Merge pull request #135 from frankmcsherry/dataplane_mockup

Dataplane mockup

Cargo.toml

@@ -16,10 +16,10 @@ license = "MIT"
 #build = "booktests.rs"
 
 [dependencies]
-abomonation = "0.5"
+abomonation = { git = "https://github.com/frankmcsherry/abomonation" }
 abomonation_derive = "0.3"
-timely_communication = "0.6"
-byteorder="1"
+bytes = { path = "./bytes" }
+timely_communication = { path = "./communication"}
 time="0.1.34"
 
 [dev-dependencies]

bytes/src/lib.rs

@@ -25,7 +25,7 @@
 //! drop(shared2);
 //! drop(shared3);
 //!
-//! if let Ok(bytes) = shared4.try_recover() {
+//! if let Ok(bytes) = shared4.try_recover::<Vec<u8>>() {
 //!     assert_eq!(bytes[200..1024].to_vec(), [1u8;824].to_vec());
 //!     assert_eq!(bytes[60..100].to_vec(),   [2u8;40].to_vec());
 //!     assert_eq!(bytes[100..200].to_vec(),  [3u8;100].to_vec());
@@ -42,9 +42,10 @@ pub mod rc {
 
     use std::ops::{Deref, DerefMut};
     use std::rc::Rc;
+    use std::any::Any;
 
     /// A thread-local byte buffer backed by a shared allocation.
-    pub struct Bytes<B: DerefMut<Target=[u8]>> {
+    pub struct Bytes {
         /// Pointer to the start of this slice (not the allocation).
         ptr: *mut u8,
         /// Length of this slice.
@@ -54,20 +55,24 @@ pub mod rc {
         /// Importantly, this is unavailable for as long as the struct exists, which may
         /// prevent shared access to ptr[0 .. len]. I'm not sure I understand Rust's rules
         /// enough to make a strong statement about this.
-        sequestered: Rc<B>,
+        sequestered: Rc<Box<Any>>,
     }
 
-    impl<B: DerefMut<Target=[u8]>> Bytes<B> {
+    impl Bytes {
 
         /// Create a new instance from a byte allocation.
-        pub fn from(bytes: B) -> Bytes<B> {
+        pub fn from<B>(bytes: B) -> Bytes where B: DerefMut<Target=[u8]>+'static {
 
-            let mut rc = Rc::new(bytes);
+            let mut boxed = Box::new(bytes) as Box<Any>;
+
+            let ptr = boxed.downcast_mut::<B>().unwrap().as_mut_ptr();
+            let len = boxed.downcast_ref::<B>().unwrap().len();
+            let sequestered = Rc::new(boxed);
 
             Bytes {
-                ptr: Rc::get_mut(&mut rc).unwrap().as_mut_ptr(),
-                len: rc.len(),
-                sequestered: rc,
+                ptr,
+                len,
+                sequestered,
             }
         }
 
@@ -77,7 +82,7 @@ pub mod rc {
         ///
         /// This method uses an `unsafe` region to advance the pointer by `index`. It first
         /// tests `index` against `self.len`, which should ensure that the offset is in-bounds.
-        pub fn extract_to(&mut self, index: usize) -> Bytes<B> {
+        pub fn extract_to(&mut self, index: usize) -> Bytes {
 
             assert!(index <= self.len);
 
@@ -97,9 +102,9 @@ pub mod rc {
         ///
         /// This method either results in the underlying storage if it is uniquely held, or the
         /// input `Bytes` if it is not uniquely held.
-        pub fn try_recover(self) -> Result<B, Bytes<B>> {
+        pub fn try_recover<B>(self) -> Result<B, Bytes> where B: DerefMut<Target=[u8]>+'static {
             match Rc::try_unwrap(self.sequestered) {
-                Ok(bytes) => Ok(bytes),
+                Ok(bytes) => Ok(*bytes.downcast::<B>().unwrap()),
                 Err(rc) => Err(Bytes {
                     ptr: self.ptr,
                     len: self.len,
@@ -109,14 +114,14 @@ pub mod rc {
         }
     }
 
-    impl<B: DerefMut<Target=[u8]>> Deref for Bytes<B> {
+    impl Deref for Bytes {
         type Target = [u8];
         fn deref(&self) -> &[u8] {
             unsafe { ::std::slice::from_raw_parts(self.ptr, self.len) }
         }
     }
 
