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Diffstat (limited to 'source3/mem_man/mem_man.c')
| -rw-r--r-- | source3/mem_man/mem_man.c | 742 |
1 files changed, 742 insertions, 0 deletions
diff --git a/source3/mem_man/mem_man.c b/source3/mem_man/mem_man.c new file mode 100644 index 0000000000..758fac4386 --- /dev/null +++ b/source3/mem_man/mem_man.c @@ -0,0 +1,742 @@ +#if MEM_MAN +/* a simple memory manager. All allocates and frees should go through here */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +#define MEM_MAN_MAIN + +#include "mem_man.h" + +#ifdef MEM_SIGNAL_HANDLER +#include <signal.h> +#endif + +/* + this module is stand alone. typically a define will occur in a C file + like this + + #define malloc(x) smb_mem_malloc(x,__FILE__,__LINE__) + #define free(x) smb_mem_free(x,__FILE__,__LINE__) + + which redirects all calls to malloc and free through this module + + Various configuration options can be set in mem_man.h. This file also + includes the defines above - so the complete system can be implemented + with just one include call. + + + */ + +extern FILE *dbf; + +/* + ACCESSING the memory manager : + + mem_init_memory_manager() : + initialises internal data structures of memory manager + + void *malloc(size_t size) : + allocates memory as per usual. also records lots of info + + int free(void *ptr) : + frees some memory as per usual. writes errors if necessary. + + void *smb_mem_resize(void *ptr,size_t newsize) : + changes the memory assignment size of a pointer. note it may return a + different pointer than the one given. memory can be sized up or down. + + int smb_mem_query_size(void *ptr) : + returns the size of the allocated memory. + + int smb_mem_query_real_size(void *ptr) : + returns the actual amount of memory allocated to a pointer. + + char *smb_mem_query_file(void *ptr) : + returns the name of the file where the pointer was allocated. + + int smb_mem_query_line(void *ptr) : + returns the line of the file where the memory was allocated. + + void smb_mem_write_status(FILE *outfile) : + writes short summary of memory stats on the stream. + + void smb_mem_write_verbose(FILE *outfile) : + writes lots of info on current allocations to stream. + + void smb_mem_write_errors(FILE *outfile) : + writes info on error blocks + + void smb_mem_write_info(void *ptr,FILE *outfile) + writes info on one pointer to outfile + + int smb_mem_test(void *ptr) : + returns true if the pointer is OK - false if it is not. + + void smb_mem_set_multiplier(int multiplier) : + sets defaults amount of memory allocated to multiplier times + amount requested. + + int smb_mem_total_errors(void) : + returns the total number of error blocks + + void smb_mem_check_buffers(void) : + checks all buffers for corruption. It marks them as corrupt if they are. + + kill -USR1 <pid> : + this will send a signal to the memory manager to do a mem_write_verbose + it also checks them for corruption. Note that the signal number can be + set in the header file mem_man.h. This can also be turned off. + + */ + + +void smb_mem_write_errors(FILE *outfile); +void smb_mem_write_verbose(FILE *outfile); +void smb_mem_write_status(FILE *outfile); +static void mem_check_buffers(void); + + +#define FREE_FAILURE 0 +#define FREE_SUCCESS 1 +#define FN +#define True (0==0) +#define False (!True) +#define BUF_SIZE (MEM_CORRUPT_BUFFER * sizeof(char) * 2) +#define BUF_OFFSET (BUF_SIZE/2) + +typedef struct +{ + void *pointer; + size_t present_size; + size_t allocated_size; + unsigned char status; + short error_number; + char file[MEM_FILE_STR_LENGTH]; + unsigned short line; +} memory_struct; + +/* the order of this enum is important. everything greater than + S_ALLOCATED is considered an error */ +enum status_types {S_UNALLOCATED,S_ALLOCATED, + S_ERROR_UNALLOCATED,S_ERROR_FREEING, + S_CORRUPT_FRONT,S_CORRUPT_BACK,S_CORRUPT_FRONT_BACK}; + +/* here is the data memory */ + +static memory_struct *memory_blocks=NULL; /* these hold the allocation data */ +static int mem_blocks_allocated=0; /* how many mem blocks are allocated */ +static int mem_multiplier; /* this is the current multiplier mor over allocation */ +static int mem_manager_initialised=False; /* has it been initialised ? */ +static int last_block_allocated=0; /* a speed up method - this will contain the + index of the last block allocated or freed + to