So, the hole length of this raw memory is set to be Data ? And to use it i should create a view on top of it like with typedarrays?
So to call arraybuffer::append i should first, try to make the typed array bigger that action will call the arraybuffer::append ? i didn't ask how memcpy work, i didn't get the Data() thing, in the class that's all. Il giorno lun 10 set 2018 alle ore 22:55 @soylentgraham < gra...@grahamreeves.com> ha scritto: > > How can i understand the structure in memory of an arraybuffer and how big > > is the data field which is pointed by this void pointerIt has no structure. > > It is just a series of linear bytes, raw memory, allocated by the memory > > allocator. (If you implement your own memory allocator you can catch when > > this happens)It's just the data(buffer) for an array. > > How are they represented in memory....It IS memory. It's nothing more (it's > > an array of bytes) > > How big is the data field ?If by "field", you mean, the data buffer... it's > > Capacity > > <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=76&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523kB%25252BJ1WxDvoDqf1c8Tz5Ol3yne4lD03cRpevK2LHMUZk%25253D&gsn=Capacity&ct=xref_usages> > > (capacity is how much it can fit) in length. But not how much is being > > used. (bytes_used) > If you're curious about when memory grows, reallocates, is written to, > accessed... it might be worth setting up your environment so you can debug it > by stepping through the code as it executes. You can watch memory, (this > would show what memcpy changes) see the values passed around, track when > memory gets allocated etc. > Your questions are a mix of very broad, ("How does v8 work") and very > specific programming questions (what is memcpy() doing)Broad questions are > very hard to answer in general. ("How does a car work") > > I agree, simply browsing the code doesn't give a good overview of say, how > the javascript compiler works, or how memory is utilised. (How it is > allocated is very simple, on the C/++ side it doesn't implement any memory > management, and the array buffer/view is a view of the C-side memory)But > after using it for a little while, I have found v8 in general is pretty > simple. It provides an interface to C functions and memory. This is kinda > what it's for. > But the point of v8 is that it does a lot of that for you. I don't REALLY > need to know how the memory is tracked on the javascript side, it just works > (if I'm using the API correctly)Then again, if you NEED to know how it works > for a specific purpose (very restricted memory, fixing a bug), we can help > you a lot more easily by answering a very specific question. ("My car's > low-oil light is blinking, where do I fill it up") > If you're just curious as to how the entire v8 engine works... that's a > massive ask. A lot of people work on it, and there is a lot of work and > topics involved.Your best bet is reading the (limited) documentation on the > wiki, and read the blog posts https://v8project.blogspot.com/ which go into > quite a lot of detail on each post topic.I've not seen any real general > overview (the wiki itself says it's out of date) so, stepping through all the > code as it executes is probably your best bet. > > > On Monday, 10 September 2018 21:25:37 UTC+1, dan Med wrote: >> >> in this snippet for example >> >> namespace WTF >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=40&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%2523WTF%252523n%252523namespace&gsn=WTF&ct=xref_usages> >> {// A utility class to build an ArrayBuffer instance. Validity must be >> checked// by isValid() before using an instance.class WTF_EXPORT >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/wtf_export.h?l=46&ct=xref_jump_to_def&gsn=WTF_EXPORT> >> ArrayBufferBuilder >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=44&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523ArrayBufferBuilder%25253AWTF%252523c%252523hTnYOn1mFcU%2Bkythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523NyhHD05MjDx8XOe1m%25252BLqXBLvqdjWPsLmDrRvvmR2Ywk%25253D&gsn=ArrayBufferBuilder&ct=xref_usages> >> final { // Disallow copying since it's expensive and we don't want code to >> do it by // accident. USING_FAST_MALLOC >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/allocator.h?l=146&ct=xref_jump_to_def&gsn=USING_FAST_MALLOC>(ArrayBufferBuilder >> >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=44&ct=xref_jump_to_def&gsn=ArrayBufferBuilder>); >> public: // Creates an ArrayBufferBuilder using the default capacity. >> ArrayBufferBuilder >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=51&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523me5JBk4wDIaIJCK86MiUpy%25252BnGYRZwEr0AvVg3KaU0pw%25253D&gsn=ArrayBufferBuilder&ct=xref_usages>(); >> ArrayBufferBuilder >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=53&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523VW0P45Tk9IGjtOqM%25252B9dHdJ64so3WDAfcY1jNBLt0GNY%25253D&gsn=ArrayBufferBuilder&ct=xref_usages>(unsigned >> capacity >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=53&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523trfcCH7BPCRWiubGq1QF9bypkCRNYtWGHb2AzglMces%25253D&gsn=capacity&ct=xref_usages>) >> : bytes_used_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=92&ct=xref_jump_to_def&gsn=bytes_used_>(0), >> variable_capacity_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=93&ct=xref_jump_to_def&gsn=variable_capacity_>(true) >> { buffer_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=94&ct=xref_jump_to_def&gsn=buffer_> >> = >> <https://cs.chromium.org/chromium/src/base/memory/scoped_refptr.h?l=226&ct=xref_jump_to_def&gsn=%3D> >> ArrayBuffer >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer.h?l=42&ct=xref_jump_to_def&gsn=ArrayBuffer>::Create >> >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer.h?l=125&ct=xref_jump_to_def&gsn=Create>(capacity >> >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=53&ct=xref_jump_to_def&gsn=capacity>, >> 1); } bool IsValid >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=58&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523Bx72YH%25252BiA4nF5ZIPsFhA9MQpdVCDOCRHSZa0Ksg6Wp4%25253D&gsn=IsValid&ct=xref_usages>() >> const { return buffer_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=94&ct=xref_jump_to_def&gsn=buffer_>.get >> >> <https://cs.chromium.org/chromium/src/base/memory/scoped_refptr.h?l=211&ct=xref_jump_to_def&gsn=get>(); >> } // Appending empty data is not allowed. unsigned Append >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=61&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523BHKR8BlIFhr03faCJF5mu7RDXZ%25252FPtZDAlnACyKmv1XM%25253D&gsn=Append&ct=xref_usages>(const >> char* data >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=61&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%25233VvJP%25252BUI3abzouA4%25252FYSBHt09pw3AiNI9e9QAJGooqYI%25253D&gsn=data&ct=xref_usages>, >> unsigned length >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=61&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523xOZXOK9mCrzsbUtqCxdbDuLg939IJhl7gbf0EykKwnY%25253D&gsn=length&ct=xref_usages>); >> // Returns the accumulated data as an ArrayBuffer instance. If needed, // >> creates a new ArrayBuffer instance and copies contents from the internal // >> buffer to it. Otherwise, returns a RefPtr pointing to the internal // >> buffer. scoped_refptr >> <https://cs.chromium.org/chromium/src/base/memory/scoped_refptr.h?l=167&ct=xref_jump_to_def&gsn=scoped_refptr><ArrayBuffer >> >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer.h?l=42&ct=xref_jump_to_def&gsn=ArrayBuffer>> >> ToArrayBuffer >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=67&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523JX559OA9Zt0rALNU4DOTOkzcmtws4U5V42xhN0rrbow%25253D&gsn=ToArrayBuffer&ct=xref_usages>(); >> // Converts the accumulated data into a String using the default encoding. >> String >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/text/wtf_string.h?l=64&ct=xref_jump_to_def&gsn=String> >> ToString >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=70&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523VMCyw7t%25252FF0UIo65pz8LTbfX5k5G4pIXrUNQbDNKDjaE%25253D&gsn=ToString&ct=xref_usages>(); >> // Number of bytes currently accumulated. unsigned ByteLength >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=73&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523P5Klo%25252BJeJiug%25252FrSAfsaHI8wAnW8h5UBg2%25252BoJByO85kA%25253D&gsn=ByteLength&ct=xref_usages>() >> const { return bytes_used_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=92&ct=xref_jump_to_def&gsn=bytes_used_>; >> } // Number of bytes allocated. unsigned Capacity >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=76&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523kB%25252BJ1WxDvoDqf1c8Tz5Ol3yne4lD03cRpevK2LHMUZk%25253D&gsn=Capacity&ct=xref_usages>() >> const { return buffer_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=94&ct=xref_jump_to_def&gsn=buffer_>-> >> >> <https://cs.chromium.org/chromium/src/base/memory/scoped_refptr.h?l=218&ct=xref_jump_to_def&gsn=-%3E>ByteLength >> >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer.h?l=249&ct=xref_jump_to_def&gsn=ByteLength>(); >> } void ShrinkToFit >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=78&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523WBvAUuWtgva6ffSXIiEGEkt%25252FFFbeCcQcsCz5E%25252FHCKOo%25253D&gsn=ShrinkToFit&ct=xref_usages>(); >> const void* Data >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=80&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523b8F1aEDx%25252F6En%25252FkOKh2zVkvONjtDNg9gr5KG7gT9XeJk%25253D&gsn=Data&ct=xref_usages>() >> const { return buffer_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=94&ct=xref_jump_to_def&gsn=buffer_>-> >> >> <https://cs.chromium.org/chromium/src/base/memory/scoped_refptr.h?l=218&ct=xref_jump_to_def&gsn=-%3E>Data >> >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer.h?l=225&ct=xref_jump_to_def&gsn=Data>(); >> } // If set to false, the capacity won't be expanded and when appended >> data // overflows, the overflowed part will be dropped. void >> SetVariableCapacity >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=84&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%25232ib6USbezkKcLs8hjPaCz4GUGrUHdD%25252BeN%25252FKenERnRLA%25253D&gsn=SetVariableCapacity&ct=xref_usages>(bool >> value >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=84&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523vUjrriXMW5FurGjU87jcAlZRQs3b8JSgA4Tt1xrSq7I%25253D&gsn=value&ct=xref_usages>) >> { variable_capacity_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=93&ct=xref_jump_to_def&gsn=variable_capacity_> >> = value >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=84&ct=xref_jump_to_def&gsn=value>; >> } private: // Expands the size of m_buffer to size + m_bytesUsed bytes. >> Returns true // iff successful. If reallocation is needed, copies only data >> in // [0, m_bytesUsed) range. bool ExpandCapacity >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=90&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523szv9AYLlP3J7qhn%25252Fm%25252BJqzPmSgWf45%25252BRVwVxvXDk3WYQ%25253D&gsn=ExpandCapacity&ct=xref_usages>(unsigned >> size >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=90&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523mXwymG5xtblCCeS4C9QcnmOwJxql8nYDr2HLqNZVJ8I%25253D&gsn=size&ct=xref_usages>); >> unsigned bytes_used_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=92&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523x95FyaH%25252BSeW1SF4BFhX9oIq7qgtHy3xzXCMmc37LcL8%25253D&gsn=bytes_used_&ct=xref_usages>; >> bool variable_capacity_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=93&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523FKWGJXbcZ%25252BRuy6YD7uxQ765XV8Mhciv4FM%25252FF5B3bNvU%25253D&gsn=variable_capacity_&ct=xref_usages>; >> scoped_refptr >> <https://cs.chromium.org/chromium/src/base/memory/scoped_refptr.h?l=167&ct=xref_jump_to_def&gsn=scoped_refptr><ArrayBuffer >> >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer.h?l=42&ct=xref_jump_to_def&gsn=ArrayBuffer>> >> buffer_ >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=94&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523aFDjYtlmS2tmLXL2XyJ158HoigBmsAdzguhOSb6XQIw%25253D&gsn=buffer_&ct=xref_usages>; >> DISALLOW_COPY_AND_ASSIGN >> <https://cs.chromium.org/chromium/src/base/macros.h?l=33&ct=xref_jump_to_def&gsn=DISALLOW_COPY_AND_ASSIGN>(ArrayBufferBuilder >> >> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=96&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.h%2523E6nSXqAY3ipexrHDKPfjzHqWqWIsAlT3EH3KVhT57GQ%25253D&gsn=ArrayBufferBuilder&ct=xref_usages>);};} >> // namespace WTF >> >> >> >> How can i understand the structure in memory of an arraybuffer and how big >> is the data field which is pointed by this void pointerHow are they >> represented in memory....How big is the data field ? >> >> >> Il giorno lun 10 set 2018 alle ore 22:19 dan Med <litoki...@gmail.com> >> ha scritto: >> >>> i already did that and btw it is under the WTF/webkit . >>> I'm interested how v8 handles javascript into every detail if u can >>> guide me... >>> Tell me which repository are being used by v8 on the related topic that >>> would help me really much. >>> >>> By when it is called i mean, which javascript code will enable me to >>> call that funciton cause if u click u can't go any further than that, >>> >>> Il giorno lun 10 set 2018 alle ore 21:53 Jakob Kummerow < >>> jkum...@chromium.org> ha scritto: >>> >>>> On Mon, Sep 10, 2018 at 12:22 PM dan Med <litoki...@gmail.com> wrote: >>>> >>>>> I don't quite see if this google group is useful or not, everybody >>>>> keeps answering me with superficial things, >>>>> >>>> >>>> You said you wanted to read the compiler's source but couldn't find it, >>>> so I told you that it's in src/compiler/. If that was not the answer you >>>> wanted, then try asking a different question? >>>> >>>> Please also keep in mind that people's time is limited. The >>>> easier/quicker it is to answer your question, the more likely you are to >>>> get an answer. >>>> >>>> i don't care about the trminology like tell me which allocator it uses >>>>> when and why or at least if there's something i can read to >>>>> understand..... >>>>> I'm surprised u don't know what a JIT page is, basically if you call a >>>>> function foo() let's say 100 times then v8,had enough time to understand >>>>> the parameters given to that specific function and how to optimize it >>>>> efficently based on it's prediction/observation. >>>>> >>>>> I'm not interested in the terminology of things, (that's just a matter >>>>> of reading the source code ) i'm more in reading how it works when and >>>>> why.. >>>>> >>>> >>>> It's great that you want to understand how things work. Terminology is >>>> an important aspect of that though, because it enables communication. If we >>>> use different words for the same thing, we won't understand each other. >>>> Based on your explanation, I'm guessing that by "JIT page" you mean >>>> "the strategy V8 uses to select functions for optimization". The core of >>>> that logic is in MarkCandidatesForOptimization in src/runtime-profiler.cc. >>>> >>>> >>>>> For example when is ArrayBufferBuilder::Append called ?? >>>>> >>>> >>>> I don't know; it's not part of V8. But you can use Code Search to find >>>> out where anything is called, just click the function in question to get a >>>> list of call sites: >>>> https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?q=ArrayBufferBuilder&sq=package:chromium&g=0&l=61 >>>> >>>> >>>>> And i thing i've looked at the entire v8 source code but didn't find >>>>> much, apart from the array.js file which describes some javascript >>>>> function, i don't understand where's the rest.... >>>>> >>>> >>>> >>>> Il giorno lun 10 set 2018 alle ore 20:45 Jakob Kummerow < >>>>> jkum...@chromium.org> ha scritto: >>>>> >>>>>> On Sun, Sep 9, 2018 at 8:54 AM dan Med <litoki...