drm_hwcomposer: Reduce time spent in display_lock

This reduces the amount of time set will block on the
worker.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Change-Id: If5d110ce78e98642265ffa7dcc25710bc227330b

diff --git a/hwcomposer.cpp b/hwcomposer.cpp
index ded7b0f..0ae9381 100644 (file)
--- a/hwcomposer.cpp
+++ b/hwcomposer.cpp
@@ -268,28 +268,28 @@ static int hwc_flip(struct hwc_drm_display *hd, struct hwc_drm_bo *buf)
        return 0;
 }
 
-static int hwc_wait_and_set(struct hwc_drm_display *hd)
+static int hwc_wait_and_set(struct hwc_drm_display *hd,
+                       struct hwc_drm_bo *buf)
 {
        int ret;
-       struct hwc_drm_bo buf = hd->buf_queue.front();
 
-       ret = drmModeAddFB2(hwc_get_fd_for_bo(hd->ctx, &buf), buf.width,
-               buf.height, buf.format, buf.gem_handles, buf.pitches,
-               buf.offsets, &buf.fb_id, 0);
+       ret = drmModeAddFB2(hwc_get_fd_for_bo(hd->ctx, buf), buf->width,
+               buf->height, buf->format, buf->gem_handles, buf->pitches,
+               buf->offsets, &buf->fb_id, 0);
        if (ret) {
                ALOGE("could not create drm fb %d", ret);
                return ret;
        }
 
-       if (buf.acquire_fence_fd >= 0) {
-               ret = sync_wait(buf.acquire_fence_fd, -1);
+       if (buf->acquire_fence_fd >= 0) {
+               ret = sync_wait(buf->acquire_fence_fd, -1);
                if (ret) {
                        ALOGE("Failed to wait for acquire %d", ret);
                        return ret;
                }
        }
 
-       ret = hwc_flip(hd, &buf);
+       ret = hwc_flip(hd, buf);
        if (ret) {
                ALOGE("Failed to perform flip\n");
                return ret;
@@ -303,8 +303,8 @@ static int hwc_wait_and_set(struct hwc_drm_display *hd)
                        return ret;
                }
        }
-       hd->front = buf;
-       hd->buf_queue.pop();
+       hd->front = *buf;
+
        return ret;
 }
 
@@ -315,32 +315,45 @@ static void *hwc_set_worker(void *arg)
 
        setpriority(PRIO_PROCESS, 0, HAL_PRIORITY_URGENT_DISPLAY);
 
-       ret = pthread_mutex_lock(&hd->set_worker.lock);
-       if (ret) {
-               ALOGE("Failed to lock set lock %d", ret);
-               return NULL;
-       }
-
        do {
-               ret = pthread_cond_wait(&hd->set_worker.cond,
-                               &hd->set_worker.lock);
+               struct hwc_drm_bo buf;
+
+               ret = pthread_mutex_lock(&hd->set_worker.lock);
                if (ret) {
-                       ALOGE("Failed to wait on set condition %d", ret);
-                       break;
-               } else if (hd->set_worker.exit) {
-                       break;
+                       ALOGE("Failed to lock set lock %d", ret);
+                       return NULL;
+               }
+
+               if (hd->set_worker.exit)
+                       goto out;
+
+               if (hd->buf_queue.empty()) {
+                       ret = pthread_cond_wait(&hd->set_worker.cond,
+                                       &hd->set_worker.lock);
+                       if (ret) {
+                               ALOGE("Failed to wait on condition %d", ret);
+                               goto out;
+                       }
+               }
+
+               buf = hd->buf_queue.front();
+               hd->buf_queue.pop();
+
+               ret = pthread_mutex_unlock(&hd->set_worker.lock);
+               if (ret) {
+                       ALOGE("Failed to unlock set lock %d", ret);
+                       return NULL;
                }
 
-               ret = hwc_wait_and_set(hd);
+               ret = hwc_wait_and_set(hd, &buf);
                if (ret)
                        ALOGE("Failed to wait and set %d", ret);
        } while (true);
 
+out:
        ret = pthread_mutex_unlock(&hd->set_worker.lock);
-       if (ret) {
-               ALOGE("Failed to unlock set lock %d", ret);
-               return NULL;
-       }
+       if (ret)
+               ALOGE("Failed to unlock set lock while exiting %d", ret);
 
        return NULL;
 }
@@ -385,21 +398,20 @@ static int hwc_set_display(hwc_context_t *ctx, int display,
                }
        }
 
-       ret = pthread_mutex_lock(&hd->set_worker.lock);
-       if (ret) {
-               ALOGE("Failed to lock set lock in set() %d", ret);
-               return ret;
-       }
-
        ret = hwc_create_bo_from_import(ctx->fd, ctx->import_ctx, layer->handle,
                                &buf);
        if (ret) {
                ALOGE("Failed to import handle to drm bo %d", ret);
-               goto out;
+               return ret;
        }
        buf.acquire_fence_fd = layer->acquireFenceFd;
        layer->releaseFenceFd = -1;
 
+       ret = pthread_mutex_lock(&hd->set_worker.lock);
+       if (ret) {
+               ALOGE("Failed to lock set lock in set() %d", ret);
+               return ret;
+       }
        hd->buf_queue.push(buf);
 
        ret = pthread_cond_signal(&hd->set_worker.cond);