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authorSverker Eriksson <[email protected]>2015-12-15 20:32:39 +0100
committerSverker Eriksson <[email protected]>2016-01-13 19:59:53 +0100
commitfa44f865c3fc6253cf4691cf94839c303a3ee40f (patch)
tree47ec77902253825bceab86035a6c960b801188e2 /erts/emulator
parentc612edf4ada1f00b2bdb8404103e0d8307dc8f4c (diff)
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erts: Make erlang:purge_module/1 safe
Problem: erlang:purge_module/1 is not safe in the sense that very bad things may happen if the code to be purged is still referred to by live processes. Introduce erts_internal:purge_module which is the same as the old erlang:purge_module BIF (except it returns false if no such old module). Implement erlang:purge_module in Erlang and let it invoke erts_code_purger for safe purging where all clogging processes first are killed.
Diffstat (limited to 'erts/emulator')
-rw-r--r--erts/emulator/beam/beam_bif_load.c14
-rw-r--r--erts/emulator/beam/bif.tab2
2 files changed, 11 insertions, 5 deletions
diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index 6bb70cc5a7..014ee35fd0 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -1094,7 +1094,12 @@ static void copy_literals_commit(void* null) {
#endif /* ERTS_SMP */
-BIF_RETTYPE purge_module_1(BIF_ALIST_1)
+/* Do the actualy module purging and return:
+ * true for success
+ * false if no such old module
+ * BADARG if not an atom
+ */
+BIF_RETTYPE erts_internal_purge_module_1(BIF_ALIST_1)
{
ErtsCodeIndex code_ix;
BeamInstr* code;
@@ -1108,7 +1113,8 @@ BIF_RETTYPE purge_module_1(BIF_ALIST_1)
}
if (!erts_try_seize_code_write_permission(BIF_P)) {
- ERTS_BIF_YIELD1(bif_export[BIF_purge_module_1], BIF_P, BIF_ARG_1);
+ ERTS_BIF_YIELD1(bif_export[BIF_erts_internal_purge_module_1],
+ BIF_P, BIF_ARG_1);
}
code_ix = erts_active_code_ix();
@@ -1118,7 +1124,7 @@ BIF_RETTYPE purge_module_1(BIF_ALIST_1)
*/
if ((modp = erts_get_module(BIF_ARG_1, code_ix)) == NULL) {
- ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
+ ERTS_BIF_PREP_RET(ret, am_false);
}
else {
erts_rwlock_old_code(code_ix);
@@ -1127,7 +1133,7 @@ BIF_RETTYPE purge_module_1(BIF_ALIST_1)
* Any code to purge?
*/
if (!modp->old.code_hdr) {
- ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
+ ERTS_BIF_PREP_RET(ret, am_false);
}
else {
/*
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 0aee8681c6..3b95ec508c 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -125,7 +125,6 @@ bif erlang:process_flag/3
bif erlang:process_info/1
bif erlang:process_info/2
bif erlang:processes/0
-bif erlang:purge_module/1
bif erlang:put/2
bif erlang:register/2
bif erlang:registered/0
@@ -643,6 +642,7 @@ bif erts_debug:map_info/1
#
bif erlang:copy_literals/2
+bif erts_internal:purge_module/1
bif binary:split/2
bif binary:split/3
bif erts_debug:size_shared/1