Merge branch 'master' into sverk/master/halt-INT_MIN

1 files changed, 486 insertions, 0 deletions

diff --git a/erts/emulator/beam/erl_msacc.c b/erts/emulator/beam/erl_msacc.c
new file mode 100644
index 0000000000..71e3fd8b6e
--- /dev/null
+++ b/erts/emulator/beam/erl_msacc.c
@@ -0,0 +1,486 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2014-2015. 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%
+ */
+
+/*
+ * Description: Microstate accounting.
+ *
+ *              We keep track of the different states that the
+ *              Erlang VM threads are in, in order to provide
+ *              performance/debugging statistics. There is a
+ *              small overhead in enabling this, but in the big
+ *              scheme of things it should be negligible.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#define ERTS_MSACC_STATE_STRINGS 1
+
+#include "sys.h"
+#include "global.h"
+#include "erl_threads.h"
+#include "erl_bif_unique.h"
+#include "erl_map.h"
+#include "erl_msacc.h"
+
+#if ERTS_ENABLE_MSACC
+
+static Eterm erts_msacc_gather_stats(ErtsMsAcc *msacc, Eterm **hpp, Uint *szp);
+static void erts_msacc_reset(ErtsMsAcc *msacc);
+static ErtsMsAcc* get_msacc(void);
+
+#ifdef USE_THREADS
+erts_tsd_key_t ERTS_WRITE_UNLIKELY(erts_msacc_key);
+#else
+ErtsMsAcc *ERTS_WRITE_UNLIKELY(erts_msacc) = NULL;
+#endif
+int ERTS_WRITE_UNLIKELY(erts_msacc_enabled);
+
+static Eterm *erts_msacc_state_atoms = NULL;
+static erts_rwmtx_t msacc_mutex;
+static ErtsMsAcc *msacc_managed = NULL;
+#ifdef USE_THREADS
+static ErtsMsAcc *msacc_unmanaged = NULL;
+static Uint msacc_unmanaged_count = 0;
+#endif
+
+/* we have to split initiation as atoms are not inited in early init */
+void erts_msacc_early_init(void) {
+#ifndef ERTS_MSACC_ALWAYS_ON
+    erts_msacc_enabled = 0;
+#endif
+    erts_rwmtx_init(&msacc_mutex,"msacc_list_mutex");
+#ifdef USE_THREADS
+    erts_tsd_key_create(&erts_msacc_key,"erts_msacc_key");
+#else
+    erts_msacc = NULL;
+#endif
+}
+
+void erts_msacc_init(void) {
+    int i;
+    erts_msacc_state_atoms = erts_alloc(ERTS_ALC_T_MSACC,
+                                        sizeof(Eterm)*ERTS_MSACC_STATE_COUNT);
+    for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++) {
+        erts_msacc_state_atoms[i] = am_atom_put(erts_msacc_states[i],
+                                                strlen(erts_msacc_states[i]));
+    }
+}
+
+void erts_msacc_init_thread(char *type, int id, int managed) {
+    ErtsMsAcc *msacc;
+
+    msacc = erts_alloc(ERTS_ALC_T_MSACC, sizeof(ErtsMsAcc));
+
+    msacc->type = strdup(type);
+    msacc->id = make_small(id);
+    msacc->unmanaged = !managed;
+    msacc->tid = erts_thr_self();
+    msacc->perf_counter = 0;
+
+#ifdef USE_THREADS
+    erts_rwmtx_rwlock(&msacc_mutex);
+    if (!managed) {
+        erts_mtx_init(&msacc->mtx,"msacc_unmanaged_mutex");
+        msacc->next = msacc_unmanaged;
+        msacc_unmanaged = msacc;
+        msacc_unmanaged_count++;
+        ERTS_MSACC_TSD_SET(msacc);
+    } else {
+        msacc->next = msacc_managed;
+        msacc_managed = msacc;
+    }
+    erts_rwmtx_rwunlock(&msacc_mutex);
+#else
+    msacc_managed = msacc;
+#endif
+
+    erts_msacc_reset(msacc);
+
+#ifdef ERTS_MSACC_ALWAYS_ON
+    ERTS_MSACC_TSD_SET(msacc);
+    msacc->perf_counter = erts_sys_perf_counter();
+    msacc->state = ERTS_MSACC_STATE_OTHER;
+#endif
+}
+
+/*
+ * Creates a structure looking like this
+ * #{ type => scheduler, id => 1, counters => #{ State1 => Counter1 ... StateN => CounterN}}
+ */
+static
+Eterm erts_msacc_gather_stats(ErtsMsAcc *msacc, Eterm **hpp, Uint *szp) {
