#include "portable.h"
#include "xbt/xbt_os_thread.h"
#include "xbt/mmalloc.h"
+#include "xbt/ex.h"
+#include <semaphore.h>
#ifdef HAVE_LIMITS_H
# include <limits.h>
# endif
#endif
-#ifndef MIN
-# define MIN(A, B) ((A) < (B) ? (A) : (B))
-#endif
-
#define MMALLOC_MAGIC "mmalloc" /* Mapped file magic number */
#define MMALLOC_MAGIC_SIZE 8 /* Size of magic number buf */
-#define MMALLOC_VERSION 1 /* Current mmalloc version */
-#define MMALLOC_KEYS 16 /* Keys for application use */
+#define MMALLOC_VERSION 2 /* Current mmalloc version */
/* The allocator divides the heap into blocks of fixed size; large
requests receive one or more whole blocks, and small requests
receive a fragment of a block. Fragment sizes are powers of two,
and all fragments of a block are the same size. When all the
- fragments in a block have been freed, the block itself is freed. */
+ fragments in a block have been freed, the block itself is freed.
+
+ FIXME: we are not targeting 16bits machines anymore; update values */
#define INT_BIT (CHAR_BIT * sizeof(int))
#define BLOCKLOG (INT_BIT > 16 ? 12 : 9)
#define BLOCKSIZE ((unsigned int) 1 << BLOCKLOG)
#define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE)
+/* We keep fragment-specific meta-data for introspection purposes, and these
+ * information are kept in fixed lenght arrays. Here is the computation of
+ * that size.
+ *
+ * Never make SMALLEST_POSSIBLE_MALLOC smaller than sizeof(list) because we
+ * need to enlist the free fragments.
+ */
+
+#define SMALLEST_POSSIBLE_MALLOC (sizeof(struct list))
+#define MAX_FRAGMENT_PER_BLOCK (BLOCKSIZE / SMALLEST_POSSIBLE_MALLOC)
+
/* The difference between two pointers is a signed int. On machines where
the data addresses have the high bit set, we need to ensure that the
difference becomes an unsigned int when we are using the address as an
#define HEAP (INT_BIT > 16 ? 4194304 : 65536)
/* Number of contiguous free blocks allowed to build up at the end of
- memory before they will be returned to the system. */
-
+ memory before they will be returned to the system.
+ FIXME: this is not used anymore: we never return memory to the system. */
#define FINAL_FREE_BLOCKS 8
/* Where to start searching the free list when looking for new memory.
#define ADDRESS(B) ((void*) (((ADDR2UINT(B)) - 1) * BLOCKSIZE + (char*) mdp -> heapbase))
-const char *xbt_thread_self_name(void);
-
-/* Data structure giving per-block information. */
-typedef union {
- /* Heap information for a busy block. */
- struct {
- /* Zero for a large block, or positive giving the
- logarithm to the base two of the fragment size. */
- int type;
- union {
- struct {
- size_t nfree; /* Free fragments in a fragmented block. */
- size_t first; /* First free fragment of the block. */
- } frag;
- /* Size (in blocks) of a large cluster. */
- size_t size;
- } info;
- } busy;
- /* Heap information for a free block (that may be the first of
- a free cluster). */
- struct {
- size_t size; /* Size (in blocks) of a free cluster. */
- size_t next; /* Index of next free cluster. */
- size_t prev; /* Index of previous free cluster. */
- } free;
-} malloc_info;
-
-/* List of blocks allocated with `mmemalign' (or `mvalloc'). */
-
-struct alignlist {
- struct alignlist *next;
- void *aligned; /* The address that mmemaligned returned. */
- void *exact; /* The address that malloc returned. */
-};
-
/* Doubly linked lists of free fragments. */
-
struct list {
- struct list *next;
- struct list *prev;
+ struct list *next;
+ struct list *prev;
};
-/* Statistics available to the user.
