From 4a0531abc519f1b7ee396763b779efd7b91c4723 Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Sat, 12 Jul 2014 22:25:12 -0700
Subject: [PATCH] Posix code cache.

---
 src/alloy/backend/x64/sources.gypi            | 14 ++-
 src/alloy/backend/x64/x64_code_cache_posix.cc | 97 +++++++++++++++++++
 ...64_code_cache.cc => x64_code_cache_win.cc} |  0
 src/alloy/hir/opcodes.cc                      |  2 +-
 4 files changed, 111 insertions(+), 2 deletions(-)
 create mode 100644 src/alloy/backend/x64/x64_code_cache_posix.cc
 rename src/alloy/backend/x64/{x64_code_cache.cc => x64_code_cache_win.cc} (100%)

diff --git a/src/alloy/backend/x64/sources.gypi b/src/alloy/backend/x64/sources.gypi
index 38167e3f1..02d8163b1 100644
--- a/src/alloy/backend/x64/sources.gypi
+++ b/src/alloy/backend/x64/sources.gypi
@@ -6,7 +6,6 @@
     'x64_assembler.h',
     'x64_backend.cc',
     'x64_backend.h',
-    'x64_code_cache.cc',
     'x64_code_cache.h',
     'x64_emitter.cc',
     'x64_emitter.h',
@@ -20,4 +19,17 @@
     'x64_tracers.cc',
     'x64_tracers.h',
   ],
+
+  'conditions': [
+    ['OS == "mac" or OS == "linux"', {
+      'sources': [
+        'x64_code_cache_posix.cc',
+      ],
+    }],
+    ['OS == "win"', {
+      'sources': [
+        'x64_code_cache_win.cc',
+      ],
+    }],
+  ],
 }
diff --git a/src/alloy/backend/x64/x64_code_cache_posix.cc b/src/alloy/backend/x64/x64_code_cache_posix.cc
new file mode 100644
index 000000000..09dbeccb5
--- /dev/null
+++ b/src/alloy/backend/x64/x64_code_cache_posix.cc
@@ -0,0 +1,97 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2014 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <alloy/backend/x64/x64_code_cache.h>
+
+#include <sys/mman.h>
+
+#include <alloy/backend/x64/tracing.h>
+
+namespace alloy {
+namespace backend {
+namespace x64 {
+
+class X64CodeChunk {
+ public:
+  X64CodeChunk(size_t chunk_size);
+  ~X64CodeChunk();
+
+ public:
+  X64CodeChunk* next;
+  size_t capacity;
+  uint8_t* buffer;
+  size_t offset;
+};
+
+X64CodeCache::X64CodeCache(size_t chunk_size)
+    : chunk_size_(chunk_size), head_chunk_(NULL), active_chunk_(NULL) {}
+
+X64CodeCache::~X64CodeCache() {
+  std::lock_guard<std::mutex> guard(lock_);
+  auto chunk = head_chunk_;
+  while (chunk) {
+    auto next = chunk->next;
+    delete chunk;
+    chunk = next;
+  }
+  head_chunk_ = NULL;
+}
+
+int X64CodeCache::Initialize() { return 0; }
+
+void* X64CodeCache::PlaceCode(void* machine_code, size_t code_size,
+                              size_t stack_size) {
+  SCOPE_profile_cpu_f("alloy");
+
+  // Always move the code to land on 16b alignment. We do this by rounding up
+  // to 16b so that all offsets are aligned.
+  code_size = XEROUNDUP(code_size, 16);
+
+  lock_.lock();
+
+  if (active_chunk_) {
+    if (active_chunk_->capacity - active_chunk_->offset < code_size) {
+      auto next = active_chunk_->next;
+      if (!next) {
+        assert_true(code_size < chunk_size_, "need to support larger chunks");
+        next = new X64CodeChunk(chunk_size_);
+        active_chunk_->next = next;
+      }
+      active_chunk_ = next;
+    }
+  } else {
+    head_chunk_ = active_chunk_ = new X64CodeChunk(chunk_size_);
+  }
+
+  uint8_t* final_address = active_chunk_->buffer + active_chunk_->offset;
+  active_chunk_->offset += code_size;
+
+  lock_.unlock();
+
+  // Copy code.
+  xe_copy_struct(final_address, machine_code, code_size);
+
+  return final_address;
+}
+
+X64CodeChunk::X64CodeChunk(size_t chunk_size)
+    : next(NULL), capacity(chunk_size), buffer(0), offset(0) {
+  buffer = (uint8_t*)mmap(nullptr, chunk_size, PROT_WRITE | PROT_EXEC,
+                          MAP_ANON | MAP_PRIVATE, -1, 0);
+}
+
+X64CodeChunk::~X64CodeChunk() {
+  if (buffer) {
+    munmap(buffer, capacity);
+  }
+}
+
+}  // namespace x64
+}  // namespace backend
+}  // namespace alloy
diff --git a/src/alloy/backend/x64/x64_code_cache.cc b/src/alloy/backend/x64/x64_code_cache_win.cc
similarity index 100%
rename from src/alloy/backend/x64/x64_code_cache.cc
rename to src/alloy/backend/x64/x64_code_cache_win.cc
diff --git a/src/alloy/hir/opcodes.cc b/src/alloy/hir/opcodes.cc
index 5c66c8b1d..df922c493 100644
--- a/src/alloy/hir/opcodes.cc
+++ b/src/alloy/hir/opcodes.cc
@@ -13,7 +13,7 @@ namespace alloy {
 namespace hir {
 
 #define DEFINE_OPCODE(num, name, sig, flags) \
-  static const OpcodeInfo num##_info = {     \
+  const OpcodeInfo num##_info = {            \
       flags, sig, name, num,                 \
   };
 #include <alloy/hir/opcodes.inl>