+++ /dev/null
-// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
-// vim: ts=8 sw=2 smarttab
-/*
- * Ceph - scalable distributed file system
- *
- * Copyright (C) 2008-2011 New Dream Network
- *
- * This is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License version 2.1, as published by the Free Software
- * Foundation. See file COPYING.
- *
- */
-#include "lockdep.h"
-#include "common/dout.h"
-#include "common/valgrind.h"
-
-#if defined(__FreeBSD__) && defined(__LP64__) // On FreeBSD pthread_t is a pointer.
-namespace std {
- template<>
- struct hash<pthread_t>
- {
- size_t
- operator()(pthread_t __x) const
- { return (uintptr_t)__x; }
- };
-} // namespace std
-#endif
-
-/******* Constants **********/
-#define lockdep_dout(v) lsubdout(g_lockdep_ceph_ctx, lockdep, v)
-#define MAX_LOCKS 4096 // increase me as needed
-#define BACKTRACE_SKIP 2
-
-/******* Globals **********/
-int g_lockdep = 0;
-struct lockdep_stopper_t {
- // disable lockdep when this module destructs.
- ~lockdep_stopper_t() {
- g_lockdep = 0;
- }
-};
-static pthread_mutex_t lockdep_mutex = PTHREAD_MUTEX_INITIALIZER;
-static CephContext *g_lockdep_ceph_ctx = NULL;
-static lockdep_stopper_t lockdep_stopper;
-static ceph::unordered_map<std::string, int> lock_ids;
-static map<int, std::string> lock_names;
-static map<int, int> lock_refs;
-static char free_ids[MAX_LOCKS/8]; // bit set = free
-static ceph::unordered_map<pthread_t, map<int,BackTrace*> > held;
-static char follows[MAX_LOCKS][MAX_LOCKS/8]; // follows[a][b] means b taken after a
-static BackTrace *follows_bt[MAX_LOCKS][MAX_LOCKS];
-unsigned current_maxid;
-int last_freed_id;
-
-static bool lockdep_force_backtrace()
-{
- return (g_lockdep_ceph_ctx != NULL &&
- g_lockdep_ceph_ctx->_conf->lockdep_force_backtrace);
-}
-
-/******* Functions **********/
-void lockdep_register_ceph_context(CephContext *cct)
-{
- static_assert((MAX_LOCKS > 0) && (MAX_LOCKS % 8 == 0),
- "lockdep's MAX_LOCKS needs to be divisible by 8 to operate correctly.");
- pthread_mutex_lock(&lockdep_mutex);
- if (g_lockdep_ceph_ctx == NULL) {
- ANNOTATE_BENIGN_RACE_SIZED(&g_lockdep_ceph_ctx, sizeof(g_lockdep_ceph_ctx),
- "lockdep cct");
- ANNOTATE_BENIGN_RACE_SIZED(&g_lockdep, sizeof(g_lockdep),
- "lockdep enabled");
- g_lockdep = true;
- g_lockdep_ceph_ctx = cct;
- lockdep_dout(1) << "lockdep start" << dendl;
- current_maxid = 0;
- last_freed_id = -1;
-
- memset((void*) &free_ids[0], 255, sizeof(free_ids));
- }
- pthread_mutex_unlock(&lockdep_mutex);
-}
-
-void lockdep_unregister_ceph_context(CephContext *cct)
-{
- pthread_mutex_lock(&lockdep_mutex);
- if (cct == g_lockdep_ceph_ctx) {
- lockdep_dout(1) << "lockdep stop" << dendl;
- // this cct is going away; shut it down!
- g_lockdep = false;
- g_lockdep_ceph_ctx = NULL;
-
- // blow away all of our state, too, in case it starts up again.
