diff options
Diffstat (limited to 'src/alloc.c')
| -rw-r--r-- | src/alloc.c | 424 |
1 files changed, 36 insertions, 388 deletions
diff --git a/src/alloc.c b/src/alloc.c index 0bfbb0c88b..fb7d35b559 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -85,68 +85,8 @@ extern void *sbrk (); #define MMAP_MAX_AREAS 100000000 -#else /* not DOUG_LEA_MALLOC */ - -/* The following come from gmalloc.c. */ - -extern size_t _bytes_used; -extern size_t __malloc_extra_blocks; -extern void *_malloc_internal (size_t); -extern void _free_internal (void *); - #endif /* not DOUG_LEA_MALLOC */ -#if ! defined SYSTEM_MALLOC && ! defined SYNC_INPUT -#ifdef HAVE_PTHREAD - -# include "syssignal.h" - -/* When GTK uses the file chooser dialog, different backends can be loaded - dynamically. One such a backend is the Gnome VFS backend that gets loaded - if you run Gnome. That backend creates several threads and also allocates - memory with malloc. - - Also, gconf and gsettings may create several threads. - - If Emacs sets malloc hooks (! SYSTEM_MALLOC) and the emacs_blocked_* - functions below are called from malloc, there is a chance that one - of these threads preempts the Emacs main thread and the hook variables - end up in an inconsistent state. So we have a mutex to prevent that (note - that the backend handles concurrent access to malloc within its own threads - but Emacs code running in the main thread is not included in that control). - - When UNBLOCK_INPUT is called, reinvoke_input_signal may be called. If this - happens in one of the backend threads we will have two threads that tries - to run Emacs code at once, and the code is not prepared for that. - To prevent that, we only call BLOCK/UNBLOCK from the main thread. */ - -static pthread_mutex_t alloc_mutex; - -#define BLOCK_INPUT_ALLOC \ - do \ - { \ - if (pthread_equal (pthread_self (), main_thread)) \ - BLOCK_INPUT; \ - pthread_mutex_lock (&alloc_mutex); \ - } \ - while (0) -#define UNBLOCK_INPUT_ALLOC \ - do \ - { \ - pthread_mutex_unlock (&alloc_mutex); \ - if (pthread_equal (pthread_self (), main_thread)) \ - UNBLOCK_INPUT; \ - } \ - while (0) - -#else /* ! defined HAVE_PTHREAD */ - -#define BLOCK_INPUT_ALLOC BLOCK_INPUT -#define UNBLOCK_INPUT_ALLOC UNBLOCK_INPUT - -#endif /* ! defined HAVE_PTHREAD */ -#endif /* ! defined SYSTEM_MALLOC && ! defined SYNC_INPUT */ - /* Mark, unmark, query mark bit of a Lisp string. S must be a pointer to a struct Lisp_String. */ @@ -205,10 +145,6 @@ static char *spare_memory[7]; #define SPARE_MEMORY (1 << 14) -/* Number of extra blocks malloc should get when it needs more core. */ - -static int malloc_hysteresis; - /* Initialize it to a nonzero value to force it into data space (rather than bss space). That way unexec will remap it into text space (pure), on some systems. We have not implemented the @@ -413,12 +349,12 @@ static void mark_memory (void *, void *); static void mem_init (void); static struct mem_node *mem_insert (void *, void *, enum mem_type); static void mem_insert_fixup (struct mem_node *); -#endif static void mem_rotate_left (struct mem_node *); static void mem_rotate_right (struct mem_node *); static void mem_delete (struct mem_node *); static void mem_delete_fixup (struct mem_node *); static inline struct mem_node *mem_find (void *); +#endif #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS @@ -587,39 +523,17 @@ xmalloc_get_size (unsigned