dfs_task_manager(std::size_t concurrency = std::thread::hardware_concurrency())
: spawned_threads_{0}
, concurrency_{0}
, idle_threads_{0}
{
set_concurrency(concurrency);
}
void submit_job(JOB_CRUNCHER f, void *data)
{
set_concurrency(get_max_threads());
thread_mutex_lock(&jobs_mutex);
if(jobs_free>=jobs_size)expand_jobs();
jobs_submitted++;
job[jobs_free].data=data;
job[jobs_free].job=f;
jobs_free++;
thread_cond_broadcast(&wait_for_more_jobs_condition);
thread_mutex_unlock(&jobs_mutex);
}
void init_threads(int mt)
{
max_threads=mt-1;
if(max_threads<0) {
max_threads=cpu_count()-1;
}
if(max_threads<0) max_threads=0;
thread_id=do_alloc(max_threads, sizeof(*thread_id));
num_threads=0;
threads_started=0;
thread_cond_init(&thread_not_needed);
thread_mutex_init(&thread_num_mutex);
set_concurrency(1);
fprintf(stderr, "maximum threads: %d\n", max_threads+1);
fprintf(LOG, "maximum threads: %d\n", max_threads+1);
}
int do_single_job(int thread_id)
{
long i;
thread_mutex_lock(&jobs_mutex);
i=next_job_to_do;
if(i>=jobs_free){
thread_mutex_unlock(&jobs_mutex);
return 0;
}
next_job_to_do++;
thread_mutex_unlock(&jobs_mutex);
job[i].job(thread_id, job[i].data);
thread_mutex_lock(&jobs_mutex);
jobs_done++;
if(jobs_done==jobs_submitted) {
thread_cond_broadcast(&all_done_condition);
set_concurrency(1);
thread_mutex_unlock(&jobs_mutex);
return 0;
}
thread_mutex_unlock(&jobs_mutex);
return 1;
}
/*
* This program acts as a generic gateway. It listens for connections
* to a local address ('-l' option). Upon accepting a client connection,
* it connects to the specified remote address ('-r' option) and then
* just pumps the data through without any modification.
*/
int main(int argc, char *argv[])
{
extern char *optarg;
int opt, sock, n;
int laddr, raddr, num_procs;
int serialize_accept = 0;
struct sockaddr_in lcl_addr, cli_addr;
st_netfd_t cli_nfd, srv_nfd;
prog = argv[0];
num_procs = laddr = raddr = 0;
/* Parse arguments */
while((opt = getopt(argc, argv, "l:r:p:Sh")) != EOF) {
switch (opt) {
case 'l':
read_address(optarg, &lcl_addr);
laddr = 1;
break;
case 'r':
read_address(optarg, &rmt_addr);
if (rmt_addr.sin_addr.s_addr == INADDR_ANY) {
fprintf(stderr, "%s: invalid remote address: %s\n", prog, optarg);
exit(1);
}
raddr = 1;
break;
case 'p':
num_procs = atoi(optarg);
if (num_procs < 1) {
fprintf(stderr, "%s: invalid number of processes: %s\n", prog, optarg);
exit(1);
}
break;
case 'S':
/*
* Serialization decision is tricky on some platforms. For example,
* Solaris 2.6 and above has kernel sockets implementation, so supposedly
* there is no need for serialization. The ST library may be compiled
* on one OS version, but used on another, so the need for serialization
* should be determined at run time by the application. Since it's just
* an example, the serialization decision is left up to user.
* Only on platforms where the serialization is never needed on any OS
* version st_netfd_serialize_accept() is a no-op.
*/
serialize_accept = 1;
break;
case 'h':
case '?':
fprintf(stderr, "Usage: %s -l <[host]:port> -r <host:port> "
"[-p <num_processes>] [-S]\n", prog);
exit(1);
}
}
if (!laddr) {
fprintf(stderr, "%s: local address required\n", prog);
exit(1);
}
if (!raddr) {
fprintf(stderr, "%s: remote address required\n", prog);
exit(1);
}
if (num_procs == 0)
num_procs = cpu_count();
fprintf(stderr, "%s: starting proxy daemon on %s:%d\n", prog,
inet_ntoa(lcl_addr.sin_addr), ntohs(lcl_addr.sin_port));
/* Start the daemon */
start_daemon();
/* Initialize the ST library */
if (st_init() < 0) {
print_sys_error("st_init");
exit(1);
}
/* Create and bind listening socket */
if ((sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
print_sys_error("socket");
exit(1);
}
n = 1;
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&n, sizeof(n)) < 0) {
print_sys_error("setsockopt");
exit(1);
}
if (bind(sock, (struct sockaddr *)&lcl_addr, sizeof(lcl_addr)) < 0) {
print_sys_error("bind");
exit(1);
}
listen(sock, 128);
if ((srv_nfd = st_netfd_open_socket(sock)) == NULL) {
print_sys_error("st_netfd_open");
exit(1);
}
/* See the comment regarding serialization decision above */
if (num_procs > 1 && serialize_accept && st_netfd_serialize_accept(srv_nfd)
< 0) {
print_sys_error("st_netfd_serialize_accept");
exit(1);
}
/* Start server processes */
set_concurrency(num_procs);
for ( ; ; ) {
n = sizeof(cli_addr);
cli_nfd = st_accept(srv_nfd, (struct sockaddr *)&cli_addr, &n, -1);
if (cli_nfd == NULL) {
print_sys_error("st_accept");
exit(1);
}
if (st_thread_create(handle_request, cli_nfd, 0, 0) == NULL) {
print_sys_error("st_thread_create");
exit(1);
}
}
/* NOTREACHED */
return 1;
}
~dfs_task_manager()
{
set_concurrency(0);
}
