drm_hwcomposer: Add Worker class to abstract thread nasties

This will allow us to spin up threads more easily.

Change-Id: I74add3d20ab14a61f3c646877a3ee17d0bd99ac4
Signed-off-by: Sean Paul <seanpaul@chromium.org>

1 files changed, 72 insertions, 0 deletions

diff --git a/worker.h b/worker.h
new file mode 100644
index 0000000..492693c
--- /dev/null
+++ b/worker.h
@@ -0,0 +1,72 @@
+/*
+ * 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.
+ */
+
+#ifndef ANDROID_WORKER_H_
+#define ANDROID_WORKER_H_
+
+#include <pthread.h>
+#include <string>
+
+namespace android {
+
+class Worker {
+ public:
+  int Lock();
+  int Unlock();
+
+  // Must be called with the lock acquired
+  int SignalLocked();
+  int ExitLocked();
+
+  // Convenience versions of above, acquires the lock
+  int Signal();
+  int Exit();
+
+ protected:
+  Worker(const char *name, int priority);
+  virtual ~Worker();
+
+  int InitWorker();
+
+  bool initialized() const;
+
+  virtual void Routine() = 0;
+
+  /*
+   * Must be called with the lock acquired.
+   * Returns -EINTR if interrupted by exit request
+   */
+  int WaitForSignalOrExitLocked();
+
+ private:
+  static void *InternalRoutine(void *worker);
+
+  // Must be called with the lock acquired
+  int SignalThreadLocked(bool exit);
+
+  std::string name_;
+  int priority_;
+
+  pthread_t thread_;
+  pthread_mutex_t lock_;
+  pthread_cond_t cond_;
+
+  bool exit_;
+  bool initialized_;
+};
+}
+
+#endif