Initial Alloy implementation.

This is a regression in functionality and performance, but a much better
foundation for the future of the project (I think). It can run basic
apps under an SSA interpreter but doesn't support some of the features
required to do real 360 apps yet.

src/alloy/mutex_posix.cc

@@ -0,0 +1,65 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2013 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <alloy/mutex.h>
+
+using namespace alloy;
+
+
+namespace alloy {
+  struct Mutex_t {
+    pthread_mutex_t value;
+  };
+}  // namespace alloy
+
+
+Mutex* alloy::AllocMutex(uint32_t spin_count) {
+  Mutex* mutex = (Mutex*)calloc(1, sizeof(Mutex));
+
+  int result = pthread_mutex_init(&mutex->value, NULL);
+  switch (result) {
+    case ENOMEM:
+    case EINVAL:
+      xe_free(mutex);
+      return NULL;
+  }
+
+  return mutex;
+}
+
+void alloy::FreeMutex(Mutex* mutex) {
+  int result = pthread_mutex_destroy(&mutex->value);
+  switch (result) {
+    case EBUSY:
+    case EINVAL:
+      break;
+    default:
+      break;
+  }
+  free(mutex);
+}
+
+int alloy::LockMutex(Mutex* mutex) {
+  return pthread_mutex_lock(&mutex->value) == EINVAL ? 1 : 0;
+}
+
+int alloy::TryLockMutex(Mutex* mutex) {
+  int result = pthread_mutex_trylock(&mutex->value);
+  switch (result) {
+    case EBUSY:
+    case EINVAL:
+      return 1;
+    default:
+      return 0;
+  }
+}
+
+int alloy::UnlockMutex(Mutex* mutex) {
+  return pthread_mutex_unlock(&mutex->value) == EINVAL ? 1 : 0;
+}