move executable allocator out of System class

include/avian/system/memory.h

@@ -0,0 +1,49 @@
+  /* Copyright (c) 2008-2014, Avian Contributors
+
+   Permission to use, copy, modify, and/or distribute this software
+   for any purpose with or without fee is hereby granted, provided
+   that the above copyright notice and this permission notice appear
+   in all copies.
+
+   There is NO WARRANTY for this software.  See license.txt for
+   details. */
+
+#ifndef AVIAN_SYSTEM_MEMORY_H
+#define AVIAN_SYSTEM_MEMORY_H
+
+#include <avian/util/slice.h>
+
+#include <stdint.h>
+
+namespace avian {
+namespace system {
+
+class Memory {
+ public:
+  enum Permissions {
+    Read = 1 << 0,
+    Write = 1 << 1,
+    Execute = 1 << 2,
+
+    // Utility munged constants
+    ReadWrite = Read | Write,
+    ReadExecute = Read | Execute,
+    ReadWriteExecute = Read | Write | Execute
+  };
+
+  static const size_t PageSize;
+
+  // Allocate a contiguous range of pages.
+  static util::Slice<uint8_t> allocate(size_t sizeInBytes, Permissions perms = ReadWrite);
+
+  // Free a contiguous range of pages.
+  static void free(util::Slice<uint8_t> pages);
+
+  // TODO: In the future:
+  // static void setPermissions(util::Slice<uint8_t> pages, Permissions perms);
+};
+
+}  // namespace system
+}  // namespace avian
+
+#endif

include/avian/system/system.h

@@ -113,10 +113,6 @@ class System : public avian::util::Aborter {
   virtual bool success(Status) = 0;
   virtual void* tryAllocate(unsigned sizeInBytes) = 0;
   virtual void free(const void* p) = 0;
-#if !defined(AVIAN_AOT_ONLY)
-  virtual void* tryAllocateExecutable(unsigned sizeInBytes) = 0;
-  virtual void freeExecutable(const void* p, unsigned sizeInBytes) = 0;
-#endif
   virtual Status attach(Runnable*) = 0;
   virtual Status start(Runnable*) = 0;
   virtual Status make(Mutex**) = 0;

makefile

@@ -1138,6 +1138,7 @@ vm-depends := $(generated-code) \
 vm-sources = \
 	$(src)/system/$(system).cpp \
 	$(src)/system/$(system)/signal.cpp \
+	$(src)/system/$(system)/memory.cpp \
 	$(src)/finder.cpp \
 	$(src)/machine.cpp \
 	$(src)/util.cpp \
@@ -1273,6 +1274,7 @@ generator-sources = \
 	$(src)/tools/type-generator/main.cpp \
 	$(src)/system/$(build-system).cpp \
 	$(src)/system/$(build-system)/signal.cpp \
+	$(src)/system/$(build-system)/memory.cpp \
 	$(src)/finder.cpp \
 	$(src)/util/arg-parser.cpp
 

src/compile.cpp

@@ -15,6 +15,8 @@
 #include "avian/target.h"
 #include "avian/arch.h"
 
+#include <avian/system/memory.h>
+
 #include <avian/codegen/assembler.h>
 #include <avian/codegen/architecture.h>
 #include <avian/codegen/compiler.h>
@@ -8842,8 +8844,7 @@ class MyProcessor : public Processor {
   {
     if (codeAllocator.memory.begin()) {
 #if !defined(AVIAN_AOT_ONLY)
-      s->freeExecutable(codeAllocator.memory.begin(),
-                        codeAllocator.memory.count);
+      Memory::free(codeAllocator.memory);
 #endif
     }
 
@@ -9023,12 +9024,10 @@ class MyProcessor : public Processor {
   {
 #if !defined(AVIAN_AOT_ONLY)
     if (codeAllocator.memory.begin() == 0) {
-      codeAllocator.memory.items = static_cast<uint8_t*>(
-          s->tryAllocateExecutable(ExecutableAreaSizeInBytes));
+      codeAllocator.memory = Memory::allocate(ExecutableAreaSizeInBytes,
+                                              Memory::ReadWriteExecute);
 
-      expect(t, codeAllocator.memory.items);
-
-      codeAllocator.memory.count = ExecutableAreaSizeInBytes;
+      expect(t, codeAllocator.memory.begin());
     }
 #endif
 

src/system/posix.cpp

@@ -54,6 +54,7 @@ typedef struct ucontext {
 
 #include <avian/system/system.h>
 #include <avian/system/signal.h>
+#include <avian/system/memory.h>
 #include <avian/util/math.h>
 
 #define ACQUIRE(x) MutexResource MAKE_NAME(mutexResource_)(x)
@@ -664,39 +665,7 @@ class MySystem : public System {
       ::free(const_cast<void*>(p));
   }
 
