In-progress work: refactoring PAL not to be instanced.

This removes a lot of useless passing around of the PAL object.

src/xenia/core/pal_win.cc

@@ -0,0 +1,145 @@
+/**
+ ******************************************************************************
+ * 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 <xenia/core/pal.h>
+
+
+namespace {
+typedef struct xe_pal_win {
+  bool    use_high_perf_timer;
+  double  inv_ticks_per_sec;
+} xe_pal_win_t;
+
+xe_pal_win_t* pal;
+}
+
+
+void xe_pal_dealloc();
+int xe_pal_init(xe_pal_options_t options) {
+  pal = (xe_pal_win_t)xe_calloc(sizeof(pal));
+
+  // Get QPC timing frequency... hopefully stable over the life of the app,
+  // but likely not.
+  // TODO(benvanik): requery periodically/etc.
+  LARGE_INTEGER ticks_per_sec;
+  if (QueryPerformanceFrequency(&ticks_per_sec)) {
+    pal->use_high_perf_timer  = true;
+    pal->inv_ticks_per_sec    = 1.0 / (double)ticks_per_sec.QuadPart;
+  } else {
+    pal->use_high_perf_timer  = false;
+    XELOGW("Falling back from high performance timer");
+  }
+
+  // Setup COM on the main thread.
+  // NOTE: this may fail if COM has already been initialized - that's OK.
+  XEIGNORE(CoInitializeEx(NULL, COINIT_MULTITHREADED));
+
+  atexit(xe_pal_dealloc);
+  return 0;
+}
+
+void xe_pal_dealloc() {
+  //
+
+  xe_free(pal);
+}
+
+// http://msdn.microsoft.com/en-us/library/ms683194.aspx
+namespace {
+DWORD CountSetBits(ULONG_PTR bitMask) {
+  DWORD LSHIFT = sizeof(ULONG_PTR)*8 - 1;
+  DWORD bitSetCount = 0;
+  ULONG_PTR bitTest = (ULONG_PTR)1 << LSHIFT;
+  for (DWORD i = 0; i <= LSHIFT; ++i, bitTest /= 2) {
+    bitSetCount += ((bitMask & bitTest)?1:0);
+  }
+  return bitSetCount;
+}
+}
+int xe_pal_get_system_info(xe_system_info* out_info) {
+  int result_code = 1;
+  xe_zero_struct(out_info, sizeof(xe_system_info));
+  out_info->processors.physical_count = 1;
+  out_info->processors.logical_count  = 1;
+
+  typedef BOOL (WINAPI *LPFN_GLPI)(
+      PSYSTEM_LOGICAL_PROCESSOR_INFORMATION, PDWORD);
+
+  HMODULE   kernel32  = NULL;
+  LPFN_GLPI glpi      = NULL;
+  PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buffer = NULL;
+
+  kernel32 = GetModuleHandle(TEXT("kernel32"));
+  XEEXPECTNOTNULL(kernel32);
+  glpi = (LPFN_GLPI)GetProcAddress(kernel32, "GetLogicalProcessorInfomration");
+  XEEXPECTNOTNULL(glpi);
+
+  // Call GLPI once to get the buffer size, allocate it, then call again.
+  DWORD buffer_length = 0;
+  XEEXPECTFALSE(glpi(NULL, &buffer_length));
+  XEEXPECT(GetLastError() == ERROR_INSUFFICIENT_BUFFER);
+  buffer = (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION)xe_malloc(buffer_length);
+  XEEXPECTNOTNULL(buffer);
+  XEEXPECTTRUE(glpi(buffer, &buffer_length));
+  XEEXPECTNOTZERO(buffer_length);
+
+  out_info->processors.physical_count = 0;
+  out_info->processors.logical_count  = 0;
+
+  size_t info_count = buffer_length /
+      sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION);
+  for (size_t n = 0; n < info_count; n++) {
+    switch (buffer[n].Relationship) {
+      case RelationProcessorPackage:
+        out_info->processors.physical_count++;
+        break;
+      case RelationProcessorCore:
+        if (buffer[n].ProcessorCore.Flags == 1) {
+          // Hyper-threaded.
+          // The number of processors is set as bits in ProcessorMask.
+          out_info.processors.logical_count +=
+              CountSetBits(buffer[n].ProcessorMask);
+        } else {
+          // A real core - just count as one.
+          out_info->processors.logical_count++;
+        }
+        break;
+    }
+  }
+
+  out_info->processors.physical_count =
+      MAX(1, out_info->processors.physical_count);
+  out_info->processors.logical_count  =
+      MAX(1, out_info->processors.logical_count);
+
+  result_code = 0;
+XECLEANUP:
+  xe_free(buffer);
+  if (kernel32) {
+    FreeLibrary(kernel32);
+  }
+  return result_code;
+}
+
+double xe_pal_now() {
+  if (pal->use_high_perf_timer) {
+    LARGE_INTEGER counter;
+    QueryPerformanceCounter(&counter);
+    return counter.QuadPart * pal->inv_ticks_per_sec;
+  } else {
+    // Using GetSystemTimeAsFileTime instead of GetSystemTime() as it has a
+    // 100ns resolution.
+    FILETIME ft;
+    GetSystemTimeAsFileTime(&ft);
+    ULARGE_INTEGER uli;
+    uli.LowPart   = ft.dwLowDateTime;
+    uli.HighPart  = ft.dwHighDateTime;
+    return uli.QuadPart / 10000000.0;
+  }
+}