@gmail.com> wrote: >>>>>> >>>>>>> Oh and one more thing, i've surfed perhaps the entire source code of >>>>>>> v8 at least the interesting parts, but what i came across was just very >>>>>>> short code execpt for some builtins written in javascript i believe, >>>>>>> can't >>>>>>> find all of the things i've found on the documentation such as the >>>>>>> interpreter >>>>>>> >>>>>> >>>>>> src/interpreter/ >>>>>> >>>>>> >>>>>>> and the JIT compilers, >>>>>>> >>>>>> >>>>>> src/compiler/ >>>>>> >>>>>> >>>>>>> one more thing i'd like to understand how the memory is handeled >>>>>>> like how can i read about the JIT pages, >>>>>>> >>>>>> >>>>>> What's a JIT page? >>>>>> >>>>>> >>>>>>> or which memory allocator does v8 use >>>>>>> >>>>>> >>>>>> It uses several allocation techniques for different purposes. >>>>>> >>>>>> >>>>>>> and it's garbage collector >>>>>>> >>>>>> >>>>>> src/heap/ >>>>>> >>>>>> >>>>>>> >>>>>>> Thank you ! >>>>>>> >>>>>>> Il giorno dom 9 set 2018 alle ore 17:51 dan Med <litoki...@gmail.com> >>>>>>> ha scritto: >>>>>>> >>>>>>>> I don't have understood this part, let me explain it to you. >>>>>>>> This is how i get it tell me if i'm wrong at any part. >>>>>>>> >>>>>>>> I need to understand how is the structure in memory of the >>>>>>>> arraybuffer how is it represented and if the data of the array are >>>>>>>> directly >>>>>>>> stored at an offset accessed by buffer_ -> data(). >>>>>>>> >>>>>>>> >>>>>>>> before the call to expand capacity it does create an array >>>>>>>> >>>>>>>> >>>>>>>> the arraybuffer in src <https://cs.chromium.org/chromium/src/>/ >>>>>>>> third_party <https://cs.chromium.org/chromium/src/third_party/>/ >>>>>>>> blink <https://cs.chromium.org/chromium/src/third_party/blink/>/ >>>>>>>> renderer >>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/>/ >>>>>>>> platform >>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/> >>>>>>>> /wtf >>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/> >>>>>>>> /typed_arrays >>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/> >>>>>>>> /array_buffer_builder.cc >>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.cc> >>>>>>>> is >>>>>>>> called whenever the renderer (has to execute some javascript which >>>>>>>> defines >>>>>>>> arraybuffers) >>>>>>>> First when is arraybuffer::append called, cause i know that if >>>>>>>> someone need to reallocate a bigger arraybuffer then a new instance >>>>>>>> will be >>>>>>>> created and filled with the old values if the length in the original >>>>>>>> array >>>>>>>> isn't has much as the user reqeusted ? >>>>>>>> >>>>>>>> One more thing is, when this class is called, the arraybuffer is >>>>>>>> always set to the initial length of static const int >>>>>>>> kDefaultBufferCapacity >>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.cc?l=38&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.cc%2523YXDT7WTpXCAcuhdyTlkuCzsfCzI%25252BoHLRFAlkbCrkx4g%25253D&gsn=kDefaultBufferCapacity&ct=xref_usages> >>>>>>>> = 32768; if in the javascript i declare an arraybuffer of 20bytes >>>>>>>> will it allocate of >>>>>>>> 32768bytes anyway =? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Il giorno mar 4 set 2018 alle ore 12:14 Graham Reeves < >>>>>>>> gra...@grahamreeves.com> ha scritto: >>>>>>>> >>>>>>>>> > is std::numeric_limits >>>>>>>>> <https://cs.chromium.org/chromium/src/buildtools/third_party/libc%2B%2B/trunk/include/limits?l=442&ct=xref_jump_to_def&gsn=numeric_limits> >>>>>>>>> <unsigned>::max >>>>>>>>> <https://cs.chromium.org/chromium/src/buildtools/third_party/libc%2B%2B/trunk/include/limits?l=450&ct=xref_jump_to_def&gsn=max>(); >>>>>>>>> referring to the max unsigned int value ? cause the source code won't >>>>>>>>> find >>>>>>>>> it >>>>>>>>> Yes, that's the maximum value unsigned (an unsigned int) can be, >>>>>>>>> but what do you mean by, the source won't find it? >>>>>>>>> >>>>>>>>> On Monday, 3 September 2018 19:55:48 UTC+1, dan Med wrote: >>>>>>>>>> >>>>>>>>>> Can someone help me out? >>>>>>>>>> >>>>>>>>>> Il giorno sab 1 set 2018 alle ore 15:30 <litoki...