- for (unsigned i = 0; i < current_maxid; ++i) {
- for (unsigned j = 0; j < current_maxid; ++j) {
- delete follows_bt[i][j];
- }
- }
-
- held.clear();
- lock_names.clear();
- lock_ids.clear();
- lock_refs.clear();
- memset((void*)&free_ids[0], 0, sizeof(free_ids));
- memset((void*)&follows[0][0], 0, current_maxid * MAX_LOCKS/8);
- memset((void*)&follows_bt[0][0], 0, sizeof(BackTrace*) * current_maxid * MAX_LOCKS);
- current_maxid = 0;
- last_freed_id = -1;
- }
- pthread_mutex_unlock(&lockdep_mutex);
-}
-
-int lockdep_dump_locks()
-{
- pthread_mutex_lock(&lockdep_mutex);
-
- for (ceph::unordered_map<pthread_t, map<int,BackTrace*> >::iterator p = held.begin();
- p != held.end();
- ++p) {
- lockdep_dout(0) << "--- thread " << p->first << " ---" << dendl;
- for (map<int,BackTrace*>::iterator q = p->second.begin();
- q != p->second.end();
- ++q) {
- lockdep_dout(0) << " * " << lock_names[q->first] << "\n";
- if (q->second)
- *_dout << *(q->second);
- *_dout << dendl;
- }
- }
-
- pthread_mutex_unlock(&lockdep_mutex);
- return 0;
-}
-
-int lockdep_get_free_id(void)
-{
- // if there's id known to be freed lately, reuse it
- if ((last_freed_id >= 0) &&
- (free_ids[last_freed_id/8] & (1 << (last_freed_id % 8)))) {
- int tmp = last_freed_id;
- last_freed_id = -1;
- free_ids[tmp/8] &= 255 - (1 << (tmp % 8));
- lockdep_dout(1) << "lockdep reusing last freed id " << tmp << dendl;
- return tmp;
- }
-
- // walk through entire array and locate nonzero char, then find
- // actual bit.
- for (int i = 0; i < MAX_LOCKS / 8; ++i) {
- if (free_ids[i] != 0) {
- for (int j = 0; j < 8; ++j) {
- if (free_ids[i] & (1 << j)) {
- free_ids[i] &= 255 - (1 << j);
- lockdep_dout(1) << "lockdep using id " << i * 8 + j << dendl;
- return i * 8 + j;
- }
- }
- }
- }
-
- // not found
- lockdep_dout(0) << "failing miserably..." << dendl;
- return -1;
-}
-
-int lockdep_register(const char *name)
-{
- int id;
-
- pthread_mutex_lock(&lockdep_mutex);
- ceph::unordered_map<std::string, int>::iterator p = lock_ids.find(name);
- if (p == lock_ids.end()) {
- id = lockdep_get_free_id();
- if (id < 0) {
- lockdep_dout(0) << "ERROR OUT OF IDS .. have 0"
- << " max " << MAX_LOCKS << dendl;
- for (auto& p : lock_names) {
- lockdep_dout(0) << " lock " << p.first << " " << p.second << dendl;
- }
- assert(false);
- }
- if (current_maxid <= (unsigned)id) {
- current_maxid = (unsigned)id + 1;
- }
- lock_ids[name] = id;
- lock_names[id] = name;
- lockdep_dout(10) << "registered '" << name << "' as " << id << dendl;
- } else {
- id = p->second;
- lockdep_dout(20) << "had '" << name << "' as " << id << dendl;
- }
-
- ++lock_refs[id];
- pthread_mutex_unlock(&lockdep_mutex);
-
- return id;
-}
-
-void lockdep_unregister(int id)
-{
- if (id < 0) {
- return;
- }
-
- pthread_mutex_lock(&lockdep_mutex);
-
- map<int, std::string>::iterator p = lock_names.find(id);
- assert(p != lock_names.end());
-
- int &refs = lock_refs[id];
- if (--refs == 0) {
- // reset dependency ordering
- memset((void*)&follows[id][0], 0, MAX_LOCKS/8);
- for (unsigned i=0; i<current_maxid; ++i) {
- delete follows_bt[id][i];
- follows_bt[id][i] = NULL;
-
- delete follows_bt[i][id];
- follows_bt[i][id] = NULL;
- follows[i][id / 8] &= 255 - (1 << (id % 8));
- }
-
- lockdep_dout(10) << "unregistered '" << p->second << "' from " << id
- << dendl;
- lock_ids.erase(p->second);
- lock_names.erase(id);
- lock_refs.erase(id);
- free_ids[id/8] |= (1 << (id % 8));
- last_freed_id = id;
- } else {
- lockdep_dout(20) << "have " << refs << " of '" << p->second << "' "
- << "from " << id << dendl;
- }
- pthread_mutex_unlock(&lockdep_mutex);
-}
-
-
-// does b follow a?
