Sweden-Number/server/thread.c

418 lines
11 KiB
C

/*
* Server-side thread management
*
* Copyright (C) 1998 Alexandre Julliard
*/
#include <assert.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include "winnt.h"
#include "winerror.h"
#include "server.h"
#include "server/thread.h"
/* thread queues */
struct wait_queue_entry
{
struct wait_queue_entry *next;
struct wait_queue_entry *prev;
struct object *obj;
struct thread *thread;
};
struct thread_wait
{
int count; /* count of objects */
int flags;
struct timeval timeout;
struct wait_queue_entry queues[1];
};
/* thread operations */
static void dump_thread( struct object *obj, int verbose );
static int thread_signaled( struct object *obj, struct thread *thread );
static void destroy_thread( struct object *obj );
static const struct object_ops thread_ops =
{
dump_thread,
add_queue,
remove_queue,
thread_signaled,
no_satisfied,
no_read_fd,
no_write_fd,
no_flush,
no_get_file_info,
destroy_thread
};
static struct thread *first_thread;
/* create a new thread */
struct thread *create_thread( int fd, void *pid, int *thread_handle,
int *process_handle )
{
struct thread *thread;
struct process *process;
if (!(thread = mem_alloc( sizeof(*thread) ))) return NULL;
if (pid) process = get_process_from_id( pid );
else process = create_process();
if (!process)
{
free( thread );
return NULL;
}
init_object( &thread->obj, &thread_ops, NULL );
thread->client_fd = fd;
thread->process = process;
thread->unix_pid = 0; /* not known yet */
thread->name = NULL;
thread->mutex = NULL;
thread->wait = NULL;
thread->error = 0;
thread->state = STARTING;
thread->exit_code = 0x103; /* STILL_ACTIVE */
thread->next = first_thread;
thread->prev = NULL;
if (first_thread) first_thread->prev = thread;
first_thread = thread;
add_process_thread( process, thread );
*thread_handle = *process_handle = -1;
if (current)
{
if ((*thread_handle = alloc_handle( current->process, thread,
THREAD_ALL_ACCESS, 0 )) == -1)
goto error;
}
if (current && !pid)
{
if ((*process_handle = alloc_handle( current->process, process,
PROCESS_ALL_ACCESS, 0 )) == -1)
goto error;
}
if (add_client( fd, thread ) == -1) goto error;
return thread;
error:
if (current)
{
close_handle( current->process, *thread_handle );
close_handle( current->process, *process_handle );
}
remove_process_thread( process, thread );
release_object( thread );
return NULL;
}
/* destroy a thread when its refcount is 0 */
static void destroy_thread( struct object *obj )
{
struct thread *thread = (struct thread *)obj;
assert( obj->ops == &thread_ops );
release_object( thread->process );
if (thread->next) thread->next->prev = thread->prev;
if (thread->prev) thread->prev->next = thread->next;
else first_thread = thread->next;
if (thread->name) free( thread->name );
if (debug_level) memset( thread, 0xaa, sizeof(thread) ); /* catch errors */
free( thread );
}
/* dump a thread on stdout for debugging purposes */
static void dump_thread( struct object *obj, int verbose )
{
struct thread *thread = (struct thread *)obj;
assert( obj->ops == &thread_ops );
fprintf( stderr, "Thread pid=%d fd=%d name='%s'\n",
thread->unix_pid, thread->client_fd, thread->name );
}
static int thread_signaled( struct object *obj, struct thread *thread )
{
struct thread *mythread = (struct thread *)obj;
return (mythread->state == TERMINATED);
}
/* get a thread pointer from a thread id (and increment the refcount) */
struct thread *get_thread_from_id( void *id )
{
struct thread *t = first_thread;
while (t && (t != id)) t = t->next;
if (t) grab_object( t );
return t;
}
/* get a thread from a handle (and increment the refcount) */
struct thread *get_thread_from_handle( int handle, unsigned int access )
{
return (struct thread *)get_handle_obj( current->process, handle,
access, &thread_ops );
}
/* get all information about a thread */
void get_thread_info( struct thread *thread,
struct get_thread_info_reply *reply )
{
reply->pid = thread;
reply->exit_code = thread->exit_code;
}
/* send a reply to a thread */
int send_reply( struct thread *thread, int pass_fd, int n,
... /* arg_1, len_1, ..., arg_n, len_n */ )
{
struct iovec vec[16];
va_list args;
int i;
assert( n < 16 );
va_start( args, n );
for (i = 0; i < n; i++)
{
vec[i].iov_base = va_arg( args, void * );
vec[i].iov_len = va_arg( args, int );
}
va_end( args );
return send_reply_v( thread->client_fd, thread->error, pass_fd, vec, n );
}
/* add a thread to an object wait queue; return 1 if OK, 0 on error */
int add_queue( struct object *obj, struct wait_queue_entry *entry )
{
grab_object( obj );
entry->obj = obj;
entry->prev = obj->tail;
entry->next = NULL;
if (obj->tail) obj->tail->next = entry;
else obj->head = entry;
obj->tail = entry;
return 1;
}
/* remove a thread from an object wait queue */
void remove_queue( struct object *obj, struct wait_queue_entry *entry )
{
