Clean up the interfaces and remove some obviously incorrect code.to-tytso-20011015b

6 files changed, 37 insertions, 24 deletions

diff --git a/alloc.c b/alloc.c
index 39a2585..dce15d3 100644
--- a/alloc.c
+++ b/alloc.c
@@ -19,8 +19,9 @@
  * This code uses a modified buddy system allocator for large allocations
  * and a SLAB allocator for small allocations.
  *
- * This generally assumes 8-bit bytes and 2's-complement arithmetric.
- * These days, that's oh-such-a-strech...
+ * This generally assumes 8-bit bytes and 2's-complement arithmetric,
+ * and that an all-zero bit pattern is a valid NULL.  These days, that's
+ * oh-such-a-strech...
  */
 
 #include <assert.h>
@@ -78,7 +79,6 @@ struct arena_header {
   uint16_t arena_bytesize;
   uint16_t arena_ptrsize;
   void *arena_base;		/* Base of allocation */
-  void *root_data_ptr;		/* Root data pointer - for the user */
   void *free_bitmap;		/* The free bitmap */
   void *alloc_bitmap;		/* The allocated (buddy) bitmap */
   void *data_start;		/* Beginning of data area */
@@ -86,6 +86,7 @@ struct arena_header {
   int arena_size_lg2;		/* Current arena allocation size */
   int header_size;		/* Size of this header+padding */
   struct slab_info slab[SLAB_INFO_COUNT];
+  void *root_data_ptrs[ROOT_DATA_POINTERS]; /* Root data pointers - for the user */
 };
 
 /* This is the minimal order before going to SLAB allocation. */
@@ -235,10 +236,17 @@ static struct ObjStore *os;
 static struct arena_header *ah;
     
 /*
- * Initalize the object store arena allocator.
+ * Initalize the object store arena allocator.  This returns NULL
+ * on failure, or a pointer to the "root data pointer" array if
+ * successful.
  */
-void *objstore_arena_init(void)
+void **objstore_arena_init(const char *main_file, const char *log_file)
 {
+  size_t arena_len = sizeof(struct arena_header); /* Minimum initial size */
+
+  if ( !objstore_init(main_file, log_file, &arena_len) )
+    return NULL;		/* Failed to initialize arena */
+
   os = objstore_os_struct;
   ah = (struct arena_header *)os->arena;
 
@@ -247,6 +255,8 @@ void *objstore_arena_init(void)
       size_t total_size, bitmap_size;
       int i, header_pad;
 
+      memset(ah, 0, sizeof(*ah)); /* Just in case */
+
       /* Uninitialized arena */
       memcpy(ah->arena_magic, objstore_arena_magic, 16);
       ah->arena_byteorder = 0x12345678;
@@ -309,7 +319,7 @@ void *objstore_arena_init(void)
     return NULL;		/* Incompatible or corrupt arena */
   }
 
-  return ah->data_start;
+  return ah->root_data_ptrs;
 }
 
 /*
diff --git a/arena.c b/arena.c
index 10df925..3fdbd7a 100644
--- a/arena.c
+++ b/arena.c
@@ -228,8 +228,6 @@ static int objstore_log_writeback(void)
       char *data;
       
       position += sizeof(record);
-      if ( !data )
-	return -1;		/* Badness... */
       
       lockmain.l_type   = F_WRLCK;
       lockmain.l_whence = SEEK_SET;
@@ -303,7 +301,7 @@ static int objstore_recover_log(void)
  * playback (crash recovery) if the log file exists
  * and is nonempty.
  */
-void *objstore_init(char *main_file, char *log_file, size_t *arena_len)
+void *objstore_init(const char *main_file, const char *log_file, size_t *arena_len)
 {
   struct ObjStore *os;
   void *arena_ptr;
diff --git a/ftrunctest.c b/ftrunctest.c
index dfa58b3..c8b4a05 100644
--- a/ftrunctest.c
+++ b/ftrunctest.c
@@ -7,7 +7,6 @@
 int main(int argc, char *argv[])
 {
   int fd;
-  char *mapping;
 
   fd = open("ftrunc.dat", O_RDWR|O_CREAT, 0666);
   ftruncate(fd, 1024*1024*1024);
diff --git a/lpsm.h b/lpsm.h
index e24550d..a6c08ac 100644
--- a/lpsm.h
+++ b/lpsm.h
@@ -24,17 +24,25 @@
 #include <signal.h>
 #include <inttypes.h>
 
-struct Objstore;
+/* Low-level core routines */
 
-/* Core routines */
-void *objstore_init(char *, char *, size_t *);
+void *objstore_init(const char *, const char *, size_t *);
 int objstore_checkpoint(double);
 int objstore_extend(size_t);
 
 /* Arena management routines */
-void *objstore_arena_init(void);
+
+/* The allocator gives us this many "root pointers" for our own use.  They
+   are initialized to NULL when a new arena is created, and are intended
+   to be used to find all the data structures.  objstore_arena_init()
+   returns a pointer to this array (if successful). */
+#define ROOT_DATA_POINTERS	32
+
+void **objstore_arena_init(const char *, const char *);
 void *objstore_malloc(size_t);
 void objstore_free(void *);
 void *objstore_realloc(void *, size_t);
 
+void **objstore_get_root_ptrs(void);
+
 #endif
diff --git a/testalloc.c b/testalloc.c
index 9c66d07..9a6d3ed 100644
--- a/testalloc.c
+++ b/testalloc.c
@@ -50,11 +50,10 @@ void verify_no_overlap(int slot)
 
 int main(int argc, char *argv[])
 {
-  void *buf;
   int i, slot, newsize;
   double rnd;
+  void **root_ptr;
   void *nptr;
-  size_t arena_len = 4096;
   unsigned long occupied = 0;
 
   unlink("arena.dat");
@@ -63,12 +62,14 @@ int main(int argc, char *argv[])
   memset(areas, 0, sizeof(areas));
   memset(sizes, 0, sizeof(sizes));
 
-  buf = objstore_init("arena.dat", "arena.log", &arena_len);
-  if ( !objstore_arena_init() ) {
+  if ( !(root_ptr = objstore_arena_init("arena.dat", "arena.log")) ) {
     fprintf(stderr, "%s: objstore_arena_init() failed\n", argv[0]);
     return 1;
   }
 
+  printf("Arena:   initialized, %d root pointers at %p\n",
+	 ROOT_DATA_POINTERS, root_ptr);
+
   objstore_checkpoint(0.0);
 
   for ( i = 0 ; i < COUNT ; i++ ) {
diff --git a/testbuddy.c b/testbuddy.c
index 5bde336..4cf02a8 100644
--- a/testbuddy.c
+++ b/testbuddy.c
@@ -87,15 +87,12 @@ static int testsizes[] = {
 int main(int argc, char *argv[])
 {
   void *areas[64];
-  void *buf;
-  int arena_len = 16384;
   int i;
 
-  unlink("arena.dat");
-  unlink("arena.log");
+  unlink("buddy.dat");
+  unlink("buddy.log");
 
-  buf = objstore_init("arena.dat", "arena.log", &arena_len);
-  if ( !objstore_arena_init() ) {
+  if ( !objstore_arena_init("buddy.dat", "buddy.log") ) {
     fprintf(stderr, "%s: objstore_arena_init() failed\n", argv[0]);
     return 1;
   }