cut down searching time for a new block */ + + +typedef struct +{ + int status; + char *label; +} stat_str_type; + +static stat_str_type stat_str_struct[] = +{ +{S_UNALLOCATED,"S_UNALLOCATED"}, +{S_ALLOCATED,"S_ALLOCATED"}, +{S_ERROR_UNALLOCATED,"S_ERROR_UNALLOCATED"}, +{S_ERROR_FREEING,"S_ERROR_FREEING"}, +{S_CORRUPT_FRONT,"S_CORRUPT_FRONT"}, +{S_CORRUPT_BACK,"S_CORRUPT_BACK"}, +{S_CORRUPT_FRONT_BACK,"S_CORRUPT_FRONT_BACK"}, +{-1,NULL} +}; + + +#define INIT_MANAGER() if (!mem_manager_initialised) mem_init_memory_manager() + +/******************************************************************* + returns a pointer to a static string for each status + ********************************************************************/ +static char *status_to_str(int status) +{ + int i=0; + while (stat_str_struct[i].label != NULL) + { + if (stat_str_struct[i].status == status) + return(stat_str_struct[i].label); + i++; + } + return(NULL); +} + + + +#ifdef MEM_SIGNAL_HANDLER +/******************************************************************* + this handles signals - causes a mem_write_verbose on stderr + ********************************************************************/ +static void mem_signal_handler() +{ + mem_check_buffers(); + smb_mem_write_verbose(dbf); + signal(MEM_SIGNAL_VECTOR,mem_signal_handler); +} +#endif + +#ifdef MEM_SIGNAL_HANDLER +/******************************************************************* + this handles error signals - causes a mem_write_verbose on stderr + ********************************************************************/ +static void error_signal_handler() +{ + fprintf(dbf,"Received error signal!\n"); + mem_check_buffers(); + smb_mem_write_status(dbf); + smb_mem_write_errors(dbf); + abort(); +} +#endif + + +/******************************************************************* + initialise memory manager data structures + ********************************************************************/ +static void mem_init_memory_manager(void) +{ + int i; + /* allocate the memory_blocks array */ + mem_blocks_allocated = MEM_MAX_MEM_OBJECTS; + + while (mem_blocks_allocated > 0) + { + memory_blocks = (memory_struct *) + calloc(mem_blocks_allocated,sizeof(memory_struct)); + if (memory_blocks != NULL) break; + mem_blocks_allocated /= 2; + } + + if (memory_blocks == NULL) + { + fprintf(dbf,"Panic ! can't allocate mem manager blocks!\n"); + abort(); + } + + /* just loop setting status flag to unallocated */ + for (i=0;i<mem_blocks_allocated;i++) + memory_blocks[i].status = S_UNALLOCATED; + + /* also set default mem multiplier */ + mem_multiplier = MEM_DEFAULT_MEM_MULTIPLIER; + mem_manager_initialised=True; + +#ifdef MEM_SIGNAL_HANDLER + signal(MEM_SIGNAL_VECTOR,mem_signal_handler); + signal(SIGSEGV,error_signal_handler); + signal(SIGBUS,error_signal_handler); +#endif + +} + + +/******************************************************************* + finds first available slot in memory blocks + ********************************************************************/ +static int mem_first_avail_slot(void) +{ + int i; + for (i=last_block_allocated;i<mem_blocks_allocated;i++) + if (memory_blocks[i].status == S_UNALLOCATED) + return(last_block_allocated=i); + for (i=0;i<last_block_allocated;i++) + if (memory_blocks[i].status == S_UNALLOCATED) + return(last_block_allocated=i); + return(-1); +} + + +/******************************************************************* + find which Index a pointer refers to + ********************************************************************/ +static int mem_find_Index(void *ptr) +{ + int i; + int start = last_block_allocated+mem_blocks_allocated/50; + if (start > mem_blocks_allocated-1) start = mem_blocks_allocated-1; + for (i=start;i>=0;i--) + if ((memory_blocks[i].status == S_ALLOCATED) && + (memory_blocks[i].pointer == ptr)) + return(i); + for (i=(start+1);i<mem_blocks_allocated;i++) + if ((memory_blocks[i].status == S_ALLOCATED) && + (memory_blocks[i].pointer == ptr)) + return(i); + /* it's not there! */ + return(-1); +} + +/******************************************************************* + fill the buffer areas of a mem block + ********************************************************************/ +static void mem_fill_bytes(void *p,int size,int Index) +{ + memset(p,Index%256,size); +} + +/******************************************************************* + fill