if (entry->next) entry->next->prev = entry->prev;
else obj->tail = entry->prev;
if (entry->prev) entry->prev->next = entry->next;
else obj->head = entry->next;
release_object( obj );
}
/* finish waiting */
static void end_wait( struct thread *thread )
{
struct thread_wait *wait = thread->wait;
struct wait_queue_entry *entry;
int i;
assert( wait );
for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
entry->obj->ops->remove_queue( entry->obj, entry );
if (wait->flags & SELECT_TIMEOUT) set_select_timeout( thread->client_fd, NULL );
free( wait );
thread->wait = NULL;
}
/* build the thread wait structure */
static int wait_on( struct thread *thread, int count,
int *handles, int flags, int timeout )
{
struct thread_wait *wait;
struct wait_queue_entry *entry;
struct object *obj;
int i;
if ((count < 0) || (count > MAXIMUM_WAIT_OBJECTS))
{
SET_ERROR( ERROR_INVALID_PARAMETER );
return 0;
}
if (!(wait = mem_alloc( sizeof(*wait) + (count-1) * sizeof(*entry) ))) return 0;
thread->wait = wait;
wait->count = count;
wait->flags = flags;
if (flags & SELECT_TIMEOUT)
{
gettimeofday( &wait->timeout, 0 );
if (timeout)
{
wait->timeout.tv_usec += (timeout % 1000) * 1000;
if (wait->timeout.tv_usec >= 1000000)
{
wait->timeout.tv_usec -= 1000000;
wait->timeout.tv_sec++;
}
wait->timeout.tv_sec += timeout / 1000;
}
}
for (i = 0, entry = wait->queues; i < count; i++, entry++)
{
if (!(obj = get_handle_obj( thread->process, handles[i],
SYNCHRONIZE, NULL )))
{
wait->count = i - 1;
end_wait( thread );
return 0;
}
entry->thread = thread;
if (!obj->ops->add_queue( obj, entry ))
{
wait->count = i - 1;
end_wait( thread );
return 0;
}
release_object( obj );
}
return 1;
}
/* check if the thread waiting condition is satisfied */
static int check_wait( struct thread *thread, int *signaled )
{
int i;
struct thread_wait *wait = thread->wait;
struct wait_queue_entry *entry = wait->queues;
struct timeval now;
assert( wait );
if (wait->flags & SELECT_ALL)
{
for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
if (!entry->obj->ops->signaled( entry->obj, thread )) goto check_timeout;
/* Wait satisfied: tell it to all objects */
*signaled = 0;
for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
if (entry->obj->ops->satisfied( entry->obj, thread ))
*signaled = STATUS_ABANDONED_WAIT_0;
return 1;
}
else
{
for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
{
if (!entry->obj->ops->signaled( entry->obj, thread )) continue;
/* Wait satisfied: tell it to the object */
*signaled = i;
if (entry->obj->ops->satisfied( entry->obj, thread ))
*signaled += STATUS_ABANDONED_WAIT_0;
return 1;
}
}
check_timeout:
if (!(wait->flags & SELECT_TIMEOUT)) return 0;
gettimeofday( &now, NULL );
if ((now.tv_sec > wait->timeout.tv_sec) ||
((now.tv_sec == wait->timeout.tv_sec) &&
(now.tv_usec >= wait->timeout.tv_usec)))
{
*signaled = STATUS_TIMEOUT;
return 1;
}
return 0;
}
/* sleep on a list of objects */
void sleep_on( struct thread *thread, int count, int *handles, int flags, int timeout )
{
struct select_reply reply;
assert( !thread->wait );
reply.signaled = -1;
if (!wait_on( thread, count, handles, flags, timeout )) goto done;
if (!check_wait( thread, &reply.signaled ))
{
/* we need to wait */
if (flags & SELECT_TIMEOUT)
set_select_timeout( thread->client_fd, &thread->wait->timeout );
return;
}
end_wait( thread );
done:
send_reply( thread, -1, 1, &reply, sizeof(reply) );
}
/* attempt to wake up a thread */
/* return 1 if OK, 0 if the wait condition is still not satisfied */
static int wake_thread( struct thread *thread )
{
struct select_reply reply;
if (!check_wait( thread, &reply.signaled )) return 0;
end_wait( thread );
send_reply( thread, -1, 1, &reply, sizeof(reply) );
return 1;
}
/* timeout for the current thread */
void thread_timeout(void)
{
struct select_reply reply;
assert( current->wait );
reply.signaled = STATUS_TIMEOUT;
end_wait( current );
send_reply( current, -1, 1, &reply, sizeof(reply) );
}
/* attempt to wake threads sleeping on the object wait queue */
void wake_up( struct object *obj, int max )
{
struct wait_queue_entry *entry = obj->head;
while (entry)
{
struct wait_queue_entry *next = entry->next;
if (wake_thread( entry->thread ))
{
if (max && !--max) break;
}
entry = next;
}
}
/* kill a thread on the spot */
void kill_thread( struct thread *thread, int exit_code )
{
if (thread->state == TERMINATED) return; /* already killed */
if (thread->unix_pid) kill( thread->unix_pid, SIGTERM );
remove_client( thread->client_fd, exit_code ); /* this will call thread_killed */
}
/* a thread has been killed */
void thread_killed( struct thread *thread, int exit_code )
{
thread->state = TERMINATED;
thread->exit_code = exit_code;
if (thread->wait) end_wait( thread );
abandon_mutexes( thread );
remove_process_thread( thread->process, thread );
wake_up( &thread->obj, 0 );
release_object( thread );
}