+    int i;
+    Eterm *hp;
+    Eterm key, state_key, state_map;
+    Eterm res = THE_NON_VALUE;
+    flatmap_t *map;
+
+    if (szp) {
+      *szp += MAP_HEADER_FLATMAP_SZ + 1 + 2*(3);
+      *szp += MAP_HEADER_FLATMAP_SZ + 1 + 2*(ERTS_MSACC_STATE_COUNT);
+      for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++) {
+          (void)erts_bld_sint64(NULL,szp,(Sint64)msacc->perf_counters[i]);
+#ifdef ERTS_MSACC_STATE_COUNTERS
+          (void)erts_bld_uint64(NULL,szp,msacc->state_counters[i]);
+          *szp += 3; /* tuple to put state+perf counter in */
+#endif
+      }
+    }
+
+    if (hpp) {
+        Eterm counters[ERTS_MSACC_STATE_COUNT];
+        hp = *hpp;
+        for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++) {
+            Eterm counter = erts_bld_sint64(&hp,NULL,(Sint64)msacc->perf_counters[i]);
+#ifdef ERTS_MSACC_STATE_COUNTERS
+            Eterm counter__ = erts_bld_uint64(&hp,NULL,msacc->state_counters[i]);
+            counters[i] = TUPLE2(hp,counter,counter__);
+            hp += 3;
+#else
+            counters[i] = counter;
+#endif
+        }
+
+      key = TUPLE3(hp,am_counters,am_id,am_type);
+      hp += 4;
+
+      state_key = make_tuple(hp);
+      hp[0] = make_arityval(ERTS_MSACC_STATE_COUNT);
+      
+      for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++)
+        hp[1+i] = erts_msacc_state_atoms[i];
+      hp += 1 + ERTS_MSACC_STATE_COUNT;
+
+      map = (flatmap_t*)hp;
+      hp += MAP_HEADER_FLATMAP_SZ;
+      map->thing_word = MAP_HEADER_FLATMAP;
+      map->size = ERTS_MSACC_STATE_COUNT;
+      map->keys = state_key;
+      for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++)
+            hp[i] = counters[i];
+      hp += ERTS_MSACC_STATE_COUNT;
+      state_map = make_flatmap(map);
+
+      map = (flatmap_t*)hp;
+      hp += MAP_HEADER_FLATMAP_SZ;
+      map->thing_word = MAP_HEADER_FLATMAP;
+      map->size = 3;
+      map->keys = key;
+      hp[0] = state_map;
+      hp[1] = msacc->id;
+      hp[2] = am_atom_put(msacc->type,strlen(msacc->type));
+      hp += 3;
+
+      *hpp = hp;
+      res = make_flatmap(map);
+    }
+
+    return res;
+}
+
+typedef struct {
+    int action;
+    Process *proc;
+    Eterm ref;
+    Eterm ref_heap[REF_THING_SIZE];
+    Uint req_sched;
+    erts_smp_atomic32_t refc;
+} ErtsMSAccReq;
+
+static ErtsMsAcc* get_msacc(void) {
+    ErtsMsAcc *msacc;
+    erts_rwmtx_rlock(&msacc_mutex);
+    msacc = msacc_managed;
+    while (!erts_equal_tids(msacc->tid,erts_thr_self())) {
+        msacc = msacc->next;
+        ASSERT(msacc != NULL);
+    }
+    erts_rwmtx_runlock(&msacc_mutex);
+    return msacc;
+}
+
+static void send_reply(ErtsMsAcc *msacc, ErtsMSAccReq *msaccrp) {
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    Process *rp = msaccrp->proc;
+    ErtsMessage *msgp = NULL;
+    Eterm **hpp, *hp;
+    Eterm ref_copy = NIL, msg;
+    Uint sz, *szp;
+    ErlOffHeap *ohp = NULL;
+    ErtsProcLocks rp_locks = (esdp && msaccrp->req_sched == esdp->no
+                              ? ERTS_PROC_LOCK_MAIN : 0);
+
+    sz = 0;
+    hpp = NULL;
+    szp = &sz;
+
+    if (msacc->unmanaged) erts_mtx_lock(&msacc->mtx);
+
+    while (1) {
+	if (hpp)
+            ref_copy = STORE_NC(hpp, ohp, msaccrp->ref);
+	else
+            *szp += REF_THING_SIZE;
+
+	if (msaccrp->action != ERTS_MSACC_GATHER)
+            msg = ref_copy;
+	else {
+            msg = erts_msacc_gather_stats(msacc, hpp, szp);
+            msg = erts_bld_tuple(hpp, szp, 2, ref_copy, msg);
+	}
+	if (hpp)
+            break;
+
+	msgp = erts_alloc_message_heap(rp, &rp_locks, sz, &hp, &ohp);
