Retro68/gcc/libcilkrts/runtime/local_state.h
2017-10-07 02:16:47 +02:00

443 lines
14 KiB
C++

/* local_state.h -*-C++-*-
*
*************************************************************************
*
* Copyright (C) 2009-2016, Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* *********************************************************************
*
* PLEASE NOTE: This file is a downstream copy of a file mainitained in
* a repository at cilkplus.org. Changes made to this file that are not
* submitted through the contribution process detailed at
* http://www.cilkplus.org/submit-cilk-contribution will be lost the next
* time that a new version is released. Changes only submitted to the
* GNU compiler collection or posted to the git repository at
* https://bitbucket.org/intelcilkruntime/intel-cilk-runtime.git are
* not tracked.
*
* We welcome your contributions to this open source project. Thank you
* for your assistance in helping us improve Cilk Plus.
**************************************************************************/
/**
* @file local_state.h
*
* @brief The local_state structure contains additional OS-independent
* information that's associated with a worker, but doesn't need to be visible
* to the code generated by the compiler.
*/
#ifndef INCLUDED_LOCAL_STATE_DOT_H
#define INCLUDED_LOCAL_STATE_DOT_H
#include <internal/abi.h>
#include "worker_mutex.h"
#include "global_state.h"
#include "record-replay.h"
#include "signal_node.h"
#include <setjmp.h>
#include <stddef.h>
#include <stdio.h>
#ifndef _WIN32
# include <pthread.h>
#endif
__CILKRTS_BEGIN_EXTERN_C
/* Opaque types. */
struct full_frame;
struct free_list;
struct pending_exception_info;
/// Opaque type for replay entry.
typedef struct replay_entry_t replay_entry_t;
/**
* @brief Magic numbers for local_state, used for debugging
*/
typedef unsigned long long ls_magic_t;
/**
* @brief Scheduling stack function: A function that is decided on the program stack,
* but that must be executed on the scheduling stack.
*/
typedef void (*scheduling_stack_fcn_t) (__cilkrts_worker *w,
struct full_frame *ff,
__cilkrts_stack_frame *sf);
/**
* @brief Type of this worker.
**/
typedef enum cilk_worker_type
{
WORKER_FREE, ///< Unused worker - available to be bound to user threads
WORKER_SYSTEM, ///< Worker created by runtime - able to steal from any worker
WORKER_USER ///< User thread - able to steal only from team members
} cilk_worker_type;
/**
* @brief The local_state structure contains additional OS-independent
* information that's associated with a worker, but doesn't need to be
* visible to the compiler.
*
* No compiler-generated code should need to know the layout of this
* structure.
*
* The fields of this struct can be classified as either local or
* shared.
*
* Local: This field is only accessed by the thread bound to this
* worker struct. Local fields can be freely accessed without
* acquiring locks.
*
* Shared: This field may be accessed by multiple worker threads.
* Accesses to shared fields usually requires locks, except in
* special situations where one can prove that locks are
* unnecessary.
*
* The fields of this can also be classified as "read-only" if the
* field does not change after it is initialized. Otherwise, the
* field is "read/write". Read-only fields do not require locks to
* access (ignoring the synchronization that might be needed for
* initialization if this can occur in parallel).
*
* Finally, we explicitly classify some fields as "synchronization"
* fields if they are used as part of a synchronization protocol in
* the runtime. These variables are generally shared and read/write.
* Mostly, this category includes lock variables and other variables
* that are involved in synchronization protocols (i.e., the THE
* protocol).
*/
struct local_state /* COMMON_PORTABLE */
{
/** This value should be in the first field in any local_state */
# define WORKER_MAGIC_0 ((ls_magic_t)0xe0831a4a940c60b8ULL)
/**
* Should be WORKER_MAGIC_0 or the local_state has been corrupted
* This magic field is shared because it is read on lock acquisitions.
*
* [shared read-only]
*/
ls_magic_t worker_magic_0;
/**
* Mutex used to serialize access to the local_state
* Synchronization field. [shared read/write]
*/
struct mutex lock;
/**
* Flag that indicates that the worker is interested in grabbing
* LOCK, and thus thieves should leave the worker alone.
* Written only by self, may be read by others.
*
* Synchronization field. [shared read/write]
*/
int do_not_steal;
/**
* Lock that all thieves grab in order to compete for the right
* to disturb this worker.
*
* Synchronization field. [shared read/write]
*/
struct mutex steal_lock;
/**
* Full frame that the worker is working on.
*
* While a worker w is executing, a thief may change
* w->l->frame_ff (on a successful steal) after acquiring w's
* lock.
*
* Unlocked accesses to w->l->frame_ff are safe (by w itself) when
* w's deque is empty, or when stealing from w has been disabled.
*
* [shared read/write]
*/
struct full_frame *frame_ff;
/**
* Full frame that the worker will be working on next
*
* This field is normally local for a worker w. Another worker v
* may modify w->l->next_frame_ff, however, in the special case
* when v is returning a frame to a user thread w since w is the
* team leader.
*
* [shared read/write]
*/
struct full_frame *next_frame_ff;
/**
* This is set iff this is a WORKER_USER and there has been a steal. It
* points to the first frame that was stolen since the team was last fully
* sync'd. Only this worker may continue past a sync in this function.
*
* This field is set by a thief for a victim that is a user
* thread, while holding the victim's lock.
