Implement TBB-based parallelism for C lib

1 files changed, 37 insertions, 0 deletions

diff --git a/c/blake3_tbb.cpp b/c/blake3_tbb.cpp
new file mode 100644
index 0000000..c2bc2db
--- /dev/null
+++ b/c/blake3_tbb.cpp
@@ -0,0 +1,37 @@
+#include <cstddef>
+#include <cstdint>
+
+#include <oneapi/tbb/parallel_invoke.h>
+
+#include "blake3_impl.h"
+
+static_assert(TBB_USE_EXCEPTIONS == 0,
+              "This file should be compiled with C++ exceptions disabled.");
+
+extern "C" void blake3_compress_subtree_wide_join_tbb(
+    // shared params
+    const uint32_t key[8], uint8_t flags, bool use_tbb,
+    // left-hand side params
+    const uint8_t *l_input, size_t l_input_len, uint64_t l_chunk_counter,
+    uint8_t *l_cvs, size_t *l_n,
+    // right-hand side params
+    const uint8_t *r_input, size_t r_input_len, uint64_t r_chunk_counter,
+    uint8_t *r_cvs, size_t *r_n) noexcept {
+  if (!use_tbb) {
+    *l_n = blake3_compress_subtree_wide(l_input, l_input_len, key,
+                                        l_chunk_counter, flags, l_cvs, use_tbb);
+    *r_n = blake3_compress_subtree_wide(r_input, r_input_len, key,
+                                        r_chunk_counter, flags, r_cvs, use_tbb);
+    return;
+  }
+
+  oneapi::tbb::parallel_invoke(
+      [=]() {
+        *l_n = blake3_compress_subtree_wide(
+            l_input, l_input_len, key, l_chunk_counter, flags, l_cvs, use_tbb);
+      },
+      [=]() {
+        *r_n = blake3_compress_subtree_wide(
+            r_input, r_input_len, key, r_chunk_counter, flags, r_cvs, use_tbb);
+      });
+}