New dmnsn_execute_concurrently internal API.

This gets all pthread code out of raytrace.c.

1 files changed, 20 insertions, 0 deletions

diff --git a/libdimension/threads.h b/libdimension/threads.h
index 7ae6288..fdf2df7 100644
--- a/libdimension/threads.h
+++ b/libdimension/threads.h
@@ -34,6 +34,16 @@
 typedef int dmnsn_thread_fn(void *ptr);
 
 /**
+ * Thread callback type for parallel tasks.
+ * @param[in,out] ptr       An arbitrary pointer.
+ * @param[in]     thread    An ID for this thread, in [0, \p nthreads).
+ * @param[in]     nthreads  The number of concurrent threads.
+ * @return 0 on success, non-zero on failure.
+ */
+typedef int dmnsn_concurrent_thread_fn(void *ptr, unsigned int thread,
+                                       unsigned int nthreads);
+
+/**
  * Create a thread that cleans up after itself on errors.
  * @param[in,out] progress   The progress object to associate with the thread.
  * @param[in]     thread_fn  The thread callback.
@@ -42,4 +52,14 @@ typedef int dmnsn_thread_fn(void *ptr);
 void dmnsn_new_thread(dmnsn_progress *progress, dmnsn_thread_fn *thread_fn,
                       void *arg);
 
+/**
+ * Run \p nthreads threads in parallel.
+ * @param[in]     thread_fn  The routine to run in each concurrent thread.
+ * @param[in,out] arg        The pointer to pass to the thread callbacks.
+ * @param[in]     nthreads   The number of concurrent threads to run.
+ * @return 0 if all threads were successful, and an error code otherwise.
+ */
+int dmnsn_execute_concurrently(dmnsn_concurrent_thread_fn *thread_fn,
+                               void *arg, unsigned int nthreads);
+
 #endif /* DIMENSION_IMPL_THREADS_H */