- FIXME: By design, the internals of the malloc package are no longer
- exported to the user via an include file, so access to this data needs
- to be via some other mechanism, such as mmstat_<something> where the
- return value is the <something> the user is interested in. */
-
-struct mstats {
- size_t bytes_total; /* Total size of the heap. */
- size_t chunks_used; /* Chunks allocated by the user. */
- size_t bytes_used; /* Byte total of user-allocated chunks. */
- size_t chunks_free; /* Chunks in the free list. */
- size_t bytes_free; /* Byte total of chunks in the free list. */
-};
+/* Data structure giving per-block information.
+ *
+ * There is one such structure in the mdp->heapinfo array per block used in that heap,
+ * the array index is the block number.
+ *
+ * There is several types of blocks in memory:
+ * - full busy blocks: used when we are asked to malloc a block which size is > BLOCKSIZE/2
+ * In this situation, the full block is given to the malloc.
+ *
+ * - fragmented busy blocks: when asked for smaller amount of memory.
+ * Fragment sizes are only power of 2. When looking for such a free fragment,
+ * we get one from mdp->fraghead (that contains a linked list of blocks fragmented at that
+ * size and containing a free fragment), or we get a fresh block that we fragment.
+ *
+ * - free blocks are grouped by clusters, that are chained together.
+ * When looking for free blocks, we traverse the mdp->heapinfo looking
+ * for a cluster of free blocks that would be large enough.
+ *
+ * The size of the cluster is only to be trusted in the first block of the cluster, not in the middle blocks.
+ *
+ * The type field is consistently updated for every blocks, even within clusters of blocks.
+ * You can crawl the array and rely on that value.
+ *
+ * TODO:
+ * - make room to store the backtrace of where the blocks and fragment were malloced, too.
+ */
+typedef struct {
+ int type; /* 0: busy large block
+ >0: busy fragmented (fragments of size 2^type bytes)
+ <0: free block */
+ union {
+ /* Heap information for a busy block. */
+ struct {
+ size_t nfree; /* Free fragments in a fragmented block. */
+ size_t first; /* First free fragment of the block. */
+ unsigned short frag_size[MAX_FRAGMENT_PER_BLOCK];
+ //void *bt[XBT_BACKTRACE_SIZE][MAX_FRAGMENT_PER_BLOCK]; /* Where it was malloced (or realloced lastly) */
+ } busy_frag;
+ struct {
+ size_t size; /* Size (in blocks) of a large cluster. */
+ size_t busy_size; /* Actually used space, in bytes */
+ void *bt[XBT_BACKTRACE_SIZE]; /* Where it was malloced (or realloced lastly) */
+ int bt_size;
+ } busy_block;
+ /* Heap information for a free block (that may be the first of a free cluster). */
+ struct {
+ size_t size; /* Size (in blocks) of a free cluster. */
+ size_t next; /* Index of next free cluster. */
+ size_t prev; /* Index of previous free cluster. */
+ } free_block;
+ };
+} malloc_info;
/* Internal structure that defines the format of the malloc-descriptor.
This gets written to the base address of the region that mmalloc is
if such a file exists. */
struct mdesc {
- xbt_os_mutex_t mutex;
- /* The "magic number" for an mmalloc file. */
- char magic[MMALLOC_MAGIC_SIZE];
-
- /* The size in bytes of this structure, used as a sanity check when reusing
- a previously created mapped file. */
- unsigned int headersize;
-
- /* The version number of the mmalloc package that created this file. */
- unsigned char version;
-
- /* Some flag bits to keep track of various internal things. */
- unsigned int flags;
-
- /* If a system call made by the mmalloc package fails, the errno is
- preserved for future examination. */
- int saved_errno;
-
- /* Pointer to the function that is used to get more core, or return core
- to the system, for requests using this malloc descriptor. For memory
- mapped regions, this is the mmap() based routine. There may also be
- a single malloc descriptor that points to an sbrk() based routine
- for systems without mmap() or for applications that call the mmalloc()
- package with a NULL malloc descriptor.
