+2011-09-30 Paul Eggert <eggert@cs.ucla.edu>
+
+ Remove dependency on glibc malloc internals.
+ * alloc.c (XMALLOC_OVERRUN_CHECK_OVERHEAD, XMALLOC_OVERRUN_CHECK_SIZE):
+ Move back here from lisp.h, but with their new implementations.
+ (XMALLOC_BASE_ALIGNMENT, COMMON_MULTIPLE, XMALLOC_HEADER_ALIGNMENT)
+ (XMALLOC_OVERRUN_SIZE_SIZE): Move these new lisp.h macros here.
+ * charset.c (charset_table_init): New static var.
+ (syms_of_charset): Use it instead of xmalloc. This removes a
+ dependency on glibc malloc internals. See Eli Zaretskii's comment in
+ <http://lists.gnu.org/archive/html/emacs-devel/2011-09/msg00815.html>.
+ * lisp.h (XMALLOC_OVERRUN_CHECK_OVERHEAD, XMALLOC_OVERRUN_CHECK_SIZE):
+ Move back to alloc.c.
+ (XMALLOC_BASE_ALIGNMENT, COMMON_MULTIPLE, XMALLOC_HEADER_ALIGNMENT)
+ (XMALLOC_OVERRUN_SIZE_SIZE): Move to alloc.c.
+
2011-09-30 Jan Djärv <jan.h.d@swipnet.se>
* nsterm.m (windowDidResize): Call x_set_window_size only when
xsignal (Qnil, Vmemory_signal_data);
}
-#ifdef XMALLOC_OVERRUN_CHECK
+
+#ifndef XMALLOC_OVERRUN_CHECK
+#define XMALLOC_OVERRUN_CHECK_OVERHEAD 0
+#else
/* Check for overrun in malloc'ed buffers by wrapping a header and trailer
- around each block. */
+ around each block.
+
+ The header consists of XMALLOC_OVERRUN_CHECK_SIZE fixed bytes
+ followed by XMALLOC_OVERRUN_SIZE_SIZE bytes containing the original
+ block size in little-endian order. The trailer consists of
+ XMALLOC_OVERRUN_CHECK_SIZE fixed bytes.
+
+ The header is used to detect whether this block has been allocated
+ through these functions, as some low-level libc functions may
+ bypass the malloc hooks. */
+
+#define XMALLOC_OVERRUN_CHECK_SIZE 16
+#define XMALLOC_OVERRUN_CHECK_OVERHEAD \
+ (2 * XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE)
+
+/* Define XMALLOC_OVERRUN_SIZE_SIZE so that (1) it's large enough to
+ hold a size_t value and (2) the header size is a multiple of the
+ alignment that Emacs needs for C types and for USE_LSB_TAG. */
+#define XMALLOC_BASE_ALIGNMENT \
+ offsetof ( \
+ struct { \
+ union { long double d; intmax_t i; void *p; } u; \
+ char c; \
+ }, \
+ c)
+#ifdef USE_LSB_TAG
+/* A common multiple of the positive integers A and B. Ideally this
+ would be the least common multiple, but there's no way to do that
+ as a constant expression in C, so do the best that we can easily do. */
+# define COMMON_MULTIPLE(a, b) \
+ ((a) % (b) == 0 ? (a) : (b) % (a) == 0 ? (b) : (a) * (b))
+# define XMALLOC_HEADER_ALIGNMENT \
+ COMMON_MULTIPLE (1 << GCTYPEBITS, XMALLOC_BASE_ALIGNMENT)
+#else
+# define XMALLOC_HEADER_ALIGNMENT XMALLOC_BASE_ALIGNMENT
+#endif
+#define XMALLOC_OVERRUN_SIZE_SIZE \
+ (((XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t) \
+ + XMALLOC_HEADER_ALIGNMENT - 1) \
+ / XMALLOC_HEADER_ALIGNMENT * XMALLOC_HEADER_ALIGNMENT) \
+ - XMALLOC_OVERRUN_CHECK_SIZE)
static char const xmalloc_overrun_check_header[XMALLOC_OVERRUN_CHECK_SIZE] =
{ '\x9a', '\x9b', '\xae', '\xaf',
sizeof *charset_table);
memcpy (new_table, charset_table, old_size * sizeof *new_table);
charset_table = new_table;
- /* FIXME: Doesn't this leak memory? The old charset_table becomes
- unreachable. It could be that this is intentional, because the
- old charset table may be in a dumped emacs, and reallocating such
- a table may not work. If the memory leak is intentional, a
+ /* FIXME: This leaks memory, as the old charset_table becomes
+ unreachable. If the old charset table is charset_table_init
+ then this leak is intentional; otherwise, it's unclear.
