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:");
}