- FIXME: For mapped regions shared by more than one process, this
- needs to be maintained on a per-process basis. */
- void *(*morecore) (struct mdesc * mdp, int size);
+ /* Semaphore locking the access to the heap */
+ sem_t sem;
+ char locked;
- /* Pointer to the function that causes an abort when the memory checking
- features are activated. By default this is set to abort(), but can
- be set to another function by the application using mmalloc().
+ /* Number of processes that attached the heap */
+ unsigned int refcount;
- FIXME: For mapped regions shared by more than one process, this
- needs to be maintained on a per-process basis. */
- void (*abortfunc) (void);
+ /* Chained lists of mdescs */
+ struct mdesc *next_mdesc;
- /* Debugging hook for free.
+ /* The "magic number" for an mmalloc file. */
+ char magic[MMALLOC_MAGIC_SIZE];
- FIXME: For mapped regions shared by more than one process, this
- needs to be maintained on a per-process basis. */
- void (*mfree_hook) (void *mdp, void *ptr);
-
- /* Debugging hook for `malloc'.
-
- FIXME: For mapped regions shared by more than one process, this
- needs to be maintained on a per-process basis. */
- void *(*mmalloc_hook) (void *mdp, size_t size);
-
- /* Debugging hook for realloc.
-
- FIXME: For mapped regions shared by more than one process, this
- needs to be maintained on a per-process basis. */
- void *(*mrealloc_hook) (void *mdp, void *ptr, size_t size);
-
- /* Number of info entries. */
- size_t heapsize;
-
- /* Pointer to first block of the heap (base of the first block). */
- void *heapbase;
-
- /* Current search index for the heap table. */
- /* Search index in the info table. */
- size_t heapindex;
-
- /* Limit of valid info table indices. */
- size_t heaplimit;
+ /* The size in bytes of this structure, used as a sanity check when reusing
+ a previously created mapped file. */
+ unsigned int headersize;
- /* Block information table.
- Allocated with malign/__mmalloc_free (not mmalloc/mfree). */
- /* Table indexed by block number giving per-block information. */
+ /* The version number of the mmalloc package that created this file. */
+ unsigned char version;
- malloc_info *heapinfo;
+ /* Some flag bits to keep track of various internal things. */
+ unsigned int flags;
- /* Instrumentation. */
+ /* Number of info entries. */
+ size_t heapsize;
- struct mstats heapstats;
+ /* Pointer to first block of the heap (base of the first block). */
+ void *heapbase;
- /* Free list headers for each fragment size. */
- /* Free lists for each fragment size. */
+ /* Current search index for the heap table. */
+ /* Search index in the info table. */
+ size_t heapindex;
- struct list fraghead[BLOCKLOG];
+ /* Limit of valid info table indices. */
+ size_t heaplimit;
- /* List of blocks allocated by memalign. */
+ /* Block information table.
+ Allocated with malign/mfree (not mmalloc/mfree). */
+ /* Table indexed by block number giving per-block information. */
+ malloc_info *heapinfo;
- struct alignlist *aligned_blocks;
+ /* List of all blocks containing free fragments of this size. The array indice is the log2 of requested size */
+ struct list fraghead[BLOCKLOG];
- /* The base address of the memory region for this malloc heap. This
+ /* The base address of the memory region for this malloc heap. This
is the location where the bookkeeping data for mmap and for malloc
begins. */
- void *base;
+ void *base;
- /* The current location in the memory region for this malloc heap which
+ /* The current location in the memory region for this malloc heap which
represents the end of memory in use. */
- void *breakval;
+ void *breakval;
- /* The end of the current memory region for this malloc heap. This is
+ /* The end of the current memory region for this malloc heap. This is
the first location past the end of mapped memory. */
- void *top;
+ void *top;
- /* Open file descriptor for the file to which this malloc heap is mapped.
