auto merge of #9380 : thestinger/rust/par, r=alexcrichton

This was a dead end experiment, and not a sensible way of implementing
generic data parallelism. This also removes the `graph500-bfs.rs`
benchmark because it relies on `extra::par`.

Closes #5626
This commit is contained in:
bors 2013-09-21 10:10:56 -07:00
commit 44dc3fba8b
3 changed files with 0 additions and 661 deletions

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@ -93,7 +93,6 @@ pub mod glob;
pub mod term;
pub mod time;
pub mod arena;
pub mod par;
pub mod base64;
pub mod rl;
pub mod workcache;

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@ -1,142 +0,0 @@
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::cast;
use std::num;
use std::ptr;
use std::sys;
use std::vec;
use future::Future;
/**
* The maximum number of tasks this module will spawn for a single
* operation.
*/
static MAX_TASKS : uint = 32u;
/// The minimum number of elements each task will process.
static MIN_GRANULARITY : uint = 1024u;
/**
* An internal helper to map a function over a large vector and
* return the intermediate results.
*
* This is used to build most of the other parallel vector functions,
* like map or alli.
*/
fn map_slices<A:Clone + Send,B:Clone + Send>(
xs: &[A],
f: &fn() -> ~fn(uint, v: &[A]) -> B)
-> ~[B] {
let len = xs.len();
if len < MIN_GRANULARITY {
info!("small slice");
// This is a small vector, fall back on the normal map.
~[f()(0u, xs)]
} else {
let num_tasks = num::min(MAX_TASKS, len / MIN_GRANULARITY);
let items_per_task = len / num_tasks;
let mut futures = ~[];
let mut base = 0u;
info!("spawning tasks");
while base < len {
let end = num::min(len, base + items_per_task);
do xs.as_imm_buf |p, _len| {
let f = f();
let base = base;
let f = do Future::spawn() || {
unsafe {
let len = end - base;
let slice = (ptr::offset(p, base as int),
len * sys::size_of::<A>());
info!("pre-slice: %?", (base, slice));
let slice : &[A] =
cast::transmute(slice);
info!("slice: %?", (base, slice.len(), end - base));
assert_eq!(slice.len(), end - base);
f(base, slice)
}
};
futures.push(f);
};
base += items_per_task;
}
info!("tasks spawned");
info!("num_tasks: %?", (num_tasks, futures.len()));
assert_eq!(num_tasks, futures.len());
do futures.move_iter().map |ys| {
let mut ys = ys;
ys.get()
}.collect()
}
}
/// A parallel version of map.
pub fn map<A:Clone + Send,B:Clone + Send>(
xs: &[A], fn_factory: &fn() -> ~fn(&A) -> B) -> ~[B] {
vec::concat(map_slices(xs, || {
let f = fn_factory();
let result: ~fn(uint, &[A]) -> ~[B] =
|_, slice| slice.iter().map(|x| f(x)).collect();
result
}))
}
/// A parallel version of mapi.
pub fn mapi<A:Clone + Send,B:Clone + Send>(
xs: &[A],
fn_factory: &fn() -> ~fn(uint, &A) -> B) -> ~[B] {
let slices = map_slices(xs, || {
let f = fn_factory();
let result: ~fn(uint, &[A]) -> ~[B] = |base, slice| {
slice.iter().enumerate().map(|(i, x)| {
f(i + base, x)
}).collect()
};
result
});
let r = vec::concat(slices);
info!("%?", (r.len(), xs.len()));
assert_eq!(r.len(), xs.len());
r
}
/// Returns true if the function holds for all elements in the vector.
pub fn alli<A:Clone + Send>(
xs: &[A],
fn_factory: &fn() -> ~fn(uint, &A) -> bool) -> bool
{
let mapped = map_slices(xs, || {
let f = fn_factory();
let result: ~fn(uint, &[A]) -> bool = |base, slice| {
slice.iter().enumerate().all(|(i, x)| f(i + base, x))
};
result
});
mapped.iter().all(|&x| x)
}
/// Returns true if the function holds for any elements in the vector.
pub fn any<A:Clone + Send>(
xs: &[A],
fn_factory: &fn() -> ~fn(&A) -> bool) -> bool {
let mapped = map_slices(xs, || {
let f = fn_factory();
let result: ~fn(uint, &[A]) -> bool = |_, slice| slice.iter().any(f);
result
});
mapped.iter().any(|&x| x)
}

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@ -1,518 +0,0 @@
// xfail-pretty
// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
/*!