+        hpp = &hp;
+	szp = NULL;
+    }
+
+    if (msacc->unmanaged) erts_mtx_unlock(&msacc->mtx);
+
+    erts_queue_message(rp, &rp_locks, msgp, msg, NIL);
+
+    if (esdp && msaccrp->req_sched == esdp->no)
+	rp_locks &= ~ERTS_PROC_LOCK_MAIN;
+
+    if (rp_locks)
+	erts_smp_proc_unlock(rp, rp_locks);
+
+}
+
+static void
+reply_msacc(void *vmsaccrp)
+{
+    ErtsMsAcc *msacc = ERTS_MSACC_TSD_GET();
+    ErtsMSAccReq *msaccrp = (ErtsMSAccReq *) vmsaccrp;
+
+    ASSERT(!msacc || !msacc->unmanaged);
+
+    if (msaccrp->action == ERTS_MSACC_ENABLE && !msacc) {
+        msacc = get_msacc();
+
+        msacc->perf_counter = erts_sys_perf_counter();
+
+        msacc->state = ERTS_MSACC_STATE_OTHER;
+
+        ERTS_MSACC_TSD_SET(msacc);
+
+    } else if (msaccrp->action == ERTS_MSACC_DISABLE && msacc) {
+        ERTS_MSACC_TSD_SET(NULL);
+    } else if (msaccrp->action == ERTS_MSACC_RESET) {
+        msacc = msacc ? msacc : get_msacc();
+        erts_msacc_reset(msacc);
+    } else if (msaccrp->action == ERTS_MSACC_GATHER && !msacc) {
+        msacc = get_msacc();
+    }
+
+    ASSERT(!msacc || !msacc->unmanaged);
+
+    send_reply(msacc, msaccrp);
+
+    erts_proc_dec_refc(msaccrp->proc);
+
+    if (erts_smp_atomic32_dec_read_nob(&msaccrp->refc) == 0)
+      erts_free(ERTS_ALC_T_MSACC, vmsaccrp);
+}
+
+static void erts_msacc_reset(ErtsMsAcc *msacc) {
+  int i;
+  if (msacc->unmanaged) erts_mtx_lock(&msacc->mtx);
+
+  for (i = 0; i < ERTS_MSACC_STATE_COUNT; i++) {
+      msacc->perf_counters[i] = 0;
+#ifdef ERTS_MSACC_STATE_COUNTERS
+      msacc->state_counters[i] = 0;
+#endif
+  }
+
+  if (msacc->unmanaged) erts_mtx_unlock(&msacc->mtx);
+}
+
+#endif /* ERTS_ENABLE_MSACC */
+
+
+/*
+ * This function is responsible for enabling, disabling, resetting and
+ * gathering data related to microstate accounting.
+ *
+ * Managed threads and unmanaged threads are handled differently.
+ *   - managed threads get a misc_aux job telling them to switch on msacc
+ *   - unmanaged have some fields protected by a mutex that has to be taken
+ *     before any values can be updated
+ *
+ * For performance reasons there is also a global value erts_msacc_enabled
+ * that controls the state of all threads. Statistics gathering is only on
+ * if erts_msacc_enabled && msacc is true.
+ */
+Eterm
+erts_msacc_request(Process *c_p, int action, Eterm *threads)
+{
+#ifdef ERTS_ENABLE_MSACC
+    ErtsMsAcc *msacc =  ERTS_MSACC_TSD_GET();
+    ErtsSchedulerData *esdp = ERTS_PROC_GET_SCHDATA(c_p);
+    Eterm ref;
+    ErtsMSAccReq *msaccrp;
+    Eterm *hp;
+
+
+#ifdef ERTS_MSACC_ALWAYS_ON
+    if (action == ERTS_MSACC_ENABLE || action == ERTS_MSACC_DISABLE)
+        return THE_NON_VALUE;
+#else
+    /* take care of double enable, and double disable here */
+    if (msacc && action == ERTS_MSACC_ENABLE) {
+        return THE_NON_VALUE;
+    } else if (!msacc && action == ERTS_MSACC_DISABLE) {
+        return THE_NON_VALUE;
+    }
+#endif
+
+    ref = erts_make_ref(c_p);
+
+    msaccrp = erts_alloc(ERTS_ALC_T_MSACC, sizeof(ErtsMSAccReq));
+    hp = &msaccrp->ref_heap[0];
+
+    msaccrp->action = action;
+    msaccrp->proc = c_p;
+    msaccrp->ref = STORE_NC(&hp, NULL, ref);
+    msaccrp->req_sched = esdp->no;
+
+#ifdef ERTS_SMP
+    *threads = erts_no_schedulers;
+    *threads += 1; /* aux thread */
+#else
+    *threads = 1;
+#endif
+
+    erts_smp_atomic32_init_nob(&msaccrp->refc,(erts_aint32_t)*threads);
+
+    erts_proc_add_refc(c_p, *threads);
+
+    if (erts_no_schedulers > 1)
+	erts_schedule_multi_misc_aux_work(1,
+                                          erts_no_schedulers,
