+++ /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) 2004-2006 Sage Weil <sage@newdream.net>
- *
- * 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.
- *
- */
-
-
-#ifndef CEPH_CONTEXT_H
-#define CEPH_CONTEXT_H
-
-#include "common/dout.h"
-
-#include <boost/function.hpp>
-#include <list>
-#include <set>
-#include <memory>
-
-#include "include/assert.h"
-#include "include/memory.h"
-
-#define mydout(cct, v) lgeneric_subdout(cct, context, v)
-
-/*
- * GenContext - abstract callback class
- */
-template <typename T>
-class GenContext {
- GenContext(const GenContext& other);
- const GenContext& operator=(const GenContext& other);
-
- protected:
- virtual void finish(T t) = 0;
-
- public:
- GenContext() {}
- virtual ~GenContext() {} // we want a virtual destructor!!!
-
- template <typename C>
- void complete(C &&t) {
- finish(std::forward<C>(t));
- delete this;
- }
-};
-
-template <typename T>
-using GenContextURef = std::unique_ptr<GenContext<T> >;
-
-/*
- * Context - abstract callback class
- */
-class Context {
- Context(const Context& other);
- const Context& operator=(const Context& other);
-
- protected:
- virtual void finish(int r) = 0;
-
- public:
- Context() {}
- virtual ~Context() {} // we want a virtual destructor!!!
- virtual void complete(int r) {
- finish(r);
- delete this;
- }
-};
-
-/**
- * Simple context holding a single object
- */
-template<class T>
-class ContainerContext : public Context {
- T obj;
-public:
- ContainerContext(T &obj) : obj(obj) {}
- void finish(int r) override {}
-};
-template <typename T>
-ContainerContext<T> *make_container_context(T &&t) {
- return new ContainerContext<T>(std::forward<T>(t));
-}
-
-template <class T>
-struct Wrapper : public Context {
- Context *to_run;
- T val;
- Wrapper(Context *to_run, T val) : to_run(to_run), val(val) {}
- void finish(int r) override {
- if (to_run)
- to_run->complete(r);
- }
-};
-struct RunOnDelete {
- Context *to_run;
- RunOnDelete(Context *to_run) : to_run(to_run) {}
- ~RunOnDelete() {
- if (to_run)
- to_run->complete(0);
- }
-};
-typedef ceph::shared_ptr<RunOnDelete> RunOnDeleteRef;
-
-template <typename T>
-struct LambdaContext : public Context {
- T t;
- LambdaContext(T &&t) : t(std::forward<T>(t)) {}
- void finish(int) override {
- t();
- }
-};
-template <typename T>
-LambdaContext<T> *make_lambda_context(T &&t) {
- return new LambdaContext<T>(std::move(t));
-}
-
-template <typename F, typename T>
-struct LambdaGenContext : GenContext<T> {
- F f;
- LambdaGenContext(F &&f) : f(std::forward<F>(f)) {}
- void finish(T t) override {
- f(std::forward<T>(t));
- }
-};
-template <typename T, typename F>
-GenContextURef<T> make_gen_lambda_context(F &&f) {
- return GenContextURef<T>(new LambdaGenContext<F, T>(std::move(f)));
-}
-
-/*
- * finish and destroy a list of Contexts
- */
-template<class A>
-inline void finish_contexts(CephContext *cct, std::list<A*>& finished,
- int result = 0)
-{
- if (finished.empty())
- return;
-
- list<A*> ls;
- ls.swap(finished); // swap out of place to avoid weird loops
-
- if (cct)
- mydout(cct, 10) << ls.size() << " contexts to finish with " << result << dendl;
- typename std::list<A*>::iterator it;
- for (it = ls.begin(); it != ls.end(); it++) {
- A *c = *it;
- if (cct)
- mydout(cct,10) << "---- " << c << dendl;
- c->complete(result);
- }
-}
-
-inline void finish_contexts(CephContext *cct, std::vector<Context*>& finished,
- int result = 0)
-{
- if (finished.empty())
- return;
-
- vector<Context*> ls;
- ls.swap(finished); // swap out of place to avoid weird loops
-
- if (cct)
- mydout(cct,10) << ls.size() << " contexts to finish with " << result << dendl;
- for (std::vector<Context*>::iterator it = ls.begin();
- it != ls.end();
- it++) {
- Context *c = *it;
- if (cct)
- mydout(cct,10) << "---- " << c << dendl;
- c->complete(result);
- }
-}
-
-class C_NoopContext : public Context {
-public:
- void finish(int r) override { }
-};
-
-
-struct C_Lock : public Context {
- Mutex *lock;
- Context *fin;
- C_Lock(Mutex *l, Context *c) : lock(l), fin(c) {}
- ~C_Lock() override {
- delete fin;
- }
- void finish(int r) override {
- if (fin) {
- lock->Lock();
- fin->complete(r);
- fin = NULL;
- lock->Unlock();
- }
- }
-};
-
-/*
- * C_Contexts - set of Contexts
- *
- * ContextType must be an ancestor class of ContextInstanceType, or the same class.
