v8::ResourceConstraints
类的定义如下:
class V8EXPORT ResourceConstraints {
public:
ResourceConstraints();
int max_young_space_size() const { return max_young_space_size_; }
void set_max_young_space_size(int value) { max_young_space_size_ = value; }
int max_old_space_size() const { return max_old_space_size_; }
void set_max_old_space_size(int value) { max_old_space_size_ = value; }
int max_executable_size() { return max_executable_size_; }
void set_max_executable_size(int value) { max_executable_size_ = value; }
uint32_t* stack_limit() const { return stack_limit_; }
// Sets an address beyond which the VM's stack may not grow.
void set_stack_limit(uint32_t* value) { stack_limit_ = value; }
private:
int max_young_space_size_;
int max_old_space_size_;
int max_executable_size_;
uint32_t* stack_limit_;
};
有人可以告诉我young_space_size
,old_space_size
和max_executable_size
是什么?他们的单位是什么,他们是如何相关的?等等?似乎没有太多文档。
另外,如何使用stack_limit
属性?例如,如果我希望我的V8隔离使用不超过1MB的堆栈空间,我将如何计算stack_limit
的指针值?
答案 0 :(得分:1)
v8 / test / cctest / test-api.cc使用此函数计算限制:
// Uses the address of a local variable to determine the stack top now.
// Given a size, returns an address that is that far from the current
// top of stack.
static uint32_t* ComputeStackLimit(uint32_t size) {
uint32_t* answer = &size - (size / sizeof(size));
// If the size is very large and the stack is very near the bottom of
// memory then the calculation above may wrap around and give an address
// that is above the (downwards-growing) stack. In that case we return
// a very low address.
if (answer > &size) return reinterpret_cast<uint32_t*>(sizeof(size));
return answer;
}