diff options
23 files changed, 2040 insertions, 19 deletions
diff --git a/erts/doc/src/Makefile b/erts/doc/src/Makefile index 21aa3db864..fccdd744f3 100644 --- a/erts/doc/src/Makefile +++ b/erts/doc/src/Makefile @@ -52,6 +52,7 @@ XML_REF3_EFILES = \ erlang.xml \ erl_tracer.xml \ init.xml \ + persistent_term.xml \ zlib.xml XML_REF3_FILES = \ @@ -63,6 +64,7 @@ XML_REF3_FILES = \ erlang.xml \ erts_alloc.xml \ init.xml \ + persistent_term.xml \ zlib.xml XML_PART_FILES = \ diff --git a/erts/doc/src/persistent_term.xml b/erts/doc/src/persistent_term.xml new file mode 100644 index 0000000000..d2a138d65f --- /dev/null +++ b/erts/doc/src/persistent_term.xml @@ -0,0 +1,290 @@ +<?xml version="1.0" encoding="utf-8" ?> +<!DOCTYPE erlref SYSTEM "erlref.dtd"> + +<erlref> + <header> + <copyright> + <year>2018</year><year>2018</year> + <holder>Ericsson AB. All Rights Reserved.</holder> + </copyright> + <legalnotice> + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. + + </legalnotice> + + <title>persistent_term</title> + <prepared></prepared> + <docno></docno> + <date></date> + <rev></rev> + <file>persistent_term.xml</file> + </header> + <module>persistent_term</module> + <modulesummary>Persistent terms.</modulesummary> + <description> + <p>This module is similar to <seealso + marker="stdlib:ets"><c>ets</c></seealso> in that it provides a + storage for Erlang terms that can be accessed in constant time, + but with the difference that <c>persistent_term</c> has been + highly optimized for reading terms at the expense of writing and + updating terms. When a persistent term is updated or deleted, a + global garbage collection pass is run to scan all processes for + the deleted term, and to copy it into each process that still uses + it. Therefore, <c>persistent_term</c> is suitable for storing + Erlang terms that are frequently accessed but never or + infrequently updated.</p> + + <warning><p>Persistent terms is an advanced feature and is not a + general replacement for ETS tables. Before using persistent terms, + make sure to fully understand the consequence to system + performance when updating or deleting persistent terms.</p></warning> + + <p>Term lookup (using <seealso + marker="#get/1"><c>get/1</c></seealso>), is done in constant time + and without taking any locks, and the term is <strong>not</strong> + copied to the heap (as is the case with terms stored in ETS + tables).</p> + + <p>Storing or updating a term (using <seealso + marker="#put/2"><c>put/2</c></seealso>) is proportional to the + number of already created persistent terms because the hash table + holding the keys will be copied. In addition, the term itself will + be copied.</p> + + <p>When a (complex) term is deleted (using <seealso + marker="#erase/1"><c>erase/1</c></seealso>) or replaced by another + (using <seealso marker="#put/2"><c>put/2</c></seealso>), a global + garbage collection is initiated. It works like this:</p> + + <list> + <item><p>All processes in the system will be scheduled to run a + scan of their heaps for the term that has been deleted. While + such scan is relatively light-weight, if there are many + processes, the system can become less responsive until all + process have scanned theirs heaps.</p></item> + + <item><p>If the deleted term (or any part of it) is still used + by a process, that process will do a major (fullsweep) garbage + collection and copy the term into the process. However, at most + two processes at a time will be scheduled to do that kind of + garbage collection.</p></item> + </list> + + <p>Deletion of atoms and other terms that fit in one machine word + is specially optimized to avoid doing a global GC. It is still not + recommended to update persistent terms with such values too + frequently because the hash table holding the keys is copied every + time a persistent term is updated.</p> + + <p>Some examples are suitable uses for persistent terms are:</p> + + <list> + <item><p>Storing of configuration data that must be easily + accessible by all processes.</p></item> + + <item><p>Storing of references for NIF resources.</p></item> + + <item><p>Storing of references for efficient counters.</p></item> + + <item><p>Storing an atom to indicate a logging level or whether debugging + is turned on.</p></item> + </list> + + </description> + + <section> + <title>Storing Huge Persistent Terms</title> + <p>The current implementation of persistent terms uses the literal + <seealso marker="erts_alloc">allocator</seealso> also used for + literals (constant terms) in BEAM code. By default, 1 GB of + virtual address space is reserved for literals in BEAM code and + persistent terms. The amount of virtual address space reserved for + literals can be changed by using the <seealso + marker="erts_alloc#MIscs"><c>+MIscs option</c></seealso> when + starting the emulator.</p> + + <p>Here is an example how the reserved virtual address space for literals + can be raised to 2 GB (2048 MB):</p> + + <pre> + erl +MIscs 2048</pre> + </section> + + <section> + <title>Warning For Many Persistent Terms</title> + <p>The runtime system will send a warning report to the + error logger if more than 20000 persistent terms have been + created. It will look like this:</p> + +<pre> +More than 20000 persistent terms have been created. +It is recommended to avoid creating an excessive number of +persistent terms, as creation and deletion of persistent terms +will be slower as the number of persistent terms increases.</pre> + </section> + + <section> + <title>Best Practices for Using Persistent Terms</title> + + <p>It is recommended to use keys like <c>?MODULE</c> or + <c>{?MODULE,SubKey}</c> to avoid name collisions.</p> + + <p>Prefer creating a few large persistent terms to creating many + small persistent terms. The execution time for storing a + persistent term is proportional to the number of already existing + terms.</p> + + <p>Updating a persistent term with the same value as it already + has is specially optimized to do nothing quickly; thus, there is + no need compare the old and new values and avoid calling + <seealso marker="#put/2"><c>put/2</c></seealso> if the values + are equal.</p> + + <p>When atoms or other terms that fit in one machine word are + deleted, no global GC is needed. Therefore, persistent terms that + have atoms as their values can be updated more frequently, but + note that updating such persistent terms is still much more + expensive than reading them.</p> + + <p>Updating or deleting a persistent term will trigger a global GC + if the term does not fit in one machine word. Processes will be + scheduled as usual, but all processes will be made runnable at + once, which will make the system less responsive until all process + have run and scanned their heaps for the deleted terms. One way to + minimize the effects on responsiveness could be to minimize the + number of processes on the node before updating or deleting a + persistent term. It would also be wise to avoid updating terms + when the system is at peak load.</p> + + <p>Avoid storing a retrieved persistent term in a process if that + persistent term could be deleted or updated in the future. If a + process holds a reference to a persistent term when the term is + deleted, the process will be garbage collected and the term copied + to process.</p> + + <p>Avoid updating or deleting more than one persistent term at a + time. Each deleted term will trigger its own global GC. That + means that deleting N terms will make the system less responsive N + times longer than deleting a single persistent term. Therefore, + terms that are to be updated at the same time should be collected + into a larger term, for example, a map or a tuple.</p> + </section> + + <section> + <title>Example</title> + + <p>The following example shows how lock contention for ETS tables + can be minimized by having one ETS table for each scheduler. The + table identifiers for the ETS tables are stored as a single + persistent term:</p> + +<pre> + %% There is one ETS table for each scheduler. + Sid = erlang:system_info(scheduler_id), + Tid = element(Sid, persistent_term:get(?MODULE)), + ets:update_counter(Tid, Key, 1).</pre> + + </section> + + <datatypes> + <datatype> + <name name="key"/> + <desc> + <p>Any Erlang term.