+ /* Open file descriptor for the file to which this malloc heap is mapped.
This will always be a valid file descriptor, since /dev/zero is used
by default if no open file is supplied by the client. Also note that
it may change each time the region is mapped and unmapped. */
- int fd;
+ int fd;
- /* An array of keys to data within the mapped region, for use by the
- application. */
+};
- void *keys[MMALLOC_KEYS];
+int mmalloc_compare_mdesc(struct mdesc *mdp1, struct mdesc *mdp2);
-};
+void mmalloc_display_info(void *h);
/* Bits to look at in the malloc descriptor flags word */
#define MMALLOC_DEVZERO (1 << 0) /* Have mapped to /dev/zero */
#define MMALLOC_ANONYMOUS (1 << 1) /* Use anonymous mapping */
#define MMALLOC_INITIALIZED (1 << 2) /* Initialized mmalloc */
-#define MMALLOC_MMCHECK_USED (1 << 3) /* mmcheckf() called already */
-
-/* Internal version of `mfree' used in `morecore'. */
-
-extern void __mmalloc_free(struct mdesc *mdp, void *ptr);
/* A default malloc descriptor for the single sbrk() managed region. */
extern struct mdesc *__mmalloc_default_mdp;
-/* Initialize the first use of the default malloc descriptor, which uses
- an sbrk() region. */
-
-extern struct mdesc *__mmalloc_create_default_mdp(void);
-
-/* Grow or shrink a contiguous mapped region using mmap().
- Works much like sbrk(), only faster */
-
-extern void *__mmalloc_mmap_morecore(struct mdesc *mdp, int size);
-
-
/* Remap a mmalloc region that was previously mapped. */
-extern void *__mmalloc_remap_core(struct mdesc *mdp);
-
-/* Macro to convert from a user supplied malloc descriptor to pointer to the
- internal malloc descriptor. If the user supplied descriptor is NULL, then
- use the default internal version, initializing it if necessary. Otherwise
- just cast the user supplied version (which is void *) to the proper type
- (struct mdesc *). */
-
-#define MD_TO_MDP(md) \
- ((md) == NULL \
- ? __mmalloc_default_mdp \
- : (struct mdesc *) (md))
-
-/* Thread-safety (if the mutex is already created)*/
-#define LOCK(md) \
- do { \
- struct mdesc *lock_local_mdp = MD_TO_MDP(md); \
- if (lock_local_mdp->mutex) \
- xbt_os_mutex_acquire(lock_local_mdp->mutex); \
- } while (0)
-
-#define UNLOCK(md) \
- do { \
- struct mdesc *unlock_local_mdp = MD_TO_MDP(md); \
- if (unlock_local_mdp->mutex) \
- xbt_os_mutex_release(unlock_local_mdp->mutex); \
+extern void *__mmalloc_remap_core(xbt_mheap_t mdp);
+
+/* Get core for the memory region specified by MDP, using SIZE as the
+ amount to either add to or subtract from the existing region. Works
+ like sbrk(), but using mmap(). */
+extern void *mmorecore(struct mdesc *mdp, int size);
+
+/* Thread-safety (if the sem is already created)
+ *
+ * This is mandatory in the case where the user runs a parallel simulation
+ * in a model-checking enabled tree. Without this protection, our malloc
+ * implementation will not like multi-threading AT ALL.
+ */
+#define LOCK(mdp) do { \
+ if (0 && mdp->locked) { \
+ fprintf(stderr,"panic! deadlock detected because %s is not reintrant.\n",__FUNCTION__); \
+ abort(); \
+ } \
+ sem_wait(&mdp->sem); \
+ mdp->locked=1; \
+ } while(0)
+
+#define UNLOCK(mdp) do { \
+ sem_post(&mdp->sem); \
+ mdp->locked=0; \
} while (0)
#endif /* __MMPRIVATE_H */