* It can be cleared without a lock by the worker that will
* continue exuecting past the sync.
*
* [shared read/write]
*/
struct full_frame *last_full_frame;
/**
* Team on which this worker is a participant. When a user worker enters,
* its team is its own worker struct and it can never change teams. When a
* system worker steals, it adopts the team of its victim.
*
* When a system worker w steals, it reads victim->l->team and
* joins this team. w->l->team is constant until the next time w
* returns control to the runtime.
* We must acquire the worker lock to change w->l->team.
*
* @note This field is 64-byte aligned because it is the first in
* the group of shared read-only fields. We want this group to
* fall on a different cache line from the previous group, which
* is shared read-write.
*
* [shared read-only]
*/
__attribute__((aligned(64)))
__cilkrts_worker *team;
/**
* Type of this worker
*
* This field changes only when a worker binds or unbinds.
* Otherwise, the field is read-only while the worker is bound.
*
* [shared read-only]
*/
cilk_worker_type type;
/**
* Lazy task queue of this worker - an array of pointers to stack frames.
*
* Read-only because deques are a fixed size in the current
* implementation.
*
* @note This field is 64-byte aligned because it is the first in
* the group of local fields. We want this group to fall on a
* different cache line from the previous group, which is shared
* read-only.
*
* [local read-only]
*/
__attribute__((aligned(64)))
__cilkrts_stack_frame **ltq;
/**
* Pool of fibers waiting to be reused.
* [local read/write]
*/
cilk_fiber_pool fiber_pool;
/**
* The fiber for the scheduling stacks.
* [local read/write]
*/
cilk_fiber* scheduling_fiber;
/**
* Saved pointer to the leaf node in thread-local storage, when a
* user thread is imported. This pointer gets set to a
* meaningful value when binding a user thread, and cleared on
* unbind.
*
* [local read/write]
*/
__cilkrts_pedigree* original_pedigree_leaf;
/**
* State of the random number generator
*
* [local read/write]
*/
unsigned rand_seed;
/**
* Function to execute after transferring onto the scheduling stack.
*
* [local read/write]
*/
scheduling_stack_fcn_t post_suspend;
/**
* __cilkrts_stack_frame we suspended when we transferred onto the
* scheduling stack.
*
* [local read/write]
*/
__cilkrts_stack_frame *suspended_stack;
/**
* cilk_fiber that should be freed after returning from a
* spawn with a stolen parent or after stalling at a sync.
* We calculate the stack to free when executing a reduction on
* the user stack, but we can not actually release the stack
* until control longjmps onto a runtime scheduling stack.
*
* This field is used to pass information to the runtime across
* the longjmp onto the scheduling stack.
*
* [local read/write]
*/
cilk_fiber* fiber_to_free;
/**
* Saved exception object for an exception that is being passed to
* our parent
*
* [local read/write]
*/
struct pending_exception_info *pending_exception;
/**
* Buckets for the memory allocator
*
* [local read/write]
*/
struct free_list *free_list[FRAME_MALLOC_NBUCKETS];
/**
* Potential function for the memory allocator
*
* [local read/write]
*/
size_t bucket_potential[FRAME_MALLOC_NBUCKETS];
/**
* Support for statistics
*
* Useful only when CILK_PROFIlE is compiled in.
* [local read/write]
*/
statistics* stats;
/**
* Count indicates number of failures since last successful steal. This is
* used by the scheduler to reduce contention on shared flags.
*
* [local read/write]
*/
unsigned int steal_failure_count;
/**
* Record indicating that the worker stole work at least once.
*
* [local read/write]
*/
int has_stolen;
/**
* 1 if work was stolen from another worker. When true, this will flag
* setup_for_execution_pedigree to increment the pedigree when we resume
* execution to match the increment that would have been done on a return
* from a spawn helper.
*
* [local read/write]
*/
int work_stolen;
/**
* File pointer for record or replay
* Does FILE * work on Windows?
* During record, the file will be opened in write-only mode.
* During replay, the file will be opened in read-only mode.
*
* [local read/write]
*/
FILE *record_replay_fptr;
/**
* Root of array of replay entries - NULL if we're not replaying a log
*
* [local read/write]
*/
replay_entry_t *replay_list_root;
/**
* Current replay entry - NULL if we're not replaying a log
*
* [local read/write]
*/
replay_entry_t *replay_list_entry;
/**
* Separate the signal_node from other things in the local_state by the
* sizeof a cache line for performance reasons.
*
* unused
*/
char buf[64];
/**
* Signal object for waking/sleeping the worker. This should be a pointer
* to avoid the possibility of caching problems.
*
* [shared read-only]
*/
signal_node_t *signal_node;
/** This value should be in the last field in any local_state */
# define WORKER_MAGIC_1 ((ls_magic_t)0x16164afb0ea0dff9ULL)
/**
* Should be WORKER_MAGIC_1 or the local_state has been corrupted
* This magic field is shared because it is read on lock acquisitions.
* [shared read-only]
*/
ls_magic_t worker_magic_1;
};
/**
* Perform cleanup according to the function set before the longjmp().
*
* Call this after longjmp() has completed and the worker is back on a
* scheduling stack.
*
* @param w __cilkrts_worker currently executing.
*/
void run_scheduling_stack_fcn(__cilkrts_worker *w);
__CILKRTS_END_EXTERN_C
#endif // ! defined(INCLUDED_LOCAL_STATE_DOT_H)