</p> + </desc> + </datatype> + <datatype> + <name name="value"/> + <desc> + <p>Any Erlang term.</p> + </desc> + </datatype> + </datatypes> + + <funcs> + <func> + <name name="erase" arity="1"/> + <fsummary>Erase the name for a persistent term.</fsummary> + <desc> + <p>Erase the name for the persistent term with key + <c><anno>Key</anno></c>. The return value will be <c>true</c> + if there was a persistent term with the key + <c><anno>Key</anno></c>, and <c>false</c> if there was no + persistent term associated with the key.</p> + <p>If there existed a previous persistent term associated with + key <c><anno>Key</anno></c>, a global GC has been initiated + when <c>erase/1</c> returns. See <seealso + marker="#description">Description</seealso>.</p> + </desc> + </func> + + <func> + <name name="get" arity="0"/> + <fsummary>Get all persistent terms.</fsummary> + <desc> + <p>Retrieve the keys and values for all persistent terms. + The keys will be copied to the heap for the process calling + <c>get/0</c>, but the values will not.</p> + </desc> + </func> + + <func> + <name name="get" arity="1"/> + <fsummary>Get the value for a persistent term.</fsummary> + <desc> + <p>Retrieve the value for the persistent term associated with + the key <c><anno>Key</anno></c>. The lookup will be made in + constant time and the value will not be copied to the heap + of the calling process.</p> + <p>This function fails with a <c>badarg</c> exception if no + term has been stored with the key + <c><anno>Key</anno></c>.</p> + <p>If the calling process holds on to the value of the + persistent term and the persistent term is deleted in the future, + the term will be copied to the process.</p> + </desc> + </func> + + <func> + <name name="info" arity="0"/> + <fsummary>Get information about persistent terms.</fsummary> + <desc> + <p>Return information about persistent terms in a map. The map + has the following keys:</p> + <taglist> + <tag><c>count</c></tag> + <item><p>The number of persistent terms.</p></item> + <tag><c>memory</c></tag> + <item><p>The total amount of memory (measured in bytes) + used by all persistent terms.</p></item> + </taglist> + </desc> + </func> + + <func> + <name name="put" arity="2"/> + <fsummary>Store a term.</fsummary> + <desc> + <p>Store the value <c><anno>Value</anno></c> as a persistent term and + associate it with the key <c><anno>Key</anno></c>.</p> + <p>If the value <c><anno>Value</anno></c> is equal to the value + previously stored for the key, <c>put/2</c> will do nothing and return + quickly.</p> + <p>If there existed a previous persistent term associated with + key <c><anno>Key</anno></c>, a global GC has been initiated + when <c>put/2</c> returns. See <seealso + marker="#description">Description</seealso>.</p> + </desc> + </func> + </funcs> +</erlref> diff --git a/erts/doc/src/ref_man.xml b/erts/doc/src/ref_man.xml index 0617463a7b..ff64aa86b8 100644 --- a/erts/doc/src/ref_man.xml +++ b/erts/doc/src/ref_man.xml @@ -34,6 +34,7 @@ <xi:include href="erl_prim_loader.xml"/> <xi:include href="erlang.xml"/> <xi:include href="init.xml"/> + <xi:include href="persistent_term.xml"/> <xi:include href="zlib.xml"/> <xi:include href="epmd.xml"/> <xi:include href="erl.xml"/> diff --git a/erts/doc/src/specs.xml b/erts/doc/src/specs.xml index ed6be650e5..1ab6cdc19e 100644 --- a/erts/doc/src/specs.xml +++ b/erts/doc/src/specs.xml @@ -4,5 +4,6 @@ <xi:include href="../specs/specs_erlang.xml"/> <xi:include href="../specs/specs_erl_tracer.xml"/> <xi:include href="../specs/specs_init.xml"/> + <xi:include href="../specs/specs_persistent_term.xml"/> <xi:include href="../specs/specs_zlib.xml"/> </specs> diff --git a/erts/emulator/Makefile.in b/erts/emulator/Makefile.in index 054692819e..d5ceb4b00b 100644 --- a/erts/emulator/Makefile.in +++ b/erts/emulator/Makefile.in @@ -633,21 +633,22 @@ GENERATE += $(TTF_DIR)/driver_tab.c # This list must be consistent with PRE_LOADED_MODULES in # erts/preloaded/src/Makefile. -PRELOAD_BEAM = $(ERL_TOP)/erts/preloaded/ebin/otp_ring0.beam \ - $(ERL_TOP)/erts/preloaded/ebin/erts_code_purger.beam \ - $(ERL_TOP)/erts/preloaded/ebin/init.beam \ - $(ERL_TOP)/erts/preloaded/ebin/prim_buffer.beam \ - $(ERL_TOP)/erts/preloaded/ebin/prim_eval.beam \ - $(ERL_TOP)/erts/preloaded/ebin/prim_inet.beam \ - $(ERL_TOP)/erts/preloaded/ebin/prim_file.beam \ - $(ERL_TOP)/erts/preloaded/ebin/zlib.beam \ - $(ERL_TOP)/erts/preloaded/ebin/prim_zip.beam \ - $(ERL_TOP)/erts/preloaded/ebin/erl_prim_loader.beam \ - $(ERL_TOP)/erts/preloaded/ebin/erlang.beam \ - $(ERL_TOP)/erts/preloaded/ebin/erts_internal.beam \ - $(ERL_TOP)/erts/preloaded/ebin/erl_tracer.beam \ - $(ERL_TOP)/erts/preloaded/ebin/erts_literal_area_collector.beam \ - $(ERL_TOP)/erts/preloaded/ebin/erts_dirty_process_signal_handler.beam +PRELOAD_BEAM = $(ERL_TOP)/erts/preloaded/ebin/otp_ring0.beam \ + $(ERL_TOP)/erts/preloaded/ebin/erts_code_purger.beam \ + $(ERL_TOP)/erts/preloaded/ebin/init.beam \ + $(ERL_TOP)/erts/preloaded/ebin/prim_buffer.beam \ + $(ERL_TOP)/erts/preloaded/ebin/prim_eval.beam \ + $(ERL_TOP)/erts/preloaded/ebin/prim_inet.beam \ + $(ERL_TOP)/erts/preloaded/ebin/prim_file.beam \ + $(ERL_TOP)/erts/preloaded/ebin/zlib.beam \ + $(ERL_TOP)/erts/preloaded/ebin/prim_zip.beam \ + $(ERL_TOP)/erts/preloaded/ebin/erl_prim_loader.beam \ + $(ERL_TOP)/erts/preloaded/ebin/erlang.beam \ + $(ERL_TOP)/erts/preloaded/ebin/erts_internal.beam \ + $(ERL_TOP)/erts/preloaded/ebin/erl_tracer.beam \ + $(ERL_TOP)/erts/preloaded/ebin/erts_literal_area_collector.beam \ + $(ERL_TOP)/erts/preloaded/ebin/erts_dirty_process_signal_handler.beam \ + $(ERL_TOP)/erts/preloaded/ebin/persistent_term.beam ifeq ($(TARGET),win32) # On windows the preloaded objects are in a resource object. @@ -839,6 +840,7 @@ RUN_OBJS += \ $(OBJDIR)/erl_bif_ddll.o $(OBJDIR)/erl_bif_guard.o \ $(OBJDIR)/erl_bif_info.o $(OBJDIR)/erl_bif_op.o \ $(OBJDIR)/erl_bif_os.o $(OBJDIR)/erl_bif_lists.o \ + $(OBJDIR)/erl_bif_persistent.o \ $(OBJDIR)/erl_bif_trace.o $(OBJDIR)/erl_bif_unique.o \ $(OBJDIR)/erl_bif_wrap.o $(OBJDIR)/erl_nfunc_sched.o \ $(OBJDIR)/erl_guard_bifs.o $(OBJDIR)/erl_dirty_bif_wrap.o \ diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names index 45b7540aeb..82bb620d62 100644 --- a/erts/emulator/beam/atom.names +++ b/erts/emulator/beam/atom.names @@ -182,6 +182,7 @@ atom control atom copy atom copy_literals atom counters +atom count atom cpu atom cpu_timestamp atom cr @@ -287,6 +288,7 @@ atom gc_minor_end atom gc_minor_start atom Ge='>=' atom generational +atom get_all_trap atom get_seq_token atom get_tcw atom gather_gc_info_result @@ -325,6 +327,7 @@ atom index atom infinity atom info atom info_msg +atom info_trap atom init atom initial_call atom input diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab index 7548924178..f1f34ae323 100644 --- a/erts/emulator/beam/bif.tab +++ b/erts/emulator/beam/bif.tab @@ -40,6 +40,7 @@ # Note: Guards BIFs usually require special support in the compiler. # + gcbif erlang:abs/1 bif erlang:adler32/1 bif erlang:adler32/2 @@ -698,3 +699,14 @@ ubif erlang:map_get/2 ubif erlang:is_map_key/2 bif ets:internal_delete_all/2 bif ets:internal_select_delete/2 + +# +# New in 21.2 +# + +bif persistent_term:put/2 +bif persistent_term:get/1 +bif persistent_term:get/0 +bif persistent_term:erase/1 +bif persistent_term:info/0 +bif erts_internal:erase_persistent_terms/0 diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types index 5409b89bab..86d93d94c4 100644 --- a/erts/emulator/beam/erl_alloc.types +++ b/erts/emulator/beam/erl_alloc.types @@ -277,6 +277,9 @@ type SETUP_CONN_ARG SHORT_LIVED PROCESSES setup_connection_argument type ENVIRONMENT SYSTEM SYSTEM environment +type PERSISTENT_TERM LONG_LIVED CODE persisten_term +type PERSISTENT_LOCK_Q SHORT_LIVED SYSTEM persistent_lock_q + # # Types used for special emulators # diff --git a/erts/emulator/beam/erl_bif_persistent.c b/erts/emulator/beam/erl_bif_persistent.c new file mode 100644 index 0000000000..9dca768a18 --- /dev/null +++ b/erts/emulator/beam/erl_bif_persistent.c @@ -0,0 +1,983 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2018. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +/* + * Purpose: Implement persistent term storage. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include "sys.h" +#include "erl_vm.h" +#include "global.h" +#include "erl_process.h" +#include "error.h" +#include "erl_driver.h" +#include "bif.h" +#include "erl_map.h" +#include "erl_binary.h" + +/* + * The limit for the number of persistent terms before + * a warning is issued. + */ + +#define WARNING_LIMIT 20000 +#define XSTR(s) STR(s) +#define STR(s) #s + +/* + * Parameters for the hash table. + */ +#define INITIAL_SIZE 8 +#define LOAD_FACTOR ((Uint)50) +#define MUST_GROW(t) (((Uint)100) * t->num_entries >= LOAD_FACTOR * t->allocated) +#define MUST_SHRINK(t) (((Uint)200) * t->num_entries <= LOAD_FACTOR * t->allocated && \ + t->allocated > INITIAL_SIZE) + +typedef struct hash_table { + Uint allocated; + Uint num_entries; + Uint mask; + Uint first_to_delete; + Uint num_to_delete; + erts_atomic_t refc; + struct hash_table* delete_next; + ErtsThrPrgrLaterOp thr_prog_op; + Eterm term[1]; +} HashTable; + +typedef struct trap_data { + HashTable* table; + Uint idx; + Uint remaining; + Uint memory; /* Used by info/0 to count used memory */ +} TrapData; + +/* + * Declarations of local functions. + */ + +static HashTable* create_initial_table(void); +static Uint lookup(HashTable* hash_table, Eterm key); +static HashTable* copy_table(HashTable* old_table, Uint new_size, int rehash); +static HashTable* tmp_table_copy(HashTable* old_table); +static int try_seize_update_permission(Process* c_p); +static void release_update_permission(int release_updater); +static void table_updater(void* table); +static void table_deleter(void* hash_table); +static void dec_table_refc(Process* c_p, HashTable* old_table); +static void delete_table(Process* c_p, HashTable* table); +static void mark_for_deletion(HashTable* hash_table, Uint entry_index); +static ErtsLiteralArea* term_to_area(Eterm tuple); +static void suspend_updater(Process* c_p); +static Eterm do_get_all(Process* c_p, TrapData* trap_data, Eterm res); +static Eterm do_info(Process* c_p, TrapData* trap_data); +static void append_to_delete_queue(HashTable* table); +static HashTable* next_to_delete(void); +static Eterm alloc_trap_data(Process* c_p); +static int cleanup_trap_data(Binary *bp); + +/* + * Traps + */ + +static Export persistent_term_get_all_export; +static BIF_RETTYPE persistent_term_get_all_trap(BIF_ALIST_2); +static Export persistent_term_info_export; +static BIF_RETTYPE persistent_term_info_trap(BIF_ALIST_1); + +/* + * Pointer to the current hash table. + */ + +static erts_atomic_t the_hash_table; + +/* + * Queue of processes waiting to update the hash table. + */ + +struct update_queue_item { + Process *p; + struct update_queue_item* next; +}; + +static erts_mtx_t update_table_permission_mtx; +static struct update_queue_item* update_queue = NULL; +static Process* updater_process = NULL; + +/* Protected by update_table_permission_mtx */ +static ErtsThrPrgrLaterOp thr_prog_op; +static int issued_warning = 0; + +/* + * Queue of hash tables to be deleted. + */ + +static erts_mtx_t delete_queue_mtx; +static HashTable* delete_queue_head = NULL; +static HashTable** delete_queue_tail = &delete_queue_head; + +/* + * The following variables are only used during crash dumping. They + * are intialized by erts_init_persistent_dumping(). + */ + +ErtsLiteralArea** erts_persistent_areas; +Uint erts_num_persistent_areas; + +void erts_init_bif_persistent_term(void) +{ + HashTable* hash_table; + + /* + * Initialize the mutex protecting updates. + */ + + erts_mtx_init(&update_table_permission_mtx, + "update_persistent_term_permission", + NIL, + ERTS_LOCK_FLAGS_PROPERTY_STATIC | + ERTS_LOCK_FLAGS_CATEGORY_GENERIC); + + /* + * Initialize delete queue. + */ + + erts_mtx_init(&delete_queue_mtx, + "persistent_term_delete_permission", + NIL, + ERTS_LOCK_FLAGS_PROPERTY_STATIC | + ERTS_LOCK_FLAGS_CATEGORY_GENERIC); + + /* + * Allocate a small initial hash table. + */ + + hash_table = create_initial_table(); + erts_atomic_init_nob(&the_hash_table, (erts_aint_t)hash_table); + + /* + * Initialize export entry for traps + */ + + erts_init_trap_export(&persistent_term_get_all_export, + am_persistent_term, am_get_all_trap, 2, + &persistent_term_get_all_trap); + erts_init_trap_export(&persistent_term_info_export, + am_persistent_term, am_info_trap, 1, + &persistent_term_info_trap); +} + +BIF_RETTYPE persistent_term_put_2(BIF_ALIST_2) +{ + Eterm key; + Eterm term; + Eterm heap[3]; + Eterm tuple; + HashTable* hash_table; + Uint term_size; + Uint lit_area_size; + ErlOffHeap code_off_heap; + ErtsLiteralArea* literal_area; + erts_shcopy_t info; + Eterm* ptr; + Uint entry_index; + + if (!try_seize_update_permission(BIF_P)) { + ERTS_BIF_YIELD2(bif_export[BIF_persistent_term_put_2], + BIF_P, BIF_ARG_1, BIF_ARG_2); + } + + hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + + key = BIF_ARG_1; + term = BIF_ARG_2; + + entry_index = lookup(hash_table, key); + + heap[0] = make_arityval(2); + heap[1] = key; + heap[2] = term; + tuple = make_tuple(heap); + + if (is_nil(hash_table->term[entry_index])) { + Uint size = hash_table->allocated; + if (MUST_GROW(hash_table)) { + size *= 2; + } + hash_table = copy_table(hash_table, size, 0); + entry_index = lookup(hash_table, key); + hash_table->num_entries++; + } else { + Eterm tuple = hash_table->term[entry_index]; + Eterm old_term; + + ASSERT(is_tuple_arity(tuple, 2)); + old_term = boxed_val(tuple)[2]; + if (EQ(term, old_term)) { + /* Same value. No need to update anything. */ + release_update_permission(0); + BIF_RET(am_ok); + } else { + /* Mark the old term for deletion. */ + mark_for_deletion(hash_table, entry_index); + hash_table = copy_table(hash_table, hash_table->allocated, 0); + } + } + + /* + * Preserve internal sharing in the term by using the + * sharing-preserving functions. However, literals must + * be copied in case the module holding them are unloaded. + */ + INITIALIZE_SHCOPY(info); + info.copy_literals = 1; + term_size = copy_shared_calculate(tuple, &info); + ERTS_INIT_OFF_HEAP(&code_off_heap); + lit_area_size = ERTS_LITERAL_AREA_ALLOC_SIZE(term_size); + literal_area = erts_alloc(ERTS_ALC_T_LITERAL, lit_area_size); + ptr = &literal_area->start[0]; + literal_area->end = ptr + term_size; + tuple = copy_shared_perform(tuple, term_size, &info, &ptr, &code_off_heap); + ASSERT(tuple_val(tuple) == literal_area->start); + literal_area->off_heap = code_off_heap.first; + DESTROY_SHCOPY(info); + erts_set_literal_tag(&tuple, literal_area->start, term_size); + hash_table->term[entry_index] = tuple; + + erts_schedule_thr_prgr_later_op(table_updater, hash_table, &thr_prog_op); + suspend_updater(BIF_P); + + /* + * Issue a warning once if the warning limit has been exceeded. + */ + + if (hash_table->num_entries > WARNING_LIMIT && issued_warning == 0) { + static char w[] = + "More than " XSTR(WARNING_LIMIT) " persistent terms " + "have been created.\n" + "It is recommended to avoid creating an excessive number of\n" + "persistent terms, as creation and deletion of persistent terms\n" + "will be slower as the number of persistent terms increases.\n"; + issued_warning = 1; + erts_send_warning_to_logger_str(BIF_P->group_leader, w); + } + + ERTS_BIF_YIELD_RETURN(BIF_P, am_ok); +} + +BIF_RETTYPE persistent_term_get_0(BIF_ALIST_0) +{ + HashTable* hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + TrapData* trap_data; + Eterm res = NIL; + Eterm magic_ref; + Binary* mbp; + + magic_ref = alloc_trap_data(BIF_P); + mbp = erts_magic_ref2bin(magic_ref); + trap_data = ERTS_MAGIC_BIN_DATA(mbp); + trap_data->table = hash_table; + trap_data->idx = 0; + trap_data->remaining = hash_table->num_entries; + res = do_get_all(BIF_P, trap_data, res); + if (trap_data->remaining == 0) { + BUMP_REDS(BIF_P, hash_table->num_entries); + trap_data->table = NULL; /* Prevent refc decrement */ + BIF_RET(res); + } else { + /* + * Increment the ref counter to prevent an update operation (by put/2 + * or erase/1) to delete this hash table. + */ + erts_atomic_inc_nob(&hash_table->refc); + BUMP_ALL_REDS(BIF_P); + BIF_TRAP2(&persistent_term_get_all_export, BIF_P, magic_ref, res); + } +} + +BIF_RETTYPE persistent_term_get_1(BIF_ALIST_1) +{ + Eterm key = BIF_ARG_1; + HashTable* hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + Uint entry_index; + Eterm term; + + entry_index = lookup(hash_table, key); + term = hash_table->term[entry_index]; + if (is_boxed(term)) { + ASSERT(is_tuple_arity(term, 