X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/977f0ae037cfbf3681ef2240be5b5272224a1d0c..76936ddebd0a514a3259454d475b254ce40947b3:/src/xbt/mmalloc/mmprivate.h diff --git a/src/xbt/mmalloc/mmprivate.h b/src/xbt/mmalloc/mmprivate.h index 05cdf9ae6e..423c57f5a6 100644 --- a/src/xbt/mmalloc/mmprivate.h +++ b/src/xbt/mmalloc/mmprivate.h @@ -16,6 +16,7 @@ #include "portable.h" #include "xbt/xbt_os_thread.h" #include "xbt/mmalloc.h" +#include "xbt/ex.h" #include #ifdef HAVE_LIMITS_H @@ -76,46 +77,60 @@ 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; - struct { - size_t size; /* Size (in blocks) of a large cluster. */ - size_t busy_size; - } block; - } 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; +/* Data structure giving per-block information. + * + * There is one such structure in the mdp->heapinfo array, + * that is addressed by 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: + * - add an indication of the requested size in each fragment, similarly to busy_block.busy_size + * - 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. */ + } busy_frag; + struct { + size_t size; /* Size (in blocks) of a large cluster. */ + size_t busy_size; /* Actually used space, in bytes */ + } 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; -/* 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; }; /* Internal structure that defines the format of the malloc-descriptor. @@ -125,78 +140,71 @@ struct list { struct mdesc { - /* Semaphore locking the access to the heap */ - sem_t sem; - - /* Number of processes that attached the heap */ - unsigned int refcount; + /* Semaphore locking the access to the heap */ + sem_t sem; - /* Chained lists of mdescs */ - struct mdesc *next_mdesc; - - /* The "magic number" for an mmalloc file. */ - char magic[MMALLOC_MAGIC_SIZE]; + /* Number of processes that attached the heap */ + unsigned int refcount; - /* The size in bytes of this structure, used as a sanity check when reusing - a previously created mapped file. */ - unsigned int headersize; + /* Chained lists of mdescs */ + struct mdesc *next_mdesc; - /* The version number of the mmalloc package that created this file. */ - unsigned char version; + /* The "magic number" for an mmalloc file. */ + char magic[MMALLOC_MAGIC_SIZE]; - /* Some flag bits to keep track of various internal things. */ - unsigned int flags; - - /* Number of info entries. */ - size_t heapsize; - - /* Pointer to first block of the heap (base of the first block). */ - void *heapbase; + /* The size in bytes of this structure, used as a sanity check when reusing + a previously created mapped file. */ + unsigned int headersize; - /* Current search index for the heap table. */ - /* Search index in the info table. */ - size_t heapindex; + /* The version number of the mmalloc package that created this file. */ + unsigned char version; - /* Limit of valid info table indices. */ - size_t heaplimit; + /* Some flag bits to keep track of various internal things. */ + unsigned int flags; - /* Block information table. - Allocated with malign/__mmalloc_free (not mmalloc/mfree). */ - /* Table indexed by block number giving per-block information. */ + /* Number of info entries. */ + size_t heapsize; - malloc_info *heapinfo; + /* 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; }; @@ -210,10 +218,6 @@ void mmalloc_display_info(void *h); #define MMALLOC_ANONYMOUS (1 << 1) /* Use anonymous mapping */ #define MMALLOC_INITIALIZED (1 << 2) /* Initialized mmalloc */ -/* 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; @@ -229,9 +233,9 @@ extern void *mmorecore(struct mdesc *mdp, int size); /* Thread-safety (if the sem is already created) FIXME: KILLIT*/ #define LOCK(mdp) \ - sem_wait(&mdp->sem) + sem_wait(&mdp->sem) #define UNLOCK(mdp) \ - sem_post(&mdp->sem) + sem_post(&mdp->sem) #endif /* __MMPRIVATE_H */