mariadb/newbrt/threadpool.h

/* -*- mode: C; c-basic-offset: 4 -*- */
#ifndef THREADPOOL_H
#define THREADPOOL_H
#ident "$Id$"
#ident "Copyright (c) 2007-2010 Tokutek Inc.  All rights reserved."
#ident "The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it."

#if defined(__cplusplus) || defined(__cilkplusplus)
extern "C" {
#endif


// A threadpool is a limited set of threads that can be used to apply a
// function to work contained in a work queue.  The work queue is outside
// of the scope of the threadpool; the threadpool merely provides
// mechanisms to grow the number of threads in the threadpool on demand.

typedef struct threadpool *THREADPOOL;

// Create a new threadpool
// Effects: a new threadpool is allocated and initialized. the number of
// threads in the threadpool is limited to max_threads.  initially, there
// are no threads in the pool.
// Returns: if there are no errors, the threadpool is set and zero is returned.
// Otherwise, an error number is returned.

int threadpool_create(THREADPOOL *threadpoolptr, int max_threads);

// Destroy a threadpool
// Effects: the calling thread joins with all of the threads in the threadpool.
// Effects: the threadpool memory is freed.
// Returns: the threadpool is set to null.

void threadpool_destroy(THREADPOOL *threadpoolptr);

// Maybe add a thread to the threadpool.
// Effects: the number of threads in the threadpool is expanded by 1 as long
// as the current number of threads in the threadpool is less than the max
// and there are no idle threads.
// Effects: if the thread is create, it calls the function f with argument arg
// Expects: external serialization on this function; only one thread may
// execute this function

void threadpool_maybe_add(THREADPOOL theadpool, void *(*f)(void *), void *arg);

// get the current number of threads

int threadpool_get_current_threads(THREADPOOL);

#if defined(__cplusplus) || defined(__cilkplusplus)
};
#endif


#endif