-  virtual void* tryAllocateExecutable(unsigned sizeInBytes)
-  {
-#ifdef MAP_32BIT
-    // map to the lower 32 bits of memory when possible so as to avoid
-    // expensive relative jumps
-    const unsigned Extra = MAP_32BIT;
-#else
-    const unsigned Extra = 0;
-#endif
-
-    void* p = mmap(0,
-                   sizeInBytes,
-                   PROT_EXEC | PROT_READ | PROT_WRITE,
-                   MAP_PRIVATE | MAP_ANON | Extra,
-                   -1,
-                   0);
-
-    if (p == MAP_FAILED) {
-      return 0;
-    } else {
-      //       fprintf(stderr, "executable from %p to %p\n", p,
-      //               static_cast<uint8_t*>(p) + sizeInBytes);
-      return static_cast<uint8_t*>(p);
-    }
-  }
-
-  virtual void freeExecutable(const void* p, unsigned sizeInBytes)
-  {
-    munmap(const_cast<void*>(p), sizeInBytes);
-  }
-
-  virtual bool success(Status s)
-  {
+  virtual bool success(Status s) {
     return s == 0;
   }
 

src/system/posix/memory.cpp

@@ -0,0 +1,63 @@
+/* Copyright (c) 2008-2014, Avian Contributors
+
+   Permission to use, copy, modify, and/or distribute this software
+   for any purpose with or without fee is hereby granted, provided
+   that the above copyright notice and this permission notice appear
+   in all copies.
+
+   There is NO WARRANTY for this software.  See license.txt for
+   details. */
+
+#include <avian/system/memory.h>
+
+#include <avian/util/assert.h>
+
+#include "sys/mman.h"
+
+namespace avian {
+namespace system {
+
+const size_t Memory::PageSize = 1 << 12;
+
+util::Slice<uint8_t> Memory::allocate(size_t sizeInBytes,
+                               Permissions perms)
+{
+  unsigned prot = 0;
+  if(perms & Read) {
+    prot |= PROT_READ;
+  }
+  if(perms & Write) {
+    prot |= PROT_WRITE;
+  }
+  if(perms & Execute) {
+    prot |= PROT_EXEC;
+  }
+#ifdef MAP_32BIT
+  // map to the lower 32 bits of memory when possible so as to avoid
+  // expensive relative jumps
+  const unsigned Extra = MAP_32BIT;
+#else
+  const unsigned Extra = 0;
+#endif
+
+  void* p = mmap(0,
+                 sizeInBytes,
+                 prot,
+                 MAP_PRIVATE | MAP_ANON | Extra,
+                 -1,
+                 0);
+
+  if (p == MAP_FAILED) {
+    return util::Slice<uint8_t>(0, 0);
+  } else {
+    return util::Slice<uint8_t>(static_cast<uint8_t*>(p), sizeInBytes);
+  }
+}
+
+void Memory::free(util::Slice<uint8_t> pages)
+{
+  munmap(const_cast<uint8_t*>(pages.begin()), pages.count);
+}
+
+}  // namespace system
+}  // namespace avian

src/system/windows.cpp

@@ -675,22 +675,7 @@ class MySystem : public System {
       ::free(const_cast<void*>(p));
   }
 
-#if !defined(AVIAN_AOT_ONLY)
-  virtual void* tryAllocateExecutable(unsigned sizeInBytes)
-  {
-    return VirtualAlloc(
-        0, sizeInBytes, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
-  }
-
-  virtual void freeExecutable(const void* p, unsigned)
-  {
-    int r UNUSED = VirtualFree(const_cast<void*>(p), 0, MEM_RELEASE);
-    assertT(this, r);
-  }
-#endif
-
-  virtual bool success(Status s)
-  {
+  virtual bool success(Status s) {
     return s == 0;
   }
 

src/system/windows/memory.cpp

@@ -0,0 +1,55 @@
+/* Copyright (c) 2008-2014, Avian Contributors
+
+   Permission to use, copy, modify, and/or distribute this software
+   for any purpose with or without fee is hereby granted, provided
+   that the above copyright notice and this permission notice appear
+   in all copies.
+
+   There is NO WARRANTY for this software.  See license.txt for
+   details. */
+
+#include <avian/system/memory.h>
+
+#include <avian/util/assert.h>
+
+#include <windows.h>
+
+namespace avian {
+namespace system {
+
+const size_t Memory::PageSize = 1 << 12;
+
+util::Slice<uint8_t> Memory::allocate(size_t sizeInBytes,
+                               Permissions perms)
+{
+  unsigned prot;
+  switch(perms) {
+  case Read:
+    prot = PAGE_READONLY;
+    break;
+  case ReadWrite:
+    prot = PAGE_READWRITE;
+    break;
+  case ReadExecute:
+    prot = PAGE_EXECUTE_READ;
+    break;
+  case ReadWriteExecute:
+    prot = PAGE_EXECUTE_READWRITE;
+    break;
+  default:
+    UNREACHABLE_;
+  }
+  void* ret = VirtualAlloc(
+      0, sizeInBytes, MEM_COMMIT | MEM_RESERVE, prot);
+  return util::Slice<uint8_t>((uint8_t*)ret, sizeInBytes);
+}
+
+void Memory::free(util::Slice<uint8_t> pages)
+{
+  int r = VirtualFree(pages.begin(), 0, MEM_RELEASE);
+  (void) r;
+  ASSERT(r);
+}
+
+}  // namespace system
+}  // namespace avian