/* * remote_queuelock.c - remote kernel lock with waiting queue implementation. * * Authors Alain Greiner (2016,2017,2018) * * Copyright (c) UPMC Sorbonne Universites * * This file is part of ALMOS-MKH. * * ALMOS-MKH is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2.0 of the License. * * ALMOS-MKH is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with ALMOS-MKH; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include #include #include ////////////////////////////////////////////////////////////////////////////// // Extern global variables ////////////////////////////////////////////////////////////////////////////// extern char * lock_type_str[]; // allocated in kernel_init.c ///////////////////////////////////////////// void remote_queuelock_init( xptr_t lock_xp, uint32_t type ) { // get remote lock cluster and local pointer cxy_t lock_cxy = GET_CXY( lock_xp ); remote_queuelock_t * lock_ptr = GET_PTR( lock_xp ); // initialise taken field hal_remote_s32( XPTR( lock_cxy , &lock_ptr->taken ), 0 ); // initialise xroot field xlist_root_init( XPTR( lock_cxy , &lock_ptr->xroot ) ); // initialise busylock field remote_busylock_init( XPTR( lock_cxy , &lock_ptr->lock ) , type ); #if DEBUG_QUEUELOCK_TYPE thread_t * this = CURRENT_THREAD; if( DEBUG_QUEUELOCK_TYPE == type ) printk("\n[%s] thread[%x,%x] initialise lock %s [%x,%x]\n", __FUNCTION__, this->process->pid, this->trdid, lock_type_str[type], lock_cxy, lock_ptr ); #endif } // end remote_queuelock_init() /////////////////////////////////////////////// void remote_queuelock_acquire( xptr_t lock_xp ) { thread_t * this = CURRENT_THREAD; // check calling thread can yield thread_assert_can_yield( this , __FUNCTION__ ); // get lock cluster and local pointer cxy_t lock_cxy = GET_CXY( lock_xp ); remote_queuelock_t * lock_ptr = GET_PTR( lock_xp ); #if DEBUG_QUEUELOCK_TYPE uint32_t lock_type = hal_remote_l32( XPTR( lock_cxy , &lock_ptr->lock.type ) ); #endif // build extended pointer on busylock protecting queuelock xptr_t busylock_xp = XPTR( lock_cxy , &lock_ptr->lock ); // get busylock remote_busylock_acquire( busylock_xp ); // block and deschedule if lock already taken while( hal_remote_l32( XPTR( lock_cxy, &lock_ptr->taken ) ) ) { #if DEBUG_QUEUELOCK_TYPE if( (DEBUG_QUEUELOCK_TYPE == lock_type) || (DEBUG_QUEUELOCK_TYPE == 1000) ) printk("\n[%s] thread[%x,%x] BLOCK on q_lock %s [%x,%x]\n", __FUNCTION__, this->process->pid, this->trdid, lock_type_str[lock_type], lock_cxy, lock_ptr ); #endif // get pointer on calling thread thread_t * this = CURRENT_THREAD; // block calling thread thread_block( XPTR( local_cxy , this ) , THREAD_BLOCKED_LOCK ); // register calling thread in waiting list xlist_add_last( XPTR( lock_cxy , &lock_ptr->xroot ), XPTR( local_cxy , &this->wait_xlist ) ); // release busylock remote_busylock_release( busylock_xp ); // deschedule calling thread sched_yield("wait remote_queuelock"); // get busylock remote_busylock_acquire( busylock_xp ); } #if DEBUG_QUEUELOCK_TYPE if( (DEBUG_QUEUELOCK_TYPE == lock_type) || (DEBUG_QUEUELOCK_TYPE == 1000) ) printk("\n[%s] thread[%x,%x] ACQUIRE q_lock %s [%x,%x]\n", __FUNCTION__, this->process->pid, this->trdid, lock_type_str[lock_type], lock_cxy, lock_ptr ); #endif // update remote_queuelock state hal_remote_s32( XPTR( lock_cxy , &lock_ptr->taken ) , 1 ); // release busylock remote_busylock_release( busylock_xp ); hal_fence(); } // end remote_queuelock_acquire() //////////////////////////////////////////////// void remote_queuelock_release( xptr_t lock_xp ) { // memory barrier before lock release hal_fence(); // get lock cluster and local pointer cxy_t lock_cxy = GET_CXY( lock_xp ); remote_queuelock_t * lock_ptr = GET_PTR( lock_xp ); // build extended pointer on busylock protecting queuelock xptr_t busylock_xp = XPTR( lock_cxy , &lock_ptr->lock ); // get busylock remote_busylock_acquire( busylock_xp ); #if DEBUG_QUEUELOCK_TYPE thread_t * this = CURRENT_THREAD; uint32_t lock_type = hal_remote_l32( XPTR( lock_cxy , &lock_ptr->lock.type ) ); if( (DEBUG_QUEUELOCK_TYPE == lock_type) || (DEBUG_QUEUELOCK_TYPE == 1000) ) printk("\n[%s] thread[%x,%x] RELEASE q_lock %s (%x,%x)\n", __FUNCTION__, this->process->pid, this->trdid, lock_type_str[lock_type], lock_cxy, lock_ptr ); #endif // update remote_queuelock state hal_remote_s32( XPTR( lock_cxy , &lock_ptr->taken ) , 0 ); // unblock first waiting thread if waiting list not empty if( xlist_is_empty( XPTR( lock_cxy, &lock_ptr->xroot ) ) == false ) { // get extended pointer on first waiting thread xptr_t root_xp = XPTR( lock_cxy , &lock_ptr->xroot ); xptr_t thread_xp = XLIST_FIRST( root_xp , thread_t , wait_xlist ); cxy_t thread_cxy = GET_CXY( thread_xp ); thread_t * thread_ptr = GET_PTR( thread_xp ); #if DEBUG_QUEUELOCK_TYPE if( (DEBUG_QUEUELOCK_TYPE == lock_type) || (DEBUG_QUEUELOCK_TYPE == 1000) ) { trdid_t trdid = hal_remote_l32( XPTR( thread_cxy , &thread_ptr->trdid ) ); process_t * process = hal_remote_lpt( XPTR( thread_cxy , &thread_ptr->process ) ); pid_t pid = hal_remote_l32( XPTR( thread_cxy , &process->pid ) ); printk("\n[%s] thread[%x,%x] UNBLOCK thread[%x,%x] / q_lock %s [%x,%x]\n", __FUNCTION__, this->process->pid, this->trdid, trdid, pid, lock_type_str[lock_type], lock_cxy, lock_ptr ); } #endif // remove this thread from waiting queue xlist_unlink( XPTR( thread_cxy , &thread_ptr->wait_xlist ) ); // unblock this waiting thread thread_unblock( thread_xp , THREAD_BLOCKED_LOCK ); } // release busylock remote_busylock_release( busylock_xp ); } // end remote_queuelock_release()