Reserve memory. Refs #2613. [t:2613].

git-svn-id: file:///svn/toku/tokudb@20241 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/brtloader-internal.h

@@ -136,6 +136,8 @@ struct brtloader_s {
     const char *temp_file_template;
 
     CACHETABLE cachetable;
+    uint64_t   reserved_memory; // how much memory are we allowed to use?
+
     /* To make it easier to recover from errors, we don't use FILE*, instead we use an index into the file_infos. */
     struct file_infos file_infos;
 

newbrt/brtloader.c

@@ -267,8 +267,11 @@ static void brtloader_destroy (BRTLOADER bl, BOOL is_error) {
     toku_free(bl->fractal_queues);
     toku_free(bl->fractal_threads_live);
 
+    toku_cachetable_release_reserved_memory(bl->cachetable, bl->reserved_memory);
+
     brt_loader_destroy_error_callback(&bl->error_callback);
     brt_loader_destroy_poll_callback(&bl->poll_callback);
+
     toku_free(bl);
 }
 
@@ -311,6 +314,7 @@ int toku_brt_loader_open (/* out */ BRTLOADER *blp,
 
     bl->generate_row_for_put = g;
     bl->cachetable = cachetable;
+    bl->reserved_memory = toku_cachetable_reserve_memory(cachetable, 0.5);
 
     bl->src_db = src_db;
     bl->N = N;

newbrt/cachetable.c

@@ -119,6 +119,7 @@ struct ctpair {
 static void * const zero_value = 0;
 static int const zero_size = 0;
 
+static int maybe_flush_some (CACHETABLE ct, long size);
 
 static inline void
 ctpair_add_ref(PAIR p) {
@@ -296,6 +297,29 @@ int toku_create_cachetable(CACHETABLE *result, long size_limit, LSN UU(initial_l
     return 0;
 }
 
+uint64_t toku_cachetable_reserve_memory(CACHETABLE ct, double fraction) {
+    cachetable_lock(ct);
+    cachetable_wait_write(ct);
+    uint64_t reserved_memory = fraction*ct->size_limit;
+    {
+	int r = maybe_flush_some(ct, reserved_memory);
+	if (r) {
+	    cachetable_unlock(ct);
+	    return r;
+	}
+    }
+    ct->size_current += reserved_memory;
+    cachetable_unlock(ct);
+    return reserved_memory;
+}
+
+void toku_cachetable_release_reserved_memory(CACHETABLE ct, uint64_t reserved_memory) {
+    cachetable_lock(ct);
+    ct->size_current -= reserved_memory;
+    assert(ct->size_current >= 0);
+    cachetable_unlock(ct);
+}
+
 void
 toku_cachetable_set_env_dir(CACHETABLE ct, char *env_dir) {
     assert(!ct->set_env_dir);

newbrt/cachetable.h

@@ -82,7 +82,6 @@ int toku_cachetable_openf (CACHEFILE *,CACHETABLE, const char */*fname_in_env*/,
 // Returns the limit on the cachetable size
 uint64_t toku_cachetable_get_size_limit(CACHETABLE ct);
 
-
 // Bind a file to a new cachefile object.
 int toku_cachetable_openfd (CACHEFILE *,CACHETABLE, int /*fd*/, 
 			    const char *fname_relative_to_env); /*(used for logging)*/
@@ -97,6 +96,12 @@ int toku_cachetable_reserve_filenum (CACHETABLE ct, FILENUM *reserved_filenum, B
 
 void toku_cachetable_unreserve_filenum (CACHETABLE ct, FILENUM reserved_filenum);
 
+// Effect: Reserve a fraction of the cachetable memory.
+// Returns the amount reserved.
+// To return the memory to the cachetable, call toku_cachetable_release_reserved_memory
+// Requires 0<fraction<1.
+uint64_t toku_cachetable_reserve_memory(CACHETABLE, double fraction);
+void toku_cachetable_release_reserved_memory(CACHETABLE, uint64_t);
 
 // Get access to the asynchronous work queue
 // Returns: a pointer to the work queue