-    impl<B: DerefMut<Target=[u8]>> DerefMut for Bytes<B> {
+    impl DerefMut for Bytes {
         fn deref_mut(&mut self) -> &mut [u8] {
             unsafe { ::std::slice::from_raw_parts_mut(self.ptr, self.len) }
         }
@@ -128,9 +133,10 @@ pub mod arc {
 
     use std::ops::{Deref, DerefMut};
     use std::sync::Arc;
+    use std::any::Any;
 
     /// A thread-safe byte buffer backed by a shared allocation.
-    pub struct Bytes<B: DerefMut<Target=[u8]>> {
+    pub struct Bytes {
         /// Pointer to the start of this slice (not the allocation).
         ptr: *mut u8,
         /// Length of this slice.
@@ -140,20 +146,26 @@ pub mod arc {
         /// Importantly, this is unavailable for as long as the struct exists, which may
         /// prevent shared access to ptr[0 .. len]. I'm not sure I understand Rust's rules
         /// enough to make a strong statement about this.
-        sequestered: Arc<B>,
+        sequestered: Arc<Box<Any>>,
     }
 
-    impl<B: DerefMut<Target=[u8]>> Bytes<B> {
+    unsafe impl Send for Bytes { }
+
+    impl Bytes {
 
         /// Create a new instance from a byte allocation.
-        pub fn from(bytes: B) -> Bytes<B> {
+        pub fn from<B>(bytes: B) -> Bytes where B : DerefMut<Target=[u8]>+'static {
 
-            let mut arc = Arc::new(bytes);
+            let mut boxed = Box::new(bytes) as Box<Any>;
+
+            let ptr = boxed.downcast_mut::<B>().unwrap().as_mut_ptr();
+            let len = boxed.downcast_ref::<B>().unwrap().len();
+            let sequestered = Arc::new(boxed);
 
             Bytes {
-                ptr: Arc::get_mut(&mut arc).unwrap().as_mut_ptr(),
-                len: arc.len(),
-                sequestered: arc,
+                ptr,
+                len,
+                sequestered,
             }
         }
 
@@ -163,7 +175,7 @@ pub mod arc {
         ///
         /// This method uses an `unsafe` region to advance the pointer by `index`. It first
         /// tests `index` against `self.len`, which should ensure that the offset is in-bounds.
-        pub fn extract_to(&mut self, index: usize) -> Bytes<B> {
+        pub fn extract_to(&mut self, index: usize) -> Bytes {
 
             assert!(index <= self.len);
 