An implementation of the Graph500 Breadth First Search problem in Rust.
*/
extern mod extra;
use extra::arc;
use extra::time;
use extra::ringbuf::RingBuf;
use extra::container::Deque;
use extra::par;
use std::hashmap::HashSet;
use std::num::abs;
use std::io;
use std::os;
use std::rand::RngUtil;
use std::rand;
use std::uint;
use std::vec;
type node_id = i64;
type graph = ~[~[node_id]];
type bfs_result = ~[node_id];
fn make_edges(scale: uint, edgefactor: uint) -> ~[(node_id, node_id)] {
let mut r = rand::XorShiftRng::new();
fn choose_edge<R: rand::Rng>(i: node_id,
j: node_id,
scale: uint,
r: &mut R)
-> (node_id, node_id) {
let A = 0.57;
let B = 0.19;
let C = 0.19;
if scale == 0u {
(i, j)
} else {
let i = i * 2i64;
let j = j * 2i64;
let scale = scale - 1u;
let x = r.gen::<float>();
if x < A {
choose_edge(i, j, scale, r)
}
else {
let x = x - A;
if x < B {
choose_edge(i + 1i64, j, scale, r)
}
else {
let x = x - B;
if x < C {
choose_edge(i, j + 1i64, scale, r)
}
else {
choose_edge(i + 1i64, j + 1i64, scale, r)
}
}
}
}
}
do vec::from_fn((1u << scale) * edgefactor) |_i| {
choose_edge(0i64, 0i64, scale, &mut r)
}
}
fn make_graph(N: uint, edges: ~[(node_id, node_id)]) -> graph {
let mut graph = do vec::from_fn(N) |_i| {
HashSet::new()
};
for e in edges.iter() {
match *e {
(i, j) => {
graph[i].insert(j);
graph[j].insert(i);
}
}
}
do graph.move_iter().map |v| {
let mut vec = ~[];
for i in v.move_iter() {
vec.push(i);
}
vec
}.collect()
}
fn gen_search_keys(graph: &[~[node_id]], n: uint) -> ~[node_id] {
let mut keys = HashSet::new();
let mut r = rand::rng();
while keys.len() < n {
let k = r.gen_uint_range(0u, graph.len());
if graph[k].len() > 0u && graph[k].iter().any(|i| {
*i != k as node_id
}) {
keys.insert(k as node_id);
}
}
let mut vec = ~[];
for i in keys.move_iter() {
vec.push(i);
}
return vec;
}
/**
* Returns a vector of all the parents in the BFS tree rooted at key.
*
* Nodes that are unreachable have a parent of -1.
*/
fn bfs(graph: graph, key: node_id) -> bfs_result {
let mut marks : ~[node_id]
= vec::from_elem(graph.len(), -1i64);
let mut q = RingBuf::new();
q.push_back(key);
marks[key] = key;
while !q.is_empty() {
let t = q.pop_front().unwrap();
do graph[t].iter().advance |k| {
if marks[*k] == -1i64 {
marks[*k] = t;
q.push_back(*k);
}
true
};
}
marks
}
#[deriving(Clone)]
enum color {
white,
// node_id marks which node turned this gray/black.
// the node id later becomes the parent.
gray(node_id),
black(node_id)
}
/**
* Another version of the bfs function.
*
* This one uses the same algorithm as the parallel one, just without
* using the parallel vector operators.