@gmail.com> ha >>>>>>>>>> scritto: >>>>>>>>>> >>>>>>>>>>> array_buffer_builder.cc in src >>>>>>>>>>> <https://cs.chromium.org/chromium/src/>/third_party >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/>/blink >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/>/ >>>>>>>>>>> renderer >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/> >>>>>>>>>>> /platform >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/> >>>>>>>>>>> /wtf >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/> >>>>>>>>>>> /typed_arrays >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/> >>>>>>>>>>> /array_buffer_builder.cc >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.cc> >>>>>>>>>>> >>>>>>>>>>> the ArrayBufferBuilder >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=44&ct=xref_jump_to_def&gsn=ArrayBufferBuilder> >>>>>>>>>>> ::Append >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.cc?l=74&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.cc%2523NFGzJegTouRzc7WYe5NO52sD3rtLZRfs3mHeMLIQn8I%25253D&gsn=Append&ct=xref_usages> >>>>>>>>>>> method >>>>>>>>>>> will be called through a view on top of the arraybuffer? something >>>>>>>>>>> like, >>>>>>>>>>> there's a arraybuffer of 30bytes in length and we define a view on >>>>>>>>>>> top of >>>>>>>>>>> it (so a typedarray) wehn i call on the new typedarray object the >>>>>>>>>>> .append >>>>>>>>>>> method it will call ArrayBufferBuilder >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=44&ct=xref_jump_to_def&gsn=ArrayBufferBuilder> >>>>>>>>>>> ::Append >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.cc?l=74&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.cc%2523NFGzJegTouRzc7WYe5NO52sD3rtLZRfs3mHeMLIQn8I%25253D&gsn=Append&ct=xref_usages> >>>>>>>>>>> and then inside it's code it will execute ArrayBufferBuilder >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=44&ct=xref_jump_to_def&gsn=ArrayBufferBuilder> >>>>>>>>>>> ::ExpandCapacity >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.cc?l=45&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.cc%2523Fu6GnwJLuMqh5Thz%25252BDq0LStBEA8HzkICqnAPtIOPIhY%25253D&gsn=ExpandCapacity&ct=xref_usages> >>>>>>>>>>> if >>>>>>>>>>> it needs to reallocate the array ? >>>>>>>>>>> >>>>>>>>>>> if so inside the expandCapacity definition bytes_used >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=92&ct=xref_jump_to_def&gsn=bytes_used_> >>>>>>>>>>> referes >>>>>>>>>>> to the elements inside the actual arraybuffer so if i have a >>>>>>>>>>> arraybuffer >>>>>>>>>>> which is 8 bytes in length [ ][ ][ ][ ][ ][ ][ ][ ] and i fill in >>>>>>>>>>> only 3 >>>>>>>>>>> bytes so >>>>>>>>>>> [1][2][3][ ][ ][ ][ ][ ] the bytes_used >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=92&ct=xref_jump_to_def&gsn=bytes_used_> >>>>>>>>>>> when >>>>>>>>>>> retrieved will be set to 3 bytes ?? >>>>>>>>>>> >>>>>>>>>>> ArrayBufferBuilder >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=44&ct=xref_jump_to_def&gsn=ArrayBufferBuilder>::ArrayBufferBuilder >>>>>>>>>>> >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.cc?l=40&gs=kythe%253A%252F%252Fchromium%253Flang%253Dc%25252B%25252B%253Fpath%253Dsrc%252Fthird_party%252Fblink%252Frenderer%252Fplatform%252Fwtf%252Ftyped_arrays%252Farray_buffer_builder.cc%2523lcp23D0sHKN2WnDoJe7UbBQtgQbZY3lJ%25252Bn9qnDlawck%25253D&gsn=ArrayBufferBuilder&ct=xref_usages>() >>>>>>>>>>> : bytes_used_ >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=92&ct=xref_jump_to_def&gsn=bytes_used_>(0), >>>>>>>>>>> variable_capacity_ >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=93&ct=xref_jump_to_def&gsn=variable_capacity_>(true) >>>>>>>>>>> { buffer_ >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer_builder.h?l=94&ct=xref_jump_to_def&gsn=buffer_> >>>>>>>>>>> = >>>>>>>>>>> <https://cs.chromium.org/chromium/src/base/memory/scoped_refptr.h?l=226&ct=xref_jump_to_def&gsn=%3D> >>>>>>>>>>> ArrayBuffer >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer.h?l=42&ct=xref_jump_to_def&gsn=ArrayBuffer>:: >>>>>>>>>>> >>>>>>>>>>> <https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/wtf/typed_arrays/array_buffer.h?l=125&ct=xref_jump_to_def&gsn=Create> >>>>>>>>>>> >>>>>>>>>>> -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. 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