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// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#ifndef RUST_SCHED_LOOP_H
#define RUST_SCHED_LOOP_H
#include "rust_globals.h"
#include "rust_log.h"
#include "rust_rng.h"
#include "rust_stack.h"
#include "rust_signal.h"
#include "context.h"
#include "util/indexed_list.h"
enum rust_task_state {
task_state_newborn,
task_state_running,
task_state_blocked,
task_state_dead
};
/*
The result of every turn of the scheduler loop. Instructs the loop
driver how to proceed.
*/
enum rust_sched_loop_state {
sched_loop_state_keep_going,
sched_loop_state_block,
sched_loop_state_exit
};
class rust_kernel;
class rust_scheduler;
struct rust_task;
typedef indexed_list<rust_task> rust_task_list;
struct rust_sched_loop
{
private:
lock_and_signal lock;
// Fields known only by the runtime:
rust_log _log;
const int id;
static bool tls_initialized;
#ifndef __WIN32__
static pthread_key_t task_key;
#else
static DWORD task_key;
#endif
context c_context;
rust_rng rng;
bool should_exit;
stk_seg *cached_c_stack;
stk_seg *extra_c_stack;
rust_task_list running_tasks;
rust_task_list blocked_tasks;
rust_task *dead_task;
bool killed;
rust_signal *pump_signal;
void prepare_c_stack(rust_task *task);
void unprepare_c_stack();
rust_task_list *state_list(rust_task_state state);
const char *state_name(rust_task_state state);
void pump_loop();
private:
// private and undefined to disable copying
rust_sched_loop(const rust_sched_loop& rhs);
rust_sched_loop& operator=(const rust_sched_loop& rhs);
public:
rust_kernel *kernel;
rust_scheduler *sched;
// NB: this is used to filter *runtime-originating* debug
// logging, on a per-scheduler basis. It's not likely what
// you want to expose to the user in terms of per-task
// or per-module logging control. By default all schedulers
// are set to debug-level logging here, and filtered by
// runtime category using the pseudo-modules ::rt::foo.
uint32_t log_lvl;
size_t min_stack_size;
memory_region local_region;
const char *const name; // Used for debugging
// Only a pointer to 'name' is kept, so it must live as long as this
// domain.
rust_sched_loop(rust_scheduler *sched, int id, bool killed);
void activate(rust_task *task);
rust_log & get_log();
void fail();
size_t number_of_live_tasks();
void reap_dead_tasks();
rust_task *schedule_task();
void on_pump_loop(rust_signal *signal);
rust_sched_loop_state run_single_turn();
void log_state();
void kill_all_tasks();
bool doomed();
rust_task *create_task(rust_task *spawner, const char *name);
void transition(rust_task *task,
rust_task_state src, rust_task_state dst,
rust_cond *cond, const char* cond_name);
void init_tls();
void place_task_in_tls(rust_task *task);
static rust_task *get_task_tls();
static rust_task *try_get_task_tls();
// Called by each task when they are ready to be destroyed
void release_task(rust_task *task);
// Tells the scheduler to exit it's scheduling loop and thread
void exit();
// Called by tasks when they need a stack on which to run C code
stk_seg *borrow_c_stack();
void return_c_stack(stk_seg *stack);
int get_id() { return this->id; }
};
inline rust_log &
rust_sched_loop::get_log() {
return _log;
}
inline rust_task* rust_sched_loop::try_get_task_tls()
{
if (!tls_initialized)
return NULL;
#ifdef __WIN32__
rust_task *task = reinterpret_cast<rust_task *>
(TlsGetValue(task_key));
#else
rust_task *task = reinterpret_cast<rust_task *>
(pthread_getspecific(task_key));
#endif
return task;
}
inline rust_task* rust_sched_loop::get_task_tls()
{
rust_task *task = try_get_task_tls();
assert(task && "Couldn't get the task from TLS!");
return task;
}
// NB: Runs on the Rust stack
inline stk_seg *
rust_sched_loop::borrow_c_stack() {
assert(cached_c_stack);
stk_seg *your_stack;
if (extra_c_stack) {
your_stack = extra_c_stack;
extra_c_stack = NULL;
} else {
your_stack = cached_c_stack;
cached_c_stack = NULL;
}
return your_stack;
}
// NB: Runs on the Rust stack
inline void
rust_sched_loop::return_c_stack(stk_seg *stack) {
assert(!extra_c_stack);
if (!cached_c_stack) {
cached_c_stack = stack;
} else {
extra_c_stack = stack;
}
}
// this is needed to appease the circular dependency gods
#include "rust_task.h"
//
// Local Variables:
// mode: C++
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End:
//
#endif /* RUST_SCHED_LOOP_H */
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