the buffer areas of a mem block + ********************************************************************/ +static void mem_fill_buffer(int Index) +{ + char *iptr,*tailptr; + int i; + int seed; + + /* fill the front and back ends */ + seed = MEM_CORRUPT_SEED; + iptr = (char *)((char *)memory_blocks[Index].pointer - BUF_OFFSET); + tailptr = (char *)((char *)memory_blocks[Index].pointer + + memory_blocks[Index].present_size); + + for (i=0;i<MEM_CORRUPT_BUFFER;i++) + { + iptr[i] = seed; + tailptr[i] = seed; + seed += MEM_SEED_INCREMENT; + } +} + +/******************************************************************* + check if a mem block is corrupt + ********************************************************************/ +static int mem_buffer_ok(int Index) +{ + char *iptr; + int i; + int corrupt_front = False; + int corrupt_back = False; + + /* check the front end */ + iptr = (char *)((char *)memory_blocks[Index].pointer - BUF_OFFSET); + for (i=0;i<MEM_CORRUPT_BUFFER;i++) + if (iptr[i] != (char)(MEM_CORRUPT_SEED + i*MEM_SEED_INCREMENT)) + corrupt_front = True; + + /* now check the tail end */ + iptr = (char *)((char *)memory_blocks[Index].pointer + + memory_blocks[Index].present_size); + for (i=0;i<MEM_CORRUPT_BUFFER;i++) + if (iptr[i] != (char)(MEM_CORRUPT_SEED + i*MEM_SEED_INCREMENT)) + corrupt_back = True; + + if (corrupt_front && !corrupt_back) + memory_blocks[Index].status = S_CORRUPT_FRONT; + if (corrupt_back && !corrupt_front) + memory_blocks[Index].status = S_CORRUPT_BACK; + if (corrupt_front && corrupt_back) + memory_blocks[Index].status = S_CORRUPT_FRONT_BACK; + if (!corrupt_front && !corrupt_back) + return(True); + return(False); +} + + +/******************************************************************* + check all buffers for corruption + ********************************************************************/ +static void mem_check_buffers(void) +{ + int i; + for (i=0;i<mem_blocks_allocated;i++) + if (memory_blocks[i].status == S_ALLOCATED) + mem_buffer_ok(i); +} + + +/******************************************************************* + record stats and alloc memory + ********************************************************************/ +void *smb_mem_malloc(size_t size,char *file,int line) +{ + int Index; + INIT_MANAGER(); + + /* find an open spot */ + + Index = mem_first_avail_slot(); + if (Index<0) return(NULL); + + /* record some info */ + memory_blocks[Index].present_size = size; + memory_blocks[Index].allocated_size = size*mem_multiplier; + memory_blocks[Index].line = line; + strncpy(memory_blocks[Index].file,file,MEM_FILE_STR_LENGTH); + memory_blocks[Index].file[MEM_FILE_STR_LENGTH-1] = 0; + memory_blocks[Index].error_number = 0; + + /* now try and actually get the memory */ + memory_blocks[Index].pointer = malloc(size*mem_multiplier + BUF_SIZE); + + /* if that failed then try and get exactly what was actually requested */ + if (memory_blocks[Index].pointer == NULL) + { + memory_blocks[Index].allocated_size = size; + memory_blocks[Index].pointer = malloc(size + BUF_SIZE); + } + + /* if it failed then return NULL */ + if (memory_blocks[Index].pointer == NULL) return(NULL); + + + /* it succeeded - set status flag and return */ + memory_blocks[Index].status = S_ALLOCATED; + + /* add an offset */ + memory_blocks[Index].pointer = + (void *)((char *)memory_blocks[Index].pointer + BUF_OFFSET); + + /* fill the buffer appropriately */ + mem_fill_buffer(Index); + + /* and set the fill byte */ + mem_fill_bytes(memory_blocks[Index].pointer,memory_blocks[Index].present_size,Index); + + /* return the allocated memory */ + return(memory_blocks[Index].pointer); +} + + +/******************************************************************* +dup a string + ********************************************************************/ +char *smb_mem_strdup(char *s, char *file, int line) +{ + char *ret = (char *)smb_mem_malloc(strlen(s)+1, file, line); + strcpy(ret, s); + return ret; +} + +/******************************************************************* + free some memory + ********************************************************************/ +int smb_mem_free(void *ptr,char *file,int line) +{ + int Index; + int free_ret; + static int count; + INIT_MANAGER(); + + if (count % 100 == 0) { + smb_mem_write_errors(dbf); + } + count++; + + Index = mem_find_Index(ptr); + + if (Index<0) /* we are freeing a pointer that hasn't been allocated ! */ + { + /* set up an error block */ + Index = mem_first_avail_slot(); + if (Index < 0) /* I can't even allocate an Error! */ + { + fprintf(dbf,"Panic in memory manager - can't allocate error block!