@@ -183,28 +195,115 @@ pub mod arc {
         ///
         /// This method either results in the underlying storage if it is uniquely held, or the
         /// input `Bytes` if it is not uniquely held.
-        pub fn try_recover(self) -> Result<B, Bytes<B>> {
+        ///
+        /// #Examples
+        ///
+        /// ```
+        /// use bytes::arc::Bytes;
+        ///
+        /// let bytes = vec![0u8; 1024];
+        /// let mut shared1 = Bytes::from(bytes);
+        /// let mut shared2 = shared1.extract_to(100);
+        /// let mut shared3 = shared1.extract_to(100);
+        /// let mut shared4 = shared2.extract_to(60);
+        ///
+        /// drop(shared1);
+        /// drop(shared2);
+        /// drop(shared4);
+        /// let recovered = shared3.try_recover::<Vec<u8>>().ok().expect("recovery failed");
+        /// assert!(recovered.len() == 1024);
+        /// ```
+        pub fn try_recover<B>(self) -> Result<B, Bytes> where B: DerefMut<Target=[u8]>+'static {
+            // println!("Trying recovery; strong count: {:?}", Arc::strong_count(&self.sequestered));
             match Arc::try_unwrap(self.sequestered) {
-                Ok(bytes) => Ok(bytes),
+                Ok(bytes) => Ok(*bytes.downcast::<B>().unwrap()),
                 Err(arc) => Err(Bytes {
                     ptr: self.ptr,
                     len: self.len,
                     sequestered: arc,
                 }),
             }
         }
+
+        /// Regenerates the Bytes if it is uniquely held.
+        ///
+        /// If uniquely held, this method recovers the initial pointer and length
+        /// of the sequestered allocation and re-initialized the Bytes. The return
+        /// value indicates whether this occurred.
+        ///
+        /// #Examples
+        ///
+        /// ```
+        /// use bytes::arc::Bytes;
+        ///
+        /// let bytes = vec![0u8; 1024];
+        /// let mut shared1 = Bytes::from(bytes);
+        /// let mut shared2 = shared1.extract_to(100);
+        /// let mut shared3 = shared1.extract_to(100);
+        /// let mut shared4 = shared2.extract_to(60);
+        ///
+        /// drop(shared1);
+        /// drop(shared2);
+        /// drop(shared4);
+        /// assert!(shared3.try_regenerate::<Vec<u8>>());
+        /// assert!(shared3.len() == 1024);
+        /// ```
+        pub fn try_regenerate<B>(&mut self) -> bool where B: DerefMut<Target=[u8]>+'static {
+            if let Some(boxed) = Arc::get_mut(&mut self.sequestered) {
+                let downcast = boxed.downcast_mut::<B>().expect("Downcast failed");
+                self.ptr = downcast.as_mut_ptr();
+                self.len = downcast.len();
+                true
+            }
+            else {
+                false
+            }
+        }
+
+        /// Attempts to merge adjacent slices from the same allocation.
+        ///
+        /// If the merge succeeds then `other.len` is added to `self` and the result is `Ok(())`.
+        /// If the merge fails self is unmodified and the result is `Err(other)`, returning the
+        /// bytes supplied as input.
+        ///
+        /// #Examples
+        ///
+        /// ```
+        /// use bytes::arc::Bytes;
+        ///
+        /// let bytes = vec![0u8; 1024];
+        /// let mut shared1 = Bytes::from(bytes);
+        /// let mut shared2 = shared1.extract_to(100);
+        /// let mut shared3 = shared1.extract_to(100);
+        /// let mut shared4 = shared2.extract_to(60);
+        ///
+        /// // memory in slabs [4, 2, 3, 1]: merge back in arbitrary order.
+        /// shared2.try_merge(shared3).ok().expect("Failed to merge 2 and 3");
+        /// shared2.try_merge(shared1).ok().expect("Failed to merge 23 and 1");
+        /// shared4.try_merge(shared2).ok().expect("Failed to merge 4 and 231");
+        /// ```
+        pub fn try_merge(&mut self, other: Bytes) -> Result<(), Bytes> {
+            use ::std::sync::Arc;
+            if Arc::ptr_eq(&self.sequestered, &other.sequestered) && ::std::ptr::eq(unsafe { self.ptr.offset(self.len as isize) }, other.ptr) {
+                self.len += other.len;
+                Ok(())
+            }
+            else {
+                Err(other)
+            }
+        }
     }
 
-    impl<B: DerefMut<Target=[u8]>> Deref for Bytes<B> {
+    impl Deref for Bytes {
         type Target = [u8];
         fn deref(&self) -> &[u8] {
             unsafe { ::std::slice::from_raw_parts(self.ptr, self.len) }
         }
     }
 
-    impl<B: DerefMut<Target=[u8]>> DerefMut for Bytes<B> {
+    impl DerefMut for Bytes {
         fn deref_mut(&mut self) -> &mut [u8] {
             unsafe { ::std::slice::from_raw_parts_mut(self.ptr, self.len) }
         }
     }
-}
+}

communication/Cargo.toml

@@ -17,11 +17,12 @@ default=["arg_parse"]
 arg_parse=["getopts"]
 
 [dependencies]
-byteorder="1"
+#byteorder="1"
 getopts={version="0.2.14", optional=true}
 time="0.1.34"
-abomonation = "0.5"
+abomonation = { git = "https://github.com/frankmcsherry/abomonation" }
 abomonation_derive = "0.3"
+bytes = { path = "../bytes" }
 
 [profile.release]
 opt-level = 3

communication/examples/hello.rs

@@ -1,5 +1,8 @@
 extern crate timely_communication;
 
+use std::ops::Deref;
+use timely_communication::Message;
+
 fn main() {
 
     // extract the configuration from user-supplied arguments, initialize the computation.
@@ -14,18 +17,23 @@ fn main() {
 
         // send typed data along each channel
         for i in 0 .. allocator.peers() {
-            senders[i].send(format!("hello, {}", i));
+            senders[i].send(Message::from_typed(format!("hello, {}", i)));
             senders[i].done();
         }
 
         // no support for termination notification,
         // we have to count down ourselves.
         let mut received = 0;
         while received < allocator.peers() {
+
+            allocator.pre_work();
+
             if let Some(message) = receiver.recv() {
-                println!("worker {}: received: <{}>", allocator.index(), message);
+                println!("worker {}: received: <{}>", allocator.index(), message.deref());
                 received += 1;
             }
+
+            allocator.post_work();
         }
 
         allocator.index()