1 files changed, 68 insertions, 27 deletions

diff --git a/erts/emulator/beam/erl_fun.h b/erts/emulator/beam/erl_fun.h
index 995fb41de2..4276e9a999 100644
--- a/erts/emulator/beam/erl_fun.h
+++ b/erts/emulator/beam/erl_fun.h
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  *
- * Copyright Ericsson AB 2000-2021. All Rights Reserved.
+ * Copyright Ericsson AB 2000-2022. All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,53 +26,85 @@
 /*
  * Fun entry.
  */
-
 typedef struct erl_fun_entry {
-    HashBucket bucket;          /* MUST BE LOCATED AT TOP OF STRUCT!!! */
-
-    byte uniq[16];              /* MD5 for module. */
-    int index;                  /* New style index. */
-    int old_uniq;               /* Unique number (old_style) */
-    int old_index;              /* Old style index */
-    ErtsCodePtr address;        /* Pointer to code for fun */
+    /* We start with an `ErtsDispatchable`, similar to export entries, so that
+     * we can mostly use the same code for both. This greatly reduces the
+     * complexity of instructions like `call_fun` and `is_function2`. */
+    ErtsDispatchable dispatch;
 
-    Uint arity;                     /* The arity of the fun. */
+    /* These fields identify the function and must not be altered after fun
+     * creation. */
     Eterm module;                   /* Tagged atom for module. */
+    Uint arity;                     /* The arity of the fun. */
+    int index;                      /* New style index. */
+    byte uniq[16];                  /* MD5 for module. */
+    int old_uniq;                   /* Unique number (old_style) */
+    int old_index;                  /* Old style index */
+
     erts_refc_t refc;               /* Reference count: One for code + one for
                                      * each fun object in each process. */
     ErtsCodePtr pend_purge_address; /* Address during a pending purge */
 } ErlFunEntry;
 
-/*
- * This structure represents a 'fun' (lambda). It is stored on
- * process heaps. It has variable size depending on the size
- * of the environment.
- */
+/* This structure represents a 'fun' (lambda), whether local or external. It is
+ * stored on process heaps, and has variable size depending on the size of the
+ * environment. */
 
 typedef struct erl_fun_thing {
-    Eterm thing_word;		/* Subtag FUN_SUBTAG. */
-    ErlFunEntry* fe;		/* Pointer to fun entry. */
-    struct erl_off_heap_header* next;
-    Uint arity;			/* The arity of the fun. */
-    Uint num_free;		/* Number of free variables (in env). */
-  /* -- The following may be compound Erlang terms ---------------------- */
-    Eterm creator;		/* Pid of creator process (contains node). */
-    Eterm env[1];		/* Environment (free variables). */
+    Eterm thing_word;       /* Subtag FUN_SUBTAG. */
+
+    union {
+        /* Both `ErlFunEntry` and `Export` begin with an `ErtsDispatchable`, so
+         * code that doesn't really care which (e.g. calls) can use this
+         * pointer to improve performance. */
+        ErtsDispatchable *disp;
+
+        /* Pointer to function entry, valid iff `creator != am_external`.*/
+        ErlFunEntry *fun;
+
+        /* Pointer to export entry, valid iff `creator == am_external`.*/
+        Export *exp;
+    } entry;
+
+    /* Next off-heap object, must be NULL when this is an external fun. */
+    struct erl_off_heap_header *next;
+
+    byte arity;             /* The _apparent_ arity of the fun. */
+    byte num_free;          /* Number of free variables (in env). */
+
+    /* -- The following may be compound Erlang terms ---------------------- */
+    Eterm creator;          /* Pid of creator process (contains node). */
+    Eterm env[1];           /* Environment (free variables). */
 } ErlFunThing;
 
+#define is_local_fun(FunThing) ((FunThing)->creator != am_external)
+#define is_external_fun(FunThing) ((FunThing)->creator == am_external)
+
 /* ERL_FUN_SIZE does _not_ include space for the environment */
 #define ERL_FUN_SIZE ((sizeof(ErlFunThing)/sizeof(Eterm))-1)
 
+ErlFunThing *erts_new_export_fun_thing(Eterm **hpp, Export *exp, int arity);
+ErlFunThing *erts_new_local_fun_thing(Process *p,
+                                      ErlFunEntry *fe,
+                                      int arity,
+                                      int num_free);
+
 void erts_init_fun_table(void);
 void erts_fun_info(fmtfn_t, void *);
 int erts_fun_table_sz(void);
 
-ErlFunEntry* erts_get_fun_entry(Eterm mod, int uniq, int index);
-
+/* Finds or inserts a fun entry that matches the given signature. */
 ErlFunEntry* erts_put_fun_entry2(Eterm mod, int old_uniq, int old_index,
-				const byte* uniq, int index, int arity);
+                                 const byte* uniq, int index, int arity);
+
+const ErtsCodeMFA *erts_get_fun_mfa(const ErlFunEntry *fe);
+
+void erts_set_fun_code(ErlFunEntry *fe, ErtsCodePtr address);
 
-int erts_is_fun_loaded(ErlFunEntry* fe);
+ERTS_GLB_INLINE
+ErtsCodePtr erts_get_fun_code(ErlFunEntry *fe, ErtsCodeIndex ix);
+
+int erts_is_fun_loaded(const ErlFunEntry* fe);
 
 void erts_erase_fun_entry(ErlFunEntry* fe);
 void erts_cleanup_funs(ErlFunThing* funp);
@@ -84,4 +116,13 @@ void erts_fun_purge_abort_finalize(ErlFunEntry **funs, Uint no);
 void erts_fun_purge_complete(ErlFunEntry **funs, Uint no);
 void erts_dump_fun_entries(fmtfn_t, void *);
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE
+ErtsCodePtr erts_get_fun_code(ErlFunEntry *fe, ErtsCodeIndex ix) {
+    return fe->dispatch.addresses[ix];
+}
+
+#endif
+
 #endif