Lisp_Object Qinsert_in_front_hooks;
Lisp_Object Qinsert_behind_hooks;
+static void alloc_buffer_text P_ ((struct buffer *, size_t));
+static void free_buffer_text P_ ((struct buffer *b));
+
+
/* For debugging; temporary. See set_buffer_internal. */
/* Lisp_Object Qlisp_mode, Vcheck_symbol; */
BLOCK_INPUT;
/* We allocate extra 1-byte at the tail and keep it always '\0' for
anchoring a search. */
- BUFFER_ALLOC (BUF_BEG_ADDR (b), (BUF_GAP_SIZE (b) + 1));
+ alloc_buffer_text (b, BUF_GAP_SIZE (b) + 1);
UNBLOCK_INPUT;
if (! BUF_BEG_ADDR (b))
buffer_memory_full ();
BLOCK_INPUT;
if (! b->base_buffer)
- BUFFER_FREE (BUF_BEG_ADDR (b));
+ free_buffer_text (b);
if (b->newline_cache)
{
register Lisp_Object tail, valcontents;
Lisp_Object tem;
-#ifdef REL_ALLOC_MMAP
+#ifdef USE_MMAP_FOR_BUFFERS
if (b->text->beg == NULL)
- {
- BLOCK_INPUT;
- BUFFER_REALLOC (BUF_BEG_ADDR (b),
- (BUF_Z_BYTE (b) - BUF_BEG_BYTE (b)
- + BUF_GAP_SIZE (b) + 1));
- UNBLOCK_INPUT;
- }
-#endif /* REL_ALLOC_MMAP */
+ enlarge_buffer_text (b, 0);
+#endif /* USE_MMAP_FOR_BUFFERS */
if (current_buffer == b)
return;
}
\f
+/***********************************************************************
+ Allocation with mmap
+ ***********************************************************************/
+
+#ifdef USE_MMAP_FOR_BUFFERS
+
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#ifndef MAP_ANON
+#ifdef MAP_ANONYMOUS
+#define MAP_ANON MAP_ANONYMOUS
+#else
+#define MAP_ANON 0
+#endif
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+
+#if MAP_ANON == 0
+#include <fcntl.h>
+#endif
+
+#include "coding.h"
+
+
+/* Memory is allocated in regions which are mapped using mmap(2).
+ The current implementation lets the system select mapped
+ addresses; we're not using MAP_FIXED in general, except when
+ trying to enlarge regions.
+
+ Each mapped region starts with a mmap_region structure, the user
+ area starts after that structure, aligned to MEM_ALIGN.
+
+ +-----------------------+
+ | struct mmap_info + |
+ | padding |
+ +-----------------------+
+ | user data |
+ | |
+ | |
+ +-----------------------+ */
+
+struct mmap_region
+{
+ /* User-specified size. */
+ size_t nbytes_specified;
+
+ /* Number of bytes mapped */
+ size_t nbytes_mapped;
+
+ /* Pointer to the location holding the address of the memory
+ allocated with the mmap'd block. The variable actually points
+ after this structure. */
+ POINTER_TYPE **var;
+
+ /* Next and previous in list of all mmap'd regions. */
+ struct mmap_region *next, *prev;
+};
+
+/* Doubly-linked list of mmap'd regions. */
+
+static struct mmap_region *mmap_regions;
+
+/* File descriptor for mmap. If we don't have anonymous mapping,
+ /dev/zero will be opened on it. */
+
+static int mmap_fd;
+
+/* Temporary storage for mmap_set_vars, see there. */
+
+static struct mmap_region *mmap_regions_1;
+static int mmap_fd_1;
+
+/* Page size on this system. */
+
+static int mmap_page_size;
+
+/* 1 means mmap has been intialized. */
+
+static int mmap_initialized_p;
+
+/* Value is X rounded up to the next multiple of N. */
+
+#define ROUND(X, N) (((X) + (N) - 1) / (N) * (N))
+
+/* Size of mmap_region structure plus padding. */
+
+#define MMAP_REGION_STRUCT_SIZE \
+ ROUND (sizeof (struct mmap_region), MEM_ALIGN)
+
+/* Given a pointer P to the start of the user-visible part of a mapped
+ region, return a pointer to the start of the region. */
+
+#define MMAP_REGION(P) \
+ ((struct mmap_region *) ((char *) (P) - MMAP_REGION_STRUCT_SIZE))
+
+/* Given a pointer P to the start of a mapped region, return a pointer
+ to the start of the user-visible part of the region. */
