Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT executable memory. Patch inspired by Carsten Klein.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1338 2f5784b3-3f2a-0410-8824-cb99058d5e15

2 files changed, 24 insertions, 0 deletions

diff --git a/sljit/sljitConfigInternal.h b/sljit/sljitConfigInternal.h
index 340dbf1..2298191 100644
--- a/sljit/sljitConfigInternal.h
+++ b/sljit/sljitConfigInternal.h
@@ -417,6 +417,7 @@ typedef double sljit_d;
 #if (defined SLJIT_EXECUTABLE_ALLOCATOR && SLJIT_EXECUTABLE_ALLOCATOR)
 SLJIT_API_FUNC_ATTRIBUTE void* sljit_malloc_exec(sljit_uw size);
 SLJIT_API_FUNC_ATTRIBUTE void sljit_free_exec(void* ptr);
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_unused_memory_exec(void);
 #define SLJIT_MALLOC_EXEC(size) sljit_malloc_exec(size)
 #define SLJIT_FREE_EXEC(ptr) sljit_free_exec(ptr)
 #endif
diff --git a/sljit/sljitExecAllocator.c b/sljit/sljitExecAllocator.c
index 75a3899..f24ed33 100644
--- a/sljit/sljitExecAllocator.c
+++ b/sljit/sljitExecAllocator.c
@@ -287,3 +287,26 @@ SLJIT_API_FUNC_ATTRIBUTE void sljit_free_exec(void* ptr)
 
 	allocator_release_lock();
 }
+
+SLJIT_API_FUNC_ATTRIBUTE void sljit_free_unused_memory_exec(void)
+{
+	struct free_block* free_block;
+	struct free_block* next_free_block;
+
+	allocator_grab_lock();
+
+	free_block = free_blocks;
+	while (free_block) {
+		next_free_block = free_block->next;
+		if (!free_block->header.prev_size && 
+				AS_BLOCK_HEADER(free_block, free_block->size)->size == 1) {
+			total_size -= free_block->size;
+			sljit_remove_free_block(free_block);
+			free_chunk(free_block, free_block->size + sizeof(struct block_header));
+		}
+		free_block = next_free_block;
+	}
+
+	SLJIT_ASSERT((total_size && free_blocks) || (!total_size && !free_blocks));
+	allocator_release_lock();
+}