[heap] Allow a minimum semi-space size of 512K.

include/v8.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 5943 matching lines @@
  * A set of constraints that specifies the limits of the runtime's memory use.
  * You must set the heap size before initializing the VM - the size cannot be
  * adjusted after the VM is initialized.
  *
  * If you are using threads then you should hold the V8::Locker lock while
  * setting the stack limit and you must set a non-default stack limit separately
  * for each thread.
  *
  * The arguments for set_max_semi_space_size, set_max_old_space_size,
  * set_max_executable_size, set_code_range_size specify limits in MB.
+ *
+ * The argument for set_max_semi_space_size_in_kb is in KB.
  */
 class V8_EXPORT ResourceConstraints {
  public:
   ResourceConstraints();
 
   /**
    * Configures the constraints with reasonable default values based on the
    * capabilities of the current device the VM is running on.
    *
    * \param physical_memory The total amount of physical memory on the current
    *   device, in bytes.
    * \param virtual_memory_limit The amount of virtual memory on the current
    *   device, in bytes, or zero, if there is no limit.
    */
   void ConfigureDefaults(uint64_t physical_memory,
                          uint64_t virtual_memory_limit);
 
-  int max_semi_space_size() const { return max_semi_space_size_; }
+  // Returns the max semi-space size in MB.
+  int max_semi_space_size() const { return max_semi_space_size_in_kb_ / 1024; }

[Michael Lippautz, 2017/06/14 07:25:08]

Maybe deprecate?

[Hannes Payer (out of office), 2017/06/14 07:57:02]

Done.

+
+  // Sets the max semi-space size in MB.
   void set_max_semi_space_size(int limit_in_mb) {
-    max_semi_space_size_ = limit_in_mb;
+    max_semi_space_size_in_kb_ = limit_in_mb * 1024;
   }
+
+  // Returns the max semi-space size in KB.
+  int max_semi_space_size_in_kb() const { return max_semi_space_size_in_kb_; }

[Michael Lippautz, 2017/06/14 07:25:08]

I know that everything here is int, but should we introduce new APIs with
size_t? E.g. code_range_size_ is already size_t.

[Hannes Payer (out of office), 2017/06/14 07:57:02]

Done.

+
+  // Sets the max semi-space size in KB.
+  void set_max_semi_space_size_in_kb(int limit_in_kb) {
+    max_semi_space_size_in_kb_ = limit_in_kb;
+  }
+
   int max_old_space_size() const { return max_old_space_size_; }
   void set_max_old_space_size(int limit_in_mb) {
     max_old_space_size_ = limit_in_mb;
   }
   V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
                     int max_executable_size() const) {
     return max_executable_size_;
   }
   V8_DEPRECATE_SOON("max_executable_size_ is subsumed by max_old_space_size_",
                     void set_max_executable_size(int limit_in_mb)) {
     max_executable_size_ = limit_in_mb;
   }
   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; }
   size_t code_range_size() const { return code_range_size_; }
   void set_code_range_size(size_t limit_in_mb) {
     code_range_size_ = limit_in_mb;
   }
   size_t max_zone_pool_size() const { return max_zone_pool_size_; }
   void set_max_zone_pool_size(const size_t bytes) {
     max_zone_pool_size_ = bytes;
   }
 
  private:
-  int max_semi_space_size_;
+  // max_semi_space_size_ is in KB
+  int max_semi_space_size_in_kb_;
+
+  // The remaining limits are in MB
   int max_old_space_size_;
   int max_executable_size_;
   uint32_t* stack_limit_;
   size_t code_range_size_;
   size_t max_zone_pool_size_;
 };
 
 
 // --- Exceptions ---
 
@@ skipping 4219 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_