-static bool does_follow(int a, int b)
-{
- if (follows[a][b/8] & (1 << (b % 8))) {
- lockdep_dout(0) << "\n";
- *_dout << "------------------------------------" << "\n";
- *_dout << "existing dependency " << lock_names[a] << " (" << a << ") -> "
- << lock_names[b] << " (" << b << ") at:\n";
- if (follows_bt[a][b]) {
- follows_bt[a][b]->print(*_dout);
- }
- *_dout << dendl;
- return true;
- }
-
- for (unsigned i=0; i<current_maxid; i++) {
- if ((follows[a][i/8] & (1 << (i % 8))) &&
- does_follow(i, b)) {
- lockdep_dout(0) << "existing intermediate dependency " << lock_names[a]
- << " (" << a << ") -> " << lock_names[i] << " (" << i << ") at:\n";
- if (follows_bt[a][i]) {
- follows_bt[a][i]->print(*_dout);
- }
- *_dout << dendl;
- return true;
- }
- }
-
- return false;
-}
-
-int lockdep_will_lock(const char *name, int id, bool force_backtrace)
-{
- pthread_t p = pthread_self();
- if (id < 0) id = lockdep_register(name);
-
- pthread_mutex_lock(&lockdep_mutex);
- lockdep_dout(20) << "_will_lock " << name << " (" << id << ")" << dendl;
-
- // check dependency graph
- map<int, BackTrace *> &m = held[p];
- for (map<int, BackTrace *>::iterator p = m.begin();
- p != m.end();
- ++p) {
- if (p->first == id) {
- lockdep_dout(0) << "\n";
- *_dout << "recursive lock of " << name << " (" << id << ")\n";
- BackTrace *bt = new BackTrace(BACKTRACE_SKIP);
- bt->print(*_dout);
- if (p->second) {
- *_dout << "\npreviously locked at\n";
- p->second->print(*_dout);
- }
- delete bt;
- *_dout << dendl;
- ceph_abort();
- }
- else if (!(follows[p->first][id/8] & (1 << (id % 8)))) {
- // new dependency
-
- // did we just create a cycle?
- if (does_follow(id, p->first)) {
- BackTrace *bt = new BackTrace(BACKTRACE_SKIP);
- lockdep_dout(0) << "new dependency " << lock_names[p->first]
- << " (" << p->first << ") -> " << name << " (" << id << ")"
- << " creates a cycle at\n";
- bt->print(*_dout);
- *_dout << dendl;
-
- lockdep_dout(0) << "btw, i am holding these locks:" << dendl;
- for (map<int, BackTrace *>::iterator q = m.begin();
- q != m.end();
- ++q) {
- lockdep_dout(0) << " " << lock_names[q->first] << " (" << q->first << ")" << dendl;
- if (q->second) {
- lockdep_dout(0) << " ";
- q->second->print(*_dout);
- *_dout << dendl;
- }
- }
-
- lockdep_dout(0) << "\n" << dendl;
-
- // don't add this dependency, or we'll get aMutex. cycle in the graph, and
- // does_follow() won't terminate.
-
- ceph_abort(); // actually, we should just die here.
- } else {
- BackTrace *bt = NULL;
- if (force_backtrace || lockdep_force_backtrace()) {
- bt = new BackTrace(BACKTRACE_SKIP);
- }
- follows[p->first][id/8] |= 1 << (id % 8);
- follows_bt[p->first][id] = bt;
- lockdep_dout(10) << lock_names[p->first] << " -> " << name << " at" << dendl;
- //bt->print(*_dout);
- }
- }
- }
-
- pthread_mutex_unlock(&lockdep_mutex);
- return id;
-}
-
-int lockdep_locked(const char *name, int id, bool force_backtrace)
-{
- pthread_t p = pthread_self();
-
- if (id < 0) id = lockdep_register(name);
-
- pthread_mutex_lock(&lockdep_mutex);
- lockdep_dout(20) << "_locked " << name << dendl;
- if (force_backtrace || lockdep_force_backtrace())
- held[p][id] = new BackTrace(BACKTRACE_SKIP);
- else
- held[p][id] = 0;
- pthread_mutex_unlock(&lockdep_mutex);
- return id;
-}
-
-int lockdep_will_unlock(const char *name, int id)
-{
- pthread_t p = pthread_self();
-
- if (id < 0) {
- //id = lockdep_register(name);
- assert(id == -1);
- return id;
- }
-
- pthread_mutex_lock(&lockdep_mutex);
- lockdep_dout(20) << "_will_unlock " << name << dendl;
-
- // don't assert.. lockdep may be enabled at any point in time
- //assert(held.count(p));
- //assert(held[p].count(id));
-
- delete held[p][id];
- held[p].erase(id);
- pthread_mutex_unlock(&lockdep_mutex);
- return id;
-}
-
-
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