1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
//! Integration test for MPI Group range-based constructors.
//!
//! Exercises `Group::range_include` and `Group::range_exclude` using a
//! 4-rank `MPI_COMM_WORLD`. All assertions are guarded by a sentinel
//! `allreduce(Min)` before any `process::exit` so that no rank exits while
//! others are still inside MPI collective calls.
//!
//! Run with: mpiexec -n 4 ./target/debug/examples/test_group_ranges
use ferrompi::{Mpi, RankRange, ReduceOp};
fn main() {
let mpi = Mpi::init().expect("MPI init failed");
let world = mpi.world();
let rank = world.rank();
let size = world.size();
assert!(
size == 4,
"test_group_ranges requires exactly 4 processes, got {size}"
);
// local_ok tracks whether this rank passed all its assertions.
let mut local_ok = true;
let parent = match world.group() {
Ok(g) => g,
Err(e) => {
eprintln!("rank {rank}: FAIL: world.group() failed: {e}");
let _ = world.allreduce_scalar(0i32, ReduceOp::Min);
std::process::exit(1);
}
};
// ========================================================================
// Test 1: range_include with stride 1 → ranks {0, 1, 2} → size 3
// ========================================================================
{
let ranges = [RankRange {
first: 0,
last: 2,
stride: 1,
}];
match parent.range_include(&ranges) {
Ok(sub) => match sub.size() {
Ok(s) if s == 3 => {
if rank == 0 {
println!("PASS: Test 1 — range_include([0..=2 step 1]).size() = {s}");
}
}
Ok(s) => {
eprintln!("rank {rank}: FAIL Test 1: expected size 3, got {s}");
local_ok = false;
}
Err(e) => {
eprintln!("rank {rank}: FAIL Test 1: size() error: {e}");
local_ok = false;
}
},
Err(e) => {
eprintln!("rank {rank}: FAIL Test 1: range_include failed: {e}");
local_ok = false;
}
}
}
// ========================================================================
// Test 2: range_include with stride 2 → ranks {0, 2} → size 2
// ========================================================================
{
let ranges = [RankRange {
first: 0,
last: 3,
stride: 2,
}];
match parent.range_include(&ranges) {
Ok(sub) => match sub.size() {
Ok(s) if s == 2 => {
if rank == 0 {
println!("PASS: Test 2 — range_include([0..=3 step 2]).size() = {s}");
}
}
Ok(s) => {
eprintln!("rank {rank}: FAIL Test 2: expected size 2, got {s}");
local_ok = false;
}
Err(e) => {
eprintln!("rank {rank}: FAIL Test 2: size() error: {e}");
local_ok = false;
}
},
Err(e) => {
eprintln!("rank {rank}: FAIL Test 2: range_include failed: {e}");
local_ok = false;
}
}
}
// ========================================================================
// Test 3: range_exclude ranks {1, 2} → surviving ranks {0, 3} → size 2
// ========================================================================
{
let ranges = [RankRange {
first: 1,
last: 2,
stride: 1,
}];
match parent.range_exclude(&ranges) {
Ok(sub) => match sub.size() {
Ok(s) if s == 2 => {
if rank == 0 {
println!("PASS: Test 3 — range_exclude([1..=2 step 1]).size() = {s}");
}
}
Ok(s) => {
eprintln!("rank {rank}: FAIL Test 3: expected size 2, got {s}");
local_ok = false;
}
Err(e) => {
eprintln!("rank {rank}: FAIL Test 3: size() error: {e}");
local_ok = false;
}
},
Err(e) => {
eprintln!("rank {rank}: FAIL Test 3: range_exclude failed: {e}");
local_ok = false;
}
}
}
// ========================================================================
// Sentinel allreduce(Min) — gate process::exit so no rank exits early
// ========================================================================
let global_ok = world
.allreduce_scalar(local_ok as i32, ReduceOp::Min)
.expect("allreduce_scalar failed");
if global_ok == 0 {
if rank == 0 {
eprintln!("FAIL: at least one rank failed a group-ranges assertion");
}
std::process::exit(1);
}
if rank == 0 {
println!();
println!("========================================");
println!("All group range tests passed!");
println!("========================================");
}
}