overflow detection in INCR family functions

[redis.git] / src / zmalloc.c

diff --git a/src/zmalloc.c b/src/zmalloc.c
index 8658376a3462c9e4278c97eaf914b07dd6deaa8d..1917a549a61493d23cf3f00bdbcc11afed14a3e3 100644 (file)
--- a/src/zmalloc.c
+++ b/src/zmalloc.c
@@ -34,10 +34,22 @@
 #include <pthread.h>
 #include "config.h"
 
+#ifdef HAVE_MALLOC_SIZE
+#define PREFIX_SIZE (0)
+#else
 #if defined(__sun)
-#define PREFIX_SIZE sizeof(long long)
+#define PREFIX_SIZE (sizeof(long long))
 #else
-#define PREFIX_SIZE sizeof(size_t)
+#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)
 #endif
 
 #define increment_used_memory(__n) do { \
@@ -89,6 +101,20 @@ void *zmalloc(size_t size) {
 #endif
 }
 
+void *zcalloc(size_t size) {
+    void *ptr = calloc(1, size+PREFIX_SIZE);
+
+    if (!ptr) zmalloc_oom(size);
+#ifdef HAVE_MALLOC_SIZE
+    increment_used_memory(redis_malloc_size(ptr));
+    return ptr;
+#else
+    *((size_t*)ptr) = size;
+    increment_used_memory(size+PREFIX_SIZE);
+    return (char*)ptr+PREFIX_SIZE;
+#endif
+}
+
 void *zrealloc(void *ptr, size_t size) {
 #ifndef HAVE_MALLOC_SIZE
     void *realptr;
@@ -156,3 +182,86 @@ size_t zmalloc_used_memory(void) {
 void zmalloc_enable_thread_safeness(void) {
     zmalloc_thread_safe = 1;
 }
+
+/* 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
+float 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();
+}