X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/aaada3f962a9f87fb239e55e3d26c1e794d411d5..ab551808832a9f3097861a706b2c2f57302a3992:/src/zmalloc.c

diff --git a/src/zmalloc.c b/src/zmalloc.c
index 5c1b5e9a..43d60a9c 100644
--- a/src/zmalloc.c
+++ b/src/zmalloc.c
@@ -30,35 +30,76 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+
+/* 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 <string.h>
 #include <pthread.h>
 #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(__sun)
-#define PREFIX_SIZE sizeof(long long)
+#ifdef 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 PREFIX_SIZE sizeof(size_t)
+#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 increment_used_memory(__n) do { \
+#define update_zmalloc_stat_alloc(__n,__size) do { \
     size_t _n = (__n); \
     if (_n&(sizeof(long)-1)) _n += sizeof(long)-(_n&(sizeof(long)-1)); \
     if (zmalloc_thread_safe) { \
-        pthread_mutex_lock(&used_memory_mutex);  \
-        used_memory += _n; \
-        pthread_mutex_unlock(&used_memory_mutex); \
+        update_zmalloc_stat_add(_n); \
     } else { \
         used_memory += _n; \
     } \
 } while(0)
 
-#define decrement_used_memory(__n) do { \
+#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) { \
-        pthread_mutex_lock(&used_memory_mutex);  \
-        used_memory -= _n; \
-        pthread_mutex_unlock(&used_memory_mutex); \
+        update_zmalloc_stat_sub(_n); \
     } else { \
         used_memory -= _n; \
     } \
@@ -68,23 +109,25 @@ static size_t used_memory = 0;
 static int zmalloc_thread_safe = 0;
 pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
 
-static void zmalloc_oom(size_t size) {
+static void zmalloc_default_oom(size_t size) {
     fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
         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(size);
+    if (!ptr) zmalloc_oom_handler(size);
 #ifdef HAVE_MALLOC_SIZE
-    increment_used_memory(redis_malloc_size(ptr));
+    update_zmalloc_stat_alloc(zmalloc_size(ptr),size);
     return ptr;
 #else
     *((size_t*)ptr) = size;
-    increment_used_memory(size+PREFIX_SIZE);
+    update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
     return (char*)ptr+PREFIX_SIZE;
 #endif
 }
@@ -92,13 +135,13 @@ void *zmalloc(size_t size) {
 void *zcalloc(size_t size) {
     void *ptr = calloc(1, size+PREFIX_SIZE);
 
-    if (!ptr) zmalloc_oom(size);
+    if (!ptr) zmalloc_oom_handler(size);
 #ifdef HAVE_MALLOC_SIZE
-    increment_used_memory(redis_malloc_size(ptr));
+    update_zmalloc_stat_alloc(zmalloc_size(ptr),size);
     return ptr;
 #else
     *((size_t*)ptr) = size;
-    increment_used_memory(size+PREFIX_SIZE);
+    update_zmalloc_stat_alloc(size+PREFIX_SIZE,size);
     return (char*)ptr+PREFIX_SIZE;
 #endif
 }
@@ -112,26 +155,40 @@ void *zrealloc(void *ptr, size_t size) {
 
     if (ptr == NULL) return zmalloc(size);
 #ifdef HAVE_MALLOC_SIZE
-    oldsize = redis_malloc_size(ptr);
+    oldsize = zmalloc_size(ptr);
     newptr = realloc(ptr,size);
-    if (!newptr) zmalloc_oom(size);
+    if (!newptr) zmalloc_oom_handler(size);
 
-    decrement_used_memory(oldsize);
-    increment_used_memory(redis_malloc_size(newptr));
+    update_zmalloc_stat_free(oldsize);
+    update_zmalloc_stat_alloc(zmalloc_size(newptr),size);
     return newptr;
 #else
     realptr = (char*)ptr-PREFIX_SIZE;
     oldsize = *((size_t*)realptr);
     newptr = realloc(realptr,size+PREFIX_SIZE);
-    if (!newptr) zmalloc_oom(size);
+    if (!newptr) zmalloc_oom_handler(size);
 
     *((size_t*)newptr) = size;
-    decrement_used_memory(oldsize);
-    increment_used_memory(size);
+    update_zmalloc_stat_free(oldsize);
+    update_zmalloc_stat_alloc(size,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 an 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;
@@ -140,12 +197,12 @@ void zfree(void *ptr) {
 
     if (ptr == NULL) return;
 #ifdef HAVE_MALLOC_SIZE
-    decrement_used_memory(redis_malloc_size(ptr));
+    update_zmalloc_stat_free(zmalloc_size(ptr));
     free(ptr);
 #else
     realptr = (char*)ptr-PREFIX_SIZE;
     oldsize = *((size_t*)realptr);
-    decrement_used_memory(oldsize+PREFIX_SIZE);
+    update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
     free(realptr);
 #endif
 }
@@ -161,12 +218,109 @@ char *zstrdup(const char *s) {
 size_t zmalloc_used_memory(void) {
     size_t um;
 
-    if (zmalloc_thread_safe) pthread_mutex_lock(&used_memory_mutex);
-    um = used_memory;
-    if (zmalloc_thread_safe) pthread_mutex_unlock(&used_memory_mutex);
+    if (zmalloc_thread_safe) {
+#ifdef HAVE_ATOMIC
+        um = __sync_add_and_fetch(&used_memory, 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 funciton. */
+
+#if defined(HAVE_PROCFS)
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+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/<pid>/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 <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <mach/task.h>
+#include <mach/mach_init.h>
+
+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(void) {
+    return (float)zmalloc_get_rss()/zmalloc_used_memory();
+}