Rename most remaining *chunk* APIs to *extent*.

src/extent_dss.c

@@ -0,0 +1,216 @@
+#define	JEMALLOC_EXTENT_DSS_C_
+#include "jemalloc/internal/jemalloc_internal.h"
+/******************************************************************************/
+/* Data. */
+
+const char	*dss_prec_names[] = {
+	"disabled",
+	"primary",
+	"secondary",
+	"N/A"
+};
+
+/* Current dss precedence default, used when creating new arenas. */
+static dss_prec_t	dss_prec_default = DSS_PREC_DEFAULT;
+
+/*
+ * Protects sbrk() calls.  This avoids malloc races among threads, though it
+ * does not protect against races with threads that call sbrk() directly.
+ */
+static malloc_mutex_t	dss_mtx;
+
+/* Base address of the DSS. */
+static void		*dss_base;
+/* Current end of the DSS, or ((void *)-1) if the DSS is exhausted. */
+static void		*dss_prev;
+/* Current upper limit on DSS addresses. */
+static void		*dss_max;
+
+/******************************************************************************/
+
+static void *
+extent_dss_sbrk(intptr_t increment)
+{
+
+#ifdef JEMALLOC_DSS
+	return (sbrk(increment));
+#else
+	not_implemented();
+	return (NULL);
+#endif
+}
+
+dss_prec_t
+extent_dss_prec_get(tsdn_t *tsdn)
+{
+	dss_prec_t ret;
+
+	if (!have_dss)
+		return (dss_prec_disabled);
+	malloc_mutex_lock(tsdn, &dss_mtx);
+	ret = dss_prec_default;
+	malloc_mutex_unlock(tsdn, &dss_mtx);
+	return (ret);
+}
+
+bool
+extent_dss_prec_set(tsdn_t *tsdn, dss_prec_t dss_prec)
+{
+
+	if (!have_dss)
+		return (dss_prec != dss_prec_disabled);
+	malloc_mutex_lock(tsdn, &dss_mtx);
+	dss_prec_default = dss_prec;
+	malloc_mutex_unlock(tsdn, &dss_mtx);
+	return (false);
+}
+
+void *
+extent_alloc_dss(tsdn_t *tsdn, arena_t *arena, void *new_addr, size_t size,
+    size_t alignment, bool *zero, bool *commit)
+{
+	void *ret;
+	extent_t *pad;
+
+	cassert(have_dss);
+	assert(size > 0);
+	assert(alignment > 0);
+
+	/*
+	 * sbrk() uses a signed increment argument, so take care not to
+	 * interpret a large allocation request as a negative increment.
+	 */
+	if ((intptr_t)size < 0)
+		return (NULL);
+
+	pad = extent_alloc(tsdn, arena);
+	if (pad == NULL)
+		return (NULL);
+
+	malloc_mutex_lock(tsdn, &dss_mtx);
+	if (dss_prev != (void *)-1) {
+		/*
+		 * The loop is necessary to recover from races with other
+		 * threads that are using the DSS for something other than
+		 * malloc.
+		 */
+		while (true) {
+			void *pad_addr, *dss_next;
+			size_t pad_size;
+			intptr_t incr;
+
+			/* Avoid an unnecessary system call. */
+			if (new_addr != NULL && dss_max != new_addr)
+				break;
+
+			/* Get the current end of the DSS. */
+			dss_max = extent_dss_sbrk(0);
+
+			/* Make sure the earlier condition still holds. */
+			if (new_addr != NULL && dss_max != new_addr)
+				break;
+
+			/*
+			 * Compute how much pad space (if any) is necessary to
+			 * satisfy alignment.  This space can be recycled for
+			 * later use.
+			 */
+			pad_addr = (void *)((uintptr_t)dss_max);
+			ret = (void *)ALIGNMENT_CEILING((uintptr_t)dss_max,
+			    alignment);
+			pad_size = (uintptr_t)ret - (uintptr_t)pad_addr;
+			if (pad_size != 0) {
+				extent_init(pad, arena, pad_addr, pad_size,
+				    pad_size, false, false, true, false);
+			}
+			dss_next = (void *)((uintptr_t)ret + size);
+			if ((uintptr_t)ret < (uintptr_t)dss_max ||
+			    (uintptr_t)dss_next < (uintptr_t)dss_max)
+				break; /* Wrap-around. */
+			incr = pad_size + size;
+			dss_prev = extent_dss_sbrk(incr);
+			if (dss_prev == (void *)-1)
+				break;
+			if (dss_prev == dss_max) {
+				/* Success. */
+				dss_max = dss_next;
+				malloc_mutex_unlock(tsdn, &dss_mtx);
+				if (pad_size != 0) {
+					extent_hooks_t extent_hooks =
+					    EXTENT_HOOKS_INITIALIZER;
+					extent_dalloc_wrapper(tsdn, arena,
+					    &extent_hooks, pad);
+				} else
+					extent_dalloc(tsdn, arena, pad);
+				if (*zero)
+					memset(ret, 0, size);
+				if (!*commit)
+					*commit = pages_decommit(ret, size);
+				return (ret);
+			}
+		}
+	}
+	/* OOM. */
+	malloc_mutex_unlock(tsdn, &dss_mtx);
+	extent_dalloc(tsdn, arena, pad);
+	return (NULL);
+}
+
+bool
+extent_in_dss(tsdn_t *tsdn, void *addr)
+{
+	bool ret;
+
+	cassert(have_dss);
+
+	malloc_mutex_lock(tsdn, &dss_mtx);
+	if ((uintptr_t)addr >= (uintptr_t)dss_base
+	    && (uintptr_t)addr < (uintptr_t)dss_max)
+		ret = true;
+	else
+		ret = false;
+	malloc_mutex_unlock(tsdn, &dss_mtx);
+
+	return (ret);
+}
+
+bool
+extent_dss_boot(void)
+{
+
+	cassert(have_dss);
+
+	if (malloc_mutex_init(&dss_mtx, "dss", WITNESS_RANK_DSS))
+		return (true);
+	dss_base = extent_dss_sbrk(0);
+	dss_prev = dss_base;
+	dss_max = dss_base;
+
+	return (false);
+}
+
+void
+extent_dss_prefork(tsdn_t *tsdn)
+{
+
+	if (have_dss)
+		malloc_mutex_prefork(tsdn, &dss_mtx);
+}
+
+void
+extent_dss_postfork_parent(tsdn_t *tsdn)
+{
+
+	if (have_dss)
+		malloc_mutex_postfork_parent(tsdn, &dss_mtx);
+}
+
+void
+extent_dss_postfork_child(tsdn_t *tsdn)
+{
+
+	if (have_dss)
+		malloc_mutex_postfork_child(tsdn, &dss_mtx);
+}
+
+/******************************************************************************/