*/
fn bfs2(graph: graph, key: node_id) -> bfs_result {
// This works by doing functional updates of a color vector.
let mut colors = do vec::from_fn(graph.len()) |i| {
if i as node_id == key {
gray(key)
}
else {
white
}
};
fn is_gray(c: &color) -> bool {
match *c {
gray(_) => { true }
_ => { false }
}
}
let mut i = 0;
while colors.iter().any(is_gray) {
// Do the BFS.
info!("PBFS iteration %?", i);
i += 1;
colors = do colors.iter().enumerate().map |(i, c)| {
let c : color = *c;
match c {
white => {
let i = i as node_id;
let neighbors = &graph[i];
let mut color = white;
do neighbors.iter().advance |k| {
if is_gray(&colors[*k]) {
color = gray(*k);
false
}
else { true }
};
color
}
gray(parent) => { black(parent) }
black(parent) => { black(parent) }
}
}.collect()
}
// Convert the results.
do colors.iter().map |c| {
match *c {
white => { -1i64 }
black(parent) => { parent }
_ => { fail!("Found remaining gray nodes in BFS") }
}
}.collect()
}
/// A parallel version of the bfs function.
fn pbfs(graph: &arc::Arc<graph>, key: node_id) -> bfs_result {
// This works by doing functional updates of a color vector.
let graph_vec = graph.get(); // FIXME #3387 requires this temp
let mut colors = do vec::from_fn(graph_vec.len()) |i| {
if i as node_id == key {
gray(key)
}
else {
white
}
};
#[inline(always)]
fn is_gray(c: &color) -> bool {
match *c {
gray(_) => { true }
_ => { false }
}
}
fn is_gray_factory() -> ~fn(c: &color) -> bool {
let r: ~fn(c: &color) -> bool = is_gray;
r
}
let mut i = 0;
while par::any(colors, is_gray_factory) {
// Do the BFS.
info!("PBFS iteration %?", i);
i += 1;
let old_len = colors.len();
let color = arc::Arc::new(colors);
let color_vec = color.get(); // FIXME #3387 requires this temp
colors = do par::mapi(*color_vec) {
let colors = color.clone();
let graph = graph.clone();
let result: ~fn(x: uint, y: &color) -> color = |i, c| {
let colors = colors.get();
let graph = graph.get();
match *c {
white => {
let i = i as node_id;
let neighbors = graph[i].clone();
let mut color = white;
do neighbors.iter().advance |k| {
if is_gray(&colors[*k]) {
color = gray(*k);
false
}
else { true }
};
color
}
gray(parent) => { black(parent) }
black(parent) => { black(parent) }
}
};
result
};
assert_eq!(colors.len(), old_len);
}
// Convert the results.
do par::map(colors) {
let result: ~fn(c: &color) -> i64 = |c| {
match *c {
white => { -1i64 }
black(parent) => { parent }
_ => { fail!("Found remaining gray nodes in BFS") }
}
};
result
}
}
/// Performs at least some of the validation in the Graph500 spec.
fn validate(edges: ~[(node_id, node_id)],
root: node_id, tree: bfs_result) -> bool {
// There are 5 things to test. Below is code for each of them.
// 1. The BFS tree is a tree and does not contain cycles.
//
// We do this by iterating over the tree, and tracing each of the
// parent chains back to the root. While we do this, we also
// compute the levels for each node.
info!(~"Verifying tree structure...");
let mut status = true;
let level = do tree.map() |parent| {
let mut parent = *parent;
let mut path = ~[];
if parent == -1i64 {
// This node was not in the tree.
-1
}
else {
while parent != root {
if path.contains(&parent) {
status = false;
}
path.push(parent);
parent = tree[parent];
}
// The length of the path back to the root is the current
// level.
path.len() as int
}
};
if !status { return status }
// 2. Each tree edge connects vertices whose BFS levels differ by
// exactly one.
info!(~"Verifying tree edges...");
let status = do tree.iter().enumerate().all |(k, parent)| {
if *parent != root && *parent != -1i64 {
level[*parent] == level[k] - 1
}
else {
true
}
};
if !status { return status }
// 3. Every edge in the input list has vertices with levels that
// differ by at most one or that both are not in the BFS tree.
info!(~"Verifying graph edges...");
let status = do edges.iter().all |e| {
let (u, v) = *e;
abs(level[u] - level[v]) <= 1
};
if !status { return status }
// 4. The BFS tree spans an entire connected component's vertices.
