redisソースzmalloc.c実装

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zmalloc.cファイルソース:
#include 
#include 

/* This function provide us access to the original libc free(). This is useful
 * for instance to free results obtained by backtrace_symbols(). We need
 * to define this function before including zmalloc.h that may shadow the
 * free implementation if we use jemalloc or another non standard allocator. */
void zlibc_free(void *ptr) {
    free(ptr);
}

#include 
#include 
#include "config.h"
#include "zmalloc.h"

#ifdef HAVE_MALLOC_SIZE
#define PREFIX_SIZE (0)
#else
#if defined(__sun) || defined(__sparc) || defined(__sparc__)
#define PREFIX_SIZE (sizeof(long long))
#else
#define PREFIX_SIZE (sizeof(size_t))
#endif
#endif

/* Explicitly override malloc/free etc when using tcmalloc. */
#if defined(USE_TCMALLOC)
#define malloc(size) tc_malloc(size)
#define calloc(count,size) tc_calloc(count,size)
#define realloc(ptr,size) tc_realloc(ptr,size)
#define free(ptr) tc_free(ptr)
#elif defined(USE_JEMALLOC)
#define malloc(size) je_malloc(size)
#define calloc(count,size) je_calloc(count,size)
#define realloc(ptr,size) je_realloc(ptr,size)
#define free(ptr) je_free(ptr)
#endif

#if defined(__ATOMIC_RELAXED)
#define update_zmalloc_stat_add(__n) __atomic_add_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
#define update_zmalloc_stat_sub(__n) __atomic_sub_fetch(&used_memory, (__n), __ATOMIC_RELAXED)
#elif defined(HAVE_ATOMIC)
#define update_zmalloc_stat_add(__n) __sync_add_and_fetch(&used_memory, (__n))
#define update_zmalloc_stat_sub(__n) __sync_sub_and_fetch(&used_memory, (__n))
#else
#define update_zmalloc_stat_add(__n) do { \
    pthread_mutex_lock(&used_memory_mutex); \
    used_memory += (__n); \
    pthread_mutex_unlock(&used_memory_mutex); \
} while(0)

#define update_zmalloc_stat_sub(__n) do { \
    pthread_mutex_lock(&used_memory_mutex); \
    used_memory -= (__n); \
    pthread_mutex_unlock(&used_memory_mutex); \
} while(0)

#endif

#define update_zmalloc_stat_alloc(__n) do { \
    size_t _n = (__n); \
    if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
    if (zmalloc_thread_safe) { \
        update_zmalloc_stat_add(_n); \
    } else { \
        used_memory += _n; \
    } \
} while(0)

#define update_zmalloc_stat_free(__n) do { \
    size_t _n = (__n); \
    if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
    if (zmalloc_thread_safe) { \
        update_zmalloc_stat_sub(_n); \
    } else { \
        used_memory -= _n; \
    } \
} while(0)

static size_t used_memory = 0;
static int zmalloc_thread_safe = 0;
pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;