+ If the latter memory leak is intentional, a
comment should be added to explain this. If not, the old
charset_table should be freed, by passing it as the 1st argument
to xpalloc and removing the memcpy. */
#ifdef emacs
+/* Allocate an initial charset table that is large enough to handle
+ Emacs while it is bootstrapping. As of September 2011, the size
+ needs to be at least 166; make it a bit bigger to allow for future
+ expansion.
+
+ Don't make the value so small that the table is reallocated during
+ bootstrapping, as glibc malloc calls larger than just under 64 KiB
+ during an initial bootstrap wreak havoc after dumping; see the
+ M_MMAP_THRESHOLD value in alloc.c, plus there is a extra overhead
+ internal to glibc malloc and perhaps to Emacs malloc debugging. */
+static struct charset charset_table_init[180];
+
void
syms_of_charset (void)
{
- /* Allocate an initial charset table that is just under 64 KiB in size.
- This should be large enough so that the charset table need not be
- reallocated during an initial bootstrap. Allocating anything larger than
- 64 KiB in an initial run may not work, because glibc malloc might use
- mmap for larger allocations, and these don't work well across dumped
- systems. */
- enum {
- glibc_malloc_overhead = 3 * sizeof (size_t) - 1,
- initial_malloc_max =
- (1 << 16) - 1 - glibc_malloc_overhead - XMALLOC_OVERRUN_CHECK_OVERHEAD,
- charset_table_size_init = initial_malloc_max / sizeof (struct charset)
- };
-
DEFSYM (Qcharsetp, "charsetp");
DEFSYM (Qascii, "ascii");
Vcharset_hash_table = Fmake_hash_table (2, args);
}
- charset_table = (struct charset *) xmalloc (sizeof (struct charset)
- * charset_table_size_init);
- charset_table_size = charset_table_size_init;
+ charset_table = charset_table_init;
+ charset_table_size = sizeof charset_table_init / sizeof *charset_table_init;
charset_table_used = 0;
defsubr (&Scharsetp);
extern int immediate_quit; /* Nonzero means ^G can quit instantly */
-/* Overhead for overrun check in malloc'ed buffers. The check
- operates by wrapping a header and trailer around each block.
-
- The header consists of XMALLOC_OVERRUN_CHECK_SIZE fixed bytes
- followed by XMALLOC_OVERRUN_SIZE_SIZE bytes containing the original
- block size in little-endian order. The trailer consists of
- XMALLOC_OVERRUN_CHECK_SIZE fixed bytes.
-
- The header is used to detect whether this block has been allocated
- through these functions, as some low-level libc functions may
- bypass the malloc hooks. */
-
-#ifndef XMALLOC_OVERRUN_CHECK
-# define XMALLOC_OVERRUN_CHECK_OVERHEAD 0
-#else
-
-# define XMALLOC_OVERRUN_CHECK_SIZE 16
-# define XMALLOC_OVERRUN_CHECK_OVERHEAD \
- (2 * XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE)
-
-/* Define XMALLOC_OVERRUN_SIZE_SIZE so that (1) it's large enough to
- hold a size_t value and (2) the header size is a multiple of the
- alignment that Emacs needs for C types and for USE_LSB_TAG. */
-# define XMALLOC_BASE_ALIGNMENT \
- offsetof ( \
- struct { \
- union { long double d; intmax_t i; void *p; } u; \
- char c; \
- }, \
- c)
-# ifdef USE_LSB_TAG
-/* A common multiple of the positive integers A and B. Ideally this
- would be the least common multiple, but there's no way to do that
- as a constant expression in C, so do the best that we can easily do. */
-# define COMMON_MULTIPLE(a, b) \
- ((a) % (b) == 0 ? (a) : (b) % (a) == 0 ? (b) : (a) * (b))
-# define XMALLOC_HEADER_ALIGNMENT \
- COMMON_MULTIPLE (1 << GCTYPEBITS, XMALLOC_BASE_ALIGNMENT)
-# else
-# define XMALLOC_HEADER_ALIGNMENT XMALLOC_BASE_ALIGNMENT
-# endif
-# define XMALLOC_OVERRUN_SIZE_SIZE \
- (((XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t) \
- + XMALLOC_HEADER_ALIGNMENT - 1) \
- / XMALLOC_HEADER_ALIGNMENT * XMALLOC_HEADER_ALIGNMENT) \
- - XMALLOC_OVERRUN_CHECK_SIZE)
-#endif
-
extern POINTER_TYPE *xmalloc (size_t);
extern POINTER_TYPE *xrealloc (POINTER_TYPE *, size_t);
extern void xfree (POINTER_TYPE *);
projects / emacs.git / commitdiff