_int32 (answer);
+
+               answer = g_dbus_proxy_call_sync (proxy,
+                                                "MakeThreadRealtime",
+                                                g_variant_new ("(tu)", thread_id, priority),
+                                                G_DBUS_CALL_FLAGS_NONE, -1, NULL, &error);
+
+               if (error != NULL) {
+                       g_warning ("[::make_realtime] Failed to set realtime scheduling using rtkit (%s)",
+                                  error->message);
+                       g_clear_pointer (&error, g_error_free);
+               }
+
+               g_object_unref (proxy);
+
+               if (answer != NULL) 
+                       g_variant_unref (answer);
+               else
+                       return FALSE;
+       }
+
+       return TRUE;
+}
+
+#else
+
+gboolean
+arv_make_realtime (void)
+{
+       return FALSE;
+}
+
+#endif
 
 /**
  * SECTION: arvstatistic
diff --git a/src/arvmisc.h b/src/arvmisc.h
index 3b944dc..2320cfb 100644
--- a/src/arvmisc.h
+++ b/src/arvmisc.h
@@ -27,6 +27,8 @@
 
 G_BEGIN_DECLS
 
+gboolean               arv_make_realtime               (void);
+
 typedef struct _ArvStatistic ArvStatistic;
 
 ArvStatistic *         arv_statistic_new               (guint n_histograms, guint n_bins, guint bin_step, 
int offset);
diff --git a/tests/.gitignore b/tests/.gitignore
index cf27c42..8925eeb 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -5,6 +5,7 @@ misc
 fake
 cpp
 arv-test
+dbus
 arv-genicam-test
 arv-evaluator-test
 arv-zip-test
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 6fdba2f..02700de 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -32,7 +32,7 @@ arv_example_LDADD = $(test_progs_ldadd)
 time_test_SOURCES = timetest.c
 time_test_LDADD = $(test_progs_ldadd)
 
-TEST_PROGS += evaluator buffer misc fake genicam
+TEST_PROGS += evaluator buffer misc fake genicam dbus
 if ARAVIS_BUILD_CPP_TEST
 TEST_PROGS += cpp
 endif
@@ -56,6 +56,9 @@ genicam_SOURCES = genicam.c
 genicam_CFLAGS = -DGENICAM_FILENAME="\"$(top_srcdir)/tests/data/genicam.xml\""
 genicam_LDADD = $(test_progs_ldadd)
 
+dbus_SOURCES = dbus.c
+dbus_LDADD = $(test_progs_ldadd)
+
 cpp_SOURCES = cpp.cc
 cpp_LDADD = $(test_progs_ldadd)
 
diff --git a/tests/dbus.c b/tests/dbus.c
new file mode 100644
index 0000000..fa45679
--- /dev/null
+++ b/tests/dbus.c
@@ -0,0 +1,68 @@
+#include <gio/gio.h>
+#include <linux/sched.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <memory.h>
+#include <errno.h>
+
+gboolean
+arv_make_realtime (void)
+{
+               GDBusProxy *proxy;
+               GVariant *answer;
+               pid_t thread_id;
+               GError *error = NULL;
+               gint32 priority = 19;
+
+               thread_id = syscall(SYS_gettid);
+               
+               proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
+                                                      G_DBUS_PROXY_FLAGS_NONE,
+                                                      NULL,
+                                                      "org.freedesktop.RealtimeKit1",
+                                                      "/org/freedesktop/RealtimeKit1",
+                                                      "org.freedesktop.RealtimeKit1",
+                                                      NULL, &error);
+
+               if (error != NULL) {
+                       g_warning ("[::make_realtime] Failed to create dbus proxy (%s)",
+                                  error->message);
+                       g_clear_pointer (&error, g_error_free);
+               }
+
+               answer = g_dbus_proxy_get_cached_property (proxy, "MaxRealtimePriority");
+
+               if (answer == NULL) {
+                       g_warning ("[::make_realtime] Failed to get MaxRealtimePriority");
+               } else {
+                       priority = g_variant_get_int32 (answer);
+                       g_variant_unref (answer);
+               }
+
+               g_message ("thread_id = %d", thread_id);
+               g_message ("priority = %d", priority);
+
+               answer = g_dbus_proxy_call_sync (proxy,
+                                                "MakeThreadRealtime",
+                                                g_variant_new ("(tu)", thread_id, priority),
+                                                G_DBUS_CALL_FLAGS_NONE, -1, NULL, &error);
+
+               if (error != NULL) {
+                       g_warning ("[::make_realtime] Failed to set realtime scheduling using rtkit (%s)",
+                                  error->message);
+                       g_clear_pointer (&error, g_error_free);
+               }
+
+               g_object_unref (proxy);
+
+               if (answer != NULL) 
+                       g_variant_unref (answer);
+               else
+                       return FALSE;
+}
+
+int
+main (int argc, char **argv)
+{
+       arv_make_realtime ();
+}
diff --git a/tests/misc.c b/tests/misc.c
index b95262b..9d32c5b 100644
--- a/tests/misc.c
+++ b/tests/misc.c
@@ -81,6 +81,14 @@ arv_str_strip_test (void)
        g_assert (arv_str_strip (NULL, NULL, REPLACEMENT_CHARACTER) == NULL);
 }
 
+static void
+arv_make_realtime_test (void)
+{
+       arv_make_realtime ();
+
+       sleep (20);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -93,6 +101,7 @@ main (int argc, char *argv[])
 
        g_test_add_func ("/buffer/unaligned-from-le", unaligned_from_le_ptr_test);
        g_test_add_func ("/str/arv-str-strip", arv_str_strip_test);
+       g_test_add_func ("/sys/arv-make-realtime", arv_make_realtime_test);
 
        result = g_test_run();