Use local mutex for each `AstFile.arena`

1 files changed, 16 insertions, 4 deletions

diff --git a/src/common_memory.cpp b/src/common_memory.cpp
index ffdc9118a..dfc86b5f3 100644
--- a/src/common_memory.cpp
+++ b/src/common_memory.cpp
@@ -59,6 +59,8 @@ struct MemoryBlock {
 struct Arena {
 	MemoryBlock * curr_block;
 	isize minimum_block_size;
+	bool use_local_mutex;
+	BlockingMutex local_mutex;
 };
 
 enum { DEFAULT_MINIMUM_BLOCK_SIZE = 8ll*1024ll*1024ll };
@@ -79,15 +81,25 @@ isize arena_align_forward_offset(Arena *arena, isize alignment) {
 	return alignment_offset;
 }
 
+void arena_init_local_mutex(Arena *arena) {
+	mutex_init(&arena->local_mutex);
+	arena->use_local_mutex = true;
+}
+
+
 
 void *arena_alloc(Arena *arena, isize min_size, isize alignment) {
 	GB_ASSERT(gb_is_power_of_two(alignment));
 	
-	isize size = 0;
+	
+	BlockingMutex *mutex = &global_memory_allocator_mutex;
+	if (arena->use_local_mutex) {
+		mutex = &arena->local_mutex;
+	}
 		
-	// TODO(bill): make it so that this can be done lock free (if possible)
-	mutex_lock(&global_memory_allocator_mutex);
+	mutex_lock(mutex);
 	
+	isize size = 0;
 	if (arena->curr_block != nullptr) {
 		size = min_size + arena_align_forward_offset(arena, alignment);
 	}
@@ -112,7 +124,7 @@ void *arena_alloc(Arena *arena, isize min_size, isize alignment) {
 	curr_block->used += size;
 	GB_ASSERT(curr_block->used <= curr_block->size);
 	
-	mutex_unlock(&global_memory_allocator_mutex);
+	mutex_unlock(mutex);
 	
 	// NOTE(bill): memory will be zeroed by default due to virtual memory 
 	return ptr;