v8/src/allocation.cc

// Copyright 2008 the V8 project authors. All rights reserved.
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#include "v8.h"
#include "isolate.h"
#include "allocation.h"

/* TODO(isolates): this is what's included in bleeding_edge
   including of v8.h was replaced with these in
   http://codereview.chromium.org/5005001/
   we need Isolate and Isolate needs a lot more so I'm including v8.h back.
#include "../include/v8stdint.h"
#include "globals.h"
#include "checks.h"
#include "allocation.h"
#include "utils.h"
*/

namespace v8 {
namespace internal {

#ifdef DEBUG

NativeAllocationChecker::NativeAllocationChecker(
    NativeAllocationChecker::NativeAllocationAllowed allowed)
    : allowed_(allowed) {
  if (allowed == DISALLOW) {
    Isolate* isolate = Isolate::Current();
    isolate->set_allocation_disallowed(isolate->allocation_disallowed() + 1);
  }
}


NativeAllocationChecker::~NativeAllocationChecker() {
  Isolate* isolate = Isolate::Current();
  if (allowed_ == DISALLOW) {
    isolate->set_allocation_disallowed(isolate->allocation_disallowed() - 1);
  }
  ASSERT(isolate->allocation_disallowed() >= 0);
}


bool NativeAllocationChecker::allocation_allowed() {
  // TODO(isolates): either find a way to make this work that doesn't
  // require initializing an isolate before we can use malloc or drop
  // it completely.
  return true;
  // return Isolate::Current()->allocation_disallowed() == 0;
}

#endif  // DEBUG


void* Malloced::New(size_t size) {
  ASSERT(NativeAllocationChecker::allocation_allowed());
  void* result = malloc(size);
  if (result == NULL) {
    v8::internal::FatalProcessOutOfMemory("Malloced operator new");
  }
  return result;
}


void Malloced::Delete(void* p) {
  free(p);
}


void Malloced::FatalProcessOutOfMemory() {
  v8::internal::FatalProcessOutOfMemory("Out of memory");
}


#ifdef DEBUG

static void* invalid = static_cast<void*>(NULL);

void* Embedded::operator new(size_t size) {
  UNREACHABLE();
  return invalid;
}


void Embedded::operator delete(void* p) {
  UNREACHABLE();
}


void* AllStatic::operator new(size_t size) {
  UNREACHABLE();
  return invalid;
}


void AllStatic::operator delete(void* p) {
  UNREACHABLE();
}

#endif


char* StrDup(const char* str) {
  int length = StrLength(str);
  char* result = NewArray<char>(length + 1);
  memcpy(result, str, length);
  result[length] = '\0';
  return result;
}


char* StrNDup(const char* str, int n) {
  int length = StrLength(str);
  if (n < length) length = n;
  char* result = NewArray<char>(length + 1);
  memcpy(result, str, length);
  result[length] = '\0';
  return result;
}


void Isolate::PreallocatedStorageInit(size_t size) {
  ASSERT(free_list_.next_ == &free_list_);
  ASSERT(free_list_.previous_ == &free_list_);
  PreallocatedStorage* free_chunk =
      reinterpret_cast<PreallocatedStorage*>(new char[size]);
  free_list_.next_ = free_list_.previous_ = free_chunk;
  free_chunk->next_ = free_chunk->previous_ = &free_list_;
  free_chunk->size_ = size - sizeof(PreallocatedStorage);
  preallocated_storage_preallocated_ = true;
}


void* Isolate::PreallocatedStorageNew(size_t size) {
  if (!preallocated_storage_preallocated_) {
    return FreeStoreAllocationPolicy::New(size);
  }
  ASSERT(free_list_.next_ != &free_list_);
  ASSERT(free_list_.previous_ != &free_list_);

  size = (size + kPointerSize - 1) & ~(kPointerSize - 1);
  // Search for exact fit.
  for (PreallocatedStorage* storage = free_list_.next_;
       storage != &free_list_;
       storage = storage->next_) {
    if (storage->size_ == size) {
      storage->Unlink();
      storage->LinkTo(&in_use_list_);
      return reinterpret_cast<void*>(storage + 1);
    }
  }
  // Search for first fit.
  for (PreallocatedStorage* storage = free_list_.next_;
       storage != &free_list_;
       storage = storage->next_) {
    if (storage->size_ >= size + sizeof(PreallocatedStorage)) {
      storage->Unlink();
      storage->LinkTo(&in_use_list_);
      PreallocatedStorage* left_over =
          reinterpret_cast<PreallocatedStorage*>(
              reinterpret_cast<char*>(storage + 1) + size);
      left_over->size_ = storage->size_ - size - sizeof(PreallocatedStorage);
      ASSERT(size + left_over->size_ + sizeof(PreallocatedStorage) ==
             storage->size_);
      storage->size_ = size;
      left_over->LinkTo(&free_list_);
      return reinterpret_cast<void*>(storage + 1);
    }
  }
  // Allocation failure.
  ASSERT(false);
  return NULL;
}


// We don't attempt to coalesce.
void Isolate::PreallocatedStorageDelete(void* p) {
  if (p == NULL) {
    return;
  }
  if (!preallocated_storage_preallocated_) {
    FreeStoreAllocationPolicy::Delete(p);
    return;
  }
  PreallocatedStorage* storage = reinterpret_cast<PreallocatedStorage*>(p) - 1;
  ASSERT(storage->next_->previous_ == storage);
  ASSERT(storage->previous_->next_ == storage);
  storage->Unlink();
  storage->LinkTo(&free_list_);
}


void PreallocatedStorage::LinkTo(PreallocatedStorage* other) {
  next_ = other->next_;
  other->next_->previous_ = this;
  previous_ = other;
  other->next_ = this;
}


void PreallocatedStorage::Unlink() {
  next_->previous_ = previous_;
  previous_->next_ = next_;
}


PreallocatedStorage::PreallocatedStorage(size_t size)
  : size_(size) {
  previous_ = next_ = this;
}

} }  // namespace v8::internal