+
+#define MMAP_USER_AREA(P) \
+ ((POINTER_TYPE *) ((char *) (P) + MMAP_REGION_STRUCT_SIZE))
+
+#define MEM_ALIGN sizeof (double)
+
+/* Function prototypes. */
+
+static int mmap_free_1 P_ ((struct mmap_region *));
+static int mmap_enlarge P_ ((struct mmap_region *, int));
+static struct mmap_region *mmap_find P_ ((POINTER_TYPE *, POINTER_TYPE *));
+static POINTER_TYPE *mmap_alloc P_ ((POINTER_TYPE **, size_t));
+static POINTER_TYPE *mmap_realloc P_ ((POINTER_TYPE **, size_t));
+static void mmap_free P_ ((POINTER_TYPE **ptr));
+static void mmap_init P_ ((void));
+
+
+/* Return a region overlapping address range START...END, or null if
+ none. END is not including, i.e. the last byte in the range
+ is at END - 1. */
+
+static struct mmap_region *
+mmap_find (start, end)
+ POINTER_TYPE *start, *end;
+{
+ struct mmap_region *r;
+ char *s = (char *) start, *e = (char *) end;
+
+ for (r = mmap_regions; r; r = r->next)
+ {
+ char *rstart = (char *) r;
+ char *rend = rstart + r->nbytes_mapped;
+
+ if (/* First byte of range, i.e. START, in this region? */
+ (s >= rstart && s < rend)
+ /* Last byte of range, i.e. END - 1, in this region? */
+ || (e > rstart && e <= rend)
+ /* First byte of this region in the range? */
+ || (rstart >= s && rstart < e)
+ /* Last byte of this region in the range? */
+ || (rend > s && rend <= e))
+ break;
+ }
+
+ return r;
+}
+
+
+/* Unmap a region. P is a pointer to the start of the user-araa of
+ the region. Value is non-zero if successful. */
+
+static int
+mmap_free_1 (r)
+ struct mmap_region *r;
+{
+ if (r->next)
+ r->next->prev = r->prev;
+ if (r->prev)
+ r->prev->next = r->next;
+ else
+ mmap_regions = r->next;
+
+ if (munmap (r, r->nbytes_mapped) == -1)
+ {
+ fprintf (stderr, "munmap: %s\n", emacs_strerror (errno));
+ return 0;
+ }
+
+ return 1;
+}
+
+
+/* Enlarge region R by NPAGES pages. NPAGES < 0 means shrink R.
+ Value is non-zero if successful. */
+
+static int
+mmap_enlarge (r, npages)
+ struct mmap_region *r;
+ int npages;
+{
+ char *region_end = (char *) r + r->nbytes_mapped;
+ size_t nbytes;
+ int success = 0;
+
+ if (npages < 0)
+ {
+ /* Unmap pages at the end of the region. */
+ nbytes = - npages * mmap_page_size;
+ if (munmap (region_end - nbytes, nbytes) == -1)
+ fprintf (stderr, "munmap: %s\n", emacs_strerror (errno));
+ else
+ {
+ r->nbytes_mapped -= nbytes;
+ success = 1;
+ }
+ }
+ else if (npages > 0)
+ {
+ struct mmap_region *r2;
+
+ nbytes = npages * mmap_page_size;
+
+ /* Try to map additional pages at the end of the region. We
+ cannot do this if the address range is already occupied by
+ something else because mmap deletes any previous mapping.
+ I'm not sure this is worth doing, let's see. */
+ r2 = mmap_find (region_end, region_end + nbytes);
+ if (r2 == NULL)
+ {
+ POINTER_TYPE *p;
+
+ p = mmap (region_end, nbytes, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, mmap_fd, 0);
+ if (p == MAP_FAILED)
+ fprintf (stderr, "mmap: %s\n", emacs_strerror (errno));
+ else if (p != (POINTER_TYPE *) region_end)
+ {
+ /* Kernels are free to choose a different address. In
+ that case, unmap what we've mapped above; we have
+ no use for it. */
+ if (munmap (p, nbytes) == -1)
+ fprintf (stderr, "munmap: %s\n", emacs_strerror (errno));
+ }
+ else
+ {
+ r->nbytes_mapped += nbytes;
+ success = 1;
+ }
+ }
+ }
+
+ return success;
+}
+
+
+/* Set or reset variables holding references to mapped regions. If
+ RESTORE_P is zero, set all variables to null. If RESTORE_P is
+ non-zero, set all variables to the start of the user-areas
+ of mapped regions.
