[PATCH 04/11] Add a pages_purge function to wrap madvise(JEMALLOC_MADV_PURGE) calls

[Mike Hommey]

From: unknown <mh at jigen.(none)>

This will be used to implement the feature on mingw, which doesn't have
madvise.
---
 include/jemalloc/internal/chunk_mmap.h |    2 ++
 include/jemalloc/jemalloc_defs.h.in    |    7 -------
 src/arena.c                            |    4 ++--
 src/chunk.c                            |    2 +-
 src/chunk_mmap.c                       |   13 +++++++++++++
 5 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/include/jemalloc/internal/chunk_mmap.h b/include/jemalloc/internal/chunk_mmap.h
index 04e86af..2d01ac2 100644
--- a/include/jemalloc/internal/chunk_mmap.h
+++ b/include/jemalloc/internal/chunk_mmap.h
@@ -9,6 +9,8 @@
 /******************************************************************************/
 #ifdef JEMALLOC_H_EXTERNS
 
+void	pages_purge(void *addr, size_t length);
+
 void	*chunk_alloc_mmap(size_t size, size_t alignment);
 bool	chunk_dealloc_mmap(void *chunk, size_t size);
 
diff --git a/include/jemalloc/jemalloc_defs.h.in b/include/jemalloc/jemalloc_defs.h.in
index 90baa35..6e81655 100644
--- a/include/jemalloc/jemalloc_defs.h.in
+++ b/include/jemalloc/jemalloc_defs.h.in
@@ -220,13 +220,6 @@
  */
 #undef JEMALLOC_PURGE_MADVISE_DONTNEED
 #undef JEMALLOC_PURGE_MADVISE_FREE
-#ifdef JEMALLOC_PURGE_MADVISE_DONTNEED
-#  define JEMALLOC_MADV_PURGE MADV_DONTNEED
-#elif defined(JEMALLOC_PURGE_MADVISE_FREE)
-#  define JEMALLOC_MADV_PURGE MADV_FREE
-#else
-#  error "No method defined for purging unused dirty pages."
-#endif
 
 /* sizeof(void *) == 2^LG_SIZEOF_PTR. */
 #undef LG_SIZEOF_PTR
diff --git a/src/arena.c b/src/arena.c
index 989034d..cbd92e2 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -676,8 +676,8 @@ arena_chunk_purge(arena_t *arena, arena_chunk_t *chunk)
 		if (config_debug)
 			ndirty -= npages;
 
-		madvise((void *)((uintptr_t)chunk + (pageind << LG_PAGE)),
-		    (npages << LG_PAGE), JEMALLOC_MADV_PURGE);
+		pages_purge((void *)((uintptr_t)chunk + (pageind << LG_PAGE)),
+		    (npages << LG_PAGE));
 		if (config_stats)
 			nmadvise++;
 	}
diff --git a/src/chunk.c b/src/chunk.c
index 67e0d50..bcaedea 100644
--- a/src/chunk.c
+++ b/src/chunk.c
@@ -171,7 +171,7 @@ chunk_record(void *chunk, size_t size)
 {
 	extent_node_t *xnode, *node, *prev, key;
 
-	madvise(chunk, size, JEMALLOC_MADV_PURGE);
+	pages_purge(chunk, size);
 
 	xnode = NULL;
 	malloc_mutex_lock(&chunks_mtx);
diff --git a/src/chunk_mmap.c b/src/chunk_mmap.c
index e11cc0e..3ab9095 100644
--- a/src/chunk_mmap.c
+++ b/src/chunk_mmap.c
@@ -72,6 +72,19 @@ pages_unmap(void *addr, size_t size)
 	}
 }
 
+void
+pages_purge(void *addr, size_t length)
+{
+#ifdef JEMALLOC_PURGE_MADVISE_DONTNEED
+#  define JEMALLOC_MADV_PURGE MADV_DONTNEED
+#elif defined(JEMALLOC_PURGE_MADVISE_FREE)
+#  define JEMALLOC_MADV_PURGE MADV_FREE
+#else
+#  error "No method defined for purging unused dirty pages."
+#endif
+	madvise(addr, length, JEMALLOC_MADV_PURGE);
+}
+
 static void *
 chunk_alloc_mmap_slow(size_t size, size_t alignment, bool unaligned)
 {
-- 
1.7.10