- * ContextInstanceType must be default-constructable.
- */
-template <class ContextType, class ContextInstanceType>
-class C_ContextsBase : public ContextInstanceType {
-public:
- CephContext *cct;
- std::list<ContextType*> contexts;
-
- C_ContextsBase(CephContext *cct_)
- : cct(cct_)
- {
- }
- ~C_ContextsBase() override {
- for (auto c : contexts) {
- delete c;
- }
- }
- void add(ContextType* c) {
- contexts.push_back(c);
- }
- void take(std::list<ContextType*>& ls) {
- contexts.splice(contexts.end(), ls);
- }
- void complete(int r) override {
- // Neuter any ContextInstanceType custom complete(), because although
- // I want to look like it, I don't actually want to run its code.
- Context::complete(r);
- }
- void finish(int r) override {
- finish_contexts(cct, contexts, r);
- }
- bool empty() { return contexts.empty(); }
-
- static ContextType *list_to_context(list<ContextType *> &cs) {
- if (cs.size() == 0) {
- return 0;
- } else if (cs.size() == 1) {
- ContextType *c = cs.front();
- cs.clear();
- return c;
- } else {
- C_ContextsBase<ContextType, ContextInstanceType> *c(new C_ContextsBase<ContextType, ContextInstanceType>(0));
- c->take(cs);
- return c;
- }
- }
-};
-
-typedef C_ContextsBase<Context, Context> C_Contexts;
-
-/*
- * C_Gather
- *
- * ContextType must be an ancestor class of ContextInstanceType, or the same class.
- * ContextInstanceType must be default-constructable.
- *
- * BUG:? only reports error from last sub to have an error return
- */
-template <class ContextType, class ContextInstanceType>
-class C_GatherBase : public ContextType {
-private:
- CephContext *cct;
- int result;
- ContextType *onfinish;
-#ifdef DEBUG_GATHER
- std::set<ContextType*> waitfor;
-#endif
- int sub_created_count;
- int sub_existing_count;
- mutable Mutex lock;
- bool activated;
-
- void sub_finish(ContextType* sub, int r) {
- lock.Lock();
-#ifdef DEBUG_GATHER
- assert(waitfor.count(sub));
- waitfor.erase(sub);
-#endif
- --sub_existing_count;
- mydout(cct,10) << "C_GatherBase " << this << ".sub_finish(r=" << r << ") " << sub
-#ifdef DEBUG_GATHER
- << " (remaining " << waitfor << ")"
-#endif
- << dendl;
- if (r < 0 && result == 0)
- result = r;
- if ((activated == false) || (sub_existing_count != 0)) {
- lock.Unlock();
- return;
- }
- lock.Unlock();
- delete_me();
- }
-
- void delete_me() {
- if (onfinish) {
- onfinish->complete(result);
- onfinish = 0;
- }
- delete this;
- }
-
- class C_GatherSub : public ContextInstanceType {
- C_GatherBase *gather;
- public:
- C_GatherSub(C_GatherBase *g) : gather(g) {}
- void complete(int r) override {
- // Cancel any customized complete() functionality
- // from the Context subclass we're templated for,
- // we only want to hit that in onfinish, not at each
- // sub finish. e.g. MDSInternalContext.
- Context::complete(r);
- }
- void finish(int r) override {
- gather->sub_finish(this, r);
- gather = 0;
- }
- ~C_GatherSub() override {
- if (gather)
- gather->sub_finish(this, 0);
- }
- };
-
-public:
- C_GatherBase(CephContext *cct_, ContextType *onfinish_)
- : cct(cct_), result(0), onfinish(onfinish_),
- sub_created_count(0), sub_existing_count(0),
- lock("C_GatherBase::lock", true, false), //disable lockdep
- activated(false)
- {
- mydout(cct,10) << "C_GatherBase " << this << ".new" << dendl;
- }
- ~C_GatherBase() override {
- mydout(cct,10) << "C_GatherBase " << this << ".delete" << dendl;
- }
- void set_finisher(ContextType *onfinish_) {
- Mutex::Locker l(lock);
- assert(!onfinish);
- onfinish = onfinish_;
- }
- void activate() {
- lock.Lock();
- assert(activated == false);
- activated = true;
- if (sub_existing_count != 0) {
- lock.Unlock();
- return;
- }
- lock.Unlock();
- delete_me();
- }
- ContextType *new_sub() {
- Mutex::Locker l(lock);
- assert(activated == false);
- sub_created_count++;
- sub_existing_count++;
- ContextType *s = new C_GatherSub(this);
-#ifdef DEBUG_GATHER
- waitfor.insert(s);
-#endif
- mydout(cct,10) << "C_GatherBase " << this << ".new_sub is " << sub_created_count << " " << s << dendl;
- return s;
- }
- void finish(int r) override {
- ceph_abort(); // nobody should ever call me.