+                                          reply_msacc,
+                                          (void *) msaccrp);
+#ifdef ERTS_SMP
+    /* aux thread */
+    erts_schedule_misc_aux_work(0, reply_msacc, (void *) msaccrp);
+#endif
+
+#ifdef USE_THREADS
+    /* Manage unmanaged threads */
+    switch (action) {
+    case ERTS_MSACC_GATHER: {
+        Uint unmanaged_count;
+        ErtsMsAcc *msacc, **unmanaged;
+        int i = 0;
+
+        /* we copy a list of pointers here so that we do not have to have
+           the msacc_mutex when sending messages */
+        erts_rwmtx_rlock(&msacc_mutex);
+        unmanaged_count = msacc_unmanaged_count;
+        unmanaged = erts_alloc(ERTS_ALC_T_MSACC,
+                               sizeof(ErtsMsAcc*)*unmanaged_count);
+
+        for (i = 0, msacc = msacc_unmanaged;
+             i < unmanaged_count;
+             i++, msacc = msacc->next) {
+            unmanaged[i] = msacc;
+        }
+        erts_rwmtx_runlock(&msacc_mutex);
+
+        for (i = 0; i < unmanaged_count; i++) {
+            erts_mtx_lock(&unmanaged[i]->mtx);
+            if (unmanaged[i]->perf_counter) {
+                ErtsSysPerfCounter perf_counter;
+                /* if enabled update stats */
+                perf_counter = erts_sys_perf_counter();
+                unmanaged[i]->perf_counters[unmanaged[i]->state] +=
+                    perf_counter - unmanaged[i]->perf_counter;
+                unmanaged[i]->perf_counter = perf_counter;
+            }
+            erts_mtx_unlock(&unmanaged[i]->mtx);
+            send_reply(unmanaged[i],msaccrp);
+        }
+        erts_free(ERTS_ALC_T_MSACC,unmanaged);
+        /* We have just sent unmanaged_count messages, so bump no of threads */
+        *threads += unmanaged_count;
+        break;
+    }
+    case ERTS_MSACC_RESET: {
+        ErtsMsAcc *msacc;
+        erts_rwmtx_rlock(&msacc_mutex);
+        for (msacc = msacc_unmanaged; msacc != NULL; msacc = msacc->next)
+            erts_msacc_reset(msacc);
+        erts_rwmtx_runlock(&msacc_mutex);
+        break;
+    }
+    case ERTS_MSACC_ENABLE: {
+        erts_rwmtx_rlock(&msacc_mutex);
+        for (msacc = msacc_unmanaged; msacc != NULL; msacc = msacc->next) {
+            erts_mtx_lock(&msacc->mtx);
+            msacc->perf_counter = erts_sys_perf_counter();
+            /* we assume the unmanaged thread is sleeping */
+            msacc->state = ERTS_MSACC_STATE_SLEEP;
+            erts_mtx_unlock(&msacc->mtx);
+        }
+        erts_rwmtx_runlock(&msacc_mutex);
+        break;
+    }
+    case ERTS_MSACC_DISABLE: {
+        ErtsSysPerfCounter perf_counter;
+        erts_rwmtx_rlock(&msacc_mutex);
+        /* make sure to update stats with latest results */
+        for (msacc = msacc_unmanaged; msacc != NULL; msacc = msacc->next) {
+            erts_mtx_lock(&msacc->mtx);
+            perf_counter = erts_sys_perf_counter();
+            msacc->perf_counters[msacc->state] += perf_counter - msacc->perf_counter;
+            msacc->perf_counter = 0;
+            erts_mtx_unlock(&msacc->mtx);
+        }
+        erts_rwmtx_runlock(&msacc_mutex);
+        break;
+    }
+    default: { ASSERT(0); }
+    }
+
+#endif
+
+    *threads = make_small(*threads);
+
+    reply_msacc((void *) msaccrp);
+
+#ifndef ERTS_MSACC_ALWAYS_ON
+    /* enable/disable the global value */
+    if (action == ERTS_MSACC_ENABLE) {
+        erts_msacc_enabled = 1;
+    } else if (action == ERTS_MSACC_DISABLE) {
+        erts_msacc_enabled = 0;
+    }
+#endif
+
+    return ref;
+#else
+    return THE_NON_VALUE;
+#endif
+}