char *ptr) } -/* The call depth in overrun_check functions. For example, this might happen: - xmalloc() - overrun_check_malloc() - -> malloc -> (via hook)_-> emacs_blocked_malloc - -> overrun_check_malloc - call malloc (hooks are NULL, so real malloc is called). - malloc returns 10000. - add overhead, return 10016. - <- (back in overrun_check_malloc) - add overhead again, return 10032 - xmalloc returns 10032. - - (time passes). - - xfree(10032) - overrun_check_free(10032) - decrease overhead - free(10016) <- crash, because 10000 is the original pointer. */ - -static ptrdiff_t check_depth; - /* Like malloc, but wraps allocated block with header and trailer. */ static void * overrun_check_malloc (size_t size) { register unsigned char *val; - int overhead = ++check_depth == 1 ? XMALLOC_OVERRUN_CHECK_OVERHEAD : 0; - if (SIZE_MAX - overhead < size) + if (SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD < size) emacs_abort (); - val = malloc (size + overhead); - if (val && check_depth == 1) + val = malloc (size + XMALLOC_OVERRUN_CHECK_OVERHEAD); + if (val) { memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE); val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE; @@ -627,7 +541,6 @@ overrun_check_malloc (size_t size) memcpy (val + size, xmalloc_overrun_check_trailer, XMALLOC_OVERRUN_CHECK_SIZE); } - --check_depth; return val; } @@ -639,12 +552,10 @@ static void * overrun_check_realloc (void *block, size_t size) { register unsigned char *val = (unsigned char *) block; - int overhead = ++check_depth == 1 ? XMALLOC_OVERRUN_CHECK_OVERHEAD : 0; - if (SIZE_MAX - overhead < size) + if (SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD < size) emacs_abort (); if (val - && check_depth == 1 && memcmp (xmalloc_overrun_check_header, val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE, XMALLOC_OVERRUN_CHECK_SIZE) == 0) @@ -658,9 +569,9 @@ overrun_check_realloc (void *block, size_t size) memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE); } - val = realloc (val, size + overhead); + val = realloc (val, size + XMALLOC_OVERRUN_CHECK_OVERHEAD); - if (val && check_depth == 1) + if (val) { memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE); val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE; @@ -668,7 +579,6 @@ overrun_check_realloc (void *block, size_t size) memcpy (val + size, xmalloc_overrun_check_trailer, XMALLOC_OVERRUN_CHECK_SIZE); } - --check_depth; return val; } @@ -679,9 +589,7 @@ overrun_check_free (void *block) { unsigned char *val = (unsigned char *) block; - ++check_depth; if (val - && check_depth == 1 && memcmp (xmalloc_overrun_check_header, val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE, XMALLOC_OVERRUN_CHECK_SIZE) == 0) @@ -701,7 +609,6 @@ overrun_check_free (void *block) } free (val); - --check_depth; } #undef malloc @@ -712,14 +619,33 @@ overrun_check_free (void *block) #define free overrun_check_free #endif -#ifdef SYNC_INPUT -/* When using SYNC_INPUT, we don't call malloc from a signal handler, so - there's no need to block input around malloc. */ -#define MALLOC_BLOCK_INPUT ((void)0) -#define MALLOC_UNBLOCK_INPUT ((void)0) +/* If compiled with XMALLOC_BLOCK_INPUT_CHECK, define a symbol + BLOCK_INPUT_IN_MEMORY_ALLOCATORS that is visible to the debugger. + If that variable is set, block input while in one of Emacs's memory + allocation functions. There should be no need for this