diff options
| -rw-r--r-- | libthreads/malloc.c | 80 |
1 files changed, 67 insertions, 13 deletions
diff --git a/libthreads/malloc.c b/libthreads/malloc.c index fd22d23f..3a2109bd 100644 --- a/libthreads/malloc.c +++ b/libthreads/malloc.c @@ -25,7 +25,10 @@ */ /* * HISTORY - * $Log: malloc.c,v $ + * $Log: malloc.c,v $ + * Revision 1.4 1994/05/05 11:21:42 roland + * entered into RCS + * * Revision 2.7 91/05/14 17:57:34 mrt * Correcting copyright * @@ -68,9 +71,13 @@ */ +#include <assert.h> + #include <cthreads.h> #include "cthread_internals.h" +#define MCHECK + /* * C library imports: */ @@ -82,13 +89,40 @@ extern bcopy(); * When allocated, fl points to free list. * Size of header is 4 bytes, so minimum usable block size is 8 bytes. */ + +#define CHECK_BUSY 0x8a3c743e +#define CHECK_FREE 0x66688b92 + +#ifdef MCHECK + +typedef struct header { + long check; + union { + struct header *next; + struct free_list *fl; + } u; +} *header_t; + +#define HEADER_SIZE sizeof (struct header) +#define HEADER_NEXT(h) ((h)->u.next) +#define HEADER_FREE(h) ((h)->u.fl) +#define HEADER_CHECK(h) ((h)->check) +#define MIN_SIZE 16 + +#else /* ! MCHECK */ + typedef union header { union header *next; struct free_list *fl; } *header_t; +#define HEADER_SIZE sizeof (union header) +#define HEADER_NEXT(h) ((h)->next) +#define HEADER_FREE(h) ((h)->fl) #define MIN_SIZE 8 /* minimum block size */ +#endif /* MCHECK */ + typedef struct free_list { spin_lock_t lock; /* spin lock for mutual exclusion */ header_t head; /* head of free list for this size */ @@ -131,7 +165,10 @@ more_memory(size, fl) MACH_CALL(vm_allocate(mach_task_self(), &where, (vm_size_t) amount, TRUE), r); h = (header_t) where; do { - h->next = fl->head; + HEADER_NEXT (h) = fl->head; +#ifdef MCHECK + HEADER_CHECK (h) = CHECK_FREE; +#endif fl->head = h; h = (header_t) ((char *) h + size); } while (--n != 0); @@ -148,7 +185,7 @@ malloc(size) if ((int) size < 0) /* sanity check */ return 0; - size += sizeof(union header); + size += HEADER_SIZE; /* * Find smallest power-of-two block size * big enough to hold requested size plus header. @@ -181,7 +218,13 @@ malloc(size) /* * Pop block from free list. */ - fl->head = h->next; + fl->head = HEADER_NEXT (h); + +#ifdef MCHECK + assert (HEADER_CHECK (h) == CHECK_FREE); + HEADER_CHECK (h) = CHECK_BUSY; +#endif + #ifdef DEBUG fl->in_use += 1; #endif DEBUG @@ -191,11 +234,11 @@ malloc(size) * so we can figure out where it goes * at free() time. */ - h->fl = fl; + HEADER_FREE (h) = fl; /* * Return pointer past the block header. */ - return ((char *) h) + sizeof(union header); + return ((char *) h) + HEADER_SIZE; } /* Declaration changed to standard one for GNU. */ @@ -212,8 +255,13 @@ free(base) /* * Find free list for block. */ - h = (header_t) (base - sizeof(union header)); - fl = h->fl; + h = (header_t) (base - HEADER_SIZE); + +#ifdef MCHECK + assert (HEADER_CHECK (h) == CHECK_BUSY); +#endif + + fl = HEADER_FREE (h); i = fl - malloc_free_list; /* * Sanity checks. @@ -230,7 +278,10 @@ free(base) * Push block on free list. */ spin_lock(&fl->lock); - h->next = fl->head; + HEADER_NEXT (h) = fl->head; +#ifdef MCHECK + HEADER_CHECK (h) = CHECK_FREE; +#endif fl->head = h; #ifdef DEBUG fl->in_use -= 1; @@ -257,8 +308,11 @@ realloc(old_base, new_size) /* * Find size of old block. */ - h = (header_t) (old_base - sizeof(union header)); - fl = h->fl; + h = (header_t) (old_base - HEADER_SIZE); +#ifdef MCHECK + assert (HEADER_CHECK (h) == CHECK_BUSY); +#endif + fl = HEADER_FREE (h); i = fl - malloc_free_list; /* * Sanity checks. @@ -274,7 +328,7 @@ realloc(old_base, new_size) /* * Free list with index i contains blocks of size 2^(i+3) including header. */ - old_size = (1 << (i+3)) - sizeof(union header); + old_size = (1 << (i+3)) - HEADER_SIZE; /* * Allocate new block, copy old bytes, and free old block. */ @@ -303,7 +357,7 @@ print_malloc_free_list() spin_lock(&fl->lock); if (fl->in_use != 0 || fl->head != 0) { total_used += fl->in_use * size; - for (n = 0, h = fl->head; h != 0; h = h->next, n += 1) + for (n = 0, h = fl->head; h != 0; h = HEADER_NEXT (h), n += 1) ; total_free += n * size; fprintf(stderr, "%10d %10d %10d %10d\n", |