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authorNikolaos S. Papaspyrou <[email protected]>2014-03-14 11:32:46 +0200
committerBjörn-Egil Dahlberg <[email protected]>2015-11-17 14:45:45 +0100
commit8d02ad60c88aa060ff83ff3179bc8c0ab66868ee (patch)
tree3368a591afaa2d23c9d7b38d70f80dc42785ccbb /erts/emulator/beam
parent7141fa8e4534ab7e4dcc3cad6c46872efa0e6e66 (diff)
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Add machinery to enable SHCOPY dynamically
This commit is just for debugging purposes, will probably be reverted. It comes with a the erts_debug:copy_shared/1 BIF. If SHCOPY_DISABLE is defined, SHCOPY starts disabled and is dynamically enabled the first time that the BIF is called.
Diffstat (limited to 'erts/emulator/beam')
-rw-r--r--erts/emulator/beam/beam_debug.c26
-rw-r--r--erts/emulator/beam/copy.c12
-rw-r--r--erts/emulator/beam/global.h2
3 files changed, 40 insertions, 0 deletions
diff --git a/erts/emulator/beam/beam_debug.c b/erts/emulator/beam/beam_debug.c
index 40e3f4db4e..36f3cfabbc 100644
--- a/erts/emulator/beam/beam_debug.c
+++ b/erts/emulator/beam/beam_debug.c
@@ -89,6 +89,32 @@ erts_debug_size_shared_1(BIF_ALIST_1)
}
BIF_RETTYPE
+erts_debug_copy_shared_1(BIF_ALIST_1)
+{
+ Process* p = BIF_P;
+ Eterm term = BIF_ARG_1;
+ Uint size;
+ Eterm* hp;
+ Eterm copy;
+ shcopy_info info;
+#ifdef SHCOPY_DISABLE
+ extern int disable_copy_shared;
+#endif
+ INITIALIZE_INFO(info);
+
+ size = copy_shared_calculate(term, &info, 0);
+ if (size > 0) {
+ hp = HAlloc(p, size);
+ }
+ copy = copy_shared_perform(term, size, &info, &hp, &p->off_heap, 0);
+ DESTROY_INFO(info);
+#ifdef SHCOPY_DISABLE
+ disable_copy_shared = 0;
+#endif
+ BIF_RET(copy);
+}
+
+BIF_RETTYPE
erts_debug_breakpoint_2(BIF_ALIST_2)
{
Process* p = BIF_P;
diff --git a/erts/emulator/beam/copy.c b/erts/emulator/beam/copy.c
index b31e043f08..2566707717 100644
--- a/erts/emulator/beam/copy.c
+++ b/erts/emulator/beam/copy.c
@@ -901,6 +901,10 @@ Eterm copy_struct(Eterm obj, Uint sz, Eterm** hpp, ErlOffHeap* off_heap)
* Using an ESTACK but not very transparently; consider refactoring
*/
+#ifdef SHCOPY_DISABLE
+int disable_copy_shared = ERTS_SHCOPY_FLG_NONE;
+#endif
+
#define DECLARE_SHTABLE(s) \
DECLARE_ESTACK(s); \
Uint ESTK_CONCAT(s,_offset) = 0
@@ -1028,6 +1032,10 @@ Uint copy_shared_calculate(Eterm obj, shcopy_info *info, unsigned flags)
if (IS_CONST(obj))
return 0;
+#ifdef SHCOPY_DISABLE
+ flags |= disable_copy_shared;
+#endif
+
myself = erts_get_current_process();
if (myself == NULL || (flags & ERTS_SHCOPY_FLG_NONE))
return size_object(obj);
@@ -1276,6 +1284,10 @@ Uint copy_shared_perform(Eterm obj, Uint size, shcopy_info *info, Eterm** hpp, E
if (IS_CONST(obj))
return obj;
+#ifdef SHCOPY_DISABLE
+ flags |= disable_copy_shared;
+#endif
+
myself = erts_get_current_process();
if (myself == NULL || (flags & ERTS_SHCOPY_FLG_NONE))
return copy_struct(obj, size, hpp, off_heap);
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index a5e6ff6f1c..3e1f3664bc 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -1044,6 +1044,8 @@ void erl_error(char*, va_list);
#if defined(SHCOPY_SEND) \
|| defined(SHCOPY_SPAWN)
#define SHCOPY
+/* Use this if you want sharing-preserving copy to be initially disabled */
+#undef SHCOPY_DISABLE
/* Use this with care, it is *very* verbose! */
#undef SHCOPY_DEBUG
#endif