Index: doc/papers/concurrency/response2 =================================================================== --- doc/papers/concurrency/response2 (revision b54118ad23651a1d9e49d473d666db9fc0d8cd48) +++ doc/papers/concurrency/response2 (revision 8e9e9a2d7a14bd29799dcae8c81b6a96b111f6b3) @@ -27,24 +27,9 @@ thread creation and destruction? -The best description of Smalltalk concurrency I can find is in J. Hunt, -Smalltalk and Object Orientation, Springer-Verlag London Limited, 1997, Chapter -31 Concurrency in Smalltalk. It states on page 332: - - For a process to be spawned from the current process there must be some way - of creating a new process. This is done using one of four messages to a - block. These messages are: - - aBlock fork: This creates and schedules a process which will execute the - block. The priority of this process is inherited from the parent process. - ... - - The Semaphore class provides facilities for achieving simple synchronization, - it is simple because it only allows for two forms of communication signal and - wait. - -Hence, "aBlock fork" creates, "Semaphore" blocks/unblocks (as does message send -to an aBlock object), and garbage collection of an aBlock joins with its -thread. The fact that a programmer *implicitly* does "fork", "block"/"unblock", -and "join", does not change their fundamental requirement. +Fixed, changed sentence to: + + A programmer needs mechanisms to create, block and unblock, and join with a + thread, even if these basic mechanisms are supplied indirectly through + high-level features. @@ -103,5 +88,5 @@ storage, too, which is a single instance across all generator instances of that type, as for static storage in an object type. All the kinds of storage are -at play with semantics that is virtually the same as in other languages. +at play with semantics that is the same as in other languages. @@ -118,11 +103,9 @@ Just-in-Time Compiler. We modified our test programs based on his advise, and he validated our programs as correctly measuring the specified language -feature. Hence, we have taken into account all issues related to performing -benchmarks in JITTED languages. Dave's help is recognized in the -Acknowledgment section. Also, all the benchmark programs are publicly available -for independent verification. - -Similarly, we verified our Node.js programs with Gregor Richards, an expert in -just-in-time compilation for dynamic typing. +feature. Dave's help is recognized in the Acknowledgment section. Similarly, +we verified our Node.js programs with Gregor Richards, an expert in +just-in-time compilation for dynamic typing. Hence, we have taken into account +all issues related to performing benchmarks in JITTED languages. Also, all the +benchmark programs are publicly available for independent verification. @@ -155,32 +138,9 @@ Since many aspects of Cforall are not OO, the rest of the paper *does* depend on Cforall being identified as non-OO, otherwise readers would have -significantly different expectations for the design. We believe your definition -of OO is too broad, such as including C. Just because a programming language -can support aspects of the OO programming style, does not make it OO. (Just -because a duck can swim does not make it a fish.) - -Our definition of non-OO follows directly from the Wikipedia entry: - - Object-oriented programming (OOP) is a programming paradigm based on the - concept of "objects", which can contain data, in the form of fields (often - known as attributes or properties), and code, in the form of procedures - (often known as methods). A feature of objects is an object's procedures that - can access and often modify the data fields of the object with which they are - associated (objects have a notion of "this" or "self"). - https://en.wikipedia.org/wiki/Object-oriented_programming - -Cforall fails this definition as code cannot appear in an "object" and there is -no implicit receiver. As well, Cforall, Go, and Rust do not have nominal -inheritance and they not considered OO languages, e.g.: - - "**Is Go an object-oriented language?** Yes and no. Although Go has types and - methods and allows an object-oriented style of programming, there is no type - hierarchy. The concept of "interface" in Go provides a different approach - that we believe is easy to use and in some ways more general. There are also - ways to embed types in other types to provide something analogous-but not - identical-to subclassing. Moreover, methods in Go are more general than in - C++ or Java: they can be defined for any sort of data, even built-in types - such as plain, "unboxed" integers. They are not restricted to structs (classes). - https://golang.org/doc/faq#Is_Go_an_object-oriented_language +significantly different expectations for the design. We did not mean to suggest +that languages that support function pointers with structures support an OO +style. We revised the footnote to avoid this interpretation. Finally, Golang +does not identify itself as an OO language. +https://golang.org/doc/faq#Is_Go_an_object-oriented_language @@ -219,5 +179,5 @@ Whereas, the coroutine only needs the array allocated when needed. Now a coroutine has a stack which occupies storage, but the maximum stack size only -needs to be the call chain allocating the most storage, where as the generator +needs to be the call chain allocating the most storage, whereas the generator has a maximum size of all variable that could be created. @@ -314,8 +274,8 @@ \item[\newterm{execution state}:] is the state information needed by a - control-flow feature to initialize, manage compute data and execution - location(s), and de-initialize, \eg calling a function initializes a stack - frame including contained objects with constructors, manages local data in - blocks and return locations during calls, and de-initializes the frame by + control-flow feature to initialize and manage both compute data and execution + location(s), and de-initialize. For example, calling a function initializes a + stack frame including contained objects with constructors, manages local data + in blocks and return locations during calls, and de-initializes the frame by running any object destructors and management operations. @@ -330,4 +290,5 @@ appropriate word? + "computation only" as opposed to what? @@ -335,4 +296,5 @@ i.e., the operation starts with everything it needs to compute its result and runs to completion, blocking only when it is done and returns its result. +Computation only occurs in "embarrassingly parallel" problems. @@ -596,5 +558,5 @@ * coroutines/generators/threads: here there is some discussion, but it can be improved. - * interal/external scheduling: I didn't find any direct comparison between + * internal/external scheduling: I didn't find any direct comparison between these features, except by way of example. @@ -672,5 +634,6 @@ } -Additonal text has been added to the start of Section 3.2 address this comment. +Additional text has been added to the start of Section 3.2 addressing this +comment. @@ -787,8 +750,8 @@ and its shorthand form (not shown in the paper) - waitfor( remove, remove2 : t ); - -A call to one these remove functions satisfies the waitfor (exact selection -details are discussed in Section 6.4). + waitfor( remove, remove2 : buffer ); + +A call to either of these remove functions satisfies the waitfor (exact +selection details are discussed in Section 6.4). @@ -835,4 +798,5 @@ signal or signal_block. + I believe that one difference between the Go program and the Cforall equivalent is that the Goroutine has an associated queue, so that @@ -842,4 +806,5 @@ Actually, the buffer length is 0 for the Cforall call and the Go unbuffered send so both are synchronous communication. + I think this should be stated explicitly. (Presumably, one could modify the @@ -985,4 +950,5 @@ sout | "join"; } + int main() { T t[3]; // threads start and delay