+
+ This function is called from Fdump_emacs to ensure that the dumped
+ Emacs doesn't contain references to memory that won't be mapped
+ when Emacs starts. */
+
+void
+mmap_set_vars (restore_p)
+ int restore_p;
+{
+ struct mmap_region *r;
+
+ if (restore_p)
+ {
+ mmap_regions = mmap_regions_1;
+ mmap_fd = mmap_fd_1;
+ for (r = mmap_regions; r; r = r->next)
+ *r->var = MMAP_USER_AREA (r);
+ }
+ else
+ {
+ for (r = mmap_regions; r; r = r->next)
+ *r->var = NULL;
+ mmap_regions_1 = mmap_regions;
+ mmap_regions = NULL;
+ mmap_fd_1 = mmap_fd;
+ mmap_fd = -1;
+ }
+}
+
+
+/* Allocate a block of storage large enough to hold NBYTES bytes of
+ data. A pointer to the data is returned in *VAR. VAR is thus the
+ address of some variable which will use the data area.
+
+ The allocation of 0 bytes is valid.
+
+ If we can't allocate the necessary memory, set *VAR to null, and
+ return null. */
+
+static POINTER_TYPE *
+mmap_alloc (var, nbytes)
+ POINTER_TYPE **var;
+ size_t nbytes;
+{
+ void *p;
+ size_t map;
+
+ mmap_init ();
+
+ map = ROUND (nbytes + MMAP_REGION_STRUCT_SIZE, mmap_page_size);
+ p = mmap (NULL, map, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE,
+ mmap_fd, 0);
+
+ if (p == MAP_FAILED)
+ {
+ if (errno != ENOMEM)
+ fprintf (stderr, "mmap: %s\n", emacs_strerror (errno));
+ p = NULL;
+ }
+ else
+ {
+ struct mmap_region *r = (struct mmap_region *) p;
+
+ r->nbytes_specified = nbytes;
+ r->nbytes_mapped = map;
+ r->var = var;
+ r->prev = NULL;
+ r->next = mmap_regions;
+ if (r->next)
+ r->next->prev = r;
+ mmap_regions = r;
+
+ p = MMAP_USER_AREA (p);
+ }
+
+ return *var = p;
+}
+
+
+/* Given a pointer at address VAR to data allocated with mmap_alloc,
+ resize it to size NBYTES. Change *VAR to reflect the new block,
+ and return this value. If more memory cannot be allocated, then
+ leave *VAR unchanged, and return null. */
+
+static POINTER_TYPE *
+mmap_realloc (var, nbytes)
+ POINTER_TYPE **var;
+ size_t nbytes;
+{
+ POINTER_TYPE *result;
+
+ mmap_init ();
+
+ if (*var == NULL)
+ result = mmap_alloc (var, nbytes);
+ else if (nbytes == 0)
+ {
+ mmap_free (var);
+ result = mmap_alloc (var, nbytes);
+ }
+ else
+ {
+ struct mmap_region *r = MMAP_REGION (*var);
+ size_t room = r->nbytes_mapped - MMAP_REGION_STRUCT_SIZE;
+
+ if (room < nbytes)
+ {
+ /* Must enlarge. */
+ POINTER_TYPE *old_ptr = *var;
+
+ /* Try to map additional pages at the end of the region.
+ If that fails, allocate a new region, copy data
+ from the old region, then free it. */
+ if (mmap_enlarge (r, (ROUND (nbytes - room, mmap_page_size)
+ / mmap_page_size)))
+ {
+ r->nbytes_specified = nbytes;
+ *var = result = old_ptr;
+ }
+ else if (mmap_alloc (var, nbytes))
+ {
+ bcopy (old_ptr, *var, r->nbytes_specified);
+ mmap_free_1 (MMAP_REGION (old_ptr));
+ result = *var;
+ r = MMAP_REGION (result);
+ r->nbytes_specified = nbytes;
+ }
+ else
+ {
+ *var = old_ptr;
+ result = NULL;
+ }
+ }
+ else if (room - nbytes >= mmap_page_size)
+ {
+ /* Shrinking by at least a page. Let's give some
+ memory back to the system. */
+ mmap_enlarge (r, - (room - nbytes) / mmap_page_size);
+ result = *var;
+ r->nbytes_specified = nbytes;
+ }
+ else
+ {
+ /* Leave it alone. */
+ result = *var;
+ r->nbytes_specified = nbytes;
+ }
+ }
+
+ return result;
+}
+
+
+/* Free a block of relocatable storage whose data is pointed to by
+ PTR. Store 0 in *PTR to show there's no block allocated. */
+
+static void
+mmap_free (var)
+ POINTER_TYPE **var;
+{
+ mmap_init ();
+
+ if (*var)
+ {
