working with TESTNULL

Author: mirsella

include/malloc.h

@@ -17,6 +17,7 @@
 
 #define MMAP_SHIFT(mmap) ((void *)mmap + sizeof(t_mmap))
 #define ALLOC_SHIFT(alloc) ((void *)alloc + sizeof(t_alloc))
+#define TESTNULL(mmap) ((mmap == NULL || mmap == (void *)1) ? 1 : 0)
 
 #define ALIGNMENT 16 // 8 on 32 bits, 16 on 64 bits
 #define TINY_MMAP_SIZE (4 * getpagesize())
@@ -44,7 +45,7 @@ typedef struct s_alloc {
   size_t size;
 } t_alloc;
 
-extern t_mmap g_mmap;
+extern t_mmap *g_mmap;
 
 // global_init.c
 void lock_mutex();
@@ -57,7 +58,7 @@ void *_malloc(size_t size);
 void *malloc(size_t size);
 
 // free.c
-void _free(void *ptr);
+void _free(void *mmap);
 void free(void *ptr);
 
 // realloc.c

perf.data

@@ -3,7 +3,9 @@
 // alternative method to find alloc even if the ptr is in the middle of the
 // alloc
 t_alloc *find_alloc_ptr(void *ptr) {
-  for (t_mmap *mmap = g_mmap.next; (size_t)mmap > 1; mmap = mmap->next) {
+  if (TESTNULL(g_mmap))
+    return NULL;
+  for (t_mmap *mmap = g_mmap; !TESTNULL(mmap); mmap = mmap->next) {
     if (ptr < (void *)mmap || ptr > MMAP_SHIFT(mmap) + mmap->size)
       continue;
     for (t_alloc *alloc = mmap->alloc; alloc; alloc = alloc->next) {
@@ -58,11 +60,9 @@ t_alloc *new_alloc(t_mmap *mmap, void *ptr, size_t size) {
 }
 
 t_alloc *find_alloc(size_t size) {
-  if ((size_t)g_mmap.next < 2)
+  if (TESTNULL(g_mmap))
     return NULL;
-  for (t_mmap *mmap = g_mmap.next; (size_t)mmap > 1; mmap = mmap->next) {
-    if ((size_t)mmap < 2)
-      return NULL;
+  for (t_mmap *mmap = g_mmap; !TESTNULL(mmap); mmap = mmap->next) {
     if (mmap->type != get_mmap_type(size))
       continue;
 

src/alloc.c

@@ -3,7 +3,7 @@
 #include <unistd.h>
 
 void _free(void *ptr) {
-  if (!ptr || (size_t)g_mmap.next < 2)
+  if (!ptr || TESTNULL(g_mmap))
     return;
   /* t_alloc *alloc = ptr - sizeof(t_alloc); */
   t_alloc *alloc = find_alloc_ptr(ptr);
@@ -22,20 +22,18 @@ void _free(void *ptr) {
     alloc->parent->alloc = alloc->next;
 
   // in case it's the only alloc in a t_mmap, free the mmap
+  if (alloc->parent->type != LARGE)
+    return;
   if (!alloc->next && !alloc->prev) {
     t_mmap *map = alloc->parent;
     if (map->prev)
       map->prev->next = map->next;
     if (map->next)
       map->next->prev = map->prev;
     // FIX: this cause page reclaims to skyrocket
-    /* if (map == g_mmap) */
-    /*   g_mmap = map->next; */
+    if (map == g_mmap)
+      g_mmap = map->next;
 
-    /* if (map == g_mmap.next) */
-    /*   g_mmap.next = map->next ? map->next : (void *)1; */
-    if (map == g_mmap.next)
-      g_mmap.next = (void *)1;
     munmap(map, map->size + sizeof(t_mmap));
   }
 }

src/free.c

@@ -1,7 +1,8 @@
 #include "../include/malloc.h"
 #include <string.h>
 
-t_mmap g_mmap = {NULL, NULL, ANCHOR, 0, NULL};
+/* t_mmap g_mmap = {NULL, NULL, ANCHOR, 0, NULL}; */
+t_mmap *g_mmap = NULL;
 
 pthread_mutex_t g_mutex = PTHREAD_MUTEX_INITIALIZER;
 

src/global_init.c

@@ -17,29 +17,29 @@ t_type get_mmap_type(size_t size) {
 }
 
 t_mmap *new_mmap(size_t size) {
-  t_mmap *map =
-      mmap(NULL, get_mmap_size(size) + sizeof(t_mmap), PROT_READ | PROT_WRITE,
-           MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-  if (!map) {
+  void *ptr = mmap(NULL, get_mmap_size(size) + sizeof(t_mmap),
+                   PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (!ptr) {
     errno = ENOMEM;
     return NULL;
   }
+  t_mmap *map = ptr;
   map->type = get_mmap_type(size);
   map->size = get_mmap_size(size);
   map->next = NULL;
   map->prev = NULL;
   map->alloc = NULL;
-  if ((size_t)g_mmap.next < 2)
-    return g_mmap.next = map;
-  for (t_mmap *tmp = g_mmap.next; (size_t)tmp > 1; tmp = tmp->next) {
+  if (TESTNULL(g_mmap))
+    return g_mmap = map;
+  for (t_mmap *tmp = g_mmap; !TESTNULL(tmp); tmp = tmp->next) {
     if (map < tmp) {
       map->prev = tmp->prev;
       map->next = tmp;
       tmp->prev = map;
       if (map->prev)
         map->prev->next = map;
-      if (g_mmap.next == tmp)
-        g_mmap.next = map;
+      if (g_mmap == tmp)
+        g_mmap = map;
       break;
     } else if (map > tmp && (map < tmp->next || !tmp->next)) {
       map->prev = tmp;