debugging + option, since signal handlers do not allocate memory, but Emacs + formerly allocated memory in signal handlers and this compile-time + option remains as a way to help debug the issue should it rear its + ugly head again. */ +#ifdef XMALLOC_BLOCK_INPUT_CHECK +bool block_input_in_memory_allocators EXTERNALLY_VISIBLE; +static void +malloc_block_input (void) +{ + if (block_input_in_memory_allocators) + BLOCK_INPUT; +} +static void +malloc_unblock_input (void) +{ + if (block_input_in_memory_allocators) + UNBLOCK_INPUT; +} +# define MALLOC_BLOCK_INPUT malloc_block_input () +# define MALLOC_UNBLOCK_INPUT malloc_unblock_input () #else -#define MALLOC_BLOCK_INPUT BLOCK_INPUT -#define MALLOC_UNBLOCK_INPUT UNBLOCK_INPUT +# define MALLOC_BLOCK_INPUT ((void) 0) +# define MALLOC_UNBLOCK_INPUT ((void) 0) #endif /* Like malloc but check for no memory and block interrupt input.. */ @@ -788,8 +714,7 @@ xfree (void *block) free (block); MALLOC_UNBLOCK_INPUT; /* We don't call refill_memory_reserve here - because that duplicates doing so in emacs_blocked_free - and the criterion should go there. */ + because in practice the call in r_alloc_free seems to suffice. */ } @@ -1216,256 +1141,6 @@ lisp_align_free (void *block) } -#ifndef SYSTEM_MALLOC - -/* Arranging to disable input signals while we're in malloc. - - This only works with GNU malloc. To help out systems which can't - use GNU malloc, all the calls to malloc, realloc, and free - elsewhere in the code should be inside a BLOCK_INPUT/UNBLOCK_INPUT - pair; unfortunately, we have no idea what C library functions - might call malloc, so we can't really protect them unless you're - using GNU malloc. Fortunately, most of the major operating systems - can use GNU malloc. */ - -#ifndef SYNC_INPUT -/* When using SYNC_INPUT, we don't call malloc from a signal handler, so - there's no need to block input around malloc. */ - -#ifndef DOUG_LEA_MALLOC -extern void * (*__malloc_hook) (size_t, const void *); -extern void * (*__realloc_hook) (void *, size_t, const void *); -extern void (*__free_hook) (void *, const void *); -/* Else declared in malloc.h, perhaps with an extra arg. */ -#endif /* DOUG_LEA_MALLOC */ -static void * (*old_malloc_hook) (size_t, const void *); -static void * (*old_realloc_hook) (void *, size_t, const void*); -static void (*old_free_hook) (void*, const void*); - -#ifdef DOUG_LEA_MALLOC -# define BYTES_USED (mallinfo ().uordblks) -#else -# define BYTES_USED _bytes_used -#endif - -#ifdef GC_MALLOC_CHECK -static bool dont_register_blocks; -#endif - -static size_t bytes_used_when_reconsidered; - -/* Value of _bytes_used, when spare_memory was freed. */ - -static size_t bytes_used_when_full; - -/* This function is used as the hook for free to call. */ - -static void -emacs_blocked_free (void *ptr, const void *ptr2) -{ - BLOCK_INPUT_ALLOC; - -#ifdef GC_MALLOC_CHECK - if (ptr) - { - struct mem_node *m; - - m = mem_find (ptr); - if (m == MEM_NIL || m->start != ptr) - { - fprintf (stderr, - "Freeing `%p' which wasn't allocated with malloc\n", ptr); - emacs_abort (); - } - else - { - /* fprintf (stderr, "free %p...