Bug 427109: Add memory reserve and xmalloc() API, r=benjamin

This re-commmit adds locking that was missing in changeset c14ab4f6cec6.

memory/jemalloc/Makefile.in

@@ -73,8 +73,9 @@ $(CRT_OBJ_DIR)/jemalloc.c: $(srcdir)/crtsp1.diff
 
 $(CRT_OBJ_DIR)/build/intel/mozcrt19.dll: \
   $(CRT_OBJ_DIR)/jemalloc.c $(srcdir)/jemalloc.c $(srcdir)/jemalloc.h \
-  $(srcdir)/rb.h
-	cp $(srcdir)/jemalloc.c $(srcdir)/jemalloc.h $(srcdir)/rb.h $(CRT_OBJ_DIR)
+  $(srcdir)/ql.h $(srcdir)/qr.h $(srcdir)/rb.h
+	cp $(srcdir)/jemalloc.c $(srcdir)/jemalloc.h $(srcdir)/ql.h \
+	$(srcdir)/qr.h $(srcdir)/rb.h $(CRT_OBJ_DIR)
 # this pretty much sucks, but nmake and make don't play well together
 	$(PYTHON) $(srcdir)/build-crt.py $(CRT_OBJ_DIR)
 	#XXX: these don't link right for some reason

memory/jemalloc/jemalloc.h

@@ -19,9 +19,7 @@ typedef struct {
 	 * Run-time configuration settings.
 	 */
 	bool	opt_abort;	/* abort(3) on error? */
-	bool	opt_dss;	/* Use sbrk(2) to map memory? */
 	bool	opt_junk;	/* Fill allocated/free memory with 0xa5/0x5a? */
-	bool	opt_mmap;	/* Use mmap(2) to map memory? */
 	bool	opt_utrace;	/* Trace all allocation events? */
 	bool	opt_sysv;	/* SysV semantics? */
 	bool	opt_xmalloc;	/* abort(3) on OOM? */
@@ -33,6 +31,8 @@ typedef struct {
 	size_t	large_max;	/* Max sub-chunksize allocation size. */
 	size_t	chunksize;	/* Size of each virtual memory mapping. */
 	size_t	dirty_max;	/* Max dirty pages per arena. */
+	size_t	reserve_min;	/* reserve_low callback threshold. */
+	size_t	reserve_max;	/* Maximum reserve size before unmapping. */
 
 	/*
 	 * Current memory usage statistics.
@@ -41,6 +41,7 @@ typedef struct {
 	size_t	committed;	/* Bytes committed (readable/writable). */
 	size_t	allocated;	/* Bytes allocted (in use by application). */
 	size_t	dirty;		/* Bytes dirty (committed unused pages). */
+	size_t	reserve_cur;	/* Current memory reserve. */
 } jemalloc_stats_t;
 
 #ifndef MOZ_MEMORY_DARWIN
@@ -55,3 +56,122 @@ int	posix_memalign(void **memptr, size_t alignment, size_t size);
 void	*memalign(size_t alignment, size_t size);
 size_t	malloc_usable_size(const void *ptr);
 void	jemalloc_stats(jemalloc_stats_t *stats);
+
+/* The x*() functions never return NULL. */
+void	*xmalloc(size_t size);
+void	*xcalloc(size_t num, size_t size);
+void	*xrealloc(void *ptr, size_t size);
+void	*xmemalign(size_t alignment, size_t size);
+
+/*
+ * The allocator maintains a memory reserve that is used to satisfy allocation
+ * requests when no additional memory can be acquired from the operating
+ * system.  Under normal operating conditions, the reserve size is at least
+ * reserve_min bytes.  If the reserve is depleted or insufficient to satisfy an
+ * allocation request, then condition notifications are sent to one or more of
+ * the registered callback functions:
+ *
+ *   RESERVE_CND_LOW: The reserve had to be used to satisfy an allocation
+ *                    request, which dropped the reserve size below the
+ *                    minimum.  The callee should try to free memory in order
+ *                    to restore the reserve.
+ *
+ *   RESERVE_CND_CRIT: The reserve was not large enough to satisfy a pending
+ *                     allocation request.  Some callee must free adequate
+ *                     memory in order to prevent application failure (unless
+ *                     the condition spontaneously desists due to concurrent
+ *                     deallocation).
+ *
+ *   RESERVE_CND_FAIL: An allocation request could not be satisfied, despite all
+ *                     attempts.  The allocator is about to terminate the
+ *                     application.
+ *
+ * The order in which the callback functions are called is only loosely
+ * specified: in the absence of interposing callback
+ * registrations/unregistrations, enabled callbacks will be called in an
+ * arbitrary round-robin order.
+ *
+ * Condition notifications are sent to callbacks only while conditions exist.
+ * For example, just before the allocator sends a RESERVE_CND_LOW condition
+ * notification to a callback, the reserve is in fact depleted.  However, due
+ * to allocator concurrency, the reserve may have been restored by the time the
+ * callback function executes.  Furthermore, if the reserve is restored at some
+ * point during the delivery of condition notifications to callbacks, no
+ * further deliveries will occur, since the condition no longer exists.
+ *
+ * Callback functions can freely call back into the allocator (i.e. the
+ * allocator releases all internal resources before calling each callback
+ * function), though allocation is discouraged, since recursive callbacks are
+ * likely to result, which places extra burden on the application to avoid
+ * deadlock.
+ *
+ * Callback functions must be thread-safe, since it is possible that multiple
+ * threads will call into the same callback function concurrently.
+ */
+
+/* Memory reserve condition types. */
+typedef enum {
+	RESERVE_CND_LOW,
+	RESERVE_CND_CRIT,
+	RESERVE_CND_FAIL
+} reserve_cnd_t;
+
+/*
+ * Reserve condition notification callback function type definition.
+ *
+ * Inputs:
+ *   ctx: Opaque application data, as passed to reserve_cb_register().
+ *   cnd: Condition type being delivered.
+ *   size: Allocation request size for the allocation that caused the condition.
+ */
+typedef void reserve_cb_t(void *ctx, reserve_cnd_t cnd, size_t size);
+
+/*
+ * Register a callback function.
+ *
+ * Inputs:
+ *   cb: Callback function pointer.
+ *   ctx: Opaque application data, passed to cb().
+ *
+ * Output:
+ *   ret: If true, failure due to OOM; success otherwise.
+ */
+bool	reserve_cb_register(reserve_cb_t *cb, void *ctx);
+
+/*
+ * Unregister a callback function.
+ *
+ * Inputs:
+ *   cb: Callback function pointer.
+ *   ctx: Opaque application data, same as that passed to reserve_cb_register().
+ *
+ * Output:
+ *   ret: False upon success, true if the {cb,ctx} registration could not be
+ *        found.
+ */
+bool	reserve_cb_unregister(reserve_cb_t *cb, void *ctx);
+
+/*
+ * Get the current reserve size.
+ *
+ * ret: Current reserve size.
+ */
+size_t	reserve_cur_get(void);
+
+/*
+ * Get the minimum acceptable reserve size.  If the reserve drops below this
+ * value, the RESERVE_CND_LOW condition notification is sent to the callbacks.
+ *
+ * ret: Minimum acceptable reserve size.
+ */
+size_t	reserve_min_get(void);
+
+/*
+ * Set the minimum acceptable reserve size.
+ *
+ * min: Reserve threshold.  This value may be internally rounded up.
+ * ret: False if the reserve was successfully resized; true otherwise.  Note
+ *      that failure to resize the reserve also results in a RESERVE_CND_LOW
+ *      condition.
+ */
+bool	reserve_min_set(size_t min);