--- /dev/null
+#ifndef SIMGRID_S4U_TASK_H_
+#define SIMGRID_S4U_TASK_H_
+
+#include <simgrid/s4u/Activity.hpp>
+#include <simgrid/s4u/Io.hpp>
+#include <xbt/Extendable.hpp>
+
+#include <atomic>
+#include <deque>
+#include <map>
+#include <memory>
+#include <set>
+
+namespace simgrid::s4u {
+
+class Task;
+using TaskPtr = boost::intrusive_ptr<Task>;
+XBT_PUBLIC void intrusive_ptr_release(Task* o);
+XBT_PUBLIC void intrusive_ptr_add_ref(Task* o);
+class ExecTask;
+using ExecTaskPtr = boost::intrusive_ptr<ExecTask>;
+class CommTask;
+using CommTaskPtr = boost::intrusive_ptr<CommTask>;
+class IoTask;
+using IoTaskPtr = boost::intrusive_ptr<IoTask>;
+
+class XBT_PUBLIC Token : public xbt::Extendable<Token> {};
+
+class Task {
+ std::set<Task*> successors_ = {};
+ std::map<Task*, unsigned int> predecessors_ = {};
+
+ bool ready_to_run() const;
+ void receive(Task* source);
+
+protected:
+ std::string name_;
+ double amount_;
+ std::shared_ptr<Token> token_ = nullptr;
+ std::deque<std::map<TaskPtr, std::shared_ptr<Token>>> tokens_received_;
+ int queued_execs_ = 0;
+ int count_ = 0;
+ bool working_ = false;
+ s4u::ActivityPtr previous_activity_;
+ s4u::ActivityPtr current_activity_;
+ xbt::signal<void(Task*)> on_this_start_;
+ xbt::signal<void(Task*)> on_this_end_;
+ explicit Task(const std::string& name);
+ virtual ~Task() = default;
+ virtual void fire() = 0;
+ void complete();
+
+ static xbt::signal<void(Task*)> on_start;
+ static xbt::signal<void(Task*)> on_end;
+ std::atomic_int_fast32_t refcount_{0};
+
+public:
+ const std::string& get_name() const { return name_; }
+ const char* get_cname() const { return name_.c_str(); }
+ void enqueue_execs(int n);
+ void set_amount(double amount);
+ double get_amount() const { return amount_; }
+ void set_token(std::shared_ptr<Token> token);
+ std::shared_ptr<Token> get_next_token_from(TaskPtr t);
+ void add_successor(TaskPtr t);
+ void remove_successor(TaskPtr t);
+ void remove_all_successors();
+ const std::set<Task*>& get_successors() const { return successors_; }
+ void on_this_start_cb(const std::function<void(Task*)>& func);
+ void on_this_end_cb(const std::function<void(Task*)>& func);
+ int get_count() const;
+
+ /** Add a callback fired before a task activity start.
+ * Triggered after the on_this_start function**/
+ static void on_start_cb(const std::function<void(Task*)>& cb) { on_start.connect(cb); }
+ /** Add a callback fired after a task activity end.
+ * Triggered after the on_this_end function, but before
+ * sending tokens to successors.**/
+ static void on_end_cb(const std::function<void(Task*)>& cb) { on_end.connect(cb); }
+
+#ifndef DOXYGEN
+ friend void intrusive_ptr_release(Task* o)
+ {
+ if (o->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
+ std::atomic_thread_fence(std::memory_order_acquire);
+ delete o;
+ }
+ }
+ friend void intrusive_ptr_add_ref(Task* o) { o->refcount_.fetch_add(1, std::memory_order_relaxed); }
+#endif
+};
+
+class ExecTask : public Task {
+ s4u::Host* host_;
+
+ explicit ExecTask(const std::string& name);
+ void fire() override;
+
+public:
+ static ExecTaskPtr init(const std::string& name);
+ static ExecTaskPtr init(const std::string& name, double flops, s4u::Host* host);
+ ExecTaskPtr set_host(s4u::Host* host);
+ s4u::Host* get_host() const { return host_; }
+ ExecTaskPtr set_flops(double flops);
+ double get_flops() const { return get_amount(); }
+};
+
+class CommTask : public Task {
+ s4u::Host* source_;
+ s4u::Host* destination_;
+
+ explicit CommTask(const std::string& name);
+ void fire() override;
+
+public:
+ static CommTaskPtr init(const std::string& name);
+ static CommTaskPtr init(const std::string& name, double bytes, s4u::Host* source, s4u::Host* destination);
+ CommTaskPtr set_source(s4u::Host* source);
+ s4u::Host* get_source() const { return source_; }
+ CommTaskPtr set_destination(s4u::Host* destination);
+ s4u::Host* get_destination() const { return destination_; }
+ CommTaskPtr set_bytes(double bytes);
+ double get_bytes() const { return get_amount(); }
+};
+
+class IoTask : public Task {
+ s4u::Disk* disk_;
+ s4u::Io::OpType type_;
+ explicit IoTask(const std::string& name);
+ void fire() override;
+
+public:
+ static IoTaskPtr init(const std::string& name);
+ static IoTaskPtr init(const std::string& name, double bytes, s4u::Disk* disk, s4u::Io::OpType type);
+ IoTaskPtr set_disk(s4u::Disk* disk);
+ s4u::Disk* get_disk() const { return disk_; }
+ IoTaskPtr set_bytes(double bytes);
+ double get_bytes() const { return get_amount(); }
+ IoTaskPtr set_op_type(s4u::Io::OpType type);
+ s4u::Io::OpType get_op_type() const { return type_; }
+};
+} // namespace simgrid::s4u
+#endif