%p (%p)\n", m->start, m->end, ptr); */ - mem_delete (m); - } - } -#endif /* GC_MALLOC_CHECK */ - - __free_hook = old_free_hook; - free (ptr); - - /* If we released our reserve (due to running out of memory), - and we have a fair amount free once again, - try to set aside another reserve in case we run out once more. */ - if (! NILP (Vmemory_full) - /* Verify there is enough space that even with the malloc - hysteresis this call won't run out again. - The code here is correct as long as SPARE_MEMORY - is substantially larger than the block size malloc uses. */ - && (bytes_used_when_full - > ((bytes_used_when_reconsidered = BYTES_USED) - + max (malloc_hysteresis, 4) * SPARE_MEMORY))) - refill_memory_reserve (); - - __free_hook = emacs_blocked_free; - UNBLOCK_INPUT_ALLOC; -} - - -/* This function is the malloc hook that Emacs uses. */ - -static void * -emacs_blocked_malloc (size_t size, const void *ptr) -{ - void *value; - - BLOCK_INPUT_ALLOC; - __malloc_hook = old_malloc_hook; -#ifdef DOUG_LEA_MALLOC - /* Segfaults on my system. --lorentey */ - /* mallopt (M_TOP_PAD, malloc_hysteresis * 4096); */ -#else - __malloc_extra_blocks = malloc_hysteresis; -#endif - - value = malloc (size); - -#ifdef GC_MALLOC_CHECK - { - struct mem_node *m = mem_find (value); - if (m != MEM_NIL) - { - fprintf (stderr, "Malloc returned %p which is already in use\n", - value); - fprintf (stderr, "Region in use is %p...%p, %td bytes, type %d\n", - m->start, m->end, (char *) m->end - (char *) m->start, - m->type); - emacs_abort (); - } - - if (!dont_register_blocks) - { - mem_insert (value, (char *) value + max (1, size), allocated_mem_type); - allocated_mem_type = MEM_TYPE_NON_LISP; - } - } -#endif /* GC_MALLOC_CHECK */ - - __malloc_hook = emacs_blocked_malloc; - UNBLOCK_INPUT_ALLOC; - - /* fprintf (stderr, "%p malloc\n", value); */ - return value; -} - - -/* This function is the realloc hook that Emacs uses. */ - -static void * -emacs_blocked_realloc (void *ptr, size_t size, const void *ptr2) -{ - void *value; - - BLOCK_INPUT_ALLOC; - __realloc_hook = old_realloc_hook; - -#ifdef GC_MALLOC_CHECK - if (ptr) - { - struct mem_node *m = mem_find (ptr); - if (m == MEM_NIL || m->start != ptr) - { - fprintf (stderr, - "Realloc of %p which wasn't allocated with malloc\n", - ptr); - emacs_abort (); - } - - mem_delete (m); - } - - /* fprintf (stderr, "%p -> realloc\n", ptr); */ - - /* Prevent malloc from registering blocks. */ - dont_register_blocks = 1; -#endif /* GC_MALLOC_CHECK */ - - value = realloc (ptr, size); - -#ifdef GC_MALLOC_CHECK - dont_register_blocks = 0; - - { - struct mem_node *m = mem_find (value); - if (m != MEM_NIL) - { - fprintf (stderr, "Realloc returns memory that is already in use\n"); - emacs_abort (); - } - - /* Can't handle zero size regions in the red-black tree. */ - mem_insert (value, (char *) value + max (size, 1), MEM_TYPE_NON_LISP); - } - - /* fprintf (stderr, "%p <- realloc\n", value); */ -#endif /* GC_MALLOC_CHECK */ - - __realloc_hook = emacs_blocked_realloc; - UNBLOCK_INPUT_ALLOC; - - return value; -} - - -#ifdef HAVE_PTHREAD -/* Called from Fdump_emacs so that when the dumped Emacs starts, it has a - normal malloc. Some thread implementations need this as they call - malloc before main. The pthread_self call in BLOCK_INPUT_ALLOC then - calls malloc because it is the first call, and we have an endless loop. */ - -void -reset_malloc_hooks (void) -{ - __free_hook = old_free_hook; - __malloc_hook = old_malloc_hook; - __realloc_hook = old_realloc_hook; -} -#endif /* HAVE_PTHREAD */ - - -/* Called from main to set up malloc to use our hooks. */ - -void -uninterrupt_malloc (void) -{ -#ifdef HAVE_PTHREAD -#ifdef DOUG_LEA_MALLOC - pthread_mutexattr_t attr; - - /* GLIBC has a faster way to do this, but let's keep it portable. - This is according to the Single UNIX Specification. */ - pthread_mutexattr_init (&attr); - pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE); - pthread_mutex_init (&alloc_mutex, &attr); -#else /* !DOUG_LEA_MALLOC */ - /* Some systems such as Solaris 2.6 don't have a recursive mutex, - and the bundled gmalloc.c doesn't require it. */ - pthread_mutex_init (&alloc_mutex, NULL); -#endif /* !DOUG_LEA_MALLOC */ -#endif /* HAVE_PTHREAD */ - - if (__free_hook != emacs_blocked_free) - old_free_hook = __free_hook; - __free_hook = emacs_blocked_free; - - if (__malloc_hook != emacs_blocked_malloc) - old_malloc_hook = __malloc_hook; - __malloc_hook = emacs_blocked_malloc; - - if (__realloc_hook != emacs_blocked_realloc) - old_realloc_hook = __realloc_hook; - __realloc_hook = emacs_blocked_realloc; -} - -#endif /* not SYNC_INPUT */ -#endif /* not SYSTEM_MALLOC */ - - - /*********************************************************************** Interval Allocation ***********************************************************************/ @@ -1511,8 +1186,6 @@ make_interval (void) { INTERVAL val; - /* eassert (!handling_signal); */ - MALLOC_BLOCK_INPUT; if (interval_free_list) @@ -1896,8 +1569,6 @@ allocate_string (void) { struct Lisp_String *s; - /* eassert (!handling_signal); */ - MALLOC_BLOCK_INPUT; /* If the free-list is empty, allocate a new string_block, and @@ -2589,8 +2260,6 @@ make_float (double float_value) { register Lisp_Object val; - /* eassert (!handling_signal); */ - MALLOC_BLOCK_INPUT; if (float_free_list) @@ -2698,8 +2367,6 @@ DEFUN ("cons", Fcons, Scons, 2, 2, 0, { register Lisp_Object val; - /* eassert (!handling_signal); */ - MALLOC_BLOCK_INPUT; if (cons_free_list) @@ -3205,9 +2872,6 @@ allocate_vectorlike (ptrdiff_t len) MALLOC_BLOCK_INPUT; - /* This gets triggered by code which I haven't bothered to fix. --Stef */ - /* eassert (!handling_signal); */ - if (len == 0) p = XVECTOR (zero_vector); else @@ -3492,8 +3156,6 @@ Its value and function definition are void, and its property list is nil. */) CHECK_STRING (name); - /* eassert (!handling_signal); */ - MALLOC_BLOCK_INPUT; if (symbol_free_list) @@ -3578,8 +3240,6 @@ allocate_misc (enum Lisp_Misc_Type type) { Lisp_Object val; - /* eassert (!handling_signal); */ - MALLOC_BLOCK_INPUT; if (marker_free_list) @@ -3799,12 +3459,6 @@ memory_full (size_t nbytes) lisp_free (spare_memory[i]); spare_memory[i] = 0; } - - /* Record the space now used. When it decreases substantially, - we can refill the memory reserve. */ -#if !defined SYSTEM_MALLOC && !defined SYNC_INPUT - bytes_used_when_full = BYTES_USED; -#endif } /* This used to call error, but if we've run out of memory, we could @@ -3942,7 +3596,7 @@ mem_insert (void *start, void *end, enum mem_type type) /* Create a new node. */ #ifdef GC_MALLOC_CHECK - x = _malloc_internal (sizeof *x); + x = malloc (sizeof *x); if (x == NULL) emacs_abort (); #else @@ -4166,7 +3820,7 @@ mem_delete (struct mem_node *z) mem_delete_fixup (x); #ifdef GC_MALLOC_CHECK - _free_internal (y); + free (y); #else xfree (y); #endif @@ -6767,12 +6421,6 @@ init_alloc_once (void) init_strings (); init_vectors (); -#ifdef REL_ALLOC - malloc_hysteresis = 32; -#else - malloc_hysteresis = 0; -#endif - refill_memory_reserve (); gc_cons_threshold = GC_DEFAULT_THRESHOLD; } |