tor-android/external/badvpn_dns/threadwork/BThreadWork.h

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2015-01-25 11:08:34 +00:00
/**
* @file BThreadWork.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the author 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 AUTHOR 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.
*
* @section DESCRIPTION
*
* System for performing computations (possibly) in parallel with the event loop
* in a different thread.
*/
#ifndef BADVPN_BTHREADWORK_BTHREADWORK_H
#define BADVPN_BTHREADWORK_BTHREADWORK_H
#ifdef BADVPN_THREADWORK_USE_PTHREAD
#include <pthread.h>
#include <semaphore.h>
#endif
#include <misc/debug.h>
#include <structure/LinkedList1.h>
#include <base/DebugObject.h>
#include <system/BReactor.h>
#define BTHREADWORK_STATE_PENDING 1
#define BTHREADWORK_STATE_RUNNING 2
#define BTHREADWORK_STATE_FINISHED 3
#define BTHREADWORK_STATE_FORGOTTEN 4
#define BTHREADWORK_MAX_THREADS 8
struct BThreadWork_s;
struct BThreadWorkDispatcher_s;
/**
* Function called to do the work for a {@link BThreadWork}.
* The function may be called in another thread, in parallel with the event loop.
*
* @param user as work_func_user in {@link BThreadWork_Init}
*/
typedef void (*BThreadWork_work_func) (void *user);
/**
* Handler called when a {@link BThreadWork} work is done.
*
* @param user as in {@link BThreadWork_Init}
*/
typedef void (*BThreadWork_handler_done) (void *user);
#ifdef BADVPN_THREADWORK_USE_PTHREAD
struct BThreadWorkDispatcher_thread {
struct BThreadWorkDispatcher_s *d;
struct BThreadWork_s *running_work;
pthread_cond_t new_cond;
pthread_t thread;
};
#endif
typedef struct BThreadWorkDispatcher_s {
BReactor *reactor;
#ifdef BADVPN_THREADWORK_USE_PTHREAD
LinkedList1 pending_list;
LinkedList1 finished_list;
pthread_mutex_t mutex;
int pipe[2];
BFileDescriptor bfd;
BPending more_job;
int cancel;
int num_threads;
struct BThreadWorkDispatcher_thread threads[BTHREADWORK_MAX_THREADS];
#endif
DebugObject d_obj;
DebugCounter d_ctr;
} BThreadWorkDispatcher;
typedef struct BThreadWork_s {
BThreadWorkDispatcher *d;
BThreadWork_handler_done handler_done;
void *user;
BThreadWork_work_func work_func;
void *work_func_user;
union {
#ifdef BADVPN_THREADWORK_USE_PTHREAD
struct {
LinkedList1Node list_node;
int state;
sem_t finished_sem;
};
#endif
struct {
BPending job;
};
};
DebugObject d_obj;
} BThreadWork;
/**
* Initializes the work dispatcher.
* Works may be started using {@link BThreadWork_Init}.
*
* @param o the object
* @param reactor reactor we live in
* @param num_threads_hint hint for the number of threads to use:
* <0 - A choice will be made automatically, probably based on the number of CPUs.
* 0 - No additional threads will be used, and computations will be performed directly
* in the event loop in job handlers.
* @return 1 on success, 0 on failure
*/
int BThreadWorkDispatcher_Init (BThreadWorkDispatcher *o, BReactor *reactor, int num_threads_hint) WARN_UNUSED;
/**
* Frees the work dispatcher.
* There must be no {@link BThreadWork}'s with this dispatcher.
*
* @param o the object
*/
void BThreadWorkDispatcher_Free (BThreadWorkDispatcher *o);
/**
* Determines whether threads are being used for computations, or computations
* are done in the event loop.
*
* @return 1 if threads are being used, 0 if not
*/
int BThreadWorkDispatcher_UsingThreads (BThreadWorkDispatcher *o);
/**
* Initializes the work.
*
* @param o the object
* @param d work dispatcher
* @param handler_done handler to call when the work is done
* @param user argument to handler
* @param work_func function that will do the work, possibly from another thread
* @param work_func_user argument to work_func
*/
void BThreadWork_Init (BThreadWork *o, BThreadWorkDispatcher *d, BThreadWork_handler_done handler_done, void *user, BThreadWork_work_func work_func, void *work_func_user);
/**
* Frees the work.
* After this function returns, the work function will either have fully executed,
* or not called at all, and never will be.
*
* @param o the object
*/
void BThreadWork_Free (BThreadWork *o);
#endif