From f1aa474faa59265ee9fa9207663488cd34bc5a18 Mon Sep 17 00:00:00 2001
From: Jussi Saavalainen <jussi.saavalainen@ixonos.com>
Date: Wed, 24 Apr 2013 13:24:54 +0300
Subject: [PATCH] Allow pausing of 3A thread instead of recreating it each time

This partially removes some of the address space leakage associated
with stack space for the threads, plus brings a tiny performance
gain for stills.

Change-Id: I712f86ca0f880e8bbe908d087b5ce734949a5b0d
---
 gst-libs/atomisphal/mfld_cam.c | 50 ++++++++++++++++++++++++++++++++----------
 1 file changed, 38 insertions(+), 12 deletions(-)

diff --git a/gst-libs/atomisphal/mfld_cam.c b/gst-libs/atomisphal/mfld_cam.c
index 3fc7574..3809448 100644
--- a/gst-libs/atomisphal/mfld_cam.c
+++ b/gst-libs/atomisphal/mfld_cam.c
@@ -102,7 +102,8 @@ struct mfld_driver_t
   int mmap;
   int first_frame;
   int g_3a_started;
-  //GThread *thread;
+  int thread_paused;
+
   pthread_t thread;
   unsigned int width, height, fourcc;
   float frame_rate;
@@ -134,6 +135,9 @@ static const int STILL_AF_MAX_TIME_IN_MS = 2200;
  * */
 static struct mfld_cam_settings_t mfld_cam_settings;
 static struct mfld_driver_t mfld_driver;
+
+G_LOCK_DEFINE(3a_thread_lock);
+
 static GstV4l2MFLDAdvCI *mfldadvci;
 
 static inline long
@@ -1199,7 +1203,10 @@ libmfld_cam_init (GstV4l2MFLDAdvCI * advci)
   mfld_driver.first_frame = 0;
 
   mfld_driver.mmap = 1;
+  G_LOCK(3a_thread_lock);
   mfld_driver.g_3a_started = 0;
+  mfld_driver.thread_paused = 0;
+  G_UNLOCK(3a_thread_lock);
 
   mfld_driver.focus_done = 0;
   mfld_driver.flash_used = FALSE;
@@ -1213,6 +1220,7 @@ libmfld_cam_init (GstV4l2MFLDAdvCI * advci)
 void
 libmfld_cam_dispose (void)
 {
+  G_LOCK(3a_thread_lock);
   if (mfld_driver.g_3a_started) {
     pthread_cancel (mfld_driver.thread);
     mfld_driver.thread = 0;
@@ -1220,6 +1228,7 @@ libmfld_cam_dispose (void)
   mfld_driver.g_3a_started = 0;
   if (mfld_driver.sensor_type == SENSOR_TYPE_RAW)
     mfldadvci->uninit ();
+  G_UNLOCK(3a_thread_lock);
   return;
 }
 
@@ -1272,7 +1281,9 @@ cam_driver_init (int fd, const char *sensor_id)
   mfld_driver.initflag = 1;     /* We are ready to call the dz_zoom */
   /* Do other driver related init here */
 
+  G_LOCK(3a_thread_lock);
   mfld_driver.thread = 0;
+  G_UNLOCK(3a_thread_lock);
   mfld_driver.frame_rate = 15.0f;
 
   return CAM_ERR_NONE;
@@ -1288,10 +1299,12 @@ cam_driver_deinit (int fd)
   /* Initialize the driver structure */
   //GstCameraSrcClass *camera_class = GST_CAMERA_SRC_GET_CLASS (camerasrc);
   mfld_driver.initflag = 0;
+  G_LOCK(3a_thread_lock);
   if (mfld_driver.g_3a_started) {
     pthread_cancel (mfld_driver.thread);
     mfld_driver.g_3a_started = 0;
   }
+  G_UNLOCK(3a_thread_lock);
   /* Do other driver related deinit here */
   led_flash_off(fd);
   return CAM_ERR_NONE;
@@ -1483,12 +1496,19 @@ mfldcam_3a_process (gpointer data)
   for (;;) {
     sem_wait(&g_sem_3a);
     /* Read 3A statistics */
-    if ((mfld_driver.ae_awb_af_enabled || mfld_driver.dis_enabled
-        || mfld_driver.dvs_enabled) && (mfld_driver.sensor_type == SENSOR_TYPE_RAW) )
-    {
+    if ( (mfld_driver.ae_awb_af_enabled
+	  || mfld_driver.dis_enabled
+	  || mfld_driver.dvs_enabled)
+	 && (mfld_driver.sensor_type == SENSOR_TYPE_RAW)) {
+      G_LOCK(3a_thread_lock);
+      if(mfld_driver.thread_paused) {
+	G_UNLOCK(3a_thread_lock);
+	continue;
+      }
       /* AE, AWB and AF Process */
-      mfldadvci->AeAfAwb_process(TRUE,&mfld_driver.timestamp);
+      G_UNLOCK(3a_thread_lock);
 
+      mfldadvci->AeAfAwb_process(TRUE,&mfld_driver.timestamp);
 
     } else
       return NULL;
@@ -1498,16 +1518,20 @@ mfldcam_3a_process (gpointer data)
 void
 mfldcam_3a_start (void)
 {
-
   if (mfld_driver.sensor_type == SENSOR_TYPE_RAW){
+    G_LOCK(3a_thread_lock);
     if (!mfld_driver.g_3a_started) {
       mfld_driver.g_3a_started = 1;
-      if (pthread_create (&mfld_driver.thread, NULL, mfldcam_3a_process,
-              NULL) != 0) {
+      mfld_driver.thread_paused = 0;
+
+      if (pthread_create (&mfld_driver.thread, NULL, mfldcam_3a_process, NULL) != 0) {
         mfld_driver.g_3a_started = 0;
         cam_driver_dbg ("Create thread failed %s\n", __func__);;
       }
+    } else if(mfld_driver.thread_paused) {
+      mfld_driver.thread_paused = 0;
     }
+    G_UNLOCK(3a_thread_lock);
   }
 }
 
@@ -1515,10 +1539,12 @@ void
 mfldcam_3a_stop (void)
 {
 
-  if (mfld_driver.sensor_type == SENSOR_TYPE_RAW){
-    if (mfld_driver.g_3a_started)
-      pthread_cancel (mfld_driver.thread);
-    mfld_driver.g_3a_started = 0;
+  if (mfld_driver.sensor_type == SENSOR_TYPE_RAW) {
+    G_LOCK(3a_thread_lock);
+    if (mfld_driver.g_3a_started) {
+      mfld_driver.thread_paused = 1;
+    }
+    G_UNLOCK(3a_thread_lock);
   }
 }
 
-- 
2.7.4