Store SELECTed database for reconnect (issue #468)

[redis.git] / src / zmalloc.c

diff --git a/src/zmalloc.c b/src/zmalloc.c
index 8cfb18d940f23b105439bd090d61fa87e4be3987..aa3ccfe963d8fa6e67eacca70dc2ce953b973c27 100644 (file)
--- a/src/zmalloc.c
+++ b/src/zmalloc.c
@@ -33,6 +33,7 @@
 #include <string.h>
 #include <pthread.h>
 #include "config.h"
+#include "zmalloc.h"
 
 #ifdef HAVE_MALLOC_SIZE
 #define PREFIX_SIZE (0)
@@ -52,19 +53,22 @@
 #define free(ptr) tc_free(ptr)
 #endif
 
-#define increment_used_memory(__n) do { \
+#define update_zmalloc_stat_alloc(__n,__size) do { \
     size_t _n = (__n); \
+    size_t _stat_slot = (__size < ZMALLOC_MAX_ALLOC_STAT) ? __size : ZMALLOC_MAX_ALLOC_STAT; \
     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; \
+        zmalloc_allocations[_stat_slot]++; \
         pthread_mutex_unlock(&used_memory_mutex); \
     } else { \
         used_memory += _n; \
+        zmalloc_allocations[_stat_slot]++; \
     } \
 } 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) { \
@@ -79,6 +83,8 @@
 static size_t used_memory = 0;
 static int zmalloc_thread_safe = 0;
 pthread_mutex_t used_memory_mutex = PTHREAD_MUTEX_INITIALIZER;
+/* Note that malloc_allocations elements are initialized to zero by C */
+size_t zmalloc_allocations[ZMALLOC_MAX_ALLOC_STAT+1];
 
 static void zmalloc_oom(size_t size) {
     fprintf(stderr, "zmalloc: Out of memory trying to allocate %zu bytes\n",
@@ -92,11 +98,11 @@ void *zmalloc(size_t size) {
 
     if (!ptr) zmalloc_oom(size);
 #ifdef HAVE_MALLOC_SIZE
-    increment_used_memory(redis_malloc_size(ptr));
+    update_zmalloc_stat_alloc(redis_malloc_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
 }
@@ -106,11 +112,11 @@ void *zcalloc(size_t size) {
 
     if (!ptr) zmalloc_oom(size);
 #ifdef HAVE_MALLOC_SIZE
-    increment_used_memory(redis_malloc_size(ptr));
+    update_zmalloc_stat_alloc(redis_malloc_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
 }
@@ -128,8 +134,8 @@ void *zrealloc(void *ptr, size_t size) {
     newptr = realloc(ptr,size);
     if (!newptr) zmalloc_oom(size);
 
-    decrement_used_memory(oldsize);
-    increment_used_memory(redis_malloc_size(newptr));
+    update_zmalloc_stat_free(oldsize);
+    update_zmalloc_stat_alloc(redis_malloc_size(newptr),size);
     return newptr;
 #else
     realptr = (char*)ptr-PREFIX_SIZE;
@@ -138,8 +144,8 @@ void *zrealloc(void *ptr, size_t size) {
     if (!newptr) zmalloc_oom(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
 }
@@ -152,12 +158,12 @@ void zfree(void *ptr) {
 
     if (ptr == NULL) return;
 #ifdef HAVE_MALLOC_SIZE
-    decrement_used_memory(redis_malloc_size(ptr));
+    update_zmalloc_stat_free(redis_malloc_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
 }
@@ -179,11 +185,24 @@ size_t zmalloc_used_memory(void) {
     return um;
 }
 
+size_t zmalloc_allocations_for_size(size_t size) {
+    if (size > ZMALLOC_MAX_ALLOC_STAT) return 0;
+    return zmalloc_allocations[size];
+}
+
 void zmalloc_enable_thread_safeness(void) {
     zmalloc_thread_safe = 1;
 }
 
-/* Fragmentation = RSS / allocated-bytes */
+/* 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>
@@ -191,8 +210,7 @@ void zmalloc_enable_thread_safeness(void) {
 #include <sys/stat.h>
 #include <fcntl.h>
 
-float zmalloc_get_fragmentation_ratio(void) {
-    size_t allocated = zmalloc_used_memory();
+size_t zmalloc_get_rss(void) {
     int page = sysconf(_SC_PAGESIZE);
     size_t rss;
     char buf[4096];
@@ -221,7 +239,7 @@ float zmalloc_get_fragmentation_ratio(void) {
 
     rss = strtoll(p,NULL,10);
     rss *= page;
-    return (float)rss/allocated;
+    return rss;
 }
 #elif defined(HAVE_TASKINFO)
 #include <unistd.h>
@@ -232,7 +250,7 @@ float zmalloc_get_fragmentation_ratio(void) {
 #include <mach/task.h>
 #include <mach/mach_init.h>
 
-float zmalloc_get_fragmentation_ratio(void) {
+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;
@@ -241,10 +259,20 @@ float zmalloc_get_fragmentation_ratio(void) {
         return 0;
     task_info(task, TASK_BASIC_INFO, (task_info_t)&t_info, &t_info_count);
 
-    return (float)t_info.resident_size/zmalloc_used_memory();
+    return t_info.resident_size;
 }
 #else
-float zmalloc_get_fragmentation_ratio(void) {
-    return 0;
+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();
+}