static void zmalloc_default_oom(size_t size) {
    fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes
", size); fflush(stderr); abort(); } static void (*zmalloc_oom_handler)(size_t) = zmalloc_default_oom; void *zmalloc(size_t size) { void *ptr = malloc(size+PREFIX_SIZE); if (!ptr) zmalloc_oom_handler(size); #ifdef HAVE_MALLOC_SIZE update_zmalloc_stat_alloc(zmalloc_size(ptr)); return ptr; #else *((size_t*)ptr) = size; update_zmalloc_stat_alloc(size+PREFIX_SIZE); return (char*)ptr+PREFIX_SIZE; #endif } void *zcalloc(size_t size) { void *ptr = calloc(1, size+PREFIX_SIZE); if (!ptr) zmalloc_oom_handler(size); #ifdef HAVE_MALLOC_SIZE update_zmalloc_stat_alloc(zmalloc_size(ptr)); return ptr; #else *((size_t*)ptr) = size; update_zmalloc_stat_alloc(size+PREFIX_SIZE); return (char*)ptr+PREFIX_SIZE; #endif } void *zrealloc(void *ptr, size_t size) { #ifndef HAVE_MALLOC_SIZE void *realptr; #endif size_t oldsize; void *newptr; if (ptr == NULL) return zmalloc(size); #ifdef HAVE_MALLOC_SIZE oldsize = zmalloc_size(ptr); newptr = realloc(ptr,size); if (!newptr) zmalloc_oom_handler(size); update_zmalloc_stat_free(oldsize); update_zmalloc_stat_alloc(zmalloc_size(newptr)); return newptr; #else realptr = (char*)ptr-PREFIX_SIZE; oldsize = *((size_t*)realptr); newptr = realloc(realptr,size+PREFIX_SIZE); if (!newptr) zmalloc_oom_handler(size); *((size_t*)newptr) = size; update_zmalloc_stat_free(oldsize); update_zmalloc_stat_alloc(size); return (char*)newptr+PREFIX_SIZE; #endif } /* Provide zmalloc_size() for systems where this function is not provided by * malloc itself, given that in that case we store a header with this * information as the first bytes of every allocation. */ #ifndef HAVE_MALLOC_SIZE size_t zmalloc_size(void *ptr) { void *realptr = (char*)ptr-PREFIX_SIZE; size_t size = *((size_t*)realptr); /* Assume at least that all the allocations are padded at sizeof(long) by * the underlying allocator. */ if (size&(sizeof(long)-1)) size += sizeof(long)-(size&(sizeof(long)-1)); return size+PREFIX_SIZE; } #endif void zfree(void *ptr) { #ifndef HAVE_MALLOC_SIZE void *realptr; size_t oldsize; #endif if (ptr == NULL) return; #ifdef HAVE_MALLOC_SIZE update_zmalloc_stat_free(zmalloc_size(ptr)); free(ptr); #else realptr = (char*)ptr-PREFIX_SIZE; oldsize = *((size_t*)realptr); update_zmalloc_stat_free(oldsize+PREFIX_SIZE); free(realptr); #endif } char *zstrdup(const char *s) { size_t l = strlen(s)+1; char *p = zmalloc(l); memcpy(p,s,l); return p; } size_t zmalloc_used_memory(void) { size_t um; if (zmalloc_thread_safe) { #if defined(__ATOMIC_RELAXED) || defined(HAVE_ATOMIC) um = update_zmalloc_stat_add(0); #else pthread_mutex_lock(&used_memory_mutex); um = used_memory; pthread_mutex_unlock(&used_memory_mutex); #endif } else { um = used_memory; } return um; } void zmalloc_enable_thread_safeness(void) { zmalloc_thread_safe = 1; } void zmalloc_set_oom_handler(void (*oom_handler)(size_t)) { zmalloc_oom_handler = oom_handler; } /* Get the RSS information in an OS-specific way. * * WARNING: the function zmalloc_get_rss() is not designed to be fast * and may not be called in the busy loops where Redis tries to release * memory expiring or swapping out objects. * * For this kind of "fast RSS reporting" usages use instead the * function RedisEstimateRSS() that is a much faster (and less precise) * version of the function. */ #if defined(HAVE_PROC_STAT) #include #include #include #include size_t zmalloc_get_rss(void) { int page = sysconf(_SC_PAGESIZE); size_t rss; char buf[4096]; char filename[256]; int fd, count; char *p, *x; snprintf(filename,256,"/proc/%d/stat",getpid()); if ((fd = open(filename,O_RDONLY)) == -1) return 0; if (read(fd,buf,4096) <= 0) { close(fd); return 0; } close(fd); p = buf; count = 23; /* RSS is the 24th field in /proc//stat */ while(p && count--) { p = strchr(p,' '); if (p) p++; } if (!p) return 0; x = strchr(p,' '); if (!x) return 0; *x = '\0'; rss = strtoll(p,NULL,10); rss *= page; return rss; } #elif defined(HAVE_TASKINFO) #include #include #include #include #include #include #include size_t zmalloc_get_rss(void) { task_t task = MACH_PORT_NULL; struct task_basic_info t_info; mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT; if (task_for_pid(current_task(), getpid(), &task) != KERN_SUCCESS) return 0; task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count); return t_info.resident_size; } #else size_t zmalloc_get_rss(void) { /* If we can't get the RSS in an OS-specific way for this system just * return the memory usage we estimated in zmalloc().. * * Fragmentation will appear to be always 1 (no fragmentation) * of course... */ return zmalloc_used_memory(); } #endif /* Fragmentation = RSS / allocated-bytes */ float zmalloc_get_fragmentation_ratio(size_t rss) { return (float)rss/zmalloc_used_memory(); } /* Get the sum of the specified field (converted form kb to bytes) in * /proc/self/smaps. The field must be specified with trailing ":" as it * apperas in the smaps output. * * Example: zmalloc_get_smap_bytes_by_field("Rss:"); */ #if defined(HAVE_PROC_SMAPS) size_t zmalloc_get_smap_bytes_by_field(char *field) { char line[1024]; size_t bytes = 0; FILE *fp = fopen("/proc/self/smaps","r"); int flen = strlen(field); if (!fp) return 0; while(fgets(line,sizeof(line),fp) != NULL) { if (strncmp(line,field,flen) == 0) { char *p = strchr(line,'k'); if (p) { *p = '\0'; bytes += strtol(line+flen,NULL,10) * 1024; } } } fclose(fp); return bytes; } #else size_t zmalloc_get_smap_bytes_by_field(char *field) { ((void) field); return 0; } #endif size_t zmalloc_get_private_dirty(void) { return zmalloc_get_smap_bytes_by_field("Private_Dirty:"); }