2)); + BIF_RET(tuple_val(term)[2]); + } + BIF_ERROR(BIF_P, BADARG); +} + +BIF_RETTYPE persistent_term_erase_1(BIF_ALIST_1) +{ + Eterm key = BIF_ARG_1; + HashTable* old_table; + HashTable* new_table; + Uint entry_index; + Eterm old_term; + + if (!try_seize_update_permission(BIF_P)) { + ERTS_BIF_YIELD1(bif_export[BIF_persistent_term_erase_1], + BIF_P, BIF_ARG_1); + } + + old_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + entry_index = lookup(old_table, key); + old_term = old_table->term[entry_index]; + if (is_boxed(old_term)) { + Uint new_size; + HashTable* tmp_table; + + /* + * Since we don't use any delete markers, we must rehash + * the table when deleting terms to ensure that all terms + * can still be reached if there are hash collisions. + * We can't rehash in place and it would not be safe to modify + * the old table yet, so we will first need a new + * temporary table copy of the same size as the old one. + */ + + ASSERT(is_tuple_arity(old_term, 2)); + tmp_table = tmp_table_copy(old_table); + + /* + * Delete the term from the temporary table. Then copy the + * temporary table to a new table, rehashing the entries + * while copying. + */ + + tmp_table->term[entry_index] = NIL; + tmp_table->num_entries--; + new_size = tmp_table->allocated; + if (MUST_SHRINK(tmp_table)) { + new_size /= 2; + } + new_table = copy_table(tmp_table, new_size, 1); + erts_free(ERTS_ALC_T_TMP, tmp_table); + + mark_for_deletion(old_table, entry_index); + erts_schedule_thr_prgr_later_op(table_updater, new_table, &thr_prog_op); + suspend_updater(BIF_P); + ERTS_BIF_YIELD_RETURN(BIF_P, am_true); + } + + /* + * Key is not present. Nothing to do. + */ + + ASSERT(is_nil(old_term)); + release_update_permission(0); + BIF_RET(am_false); +} + +BIF_RETTYPE erts_internal_erase_persistent_terms_0(BIF_ALIST_0) +{ + HashTable* old_table; + HashTable* new_table; + + if (!try_seize_update_permission(BIF_P)) { + ERTS_BIF_YIELD0(bif_export[BIF_erts_internal_erase_persistent_terms_0], + BIF_P); + } + old_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + old_table->first_to_delete = 0; + old_table->num_to_delete = old_table->allocated; + new_table = create_initial_table(); + erts_schedule_thr_prgr_later_op(table_updater, new_table, &thr_prog_op); + suspend_updater(BIF_P); + ERTS_BIF_YIELD_RETURN(BIF_P, am_true); +} + +BIF_RETTYPE persistent_term_info_0(BIF_ALIST_0) +{ + HashTable* hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + TrapData* trap_data; + Eterm res = NIL; + Eterm magic_ref; + Binary* mbp; + + magic_ref = alloc_trap_data(BIF_P); + mbp = erts_magic_ref2bin(magic_ref); + trap_data = ERTS_MAGIC_BIN_DATA(mbp); + trap_data->table = hash_table; + trap_data->idx = 0; + trap_data->remaining = hash_table->num_entries; + trap_data->memory = 0; + res = do_info(BIF_P, trap_data); + if (trap_data->remaining == 0) { + BUMP_REDS(BIF_P, hash_table->num_entries); + trap_data->table = NULL; /* Prevent refc decrement */ + BIF_RET(res); + } else { + /* + * Increment the ref counter to prevent an update operation (by put/2 + * or erase/1) to delete this hash table. + */ + erts_atomic_inc_nob(&hash_table->refc); + BUMP_ALL_REDS(BIF_P); + BIF_TRAP2(&persistent_term_info_export, BIF_P, magic_ref, res); + } +} + +Uint +erts_persistent_term_count(void) +{ + HashTable* hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + return hash_table->num_entries; +} + +void +erts_init_persistent_dumping(void) +{ + HashTable* hash_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + ErtsLiteralArea** area_p; + Uint i; + + /* + * Overwrite the array of Eterms in the current hash table + * with pointers to literal areas. + */ + + erts_persistent_areas = (ErtsLiteralArea **) hash_table->term; + erts_num_persistent_areas = hash_table->num_entries; + area_p = erts_persistent_areas; + for (i = 0; i < hash_table->allocated; i++) { + Eterm term = hash_table->term[i]; + + if (is_boxed(term)) { + *area_p++ = term_to_area(term); + } + } +} + +/* + * Local functions. + */ + +static HashTable* +create_initial_table(void) +{ + HashTable* hash_table; + int i; + + hash_table = (HashTable *) erts_alloc(ERTS_ALC_T_PERSISTENT_TERM, + sizeof(HashTable)+sizeof(Eterm) * + (INITIAL_SIZE-1)); + hash_table->allocated = INITIAL_SIZE; + hash_table->num_entries = 0; + hash_table->mask = INITIAL_SIZE-1; + hash_table->first_to_delete = 0; + hash_table->num_to_delete = 0; + erts_atomic_init_nob(&hash_table->refc, (erts_aint_t)1); + for (i = 0; i < INITIAL_SIZE; i++) { + hash_table->term[i] = NIL; + } + return hash_table; +} + +static BIF_RETTYPE +persistent_term_get_all_trap(BIF_ALIST_2) +{ + TrapData* trap_data; + Eterm res = BIF_ARG_2; + Uint bump_reds; + Binary* mbp; + + ASSERT(is_list(BIF_ARG_2)); + mbp = erts_magic_ref2bin(BIF_ARG_1); + trap_data = ERTS_MAGIC_BIN_DATA(mbp); + bump_reds = trap_data->remaining; + res = do_get_all(BIF_P, trap_data, res); + ASSERT(is_list(res)); + if (trap_data->remaining > 0) { + BUMP_ALL_REDS(BIF_P); + BIF_TRAP2(&persistent_term_get_all_export, BIF_P, BIF_ARG_1, res); + } else { + /* + * Decrement ref count (and possibly delete the hash table + * and associated literal area). + */ + dec_table_refc(BIF_P, trap_data->table); + trap_data->table = NULL; /* Prevent refc decrement */ + BUMP_REDS(BIF_P, bump_reds); + BIF_RET(res); + } +} + +static Eterm +do_get_all(Process* c_p, TrapData* trap_data, Eterm res) +{ + HashTable* hash_table; + Uint remaining; + Uint idx; + Uint max_iter; + Uint i; + Eterm* hp; + Uint heap_size; + struct copy_term { + Uint key_size; + Eterm* tuple_ptr; + } *copy_data; + + hash_table = trap_data->table; + idx = trap_data->idx; +#if defined(DEBUG) || defined(VALGRIND) + max_iter = 50; +#else + max_iter = ERTS_BIF_REDS_LEFT(c_p); +#endif + remaining = trap_data->remaining < max_iter ? + trap_data->remaining : max_iter; + trap_data->remaining -= remaining; + + copy_data = (struct copy_term *) erts_alloc(ERTS_ALC_T_TMP, + remaining * + sizeof(struct copy_term)); + i = 0; + heap_size = (2 + 3) * remaining; + while (remaining != 0) { + Eterm term = hash_table->term[idx]; + if (is_tuple(term)) { + Uint key_size; + Eterm* tup_val; + + ASSERT(is_tuple_arity(term, 2)); + tup_val = tuple_val(term); + key_size = size_object(tup_val[1]); + copy_data[i].key_size = key_size; + copy_data[i].tuple_ptr = tup_val; + heap_size += key_size; + i++; + remaining--; + } + idx++; + } + trap_data->idx = idx; + + hp = HAlloc(c_p, heap_size); + remaining = i; + for (i = 0; i < remaining; i++) { + Eterm* tuple_ptr; + Uint key_size; + Eterm key; + Eterm tup; + + tuple_ptr = copy_data[i].tuple_ptr; + key_size = copy_data[i].key_size; + key = copy_struct(tuple_ptr[1], key_size, &hp, &c_p->off_heap); + tup = TUPLE2(hp, key, tuple_ptr[2]); + hp += 3; + res = CONS(hp, tup, res); + hp += 2; + } + erts_free(ERTS_ALC_T_TMP, copy_data); + return res; +} + +static BIF_RETTYPE +persistent_term_info_trap(BIF_ALIST_1) +{ + TrapData* trap_data = (TrapData *) BIF_ARG_1; + Eterm res; + Uint bump_reds; + Binary* mbp; + + mbp = erts_magic_ref2bin(BIF_ARG_1); + trap_data = ERTS_MAGIC_BIN_DATA(mbp); + bump_reds = trap_data->remaining; + res = do_info(BIF_P, trap_data); + if (trap_data->remaining > 0) { + ASSERT(res == am_ok); + BUMP_ALL_REDS(BIF_P); + BIF_TRAP1(&persistent_term_info_export, BIF_P, BIF_ARG_1); + } else { + /* + * Decrement ref count (and possibly delete the hash table + * and associated literal area). + */ + dec_table_refc(BIF_P, trap_data->table); + trap_data->table = NULL; /* Prevent refc decrement */ + BUMP_REDS(BIF_P, bump_reds); + ASSERT(is_map(res)); + BIF_RET(res); + } +} + +#define DECL_AM(S) Eterm AM_ ## S = am_atom_put(#S, sizeof(#S) - 1) + +static Eterm +do_info(Process* c_p, TrapData* trap_data) +{ + HashTable* hash_table; + Uint remaining; + Uint idx; + Uint max_iter; + + hash_table = trap_data->table; + idx = trap_data->idx; +#if defined(DEBUG) || defined(VALGRIND) + max_iter = 50; +#else + max_iter = ERTS_BIF_REDS_LEFT(c_p); +#endif + remaining = trap_data->remaining < max_iter ? trap_data->remaining : max_iter; + trap_data->remaining -= remaining; + while (remaining != 0) { + if (is_boxed(hash_table->term[idx])) { + ErtsLiteralArea* area; + area = term_to_area(hash_table->term[idx]); + trap_data->memory += sizeof(ErtsLiteralArea) + + sizeof(Eterm) * (area->end - area->start - 