// This is harder. We'll skip it for now...
// 5. A node and its parent are joined by an edge of the original
// graph.
info!(~"Verifying tree and graph edges...");
let status = do par::alli(tree) {
let edges = edges.clone();
let result: ~fn(x: uint, v: &i64) -> bool = |u, v| {
let u = u as node_id;
if *v == -1i64 || u == root {
true
} else {
edges.iter().any(|x| x == &(u, *v)) || edges.iter().any(|x| x == &(*v, u))
}
};
result
};
if !status { return status }
// If we get through here, all the tests passed!
true
}
fn main() {
let args = os::args();
let args = if os::getenv("RUST_BENCH").is_some() {
~[~"", ~"15", ~"48"]
} else if args.len() <= 1 {
~[~"", ~"10", ~"16"]
} else {
args
};
let scale = from_str::<uint>(args[1]).unwrap();
let num_keys = from_str::<uint>(args[2]).unwrap();
let do_validate = false;
let do_sequential = true;
let start = time::precise_time_s();
let edges = make_edges(scale, 16);
let stop = time::precise_time_s();
io::stdout().write_line(fmt!("Generated %? edges in %? seconds.",
edges.len(), stop - start));
let start = time::precise_time_s();
let graph = make_graph(1 << scale, edges.clone());
let stop = time::precise_time_s();
let mut total_edges = 0;
for edges in graph.iter() { total_edges += edges.len(); }
io::stdout().write_line(fmt!("Generated graph with %? edges in %? seconds.",
total_edges / 2,
stop - start));
let mut total_seq = 0.0;
let mut total_par = 0.0;
let graph_arc = arc::Arc::new(graph.clone());
do gen_search_keys(graph, num_keys).map() |root| {
io::stdout().write_line("");
io::stdout().write_line(fmt!("Search key: %?", root));
if do_sequential {
let start = time::precise_time_s();
let bfs_tree = bfs(graph.clone(), *root);
let stop = time::precise_time_s();
//total_seq += stop - start;
io::stdout().write_line(
fmt!("Sequential BFS completed in %? seconds.",
stop - start));
if do_validate {
let start = time::precise_time_s();
assert!((validate(edges.clone(), *root, bfs_tree)));
let stop = time::precise_time_s();
io::stdout().write_line(
fmt!("Validation completed in %? seconds.",
stop - start));
}
let start = time::precise_time_s();
let bfs_tree = bfs2(graph.clone(), *root);
let stop = time::precise_time_s();
total_seq += stop - start;
io::stdout().write_line(
fmt!("Alternate Sequential BFS completed in %? seconds.",
stop - start));
if do_validate {
let start = time::precise_time_s();
assert!((validate(edges.clone(), *root, bfs_tree)));
let stop = time::precise_time_s();
io::stdout().write_line(
fmt!("Validation completed in %? seconds.",
stop - start));
}
}
let start = time::precise_time_s();
let bfs_tree = pbfs(&graph_arc, *root);
let stop = time::precise_time_s();
total_par += stop - start;
io::stdout().write_line(fmt!("Parallel BFS completed in %? seconds.",
stop - start));
if do_validate {
let start = time::precise_time_s();
assert!((validate(edges.clone(), *root, bfs_tree)));
let stop = time::precise_time_s();
io::stdout().write_line(fmt!("Validation completed in %? seconds.",
stop - start));
}
};
io::stdout().write_line("");
io::stdout().write_line(
fmt!("Total sequential: %? \t Total Parallel: %? \t Speedup: %?x",
total_seq, total_par, total_seq / total_par));
}