From d6e8bddde0887894ae70cc2c6d4230532801bf97 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Fri, 5 Oct 2018 13:15:49 +0200 Subject: Extend the sharing-preserving routines to optionally copy literals In the implementation of the zero-copying term storage, we want to preserve sharing, but not copy literals because the modules holding the literals could be unloaded under our feet. --- erts/emulator/beam/copy.c | 10 ++++++---- erts/emulator/beam/global.h | 2 ++ 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/erts/emulator/beam/copy.c b/erts/emulator/beam/copy.c index e7bfd04b73..e7bd046e18 100644 --- a/erts/emulator/beam/copy.c +++ b/erts/emulator/beam/copy.c @@ -1074,6 +1074,7 @@ Uint copy_shared_calculate(Eterm obj, erts_shcopy_t *info) Eterm* ptr; Eterm *lit_purge_ptr = info->lit_purge_ptr; Uint lit_purge_sz = info->lit_purge_sz; + int copy_literals = info->copy_literals; #ifdef DEBUG Eterm mypid = erts_get_current_pid(); #endif @@ -1119,7 +1120,7 @@ Uint copy_shared_calculate(Eterm obj, erts_shcopy_t *info) /* off heap list pointers are copied verbatim */ if (erts_is_literal(obj,ptr)) { VERBOSE(DEBUG_SHCOPY, ("[pid=%T] bypassed copying %p is %T\n", mypid, ptr, obj)); - if (in_literal_purge_area(ptr)) + if (copy_literals || in_literal_purge_area(ptr)) info->literal_size += size_object(obj); goto pop_next; } @@ -1170,7 +1171,7 @@ Uint copy_shared_calculate(Eterm obj, erts_shcopy_t *info) /* off heap pointers to boxes are copied verbatim */ if (erts_is_literal(obj,ptr)) { VERBOSE(DEBUG_SHCOPY, ("[pid=%T] bypassed copying %p is %T\n", mypid, ptr, obj)); - if (in_literal_purge_area(ptr)) + if (copy_literals || in_literal_purge_area(ptr)) info->literal_size += size_object(obj); goto pop_next; } @@ -1338,6 +1339,7 @@ Uint copy_shared_perform(Eterm obj, Uint size, erts_shcopy_t *info, unsigned remaining; Eterm *lit_purge_ptr = info->lit_purge_ptr; Uint lit_purge_sz = info->lit_purge_sz; + int copy_literals = info->copy_literals; #ifdef DEBUG Eterm mypid = erts_get_current_pid(); Eterm saved_obj = obj; @@ -1387,7 +1389,7 @@ Uint copy_shared_perform(Eterm obj, Uint size, erts_shcopy_t *info, ptr = list_val(obj); /* off heap list pointers are copied verbatim */ if (erts_is_literal(obj,ptr)) { - if (!in_literal_purge_area(ptr)) { + if (!(copy_literals || in_literal_purge_area(ptr))) { *resp = obj; } else { Uint bsz = 0; @@ -1455,7 +1457,7 @@ Uint copy_shared_perform(Eterm obj, Uint size, erts_shcopy_t *info, ptr = boxed_val(obj); /* off heap pointers to boxes are copied verbatim */ if (erts_is_literal(obj,ptr)) { - if (!in_literal_purge_area(ptr)) { + if (!(copy_literals || in_literal_purge_area(ptr))) { *resp = obj; } else { Uint bsz = 0; diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h index 21ae205237..9fc5abbf68 100644 --- a/erts/emulator/beam/global.h +++ b/erts/emulator/beam/global.h @@ -1001,6 +1001,7 @@ typedef struct { Uint literal_size; Eterm *lit_purge_ptr; Uint lit_purge_sz; + int copy_literals; } erts_shcopy_t; #define INITIALIZE_SHCOPY(info) \ @@ -1010,6 +1011,7 @@ typedef struct { info.bitstore_start = info.bitstore_default; \ info.shtable_start = info.shtable_default; \ info.literal_size = 0; \ + info.copy_literals = 0; \ if (larea__) { \ info.lit_purge_ptr = &larea__->start[0]; \ info.lit_purge_sz = larea__->end - info.lit_purge_ptr; \ -- cgit v1.2.3