Add the +t emulator option to change the maximum number of atoms

It is now possible to increase or decrease the maximum number of atoms
the VM can handle. The default value is 1048576 (1024*1024).

1 files changed, 22 insertions, 0 deletions

diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index bdf888eaff..17cf3b9597 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -119,6 +119,8 @@ int erts_disable_tolerant_timeofday; /* Time correction can be disabled it is
 				      * not and/or it is too slow.
 				      */
 
+int erts_atom_table_size = ATOM_LIMIT;	/* Maximum number of atoms */
+
 int erts_modified_timing_level;
 
 int erts_no_crash_dump = 0;	/* Use -d to suppress crash dump. */
@@ -569,6 +571,10 @@ void erts_usage(void)
     erts_fprintf(stderr, "            schedulers online (n2), valid range for both\n");
     erts_fprintf(stderr, "            numbers are [1-%d]\n",
 		 ERTS_MAX_NO_OF_SCHEDULERS);
+    erts_fprintf(stderr, "-t size     set the maximum number of atoms the "
+			 "emulator can handle\n");
+    erts_fprintf(stderr, "            valid range is [%d-%d]\n",
+		 MIN_ATOM_TABLE_SIZE, MAX_ATOM_TABLE_SIZE);
     erts_fprintf(stderr, "-T number   set modified timing level,\n");
     erts_fprintf(stderr, "            valid range is [0-%d]\n",
 		 ERTS_MODIFIED_TIMING_LEVELS-1);
@@ -1140,6 +1146,22 @@ erl_start(int argc, char **argv)
 	    }
 	    break;
 	}
+	case 't':
+	    /* set atom table size */
+	    arg = get_arg(argv[i]+2, argv[i+1], &i);
+	    errno = 0;
+	    erts_atom_table_size = strtol(arg, NULL, 10);
+	    if (errno != 0 ||
+		erts_atom_table_size < MIN_ATOM_TABLE_SIZE ||
+		erts_atom_table_size > MAX_ATOM_TABLE_SIZE) {
+		erts_fprintf(stderr, "bad atom table size %s\n", arg);
+		erts_usage();
+	    }
+	    VERBOSE(DEBUG_SYSTEM,
+                    ("setting maximum number of atoms to %d\n",
+		     erts_atom_table_size));
+	    break;
+
 	case 'T' :
 	    arg = get_arg(argv[i]+2, argv[i+1], &i);
 	    errno = 0;