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authorSverker Eriksson <[email protected]>2012-02-07 16:19:43 +0100
committerSverker Eriksson <[email protected]>2012-02-21 12:23:06 +0100
commitc2f62a3813c5c2bd2bb691df816d5fc2fb17206a (patch)
treea34e02c42382e2d234a1dec562ef7425741392bc
parent5aed8caaaf6c6b17ca2b2bd920ba76b31d6f5675 (diff)
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erts: Fix memory query for non-blocking module table
-rw-r--r--erts/emulator/beam/module.c31
1 files changed, 25 insertions, 6 deletions
diff --git a/erts/emulator/beam/module.c b/erts/emulator/beam/module.c
index 6d5f1528b4..1dab24e96a 100644
--- a/erts/emulator/beam/module.c
+++ b/erts/emulator/beam/module.c
@@ -39,9 +39,12 @@ static IndexTable module_tables[ERTS_NUM_CODE_IX];
erts_smp_rwmtx_t the_old_code_rwlocks[ERTS_NUM_CODE_IX];
-/*
- * SMP note: We don't need to look accesses to the module table because
- * there is one only scheduler thread when we update it.
+static erts_smp_atomic_t tot_module_bytes;
+
+/* SMP note: Active module table lookup and current module instance can be
+ * read without any locks. Old module instances are protected by
+ * "the_old_code_rwlocks" as purging is done on active module table.
+ * Staging table is protected by the "code_ix lock".
*/
#include "erl_smp.h"
@@ -67,6 +70,7 @@ static int module_cmp(Module* tmpl, Module* obj)
static Module* module_alloc(Module* tmpl)
{
Module* obj = (Module*) erts_alloc(ERTS_ALC_T_MODULE, sizeof(Module));
+ erts_smp_atomic_add_nob(&tot_module_bytes, sizeof(Module));
obj->module = tmpl->module;
obj->curr.code = 0;
@@ -86,6 +90,7 @@ static Module* module_alloc(Module* tmpl)
static void module_free(Module* mod)
{
erts_free(ERTS_ALC_T_MODULE, mod);
+ erts_smp_atomic_add_nob(&tot_module_bytes, -sizeof(Module));
}
void init_module_table(void)
@@ -106,6 +111,7 @@ void init_module_table(void)
for (i=0; i<ERTS_NUM_CODE_IX; i++) {
erts_smp_rwmtx_init_x(&the_old_code_rwlocks[i], "old_code", make_small(i));
}
+ erts_smp_atomic_init_nob(&tot_module_bytes, 0);
}
Module*
@@ -133,6 +139,8 @@ erts_put_module(Eterm mod)
{
Module e;
IndexTable* mod_tab;
+ int oldsz, newsz;
+ Module* res;
ASSERT(is_atom(mod));
ERTS_SMP_LC_ASSERT(erts_initialized == 0
@@ -141,7 +149,11 @@ erts_put_module(Eterm mod)
mod_tab = &module_tables[erts_staging_code_ix()];
e.module = atom_val(mod);
- return (Module*) index_put_entry(mod_tab, (void*) &e);
+ oldsz = index_table_sz(mod_tab);
+ res = (Module*) index_put_entry(mod_tab, (void*) &e);
+ newsz = index_table_sz(mod_tab);
+ erts_smp_atomic_add_nob(&tot_module_bytes, (newsz - oldsz));
+ return res;
}
Module *module_code(int i, ErtsCodeIndex code_ix)
@@ -156,7 +168,7 @@ int module_code_size(ErtsCodeIndex code_ix)
int module_table_sz(void)
{
- return index_table_sz(&module_tables[erts_active_code_ix()]);
+ return erts_smp_atomic_read_nob(&tot_module_bytes);
}
#ifdef DEBUG
@@ -171,7 +183,7 @@ void module_start_staging(void)
IndexTable* dst = &module_tables[erts_staging_code_ix()];
Module* src_mod;
Module* dst_mod;
- int i;
+ int i, oldsz, newsz;
ASSERT(dbg_load_code_ix == -1);
ASSERT(dst->entries <= src->entries);
@@ -191,6 +203,7 @@ void module_start_staging(void)
/*
* Copy all new modules from active table
*/
+ oldsz = index_table_sz(dst);
for (i = dst->entries; i < src->entries; i++) {
src_mod = (Module*) erts_index_lookup(src, i);
dst_mod = (Module*) index_put_entry(dst, src_mod);
@@ -199,6 +212,8 @@ void module_start_staging(void)
dst_mod->curr = src_mod->curr;
dst_mod->old = src_mod->old;
}
+ newsz = index_table_sz(dst);
+ erts_smp_atomic_add_nob(&tot_module_bytes, (newsz - oldsz));
entries_at_start_staging = dst->entries;
IF_DEBUG(dbg_load_code_ix = erts_staging_code_ix());
@@ -210,9 +225,13 @@ void module_end_staging(int commit)
if (!commit) { /* abort */
IndexTable* tab = &module_tables[erts_staging_code_ix()];
+ int oldsz, newsz;
ASSERT(entries_at_start_staging <= tab->entries);
+ oldsz = index_table_sz(tab);
index_erase_latest_from(tab, entries_at_start_staging);
+ newsz = index_table_sz(tab);
+ erts_smp_atomic_add_nob(&tot_module_bytes, (newsz - oldsz));
}
IF_DEBUG(dbg_load_code_ix = -1);