File 2655-erts-Introduce-hash_fetch-as-an-optimized-hash_get.patch of Package erlang
From 18e2d852469fc3c3cdf287de5ca1ed4c73c71c4d Mon Sep 17 00:00:00 2001
From: Lukas Larsson <lukas@erlang.org>
Date: Fri, 9 Aug 2019 14:26:21 +0200
Subject: [PATCH 5/6] erts: Introduce hash_fetch as an optimized hash_get
---
erts/emulator/beam/export.c | 49 +++++++++++++-------------------------
erts/emulator/beam/hash.c | 11 +--------
erts/emulator/beam/hash.h | 17 +++++++++++++
erts/emulator/beam/register.c | 55 +++++++++----------------------------------
4 files changed, 46 insertions(+), 86 deletions(-)
diff --git a/erts/emulator/beam/export.c b/erts/emulator/beam/export.c
index c17fb436e2..b928f03b2f 100644
--- a/erts/emulator/beam/export.c
+++ b/erts/emulator/beam/export.c
@@ -196,6 +196,17 @@ init_export_table(void)
}
}
+static struct export_entry* init_template(struct export_templ* templ,
+ Eterm m, Eterm f, unsigned a)
+{
+ templ->entry.ep = &templ->exp;
+ templ->entry.slot.index = -1;
+ templ->exp.info.mfa.module = m;
+ templ->exp.info.mfa.function = f;
+ templ->exp.info.mfa.arity = a;
+ return &templ->entry;
+}
+
/*
* Return a pointer to the export entry for the given function,
* or NULL otherwise. Notes:
@@ -214,41 +225,15 @@ erts_find_export_entry(Eterm m, Eterm f, unsigned int a,ErtsCodeIndex code_ix);
Export*
erts_find_export_entry(Eterm m, Eterm f, unsigned int a, ErtsCodeIndex code_ix)
{
- HashValue hval = EXPORT_HASH((BeamInstr) m, (BeamInstr) f, (BeamInstr) a);
- int ix;
- HashBucket* b;
-
- ix = hash_get_slot(&export_tables[code_ix].htable, hval);
- b = export_tables[code_ix].htable.bucket[ix];
-
- /*
- * Note: We have inlined the code from hash.c for speed.
- */
-
- while (b != (HashBucket*) 0) {
- Export* ep = ((struct export_entry*) b)->ep;
- if (ep->info.mfa.module == m &&
- ep->info.mfa.function == f &&
- ep->info.mfa.arity == a) {
- return ep;
- }
- b = b->next;
- }
+ struct export_templ templ;
+ struct export_entry *ee =
+ hash_fetch(&export_tables[code_ix].htable,
+ init_template(&templ, m, f, a),
+ (H_FUN)export_hash, (HCMP_FUN)export_cmp);
+ if (ee) return ee->ep;
return NULL;
}
-static struct export_entry* init_template(struct export_templ* templ,
- Eterm m, Eterm f, unsigned a)
-{
- templ->entry.ep = &templ->exp;
- templ->entry.slot.index = -1;
- templ->exp.info.mfa.module = m;
- templ->exp.info.mfa.function = f;
- templ->exp.info.mfa.arity = a;
- return &templ->entry;
-}
-
-
/*
* Find the export entry for a loaded function.