1); + remaining--; + } + idx++; + } + trap_data->idx = idx; + if (trap_data->remaining > 0) { + return am_ok; /* Dummy return value */ + } else { + Eterm* hp; + Eterm count_term; + Eterm memory_term; + Eterm res; + Uint memory; + Uint hsz = MAP_SZ(2); + + memory = sizeof(HashTable) + (trap_data->table->allocated-1) * + sizeof(Eterm) + trap_data->memory; + (void) erts_bld_uint(NULL, &hsz, hash_table->num_entries); + (void) erts_bld_uint(NULL, &hsz, memory); + hp = HAlloc(c_p, hsz); + count_term = erts_bld_uint(&hp, NULL, hash_table->num_entries); + memory_term = erts_bld_uint(&hp, NULL, memory); + res = MAP2(hp, am_count, count_term, am_memory, memory_term); + return res; + } +} + +#undef DECL_AM + +static Eterm +alloc_trap_data(Process* c_p) +{ + Binary* mbp = erts_create_magic_binary(sizeof(TrapData), + cleanup_trap_data); + Eterm* hp; + + hp = HAlloc(c_p, ERTS_MAGIC_REF_THING_SIZE); + return erts_mk_magic_ref(&hp, &MSO(c_p), mbp); +} + +static int +cleanup_trap_data(Binary *bp) +{ + TrapData* trap_data = ERTS_MAGIC_BIN_DATA(bp); + + if (trap_data->table) { + /* + * The process has been killed and is now exiting. + * Decrement the reference counter for the table. + */ + dec_table_refc(NULL, trap_data->table); + } + return 1; +} + +static Uint +lookup(HashTable* hash_table, Eterm key) +{ + Uint mask = hash_table->mask; + Eterm* table = hash_table->term; + Uint32 idx = make_internal_hash(key, 0); + Eterm term; + + do { + idx++; + term = table[idx & mask]; + } while (is_boxed(term) && !EQ(key, (tuple_val(term))[1])); + return idx & mask; +} + +static HashTable* +tmp_table_copy(HashTable* old_table) +{ + Uint size = old_table->allocated; + HashTable* tmp_table; + Uint i; + + tmp_table = (HashTable *) erts_alloc(ERTS_ALC_T_TMP, + sizeof(HashTable) + + sizeof(Eterm) * (size-1)); + *tmp_table = *old_table; + for (i = 0; i < size; i++) { + tmp_table->term[i] = old_table->term[i]; + } + return tmp_table; +} + +static HashTable* +copy_table(HashTable* old_table, Uint new_size, int rehash) +{ + HashTable* new_table; + Uint old_size = old_table->allocated; + Uint i; + + new_table = (HashTable *) erts_alloc(ERTS_ALC_T_PERSISTENT_TERM, + sizeof(HashTable) + + sizeof(Eterm) * (new_size-1)); + if (old_table->allocated == new_size && !rehash) { + /* + * Same size and no key deleted. Make an exact copy of the table. + */ + *new_table = *old_table; + for (i = 0; i < new_size; i++) { + new_table->term[i] = old_table->term[i]; + } + } else { + /* + * The size of the table has changed or an element has been + * deleted. Must rehash, by inserting all old terms into the + * new (empty) table. + */ + new_table->allocated = new_size; + new_table->num_entries = old_table->num_entries; + new_table->mask = new_size - 1; + for (i = 0; i < new_size; i++) { + new_table->term[i] = NIL; + } + for (i = 0; i < old_size; i++) { + if (is_tuple(old_table->term[i])) { + Eterm key = tuple_val(old_table->term[i])[1]; + Uint entry_index = lookup(new_table, key); + ASSERT(is_nil(new_table->term[entry_index])); + new_table->term[entry_index] = old_table->term[i]; + } + } + } + new_table->first_to_delete = 0; + new_table->num_to_delete = 0; + erts_atomic_init_nob(&new_table->refc, (erts_aint_t)1); + return new_table; +} + +static void +mark_for_deletion(HashTable* hash_table, Uint entry_index) +{ + hash_table->first_to_delete = entry_index; + hash_table->num_to_delete = 1; +} + +static ErtsLiteralArea* +term_to_area(Eterm tuple) +{ + ASSERT(is_tuple_arity(tuple, 2)); + return (ErtsLiteralArea *) (((char *) tuple_val(tuple)) - + offsetof(ErtsLiteralArea, start)); +} + +static void +table_updater(void* data) +{ + HashTable* old_table; + HashTable* new_table; + + old_table = (HashTable *) erts_atomic_read_nob(&the_hash_table); + new_table = (HashTable *) data; + ASSERT(new_table->num_to_delete == 0); + erts_atomic_set_nob(&the_hash_table, (erts_aint_t)new_table); + append_to_delete_queue(old_table); + erts_schedule_thr_prgr_later_op(table_deleter, + old_table, + &old_table->thr_prog_op); + release_update_permission(1); +} + +static void +table_deleter(void* data) +{ + HashTable* old_table = (HashTable *) data; + + dec_table_refc(NULL, old_table); +} + +static void +dec_table_refc(Process* c_p, HashTable* old_table) +{ + erts_aint_t refc = erts_atomic_dec_read_nob(&old_table->refc); + + if (refc == 0) { + HashTable* to_delete; + + while ((to_delete = next_to_delete()) != NULL) { + delete_table(c_p, to_delete); + } + } +} + +static void +delete_table(Process* c_p, HashTable* table) +{ + Uint idx = table->first_to_delete; + Uint n = table->num_to_delete; + + /* + * There are no longer any references to this hash table. + * + * Any literals pointed for deletion can be queued for + * deletion and the table itself can be deallocated. + */ + +#ifdef DEBUG + if (n == 1) { + ASSERT(is_tuple_arity(table->term[idx], 2)); + } +#endif + + while (n > 0) { + Eterm term = table->term[idx]; + + if (is_tuple_arity(term, 2)) { + if (is_immed(tuple_val(term)[2])) { + erts_release_literal_area(term_to_area(term)); + } else { + erts_queue_release_literals(c_p, term_to_area(term)); + } + } + idx++, n--; + } + erts_free(ERTS_ALC_T_PERSISTENT_TERM, table); +} + +/* + * Caller *must* yield if this function returns 0. + */ + +static int +try_seize_update_permission(Process* c_p) +{ + int success; + + ASSERT(!erts_thr_progress_is_blocking()); /* to avoid deadlock */ + ASSERT(c_p != NULL); + + erts_mtx_lock(&update_table_permission_mtx); + ASSERT(updater_process != c_p); + success = (updater_process == NULL); + if (success) { + updater_process = c_p; + } else { + struct update_queue_item* qitem; + qitem = erts_alloc(ERTS_ALC_T_PERSISTENT_LOCK_Q, sizeof(*qitem)); + qitem->p = c_p; + erts_proc_inc_refc(c_p); + qitem->next = update_queue; + update_queue = qitem; + erts_suspend(c_p, ERTS_PROC_LOCK_MAIN, NULL); + } + erts_mtx_unlock(&update_table_permission_mtx); + return success; +} + +static void +release_update_permission(int release_updater) +{ + erts_mtx_lock(&update_table_permission_mtx); + ASSERT(updater_process != NULL); + + if (release_updater) { + erts_proc_lock(updater_process, ERTS_PROC_LOCK_STATUS); + if (!ERTS_PROC_IS_EXITING(updater_process)) { + erts_resume(updater_process, ERTS_PROC_LOCK_STATUS); + } + erts_proc_unlock(updater_process, ERTS_PROC_LOCK_STATUS); + } + updater_process = NULL; + + while (update_queue != NULL) { /* Unleash the entire herd */ + struct update_queue_item* qitem = update_queue; + erts_proc_lock(qitem->p, ERTS_PROC_LOCK_STATUS); + if (!ERTS_PROC_IS_EXITING(qitem->p)) { + erts_resume(qitem->p, ERTS_PROC_LOCK_STATUS); + } + erts_proc_unlock(qitem->p, ERTS_PROC_LOCK_STATUS); + update_queue = qitem->next; + erts_proc_dec_refc(qitem->p); + erts_free(ERTS_ALC_T_PERSISTENT_LOCK_Q, qitem); + } + erts_mtx_unlock(&update_table_permission_mtx); +} + +static void +suspend_updater(Process* c_p) +{ +#ifdef DEBUG + ASSERT(c_p != NULL); + erts_mtx_lock(&update_table_permission_mtx); + ASSERT(updater_process == c_p); + erts_mtx_unlock(&update_table_permission_mtx); +#endif + erts_suspend(c_p, ERTS_PROC_LOCK_MAIN, NULL); +} + +static void +append_to_delete_queue(HashTable* table) +{ + erts_mtx_lock(&delete_queue_mtx); + table->delete_next = NULL; + *delete_queue_tail = table; + delete_queue_tail = &table->delete_next; + erts_mtx_unlock(&delete_queue_mtx); +} + +static HashTable* +next_to_delete(void) +{ + HashTable* table; + + erts_mtx_lock(&delete_queue_mtx); + table = delete_queue_head; + if (table) { + if (erts_atomic_read_nob(&table->refc)) { + /* + * This hash table is still referenced. Hash tables + * must be deleted in order, so we return a NULL + * pointer. + */ + table = NULL; + } else { + /* + * Remove the first hash table from the queue. + */ + delete_queue_head = table->delete_next; + if (delete_queue_head == NULL) { + delete_queue_tail = &delete_queue_head; + } + } + } + erts_mtx_unlock(&delete_queue_mtx); + return table; +} diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c index 57c6c10c7f..f687dcf335 100644 --- a/erts/emulator/beam/erl_init.c +++ b/erts/emulator/beam/erl_init.c @@ -354,6 +354,7 @@ erl_init(int ncpu, erts_init_bif(); erts_init_bif_chksum(); erts_init_bif_binary(); + erts_init_bif_persistent_term(); erts_init_bif_re(); erts_init_unicode(); /* after RE to get access to PCRE unicode */ erts_init_external(); diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c index 463ae898a3..1416c5f96c 100644 --- a/erts/emulator/beam/erl_lock_check.c +++ b/erts/emulator/beam/erl_lock_check.c @@ -97,6 +97,8 @@ static erts_lc_lock_order_t erts_lock_order[] = { { "proc_btm", "pid" }, { "dist_entry", "address" }, { "dist_entry_links", "address" }, + { "update_persistent_term_permission", NULL }, + { "persistent_term_delete_permission", NULL }, { "code_write_permission", NULL }, { "purge_state", NULL }, { "proc_status", "pid" }, diff --git a/erts/emulator/beam/erl_process_dump.c b/erts/emulator/beam/erl_process_dump.c index 243db4c734..ac5054ea10 100644 --- a/erts/emulator/beam/erl_process_dump.c +++ b/erts/emulator/beam/erl_process_dump.c @@ -58,6 +58,7 @@ static void dump_externally(fmtfn_t to, void *to_arg, Eterm term); static void mark_literal(Eterm* ptr); static void init_literal_areas(void); static void dump_literals(fmtfn_t to, void *to_arg); +static void dump_persistent_terms(fmtfn_t to, void *to_arg); static void dump_module_literals(fmtfn_t to, void *to_arg, ErtsLiteralArea* lit_area); @@ -74,6 +75,7 @@ erts_deep_process_dump(fmtfn_t to, void *to_arg) all_binaries = NULL; init_literal_areas(); + erts_init_persistent_dumping(); for (i = 0; i < max; i++) { Process *p = erts_pix2proc(i); @@ -93,6 +95,7 @@ erts_deep_process_dump(fmtfn_t to, void *to_arg) } } + dump_persistent_terms(to, to_arg); dump_literals(to, to_arg); dump_binaries(to, to_arg, all_binaries); } @@ -775,6 +778,9 @@ init_literal_areas(void) qsort(lit_areas, num_lit_areas, sizeof(ErtsLiteralArea *), compare_areas); + qsort(erts_persistent_areas, erts_num_persistent_areas, + sizeof(ErtsLiteralArea *), compare_areas); + erts_runlock_old_code(code_ix); } @@ -796,6 +802,13 @@ static void mark_literal(Eterm* ptr) ap = bsearch(ptr, lit_areas, num_lit_areas, sizeof(ErtsLiteralArea*), search_areas); + if (ap == 0) { + ap = bsearch(ptr, erts_persistent_areas, + erts_num_persistent_areas, + sizeof(ErtsLiteralArea*), + search_areas); + } + /* * If the literal was created by native code, this search will not @@ -807,12 +820,12 @@ static void mark_literal(Eterm* ptr) } } - static void dump_literals(fmtfn_t to, void *to_arg) { ErtsCodeIndex code_ix; int i; + Uint idx; code_ix = erts_active_code_ix(); erts_rlock_old_code(code_ix); @@ -825,6 +838,28 @@ dump_literals(fmtfn_t to, void *to_arg) } erts_runlock_old_code(code_ix); + + for (idx = 0; idx < erts_num_persistent_areas; idx++) { + dump_module_literals(to, to_arg, erts_persistent_areas[idx]); + } +} + +static void +dump_persistent_terms(fmtfn_t to, void *to_arg) +{ + Uint idx; + + erts_print(to, to_arg, "=persistent_terms\n"); + + for (idx = 0; idx < erts_num_persistent_areas; idx++) { + ErtsLiteralArea* ap = erts_persistent_areas[idx]; + Eterm tuple = make_tuple(ap->start); + Eterm* tup_val = tuple_val(tuple); + + dump_element(to, to_arg, tup_val[1]); + erts_putc(to, to_arg, '|'); + dump_element_nl(to, to_arg, tup_val[2]); + } } static void @@ -963,7 +998,8 @@ dump_module_literals(fmtfn_t to, void *to_arg, ErtsLiteralArea* lit_area) } erts_putc(to, to_arg, '\n'); } - } else if (is_export_header(w)) { + } else { + /* Dump everything else in the external format */ dump_externally(to, to_arg, term); erts_putc(to, to_arg, '\n'); } diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h index 54d309ff2f..0631404599 100644 --- a/erts/emulator/beam/global.h +++ b/erts/emulator/beam/global.h @@ -1242,6 +1242,13 @@ Sint erts_re_set_loop_limit(Sint limit); void erts_init_bif_binary(void); Sint erts_binary_set_loop_limit(Sint limit); +/* erl_bif_persistent.c */ +void erts_init_bif_persistent_term(void); +Uint erts_persistent_term_count(void); +void erts_init_persistent_dumping(void); +extern ErtsLiteralArea** erts_persistent_areas; +extern Uint erts_num_persistent_areas; + /* external.c */ void erts_init_external(void); diff --git a/erts/emulator/test/Makefile b/erts/emulator/test/Makefile index bf00de2204..d201ea6ee1 100644 --- a/erts/emulator/test/Makefile +++ b/erts/emulator/test/Makefile @@ -92,6 +92,7 @@ MODULES= \ port_SUITE \ port_bif_SUITE \ prim_eval_SUITE \ + persistent_term_SUITE \ process_SUITE \ pseudoknot_SUITE \ receive_SUITE \ diff --git a/erts/emulator/test/persistent_term_SUITE.erl b/erts/emulator/test/persistent_term_SUITE.erl new file mode 100644 index 0000000000..58cd3276b0 --- /dev/null +++ b/erts/emulator/test/persistent_term_SUITE.erl @@ -0,0 +1,614 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2017. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%5 +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% + +-module(persistent_term_SUITE). +-include_lib("common_test/include/ct.hrl"). + +-export([all/0,suite/0, + basic/1,purging/1,sharing/1,get_trapping/1, + info/1,info_trapping/1,killed_while_trapping/1, + off_heap_values/1,keys/1,collisions/1, + init_restart/1]). + +%% +-export([test_init_restart_cmd/1]). + +suite() -> + [{ct_hooks,[ts_install_cth]}, + {timetrap,{minutes,10}}]. + +all() -> + [basic,purging,sharing,get_trapping,info,info_trapping, + killed_while_trapping,off_heap_values,keys,collisions, + init_restart]. + +basic(_Config) -> + Chk = chk(), + N = 777, + Seq = lists:seq(1, N), + par(2, N, Seq), + seq(3, Seq), + seq(3, Seq), %Same values. + _ = [begin + Key = {?MODULE,{key,I}}, + true = persistent_term:erase(Key), + false = persistent_term:erase(Key), + {'EXIT',{badarg,_}} = (catch persistent_term:get(Key)) + end || I <- Seq], + [] = [P || {{?MODULE,_},_}=P <- persistent_term:get()], + chk(Chk). + +par(C, N, Seq) -> + _ = [spawn_link(fun() -> + ok = persistent_term:put({?MODULE,{key,I}}, + {value,C*I}) + end) || I <- Seq], + Result = wait(N), + _ = [begin + Double = C*I, + {{?MODULE,{key,I}},{value,Double}} = Res + end || {I,Res} <- lists:zip(Seq, Result)], + ok. + +seq(C, Seq) -> + _ = [ok = persistent_term:put({?MODULE,{key,I}}, {value,C*I}) || + I <- Seq], + All = persistent_term:get(), + All = [P || {{?MODULE,_},_}=P <- persistent_term:get()], + All = [{Key,persistent_term:get(Key)} || {Key,_} <- All], + Result = lists:sort(All), + _ = [begin + Double = C*I, + {{?MODULE,{key,I}},{value,Double}} = Res + end || {I,Res} <- lists:zip(Seq, Result)], + ok. + +wait(N) -> + All = [P || {{?MODULE,_},_}=P <- persistent_term:get()], + case length(All) of + N -> + All = [{Key,persistent_term:get(Key)} || {Key,_} <- All], + lists:sort(All); + _ -> + receive after 10 -> ok end, + wait(N) + end. + +%% Make sure that terms that have been erased are copied into all +%% processes that still hold a pointer to them. + +purging(_Config) -> + Chk = chk(), + do_purging(fun(K) -> persistent_term:put(K, {?MODULE,new}) end, + replaced), + do_purging(fun persistent_term:erase/1, erased), + chk(Chk). + +do_purging(Eraser, Type) -> + Parent = self(), + Key = {?MODULE,?FUNCTION_NAME}, + ok = persistent_term:put(Key, {term,[<<"abc",0:777/unit:8>>]}), + Ps0 = [spawn_monitor(fun() -> purging_tester(Parent, Key) end) || + _ <- lists:seq(1, 50)], + Ps = maps:from_list(Ps0), + purging_recv(gotten, Ps), + Eraser(Key), + _ = [P ! {Parent,Type} || P <- maps:keys(Ps)], + purging_wait(Ps). + +purging_recv(Tag, Ps) when map_size(Ps) > 0 -> + receive + {Pid,Tag} -> + true = is_map_key(Pid, Ps), + purging_recv(Tag, maps:remove(Pid, Ps)) + end; +purging_recv(_, _) -> ok. + +purging_wait(Ps) when map_size(Ps) > 0 -> + receive + {'DOWN',Ref,process,Pid,Reason} -> + normal = Reason, + Ref = map_get(Pid, Ps), + purging_wait(maps:remove(Pid, Ps)) + end; +purging_wait(_) -> ok. + +purging_tester(Parent, Key) -> + Term = persistent_term:get(Key), + purging_check_term(Term), + 0 = erts_debug:size_shared(Term), + Parent ! {self(),gotten}, + receive + {Parent,erased} -> + {'EXIT',{badarg,_}} = (catch persistent_term:get(Key)), + purging_tester_1(Term); + {Parent,replaced} -> + {?MODULE,new} = persistent_term:get(Key), + purging_tester_1(Term) + end. + +%% Wait for the term to be copied into this process. +purging_tester_1(Term) -> + purging_check_term(Term), + receive after 1 -> ok end, + case erts_debug:size_shared(Term) of + 0 -> + purging_tester_1(Term); + Size -> + %% The term has been copied into this process. + purging_check_term(Term), + Size = erts_debug:size(Term) + end. + +purging_check_term({term,[<<"abc",0:777/unit:8>>]}) -> + ok. + +%% Test