git.m6w6.name Git - awesomized/libmemcached/blob - memcached/cache.c

   1 /* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
   2 #include <config.h>
   3
   4 #include <stdlib.h>
   5 #include <string.h>
   6 #include <inttypes.h>
   7 #include <string.h>
   8
   9 #ifndef NDEBUG
  10 #include <signal.h>
  11 #endif
  12
  13 #include "cache.h"
  14
  15 #ifndef NDEBUG
  16 const uint64_t redzone_pattern = 0xdeadbeefcafebabe;
  17 int cache_error = 0;
  18 #endif
  19
  20 const int initial_pool_size = 64;
  21
  22 cache_t* cache_create(const char *name, size_t bufsize, size_t align,
  23                       cache_constructor_t* constructor,
  24                       cache_destructor_t* destructor) {
  25     cache_t* ret = calloc(1, sizeof(cache_t));
  26     char* nm = strdup(name);
  27     void** ptr = calloc(initial_pool_size, sizeof(void*));
  28     if (ret == NULL || nm == NULL || ptr == NULL ||
  29         pthread_mutex_init(&ret->mutex, NULL) == -1) {
  30         free(ret);
  31         free(nm);
  32         free(ptr);
  33         return NULL;
  34     }
  35
  36     ret->name = nm;
  37     ret->ptr = ptr;
  38     ret->freetotal = initial_pool_size;
  39     ret->constructor = constructor;
  40     ret->destructor = destructor;
  41
  42 #ifndef NDEBUG
  43     ret->bufsize = bufsize + 2 * sizeof(redzone_pattern);
  44 #else
  45     ret->bufsize = bufsize;
  46 #endif
  47
  48     return ret;
  49 }
  50
  51 static inline void* get_object(void *ptr) {
  52 #ifndef NDEBUG
  53     uint64_t *pre = ptr;
  54     return pre + 1;
  55 #else
  56     return ptr;
  57 #endif
  58 }
  59
  60 void cache_destroy(cache_t *cache) {
  61     while (cache->freecurr > 0) {
  62         void *ptr = cache->ptr[--cache->freecurr];
  63         if (cache->destructor) {
  64             cache->destructor(get_object(ptr), NULL);
  65         }
  66         free(ptr);
  67     }
  68     free(cache->name);
  69     free(cache->ptr);
  70     pthread_mutex_destroy(&cache->mutex);
  71     free(cache);
  72 }
  73
  74 void* cache_alloc(cache_t *cache) {
  75     void *ret;
  76     void *object;
  77     pthread_mutex_lock(&cache->mutex);
  78     if (cache->freecurr > 0) {
  79         ret = cache->ptr[--cache->freecurr];
  80         object = get_object(ret);
  81     } else {
  82         object = ret = malloc(cache->bufsize);
  83         if (ret != NULL) {
  84             object = get_object(ret);
  85
  86             if (cache->constructor != NULL &&
  87                 cache->constructor(object, NULL, 0) != 0) {
  88                 free(ret);
  89                 object = NULL;
  90             }
  91         }
  92     }
  93     pthread_mutex_unlock(&cache->mutex);
  94
  95 #ifndef NDEBUG
  96     if (object != NULL) {
  97         /* add a simple form of buffer-check */
  98         uint64_t *pre = ret;
  99         *pre = redzone_pattern;
 100         ret = pre+1;
 101         memcpy(((char*)ret) + cache->bufsize - (2 * sizeof(redzone_pattern)),
 102                &redzone_pattern, sizeof(redzone_pattern));
 103     }
 104 #endif
 105
 106     return object;
 107 }
 108
 109 void cache_free(cache_t *cache, void *ptr) {
 110     pthread_mutex_lock(&cache->mutex);
 111
 112 #ifndef NDEBUG
 113     /* validate redzone... */
 114     if (memcmp(((char*)ptr) + cache->bufsize - (2 * sizeof(redzone_pattern)),
 115                &redzone_pattern, sizeof(redzone_pattern)) != 0) {
 116         raise(SIGABRT);
 117         cache_error = 1;
 118         pthread_mutex_unlock(&cache->mutex);
 119         return;
 120     }
 121     uint64_t *pre = ptr;
 122     --pre;
 123     if (*pre != redzone_pattern) {
 124         raise(SIGABRT);
 125         cache_error = -1;
 126         pthread_mutex_unlock(&cache->mutex);
 127         return;
 128     }
 129     ptr = pre;
 130 #endif
 131     if (cache->freecurr < cache->freetotal) {
 132         cache->ptr[cache->freecurr++] = ptr;
 133     } else {
 134         /* try to enlarge free connections array */
 135         size_t newtotal = cache->freetotal * 2;
 136         void **new_free = realloc(cache->ptr, sizeof(char *) * newtotal);
 137         if (new_free) {
 138             cache->freetotal = newtotal;
 139             cache->ptr = new_free;
 140             cache->ptr[cache->freecurr++] = ptr;
 141         } else {
 142             if (cache->destructor) {
 143                 cache->destructor(ptr, NULL);
 144             }
 145             free(ptr);
 146
 147         }
 148     }
 149     pthread_mutex_unlock(&cache->mutex);
 150 }
 151