cli: Allow to get samples from single pid

perf lets you decide to only get events that concerns a single process
and thus make sysprof profile this process instead of the whole system
(it can happen that you don't really care about other processes that are
just then noise).

As a side effect, this allows sysprof to not run as root if you have the
rights on the process you want to profile.

collector.c

@@ -401,6 +401,7 @@ counter_disable (counter_t *counter)
 
 static counter_t *
 counter_new (Collector  *collector,
+	     pid_t	 pid,
 	     int	 cpu,
 	     counter_t  *output,
 	     GError    **err)
@@ -427,13 +428,13 @@ counter_new (Collector  *collector,
     attr.task = 1;
     attr.exclude_idle = 1;
     
-    if (!collector->use_hw_counters || (fd = sysprof_perf_counter_open (&attr, -1, cpu, -1,  0)) < 0)
+    if (!collector->use_hw_counters || (fd = sysprof_perf_counter_open (&attr, pid, cpu, -1,  0)) < 0)
     {
 	attr.type = PERF_TYPE_SOFTWARE;
 	attr.config = PERF_COUNT_SW_CPU_CLOCK;
 	attr.sample_period = 1000000;
 	
-	fd = sysprof_perf_counter_open (&attr, -1, cpu, -1, 0);
+	fd = sysprof_perf_counter_open (&attr, pid, cpu, -1, 0);
     }
     
     if (fd < 0)
@@ -717,6 +718,7 @@ process_event (Collector       *collector,
 
 gboolean
 collector_start (Collector  *collector,
+		 pid_t       pid,
 		 GError    **err)
 {
     int n_cpus = get_n_cpus ();
@@ -729,7 +731,7 @@ collector_start (Collector  *collector,
     output = NULL;
     for (i = 0; i < n_cpus; ++i)
     {
-	counter_t *counter = counter_new (collector, i, output, err);
+	counter_t *counter = counter_new (collector, pid, i, output, err);
 
 	if (!counter)
 	{

collector.h

@@ -38,6 +38,7 @@ Collector *collector_new            (gboolean        use_hw_counters,
 				     CollectorFunc   callback,
 				     gpointer        data);
 gboolean   collector_start          (Collector      *collector,
+				     pid_t           pid,
 				     GError        **err);
 void       collector_stop           (Collector      *collector);
 void       collector_reset          (Collector      *collector);

sysprof-cli.c

@@ -111,19 +111,38 @@ die (const char *err_msg)
     exit (-1);
 }
 
+static int opt_pid = -1;
+
+static GOptionEntry entries[] =
+{
+  { "pid", 'p', 0, G_OPTION_ARG_INT, &opt_pid,
+    "Make sysprof specific to a task", NULL },
+  { NULL }
+};
+
 int
 main (int argc, char *argv[])
 {
-    Application *app = g_new0 (Application, 1);
+    Application *app;
+    GOptionContext *context;
     GError *err;
     
+    err = NULL;
+
+    context = g_option_context_new ("- Sysprof");
+    g_option_context_add_main_entries (context, entries, NULL);
+    if (!g_option_context_parse (context, &argc, &argv, &err))
+    {
+	    g_print ("Failed to parse options: %s\n", err->message);
+	    return 1;
+    }
+
+    app = g_new0 (Application, 1);
     app->collector = collector_new (FALSE, NULL, NULL);
     app->outfile = g_strdup (argv[1]);
     app->main_loop = g_main_loop_new (NULL, 0);
     
-    err = NULL;
-    
-    if (!collector_start (app->collector, &err))
+    if (!collector_start (app->collector, (pid_t) opt_pid, &err))
 	die (err->message);
     
     if (argc < 2)

sysprof.c

@@ -365,7 +365,7 @@ on_start_toggled (GtkWidget *widget, gpointer data)
 	return;
     }
 
-    if (collector_start (app->collector, &err))
+    if (collector_start (app->collector, -1, &err))
     {
 	delete_data (app);