src/mmap.c

@@ -11,13 +11,13 @@ char *get_type_string(t_type type) {
 
 void show_alloc_mem() {
   lock_mutex();
-  if ((size_t)g_mmap.next < 2) {
+  if (TESTNULL(g_mmap)) {
     ft_putstr("show_alloc_mem(): No memory allocated\n");
     unlock_mutex();
     return;
   }
   size_t total = 0;
-  for (t_mmap *mmap = g_mmap.next; (size_t)mmap > 1; mmap = mmap->next) {
+  for (t_mmap *mmap = g_mmap; !TESTNULL(mmap); mmap = mmap->next) {
     ft_printf("%s : %p\n", get_type_string(mmap->type), mmap);
     for (t_alloc *alloc = mmap->alloc; alloc; alloc = alloc->next) {
       if (!alloc)
@@ -70,13 +70,13 @@ void hexdump(void *ptr, size_t size) {
 
 void show_alloc_mem_asciidump() {
   lock_mutex();
-  if ((size_t)g_mmap.next < 2) {
+  if (TESTNULL(g_mmap)) {
     ft_putstr("show_alloc_mem_ex(): No memory allocated\n");
     unlock_mutex();
     return;
   }
   size_t total = 0;
-  for (t_mmap *mmap = g_mmap.next; (size_t)mmap > 1; mmap = mmap->next) {
+  for (t_mmap *mmap = g_mmap; !TESTNULL(mmap); mmap = mmap->next) {
     ft_printf("%s : %p\n", get_type_string(mmap->type), mmap);
     for (t_alloc *alloc = mmap->alloc; alloc; alloc = alloc->next) {
       if (!alloc)
@@ -99,13 +99,13 @@ void show_alloc_mem_asciidump() {
 
 void show_alloc_mem_hexdump() {
   lock_mutex();
-  if ((size_t)g_mmap.next < 2) {
+  if (TESTNULL(g_mmap)) {
     ft_putstr("show_alloc_mem_ex(): No memory allocated\n");
     unlock_mutex();
     return;
   }
   size_t total = 0;
-  for (t_mmap *mmap = g_mmap.next; (size_t)mmap > 1; mmap = mmap->next) {
+  for (t_mmap *mmap = g_mmap; !TESTNULL(mmap); mmap = mmap->next) {
     ft_printf("%s : %p\n", get_type_string(mmap->type), mmap);
     for (t_alloc *alloc = mmap->alloc; alloc; alloc = alloc->next) {
       if (!alloc)

src/show_alloc_mem.c

@@ -1,4 +1,4 @@
-#include "include/malloc.h"
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 

test2

@@ -4,38 +4,31 @@
 
 #define M (1024 * 1024)
 
-void print(char *s)
-{
-    write(1, s, strlen(s));
-}
+void print(char *s) { write(1, s, strlen(s)); }
 
-int     main()
-{
-    char *addr1;
-    char *addr2;
-    char *addr3;
+int main() {
+  char *addr1;
+  char *addr2;
+  char *addr3;
 
-    addr1 = (char*)malloc(16*M);
-    if (addr1 == NULL)
-    {
-        print("Failed to allocate memory\n");
-        exit(1);
-    }
-    strcpy(addr1, "Hello world!\n");
-    print(addr1);
-    addr2 = (char*)malloc(16*M);
-    if (addr2 == NULL)
-    {
-        print("Failed to allocate memory\n");
-        exit(1);
-    }
-    addr3 = (char*)realloc(addr1, 128*M);
-    if (addr3 == NULL)
-    {
-        print("Failed to reallocate memory\n");
-        exit(1);
-    }
-    addr3[127*M] = 42;
-    print(addr3);
-    return (0);
+  addr1 = (char *)malloc(16 * M);
+  if (addr1 == NULL) {
+    print("Failed to allocate memory\n");
+    exit(1);
+  }
+  strcpy(addr1, "Hello world!\n");
+  print(addr1);
+  addr2 = (char *)malloc(16 * M);
+  if (addr2 == NULL) {
+    print("Failed to allocate memory\n");
+    exit(1);
+  }
+  addr3 = (char *)realloc(addr1, 128 * M);
+  if (addr3 == NULL) {
+    print("Failed to reallocate memory\n");
+    exit(1);
+  }
+  addr3[127 * M] = 42;
+  print(addr3);
+  return (0);
 }