* Returns a NULL pointer if the given function is not loaded, or
diff --git a/erts/emulator/beam/hash.c b/erts/emulator/beam/hash.c
index cdab53b3f2..177b7cc3d1 100644
--- a/erts/emulator/beam/hash.c
+++ b/erts/emulator/beam/hash.c
@@ -225,16 +225,7 @@ static void rehash(Hash* h, int grow)
*/
void* hash_get(Hash* h, void* tmpl)
{
- HashValue hval = h->fun.hash(tmpl);
- int ix = hash_get_slot(h, hval);
- HashBucket* b = h->bucket[ix];
-
- while(b != (HashBucket*) 0) {
- if ((b->hvalue == hval) && (h->fun.cmp(tmpl, (void*)b) == 0))
- return (void*) b;
- b = b->next;
- }
- return (void*) 0;
+ return hash_fetch(h, tmpl, h->fun.hash, h->fun.cmp);
}
/*
diff --git a/erts/emulator/beam/hash.h b/erts/emulator/beam/hash.h
index cbd75f3025..4e8eb6594b 100644
--- a/erts/emulator/beam/hash.h
+++ b/erts/emulator/beam/hash.h
@@ -99,6 +99,7 @@ void* hash_remove(Hash*, void*);
void hash_foreach(Hash*, HFOREACH_FUN, void *);
ERTS_GLB_INLINE Uint hash_get_slot(Hash *h, HashValue hv);
+ERTS_GLB_INLINE void* hash_fetch(Hash *, void*, H_FUN, HCMP_FUN);
#if ERTS_GLB_INLINE_INCL_FUNC_DEF
@@ -127,6 +128,22 @@ hash_get_slot(Hash *h, HashValue hv)
#endif
}
+ERTS_GLB_INLINE void* hash_fetch(Hash *h, void* tmpl, H_FUN hash, HCMP_FUN cmp)
+{
+ HashValue hval = hash(tmpl);
+ Uint ix = hash_get_slot(h, hval);
+ HashBucket* b = h->bucket[ix];
+ ASSERT(h->fun.hash == hash);
+ ASSERT(h->fun.cmp == cmp);
+
+ while(b != (HashBucket*) 0) {
+ if ((b->hvalue == hval) && (cmp(tmpl, (void*)b) == 0))
+ return (void*) b;
+ b = b->next;
+ }
+ return (void*) 0;
+}
+
#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
#endif
diff --git a/erts/emulator/beam/register.c b/erts/emulator/beam/register.c
index edf1e5b0cb..8e44b527a2 100644
--- a/erts/emulator/beam/register.c
+++ b/erts/emulator/beam/register.c
@@ -265,10 +265,8 @@ Eterm
erts_whereis_name_to_id(Process *c_p, Eterm name)
{
Eterm res = am_undefined;
- HashValue hval;
- int ix;
- HashBucket* b;
ErtsProcLocks c_p_locks = 0;
+ RegProc *rp, tmpl;
if (c_p) {
c_p_locks = ERTS_PROC_LOCK_MAIN;
ERTS_CHK_HAVE_ONLY_MAIN_PROC_LOCK(c_p);
@@ -278,29 +276,14 @@ erts_whereis_name_to_id(Process *c_p, Eterm name)
if (c_p && !c_p_locks)
erts_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
- hval = REG_HASH(name);
- ix = hash_get_slot(&process_reg, hval);
- b = process_reg.bucket[ix];
+ tmpl.name = name;
+ rp = hash_fetch(&process_reg, &tmpl, (H_FUN)reg_hash, (HCMP_FUN)reg_cmp);
- /*
- * Note: We have inlined the code from hash.c for speed.
- */
-
- while (b) {
- RegProc* rp = (RegProc *) b;
- if (rp->name == name) {
- /*
- * SMP NOTE: No need to lock registered entity since it cannot
- * be removed without acquiring write reg lock and id on entity
- * is read only.
- */
- if (rp->p)
- res = rp->p->common.id;
- else if (rp->pt)
- res = rp->pt->common.id;
- break;
- }
- b = b->next;
+ if (rp) {
+ if (rp->p)
+ res = rp->p->common.id;
+ else if (rp->pt)
+ res = rp->pt->common.id;
}
reg_read_unlock();
@@ -321,10 +304,7 @@ erts_whereis_name(Process *c_p,
Port** port,
int lock_port)
{
- RegProc* rp = NULL;
- HashValue hval;
- int ix;
- HashBucket* b;
+ RegProc* rp = NULL, tmpl;
ErtsProcLocks current_c_p_locks;
Port *pending_port = NULL;
@@ -342,21 +322,8 @@ erts_whereis_name(Process *c_p,
* - current_c_p_locks (either c_p_locks or 0) on c_p
*/
- hval = REG_HASH(name);
- ix = hash_get_slot(&process_reg, hval);
- b = process_reg.bucket[ix];
-
- /*
- * Note: We have inlined the code from hash.c for speed.
- */
-
- while (b) {
- if (((RegProc *) b)->name == name) {
- rp = (RegProc *) b;
- break;
- }
- b = b->next;
- }
+ tmpl.name = name;
+ rp = hash_fetch(&process_reg, &tmpl, (H_FUN)reg_hash, (HCMP_FUN)reg_cmp);
if (proc) {
if (!rp)
--
2.16.4