- }
-
- inline int get_sub_existing_count() const {
- Mutex::Locker l(lock);
- return sub_existing_count;
- }
-
- inline int get_sub_created_count() const {
- Mutex::Locker l(lock);
- return sub_created_count;
- }
-};
-
-/*
- * The C_GatherBuilder remembers each C_Context created by
- * C_GatherBuilder.new_sub() in a C_Gather. When a C_Context created
- * by new_sub() is complete(), C_Gather forgets about it. When
- * C_GatherBuilder notices that there are no C_Context left in
- * C_Gather, it calls complete() on the C_Context provided as the
- * second argument of the constructor (finisher).
- *
- * How to use C_GatherBuilder:
- *
- * 1. Create a C_GatherBuilder on the stack
- * 2. Call gather_bld.new_sub() as many times as you want to create new subs
- * It is safe to call this 0 times, or 100, or anything in between.
- * 3. If you didn't supply a finisher in the C_GatherBuilder constructor,
- * set one with gather_bld.set_finisher(my_finisher)
- * 4. Call gather_bld.activate()
- *
- * Example:
- *
- * C_SaferCond all_done;
- * C_GatherBuilder gb(g_ceph_context, all_done);
- * j.submit_entry(1, first, 0, gb.new_sub()); // add a C_Context to C_Gather
- * j.submit_entry(2, first, 0, gb.new_sub()); // add a C_Context to C_Gather
- * gb.activate(); // consume C_Context as soon as they complete()
- * all_done.wait(); // all_done is complete() after all new_sub() are complete()
- *
- * The finisher may be called at any point after step 4, including immediately
- * from the activate() function.
- * The finisher will never be called before activate().
- *
- * Note: Currently, subs must be manually freed by the caller (for some reason.)
- */
-template <class ContextType, class GatherType>
-class C_GatherBuilderBase
-{
-public:
- C_GatherBuilderBase(CephContext *cct_)
- : cct(cct_), c_gather(NULL), finisher(NULL), activated(false)
- {
- }
- C_GatherBuilderBase(CephContext *cct_, ContextType *finisher_)
- : cct(cct_), c_gather(NULL), finisher(finisher_), activated(false)
- {
- }
- ~C_GatherBuilderBase() {
- if (c_gather) {
- assert(activated); // Don't forget to activate your C_Gather!
- }
- else {
- delete finisher;
- }
- }
- ContextType *new_sub() {
- if (!c_gather) {
- c_gather = new GatherType(cct, finisher);
- }
- return c_gather->new_sub();
- }
- void activate() {
- if (!c_gather)
- return;
- assert(finisher != NULL);
- activated = true;
- c_gather->activate();
- }
- void set_finisher(ContextType *finisher_) {
- finisher = finisher_;
- if (c_gather)
- c_gather->set_finisher(finisher);
- }
- GatherType *get() const {
- return c_gather;
- }
- bool has_subs() const {
- return (c_gather != NULL);
- }
- int num_subs_created() {
- assert(!activated);
- if (c_gather == NULL)
- return 0;
- return c_gather->get_sub_created_count();
- }
- int num_subs_remaining() {
- assert(!activated);
- if (c_gather == NULL)
- return 0;
- return c_gather->get_sub_existing_count();
- }
-
-private:
- CephContext *cct;
- GatherType *c_gather;
- ContextType *finisher;
- bool activated;
-};
-
-typedef C_GatherBase<Context, Context> C_Gather;
-typedef C_GatherBuilderBase<Context, C_Gather > C_GatherBuilder;
-
-class FunctionContext : public Context {
-public:
- FunctionContext(boost::function<void(int)> &&callback)
- : m_callback(std::move(callback))
- {
- }
-
- void finish(int r) override {
- m_callback(r);
- }
-private:
- boost::function<void(int)> m_callback;
-};
-
-#undef mydout
-
-#endif
Code Review / stor4nfv.git / blobdiff