that sharing is preserved when storing terms. + +sharing(_Config) -> + Chk = chk(), + Depth = 10, + Size = 2*Depth, + Shared = lists:foldl(fun(_, A) -> [A|A] end, + [], lists:seq(1, Depth)), + Size = erts_debug:size(Shared), + Key = {?MODULE,?FUNCTION_NAME}, + ok = persistent_term:put(Key, Shared), + SharedStored = persistent_term:get(Key), + Size = erts_debug:size(SharedStored), + 0 = erts_debug:size_shared(SharedStored), + + {Pid,Ref} = spawn_monitor(fun() -> + Term = persistent_term:get(Key), + Size = erts_debug:size(Term), + 0 = erts_debug:size_shared(Term), + true = Term =:= SharedStored + end), + receive + {'DOWN',Ref,process,Pid,normal} -> + true = persistent_term:erase(Key), + Size = erts_debug:size(SharedStored), + chk(Chk) + end. + +%% Test trapping of persistent_term:get/0. + +get_trapping(_Config) -> + Chk = chk(), + + %% Assume that the get/0 traps after 4000 iterations + %% in a non-debug emulator. + N = case test_server:timetrap_scale_factor() of + 1 -> 10000; + _ -> 1000 + end, + spawn_link(fun() -> get_trapping_create(N) end), + All = do_get_trapping(N, []), + N = get_trapping_check_result(lists:sort(All), 1), + erlang:garbage_collect(), + get_trapping_erase(N), + chk(Chk). + +do_get_trapping(N, Prev) -> + case persistent_term:get() of + Prev when length(Prev) >= N -> + All = [P || {{?MODULE,{get_trapping,_}},_}=P <- Prev], + case length(All) of + N -> All; + _ -> do_get_trapping(N, Prev) + end; + New -> + receive after 1 -> ok end, + do_get_trapping(N, New) + end. + +get_trapping_create(0) -> + ok; +get_trapping_create(N) -> + ok = persistent_term:put({?MODULE,{get_trapping,N}}, N), + get_trapping_create(N-1). + +get_trapping_check_result([{{?MODULE,{get_trapping,N}},N}|T], N) -> + get_trapping_check_result(T, N+1); +get_trapping_check_result([], N) -> N-1. + +get_trapping_erase(0) -> + ok; +get_trapping_erase(N) -> + true = persistent_term:erase({?MODULE,{get_trapping,N}}), + get_trapping_erase(N-1). + +%% Test retrieving information about persistent terms. + +info(_Config) -> + Chk = chk(), + + %% White box test of info/0. + N = 100, + try + Overhead = info_literal_area_overhead(), + io:format("Overhead = ~p\n", [Overhead]), + info_wb(N, Overhead, info_info()) + after + _ = [_ = persistent_term:erase({?MODULE,I}) || + I <- lists:seq(1, N)] + end, + + chk(Chk). + +%% White box test of persistent_term:info/0. We take into account +%% that there might already exist persistent terms (created by the +%% OTP standard libraries), but we assume that they are not +%% changed during the execution of this test case. + +info_wb(0, _, _) -> + ok; +info_wb(N, Overhead, {BaseCount,BaseMemory}) -> + Key = {?MODULE,N}, + Value = lists:seq(1, N), + ok = persistent_term:put(Key, Value), + + %% Calculate the extra memory needed for this term. + WordSize = erlang:system_info(wordsize), + ExtraMemory = Overhead + 2 * N * WordSize, + + %% Call persistent_term:info/0. + {Count,Memory} = info_info(), + + %% There should be one more persistent term. + Count = BaseCount + 1, + + %% Verify that the amount of memory is correct. + case BaseMemory + ExtraMemory of + Memory -> + %% Exactly right. The size of the hash table was not changed. + ok; + Expected -> + %% The size of the hash table has been doubled to avoid filling + %% the table to more than 50 percent. The previous number + %% of entries must have been exactly half the size of the + %% hash table. The expected number of extra words added by + %% the resizing will be twice that number. + ExtraWords = BaseCount * 2, + true = ExtraWords * WordSize =:= (Memory - Expected) + end, + info_wb(N-1, Overhead, {Count,Memory}). + +info_info() -> + #{count:=Count,memory:=Memory} = persistent_term:info(), + true = is_integer(Count) andalso Count >= 0, + true = is_integer(Memory) andalso Memory >= 0, + {Count,Memory}. + +%% Calculate the number of extra bytes needed for storing each term in +%% the literal, assuming that the key is a tuple of size 2 with +%% immediate elements. The calculated number is the size of the +%% ErtsLiteralArea struct excluding the storage for the literal term +%% itself. + +info_literal_area_overhead() -> + Key1 = {?MODULE,1}, + Key2 = {?MODULE,2}, + #{memory:=Mem0} = persistent_term:info(), + ok = persistent_term:put(Key1, literal), + #{memory:=Mem1} = persistent_term:info(), + ok = persistent_term:put(Key2, literal), + #{memory:=Mem2} = persistent_term:info(), + true = persistent_term:erase(Key1), + true = persistent_term:erase(Key2), + + %% The size of the hash table may have doubled when inserting + %% one of the keys. To avoiding counting the change in the hash + %% table size, take the smaller size increase. + min(Mem2-Mem1, Mem1-Mem0). + +%% Test trapping of persistent_term:info/0. + +info_trapping(_Config) -> + Chk = chk(), + + %% Assume that the info/0 traps after 4000 iterations + %% in a non-debug emulator. + N = case test_server:timetrap_scale_factor() of + 1 -> 10000; + _ -> 1000 + end, + spawn_link(fun() -> info_trapping_create(N) end), + All = do_info_trapping(N, 0), + N = info_trapping_check_result(lists:sort(All), 1), + erlang:garbage_collect(), + info_trapping_erase(N), + chk(Chk). + +do_info_trapping(N, PrevMem) -> + case info_info() of + {N,Mem} -> + true = Mem >= PrevMem, + All = [P || {{?MODULE,{info_trapping,_}},_}=P <- persistent_term:get()], + case length(All) of + N -> All; + _ -> do_info_trapping(N, PrevMem) + end; + {_,Mem} -> + true = Mem >= PrevMem, + receive after 1 -> ok end, + do_info_trapping(N, Mem) + end. + +info_trapping_create(0) -> + ok; +info_trapping_create(N) -> + ok = persistent_term:put({?MODULE,{info_trapping,N}}, N), + info_trapping_create(N-1). + +info_trapping_check_result([{{?MODULE,{info_trapping,N}},N}|T], N) -> + info_trapping_check_result(T, N+1); +info_trapping_check_result([], N) -> N-1. + +info_trapping_erase(0) -> + ok; +info_trapping_erase(N) -> + true = persistent_term:erase({?MODULE,{info_trapping,N}}), + info_trapping_erase(N-1). + +%% Test that hash tables are deallocated if a process running +%% persistent_term:get/0 is killed. + +killed_while_trapping(_Config) -> + Chk = chk(), + N = case test_server:timetrap_scale_factor() of + 1 -> 20000; + _ -> 2000 + end, + kwt_put(N), + kwt_spawn(10), + kwt_erase(N), + chk(Chk). + +kwt_put(0) -> + ok; +kwt_put(N) -> + ok = persistent_term:put({?MODULE,{kwt,N}}, N), + kwt_put(N-1). + +kwt_spawn(0) -> + ok; +kwt_spawn(N) -> + Pids = [spawn(fun kwt_getter/0) || _ <- lists:seq(1, 20)], + erlang:yield(), + _ = [exit(Pid, kill) || Pid <- Pids], + kwt_spawn(N-1). + +kwt_getter() -> + _ = persistent_term:get(), + kwt_getter(). + +kwt_erase(0) -> + ok; +kwt_erase(N) -> + true = persistent_term:erase({?MODULE,{kwt,N}}), + kwt_erase(N-1). + +%% Test storing off heap values (such as ref-counted binaries). + +off_heap_values(_Config) -> + Chk = chk(), + Key = {?MODULE,?FUNCTION_NAME}, + Val = {a,list_to_binary(lists:seq(0, 255)),make_ref(),fun() -> ok end}, + ok = persistent_term:put(Key, Val), + FetchedVal = persistent_term:get(Key), + Val = FetchedVal, + true = persistent_term:erase(Key), + off_heap_values_wait(FetchedVal, Val), + chk(Chk). + +off_heap_values_wait(FetchedVal, Val) -> + case erts_debug:size_shared(FetchedVal) of + 0 -> + Val = FetchedVal, + ok; + _ -> + erlang:yield(), + off_heap_values_wait(FetchedVal, Val) + end. + +%% Test some more data types as keys. Use the module name as a key +%% to minimize the risk of collision with any key used +%% by the OTP libraries. + +keys(_Config) -> + Chk = chk(), + do_key(?MODULE), + do_key([?MODULE]), + do_key(?MODULE_STRING), + do_key(list_to_binary(?MODULE_STRING)), + chk(Chk). + +do_key(Key) -> + Val = term_to_binary(Key), + ok = persistent_term:put(Key, Val), + StoredVal = persistent_term:get(Key), + Val = StoredVal, + true = persistent_term:erase(Key). + +%% Create persistent terms with keys that are known to collide. +%% Delete them in random order, making sure that all others +%% terms can still be found. + +collisions(_Config) -> + Chk = chk(), + + %% Create persistent terms with random keys. + Keys = lists:flatten(colliding_keys()), + Kvs = [{K,rand:uniform(1000)} || K <- Keys], + _ = [ok = persistent_term:put(K, V) || {K,V} <- Kvs], + _ = [V = persistent_term:get(K) || {K,V} <- Kvs], + + %% Now delete the persistent