Differences

This shows you the differences between two versions of the page.

--- tasks-openmp [June 11, 2026 at 07:42] – created - external edit 127.0.0.1
+++ tasks-openmp [Unknown date] (current) – removed - external edit (Unknown date) 127.0.0.1
@@ Line 1: / Line 1: @@
-# Tasks (OpenMP)
-**Tasks** are the OpenMP mechanism for irregular parallelism. `parallel for` only handles loops with a known iteration count. For work like recursive algorithms, tree traversals, and producer-consumer patterns, `#pragma omp task` packages a unit of work that any idle thread in the current team can pick up and execute. Tasks are created inside a `single` region so only one thread generates them while the rest execute them.
-```c
-#pragma omp parallel
-#pragma omp single
-{
-    for (node_t *n = head; n != NULL; n = n->next) {
-        #pragma omp task firstprivate(n)
-        process(n);
-    }
-}
-```
-`firstprivate(n)` gives each task its own copy of `n` at the time the task is created. Without it, all tasks would share the same pointer, which moves on as the loop advances. Use `#pragma omp taskwait` to block until all child tasks spawned in the current scope have finished. Tasks can be nested: a task can itself create more tasks, which is natural for recursive divide-and-conquer.