+ mmap_free_1 (MMAP_REGION (*var));
+ *var = NULL;
+ }
+}
+
+
+/* Perform necessary intializations for the use of mmap. */
+
+static void
+mmap_init ()
+{
+#if MAP_ANON == 0
+ /* The value of mmap_fd is initially 0 in temacs, and -1
+ in a dumped Emacs. */
+ if (mmap_fd <= 0)
+ {
+ /* No anonymous mmap -- we need the file descriptor. */
+ mmap_fd = open ("/dev/zero", O_RDONLY);
+ if (mmap_fd == -1)
+ fatal ("Cannot open /dev/zero: %s", emacs_strerror (errno));
+ }
+#endif /* MAP_ANON == 0 */
+
+ if (mmap_initialized_p)
+ return;
+ mmap_initialized_p = 1;
+
+#if MAP_ANON != 0
+ mmap_fd = -1;
+#endif
+
+ mmap_page_size = getpagesize ();
+}
+
+#endif /* USE_MMAP_FOR_BUFFERS */
+
+
+\f
+/***********************************************************************
+ Buffer-text Allocation
+ ***********************************************************************/
+
+#ifdef REL_ALLOC
+extern POINTER_TYPE *r_alloc P_ ((POINTER_TYPE **, size_t));
+extern POINTER_TYPE *r_re_alloc P_ ((POINTER_TYPE **, size_t));
+extern void r_alloc_free P_ ((POINTER_TYPE **ptr));
+#endif /* REL_ALLOC */
+
+
+/* Allocate NBYTES bytes for buffer B's text buffer. */
+
+static void
+alloc_buffer_text (b, nbytes)
+ struct buffer *b;
+ size_t nbytes;
+{
+ POINTER_TYPE *p;
+
+ BLOCK_INPUT;
+#if defined USE_MMAP_FOR_BUFFERS
+ p = mmap_alloc ((POINTER_TYPE **) &b->text->beg, nbytes);
+#elif defined REL_ALLOC
+ p = r_alloc ((POINTER_TYPE **) &b->text->beg, nbytes);
+#else
+ p = xmalloc (b->text->beg, nbytes);
+#endif
+
+ if (p == NULL)
+ {
+ UNBLOCK_INPUT;
+ memory_full ();
+ }
+
+ b->text->beg = (unsigned char *) p;
+ UNBLOCK_INPUT;
+}
+
+/* Enlarge buffer B's text buffer by DELTA bytes. DELTA < 0 means
+ shrink it. */
+
+void
+enlarge_buffer_text (b, delta)
+ struct buffer *b;
+ int delta;
+{
+ POINTER_TYPE *p;
+ size_t nbytes = (BUF_Z_BYTE (b) - BUF_BEG_BYTE (b) + BUF_GAP_SIZE (b) + 1
+ + delta);
+ BLOCK_INPUT;
+#if defined USE_MMAP_FOR_BUFFERS
+ p = mmap_realloc ((POINTER_TYPE **) &b->text->beg, nbytes);
+#elif defined REL_ALLOC
+ p = r_re_alloc ((POINTER_TYPE **) &b->text->beg, nbytes);
+#else
+ p = xrealloc (b->text->beg, nbytes);
+#endif
+
+ if (p == NULL)
+ {
+ UNBLOCK_INPUT;
+ memory_full ();
+ }
+
+ BUF_BEG_ADDR (b) = (unsigned char *) p;
+ UNBLOCK_INPUT;
+}
+
+
+/* Free buffer B's text buffer. */
+
+static void
+free_buffer_text (b)
+ struct buffer *b;
+{
+ BLOCK_INPUT;
+
+#if defined USE_MMAP_FOR_BUFFERS
+ mmap_free ((POINTER_TYPE **) &b->text->beg);
+#elif defined REL_ALLOC
+ r_alloc_free ((POINTER_TYPE **) &b->text->beg);
+#else
+ xfree (b->text->beg);
+#endif
+
+ BUF_BEG_ADDR (b) = NULL;
+ UNBLOCK_INPUT;
+}
+
+
+\f
+/***********************************************************************
+ Initialization
+ ***********************************************************************/
+
void
init_buffer_once ()
{
Lisp_Object temp;
int rc;
-#ifdef REL_ALLOC_MMAP
+#ifdef USE_MMAP_FOR_BUFFERS
{
/* When using the ralloc implementation based on mmap(2), buffer
text pointers will have been set to null in the dumped Emacs.
Map new memory. */
struct buffer *b;
- BLOCK_INPUT;
for (b = all_buffers; b; b = b->next)
if (b->text->beg == NULL)
- BUFFER_REALLOC (BUF_BEG_ADDR (b),
- (BUF_Z_BYTE (b) - BUF_BEG_BYTE (b)
- + BUF_GAP_SIZE (b) + 1));
- UNBLOCK_INPUT;
+ enlarge_buffer_text (b, 0);
}
-#endif /* REL_ALLOC_MMAP */
+#endif /* USE_MMAP_FOR_BUFFERS */
Fset_buffer (Fget_buffer_create (build_string ("*scratch*")));
if (NILP (buffer_defaults.enable_multibyte_characters))
projects / emacs.git / commitdiff