\n"); + fprintf(dbf,"freeing un allocated pointer at %s(%d)\n",file,line); + abort(); + } + /* fill in error block */ + memory_blocks[Index].present_size = 0; + memory_blocks[Index].allocated_size = 0; + memory_blocks[Index].line = line; + strncpy(memory_blocks[Index].file,file,MEM_FILE_STR_LENGTH); + memory_blocks[Index].file[MEM_FILE_STR_LENGTH-1] = 0; + memory_blocks[Index].status = S_ERROR_UNALLOCATED; + memory_blocks[Index].pointer = ptr; + return(FREE_FAILURE); + } + + /* it is a valid pointer - check for corruption */ + if (!mem_buffer_ok(Index)) + /* it's bad ! return an error */ + return(FREE_FAILURE); + + /* the pointer is OK - try to free it */ +#ifdef MEM_FREE_RETURNS_INT + free_ret = free((char *)ptr - BUF_OFFSET); +#else + free((char *)ptr - BUF_OFFSET); + free_ret = FREE_SUCCESS; +#endif + + + /* if this failed then make an error block again */ + if (free_ret == FREE_FAILURE) + { + memory_blocks[Index].present_size = 0; + memory_blocks[Index].allocated_size = 0; + memory_blocks[Index].line = line; + strncpy(memory_blocks[Index].file,file,MEM_FILE_STR_LENGTH); + memory_blocks[Index].file[MEM_FILE_STR_LENGTH-1] = 0; + memory_blocks[Index].status = S_ERROR_FREEING; + memory_blocks[Index].pointer = ptr; + memory_blocks[Index].error_number = errno; + return(FREE_FAILURE); + } + + /* all is OK - set status and return */ + memory_blocks[Index].status = S_UNALLOCATED; + + /* this is a speedup - if it is freed then it can be allocated again ! */ + last_block_allocated = Index; + + return(FREE_SUCCESS); +} + + + +/******************************************************************* + writes info on just one Index + it must not be un allocated to do this + ********************************************************************/ +static void mem_write_Index_info(int Index,FILE *outfile) +{ + if (memory_blocks[Index].status != S_UNALLOCATED) + fprintf(outfile,"block %d file %s(%d) : size %d, alloc size %d, status %s\n", + Index,memory_blocks[Index].file,memory_blocks[Index].line, + memory_blocks[Index].present_size, + memory_blocks[Index].allocated_size, + status_to_str(memory_blocks[Index].status)); +} + + + +/******************************************************************* + writes info on one pointer + ********************************************************************/ +void smb_mem_write_info(void *ptr,FILE *outfile) +{ + int Index; + INIT_MANAGER(); + Index = mem_find_Index(ptr); + if (Index<0) return; + mem_write_Index_info(Index,outfile); +} + + + + +/******************************************************************* + return the size of the mem block + ********************************************************************/ +size_t smb_mem_query_size(void *ptr) +{ + int Index; + INIT_MANAGER(); + Index = mem_find_Index(ptr); + if (Index<0) return(0); + return(memory_blocks[Index].present_size); +} + +/******************************************************************* + return the allocated size of the mem block + ********************************************************************/ +size_t smb_mem_query_real_size(void *ptr) +{ + int Index; + INIT_MANAGER(); + Index = mem_find_Index(ptr); + if (Index<0) return(0); + return(memory_blocks[Index].allocated_size); +} + + + + +/******************************************************************* + return the file of caller of the mem block + ********************************************************************/ +char *smb_mem_query_file(void *ptr) +{ + int Index; + INIT_MANAGER(); + Index = mem_find_Index(ptr); + if (Index<0) return(NULL); + return(memory_blocks[Index].file); +} + + + +/******************************************************************* + return the line in the file of caller of the mem block + ********************************************************************/ +int smb_mem_query_line(void *ptr) +{ + int Index; + INIT_MANAGER(); + Index = mem_find_Index(ptr); + if (Index<0) return(0); + return(memory_blocks[Index].line); +} + +/******************************************************************* + return True if the pointer is OK + ********************************************************************/ +int smb_mem_test(void *ptr) +{ + int Index; + INIT_MANAGER(); + Index = mem_find_Index(ptr); + if (Index<0) return(False); + + return(mem_buffer_ok(Index)); +} + + +/******************************************************************* + write brief info on mem status + ********************************************************************/ +void smb_mem_write_status(FILE *outfile) +{ + int num_allocated=0; + int total_size=0; + int total_alloc_size=0; + int num_errors=0; + int i; + INIT_MANAGER(); + mem_check_buffers(); + for (i=0;i<mem_blocks_allocated;i++) + switch (memory_blocks[i].status) + { + case S_UNALLOCATED : + break; + case S_ALLOCATED : + num_allocated++; + total_size += memory_blocks[i].present_size; + total_alloc_size += memory_blocks[i].allocated_size; + break; + case S_ERROR_UNALLOCATED : + case S_ERROR_FREEING : + case S_CORRUPT_BACK : + case S_CORRUPT_FRONT : + num_errors++; + break; + } + + fprintf(outfile, + "Mem Manager : %d blocks, allocation %dK, real allocation %dK, %d errors\n", + num_allocated,(int)(total_size/1024),(int)(total_alloc_size/1024), + num_errors); + fflush(outfile); +} + + +/******************************************************************* + write verbose info on allocated blocks + ********************************************************************/ +void smb_mem_write_verbose(FILE *outfile) +{ + int Index; + /* first write a summary */ + INIT_MANAGER(); + smb_mem_write_status(outfile); + + /* just loop writing info on relevant indices */ + for (Index=0;Index<mem_blocks_allocated;Index++) + if (memory_blocks[Index].status != S_UNALLOCATED) + mem_write_Index_info(Index,outfile); +} + +/******************************************************************* + write verbose info on error blocks + ********************************************************************/ +void smb_mem_write_errors(FILE *outfile) +{ + int Index; + INIT_MANAGER(); + mem_check_buffers(); + /* just loop writing info on relevant indices */ + for (Index=0;Index<mem_blocks_allocated;Index++) + if (((int)memory_blocks[Index].status) > ((int)S_ALLOCATED)) + mem_write_Index_info(Index,outfile); +} + + +/******************************************************************* + sets the memory multiplier + ********************************************************************/ +void smb_mem_set_multiplier(int multiplier) +{ + /* check it is valid */ + if (multiplier < 1) return; + mem_multiplier = multiplier; +} + +/******************************************************************* + increases or decreases the memory assigned to a pointer + ********************************************************************/ +void *smb_mem_resize(void *ptr,size_t newsize) +{ + int Index; + size_t allocsize; + void *temp_ptr; + INIT_MANAGER(); + Index = mem_find_Index(ptr); + + /* if invalid return NULL */ + if (Index<0) + { +#ifdef BUG + int Error(); + Error("Invalid mem_resize to size %d\n",newsize); +#endif + return(NULL); + } + + /* now - will it fit in the current allocation ? */ + if (newsize <= memory_blocks[Index].allocated_size) + { + memory_blocks[Index].present_size = newsize; + mem_fill_buffer(Index); + return(ptr); + } + + /* can it be allocated ? */ + allocsize = newsize*mem_multiplier; + temp_ptr = malloc(newsize*mem_multiplier + BUF_SIZE); + + /* no? try with just the size asked for */ + if (temp_ptr == NULL) + { + allocsize=newsize; + temp_ptr = malloc(newsize + BUF_SIZE); + } + + /* if it's still NULL give up */ + if (temp_ptr == NULL) + return(NULL); + + /* copy the old data to the new memory area */ + memcpy(temp_ptr,(char *)memory_blocks[Index].pointer - BUF_OFFSET, + memory_blocks[Index].allocated_size + BUF_SIZE); + + /* fill the extra space */ + mem_fill_bytes((char *)temp_ptr + BUF_OFFSET + memory_blocks[Index].present_size,newsize - memory_blocks[Index].present_size,Index); + + + /* free the old mem and set vars */ + free((char *)ptr - BUF_OFFSET); + memory_blocks[Index].pointer = (void *)((char *)temp_ptr + BUF_OFFSET); + memory_blocks[Index].present_size = newsize; + memory_blocks[Index].allocated_size = allocsize; + + /* fill the buffer appropriately */ + mem_fill_buffer(Index); + + + /* now return the new pointer */ + return((char *)temp_ptr + BUF_OFFSET); +} + +#else + void dummy_mem_man(void) {} +#endif |