drm_hwcomposer: Move event worker into VSyncWorker

Using the new Worker interface, split out the event worker
now that it just handles vsyncs.

Change-Id: I7ebc6237b10411fdba3b8826935921b8c83c4b6c
Signed-off-by: Sean Paul <seanpaul@chromium.org>
diff --git a/vsyncworker.cpp b/vsyncworker.cpp
new file mode 100644
index 0000000..9626022
--- /dev/null
+++ b/vsyncworker.cpp
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "hwc-vsync-worker"
+
+#include "drmresources.h"
+#include "vsyncworker.h"
+#include "worker.h"
+
+#include <map>
+#include <stdlib.h>
+#include <time.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#include <cutils/log.h>
+#include <hardware/hardware.h>
+
+namespace android {
+
+VSyncWorker::VSyncWorker()
+    : Worker("vsync", HAL_PRIORITY_URGENT_DISPLAY),
+      drm_(NULL),
+      procs_(NULL),
+      display_(-1),
+      last_timestamp_(-1) {
+}
+
+VSyncWorker::~VSyncWorker() {
+}
+
+int VSyncWorker::Init(DrmResources *drm, int display) {
+  drm_ = drm;
+  display_ = display;
+
+  return InitWorker();
+}
+
+int VSyncWorker::SetProcs(hwc_procs_t const *procs) {
+  int ret = Lock();
+  if (ret) {
+    ALOGE("Failed to lock vsync worker lock %d\n", ret);
+    return ret;
+  }
+
+  procs_ = procs;
+
+  ret = Unlock();
+  if (ret) {
+    ALOGE("Failed to unlock vsync worker lock %d\n", ret);
+    return ret;
+  }
+  return 0;
+}
+
+int VSyncWorker::VSyncControl(bool enabled) {
+  int ret = Lock();
+  if (ret) {
+    ALOGE("Failed to lock vsync worker lock %d\n", ret);
+    return ret;
+  }
+
+  enabled_ = enabled;
+  last_timestamp_ = -1;
+  int signal_ret = SignalLocked();
+
+  ret = Unlock();
+  if (ret) {
+    ALOGE("Failed to unlock vsync worker lock %d\n", ret);
+    return ret;
+  }
+
+  return signal_ret;
+}
+
+/*
+ * Returns the timestamp of the next vsync in phase with last_timestamp_.
+ * For example:
+ *  last_timestamp_ = 137
+ *  frame_ns = 50
+ *  current = 683
+ *
+ *  ret = (50 * ((683 - 137)/50 + 1)) + 137
+ *  ret = 687
+ *
+ *  Thus, we must sleep until timestamp 687 to maintain phase with the last
+ *  timestamp.
+ */
+int64_t VSyncWorker::GetPhasedVSync(int64_t frame_ns, int64_t current) {
+  if (last_timestamp_ < 0)
+    return current + frame_ns;
+
+  return frame_ns * ((current - last_timestamp_) / frame_ns + 1) +
+         last_timestamp_;
+}
+
+static const int64_t kOneSecondNs = 1 * 1000 * 1000 * 1000;
+
+int VSyncWorker::SyntheticWaitVBlank(int64_t *timestamp) {
+  struct timespec vsync;
+  int ret = clock_gettime(CLOCK_MONOTONIC, &vsync);
+
+  int64_t refresh = 60;  // Default to 60Hz refresh rate
+  DrmConnector *conn = drm_->GetConnectorForDisplay(display_);
+  if (conn && conn->active_mode().v_refresh())
+    refresh = conn->active_mode().v_refresh();
+  else
+    ALOGW("Vsync worker active with conn=%p refresh=%d\n", conn,
+          conn ? conn->active_mode().v_refresh() : -1);
+
+  int64_t phased_timestamp = GetPhasedVSync(
+      kOneSecondNs / refresh, vsync.tv_sec * kOneSecondNs + vsync.tv_nsec);
+  vsync.tv_sec = phased_timestamp / kOneSecondNs;
+  vsync.tv_nsec = phased_timestamp - (vsync.tv_sec * kOneSecondNs);
+  do {
+    ret = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &vsync, NULL);
+  } while (ret == -1 && errno == EINTR);
+  if (ret)
+    return ret;
+
+  *timestamp = (int64_t)vsync.tv_sec * kOneSecondNs + (int64_t)vsync.tv_nsec;
+  return 0;
+}
+
+void VSyncWorker::Routine() {
+  int ret = Lock();
+  if (ret) {
+    ALOGE("Failed to lock worker %d", ret);
+    return;
+  }
+
+  if (!enabled_) {
+    ret = WaitForSignalOrExitLocked();
+    if (ret == -EINTR) {
+      return;
+    }
+  }
+
+  bool enabled = enabled_;
+  int display = display_;
+  hwc_procs_t const *procs = procs_;
+
+  ret = Unlock();
+  if (ret) {
+    ALOGE("Failed to unlock worker %d", ret);
+  }
+
+  if (!enabled)
+    return;
+
+  DrmCrtc *crtc = drm_->GetCrtcForDisplay(display);
+  if (!crtc) {
+    ALOGE("Failed to get crtc for display");
+    return;
+  }
+  uint32_t high_crtc = (crtc->pipe() << DRM_VBLANK_HIGH_CRTC_SHIFT);
+
+  drmVBlank vblank;
+  memset(&vblank, 0, sizeof(vblank));
+  vblank.request.type = (drmVBlankSeqType)(
+      DRM_VBLANK_RELATIVE | (high_crtc & DRM_VBLANK_HIGH_CRTC_MASK));
+  vblank.request.sequence = 1;
+
+  int64_t timestamp;
+  ret = drmWaitVBlank(drm_->fd(), &vblank);
+  if (ret == -EINTR) {
+    return;
+  } else if (ret) {
+    ret = SyntheticWaitVBlank(&timestamp);
+    if (ret)
+      return;
+  } else {
+    timestamp = (int64_t)vblank.reply.tval_sec * kOneSecondNs +
+                (int64_t)vblank.reply.tval_usec * 1000;
+  }
+
+  /*
+   * There's a race here where a change in procs_ will not take effect until
+   * the next subsequent requested vsync. This is unavoidable since we can't
+   * call the vsync hook while holding the thread lock.
+   *
+   * We could shorten the race window by caching procs_ right before calling
+   * the hook. However, in practice, procs_ is only updated once, so it's not
+   * worth the overhead.
+   */
+  if (procs && procs->vsync)
+    procs->vsync(procs, display, timestamp);
+  last_timestamp_ = timestamp;
+}
+}