terms in random order. + collisions_delete(lists:keysort(2, Kvs)), + + chk(Chk). + +collisions_delete([{Key,Val}|Kvs]) -> + Val = persistent_term:get(Key), + true = persistent_term:erase(Key), + true = lists:sort(persistent_term:get()) =:= lists:sort(Kvs), + _ = [V = persistent_term:get(K) || {K,V} <- Kvs], + collisions_delete(Kvs); +collisions_delete([]) -> + ok. + +colliding_keys() -> + %% Collisions found by Jesper L. Andersen for breaking maps. + L = [[764492191,2361333849], + [49527266765044,90940896816021,20062927283041,267080852079651], + [249858369443708,206247021789428,20287304470696,25847120931175], + [10645228898670,224705626119556,267405565521452,258214397180678], + [264783762221048,166955943492306,98802957003141,102012488332476], + [69425677456944,177142907243411,137138950917722,228865047699598], + [116031213307147,29203342183358,37406949328742,255198080174323], + [200358182338308,235207156008390,120922906095920,116215987197289], + [58728890318426,68877471005069,176496507286088,221041411345780], + [91094120814795,50665258299931,256093108116737,19777509566621], + [74646746200247,98350487270564,154448261001199,39881047281135], + [23408943649483,164410325820923,248161749770122,274558342231648], + [169531547115055,213630535746863,235098262267796,200508473898303], + [235098564415817,85039146398174,51721575960328,173069189684390], + [176136386396069,155368359051606,147817099696487,265419485459634], + [137542881551462,40028925519736,70525669519846,63445773516557], + [173854695142814,114282444507812,149945832627054,99605565798831], + [177686773562184,127158716984798,132495543008547], + [227073396444896,139667311071766,158915951283562], + [26212438434289,94902985796531,198145776057315], + [266279278943923,58550737262493,74297973216378], + [32373606512065,131854353044428,184642643042326], + [34335377662439,85341895822066,273492717750246]], + + %% Verify that the keys still collide (this will fail if the + %% internal hash function has been changed). + erts_debug:set_internal_state(available_internal_state, true), + try + case erlang:system_info(wordsize) of + 8 -> + verify_colliding_keys(L); + 4 -> + %% Not guaranteed to collide on a 32-bit system. + ok + end + after + erts_debug:set_internal_state(available_internal_state, false) + end, + + L. + +verify_colliding_keys([[K|Ks]|Gs]) -> + Hash = internal_hash(K), + [Hash] = lists:usort([internal_hash(Key) || Key <- Ks]), + verify_colliding_keys(Gs); +verify_colliding_keys([]) -> + ok. + +internal_hash(Term) -> + erts_debug:get_internal_state({internal_hash,Term}). + +%% Test that all persistent terms are erased by init:restart/0. + +init_restart(_Config) -> + File = "command_file", + ok = file:write_file(File, term_to_binary(restart)), + {ok,[[Erl]]} = init:get_argument(progname), + ModPath = filename:dirname(code:which(?MODULE)), + Cmd = Erl ++ " -pa " ++ ModPath ++ " -noshell " + "-run " ++ ?MODULE_STRING ++ " test_init_restart_cmd " ++ + File, + io:format("~s\n", [Cmd]), + Expected = "12ok", + case os:cmd(Cmd) of + Expected -> + ok; + Actual -> + io:format("Expected: ~s", [Expected]), + io:format("Actual: ~s\n", [Actual]), + ct:fail(unexpected_output) + end. + +test_init_restart_cmd([File]) -> + try + do_test_init_restart_cmd(File) + catch + C:R -> + io:format("\n~p ~p\n", [C,R]), + halt() + end, + receive + _ -> ok + end. + +do_test_init_restart_cmd(File) -> + {ok,Bin} = file:read_file(File), + Seq = lists:seq(1, 50), + case binary_to_term(Bin) of + restart -> + _ = [persistent_term:put({?MODULE,I}, {value,I}) || + I <- Seq], + ok = file:write_file(File, term_to_binary(was_restarted)), + io:put_chars("1"), + init:restart(), + receive + _ -> ok + end; + was_restarted -> + io:put_chars("2"), + ok = file:delete(File), + _ = [begin + Key = {?MODULE,I}, + {'EXIT',{badarg,_}} = (catch persistent_term:get(Key)) + end || I <- Seq], + io:put_chars("ok"), + init:stop() + end. + +%% Check that there is the same number of persistents terms before +%% and after each test case. + +chk() -> + persistent_term:info(). + +chk(Chk) -> + Chk = persistent_term:info(), + Key = {?MODULE,?FUNCTION_NAME}, + ok = persistent_term:put(Key, {term,Chk}), + Term = persistent_term:get(Key), + true = persistent_term:erase(Key), + chk_not_stuck(Term), + ok. + +chk_not_stuck(Term) -> + %% Hash tables to be deleted are put onto a queue. + %% Make sure that the queue isn't stuck by a table with + %% a non-zero ref count. + + case erts_debug:size_shared(Term) of + 0 -> + erlang:yield(), + chk_not_stuck(Term); + _ -> + ok + end. diff --git a/erts/preloaded/ebin/erts_internal.beam b/erts/preloaded/ebin/erts_internal.beam Binary files differindex 15c59de80a..f39c7aa8eb 100644 --- a/erts/preloaded/ebin/erts_internal.beam +++ b/erts/preloaded/ebin/erts_internal.beam diff --git a/erts/preloaded/ebin/init.beam b/erts/preloaded/ebin/init.beam Binary files differindex 858a9dc63e..1e60ef7e88 100644 --- a/erts/preloaded/ebin/init.beam +++ b/erts/preloaded/ebin/init.beam diff --git a/erts/preloaded/ebin/persistent_term.beam b/erts/preloaded/ebin/persistent_term.beam Binary files differnew file mode 100644 index 0000000000..79ef03b9a6 --- /dev/null +++ b/erts/preloaded/ebin/persistent_term.beam diff --git a/erts/preloaded/src/Makefile b/erts/preloaded/src/Makefile index 4333f6643a..e768a8edbc 100644 --- a/erts/preloaded/src/Makefile +++ b/erts/preloaded/src/Makefile @@ -47,7 +47,8 @@ PRE_LOADED_ERL_MODULES = \ erts_internal \ erl_tracer \ erts_literal_area_collector \ - erts_dirty_process_signal_handler + erts_dirty_process_signal_handler \ + persistent_term PRE_LOADED_BEAM_MODULES = \ prim_eval diff --git a/erts/preloaded/src/erts_internal.erl b/erts/preloaded/src/erts_internal.erl index 88f47e917b..63b786a473 100644 --- a/erts/preloaded/src/erts_internal.erl +++ b/erts/preloaded/src/erts_internal.erl @@ -90,6 +90,8 @@ -export([create_dist_channel/4]). +-export([erase_persistent_terms/0]). + %% %% Await result of send to port %% @@ -691,3 +693,7 @@ process_flag(_Pid, _Flag, _Value) -> create_dist_channel(_Node, _DistCtrlr, _Flags, _Ver) -> erlang:nif_error(undefined). + +-spec erase_persistent_terms() -> 'ok'. +erase_persistent_terms() -> + erlang:nif_error(undefined). diff --git a/erts/preloaded/src/init.erl b/erts/preloaded/src/init.erl index 253fcf7a1f..b4b8b3bf9b 100644 --- a/erts/preloaded/src/init.erl +++ b/erts/preloaded/src/init.erl @@ -552,6 +552,7 @@ stop(Reason,State) -> do_stop(restart,#state{start = Start, flags = Flags, args = Args}) -> %% Make sure we don't have any outstanding messages before doing the restart. flush(), + erts_internal:erase_persistent_terms(), boot(Start,Flags,Args); do_stop(reboot,_) -> halt(); diff --git a/erts/preloaded/src/persistent_term.erl b/erts/preloaded/src/persistent_term.erl new file mode 100644 index 0000000000..5d0c266127 --- /dev/null +++ b/erts/preloaded/src/persistent_term.erl @@ -0,0 +1,55 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2018. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% +-module(persistent_term). + +-export([erase/1,get/0,get/1,info/0,put/2]). + +-type key() :: term(). +-type value() :: term(). + +-spec erase(Key) -> Result when + Key :: key(), + Result :: boolean(). +erase(_Key) -> + erlang:nif_error(undef). + +-spec get() -> List when + List :: [{key(),value()}]. +get() -> + erlang:nif_error(undef). + +-spec get(Key) -> Value when + Key :: key(), + Value :: value(). +get(_Key) -> + erlang:nif_error(undef). + +-spec info() -> Info when + Info :: #{'count':=Count,'memory':=Memory}, + Count :: non_neg_integer(), + Memory :: non_neg_integer(). +info() -> + erlang:nif_error(undef). + +-spec put(Key, Value) -> 'ok' when + Key :: key(), + Value :: value(). +put(_Key, _Value) -> + erlang:nif_error(undef). diff --git a/lib/sasl/src/systools_make.erl b/lib/sasl/src/systools_make.erl index 6916107623..983df58ef7 100644 --- a/lib/sasl/src/systools_make.erl +++ b/lib/sasl/src/systools_make.erl @@ -1565,7 +1565,7 @@ preloaded() -> [erl_prim_loader,erl_tracer,erlang, erts_code_purger,erts_dirty_process_signal_handler, erts_internal,erts_literal_area_collector, - init,otp_ring0,prim_buffer,prim_eval,prim_file, + init,otp_ring0,persistent_term,prim_buffer,prim_eval,prim_file, prim_inet,prim_zip,zlib]. %%______________________________________________________________________ |