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author | 2015-08-28 09:58:54 +0800 | |
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committer | 2015-09-01 12:44:00 +0800 | |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/roms/ipxe/src/core/process.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/roms/ipxe/src/core/process.c')
-rw-r--r-- | qemu/roms/ipxe/src/core/process.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/core/process.c b/qemu/roms/ipxe/src/core/process.c new file mode 100644 index 000000000..d341a2c37 --- /dev/null +++ b/qemu/roms/ipxe/src/core/process.c @@ -0,0 +1,133 @@ +/* + * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>. + * + * This program 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; either version 2 of the + * License, or any later version. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <ipxe/list.h> +#include <ipxe/init.h> +#include <ipxe/process.h> + +/** @file + * + * Processes + * + * We implement a trivial form of cooperative multitasking, in which + * all processes share a single stack and address space. + */ + +/** Process run queue */ +static LIST_HEAD ( run_queue ); + +/** + * Get pointer to object containing process + * + * @v process Process + * @ret object Containing object + */ +void * process_object ( struct process *process ) { + return ( ( ( void * ) process ) - process->desc->offset ); +} + +/** + * Add process to process list + * + * @v process Process + * + * It is safe to call process_add() multiple times; further calls will + * have no effect. + */ +void process_add ( struct process *process ) { + if ( ! process_running ( process ) ) { + DBGC ( PROC_COL ( process ), "PROCESS " PROC_FMT + " starting\n", PROC_DBG ( process ) ); + ref_get ( process->refcnt ); + list_add_tail ( &process->list, &run_queue ); + } else { + DBGC ( PROC_COL ( process ), "PROCESS " PROC_FMT + " already started\n", PROC_DBG ( process ) ); + } +} + +/** + * Remove process from process list + * + * @v process Process + * + * It is safe to call process_del() multiple times; further calls will + * have no effect. + */ +void process_del ( struct process *process ) { + if ( process_running ( process ) ) { + DBGC ( PROC_COL ( process ), "PROCESS " PROC_FMT + " stopping\n", PROC_DBG ( process ) ); + list_del ( &process->list ); + INIT_LIST_HEAD ( &process->list ); + ref_put ( process->refcnt ); + } else { + DBGC ( PROC_COL ( process ), "PROCESS " PROC_FMT + " already stopped\n", PROC_DBG ( process ) ); + } +} + +/** + * Single-step a single process + * + * This executes a single step of the first process in the run queue, + * and moves the process to the end of the run queue. + */ +void step ( void ) { + struct process *process; + struct process_descriptor *desc; + void *object; + + if ( ( process = list_first_entry ( &run_queue, struct process, + list ) ) ) { + ref_get ( process->refcnt ); /* Inhibit destruction mid-step */ + desc = process->desc; + object = process_object ( process ); + if ( desc->reschedule ) { + list_del ( &process->list ); + list_add_tail ( &process->list, &run_queue ); + } else { + process_del ( process ); + } + DBGC2 ( PROC_COL ( process ), "PROCESS " PROC_FMT + " executing\n", PROC_DBG ( process ) ); + desc->step ( object ); + DBGC2 ( PROC_COL ( process ), "PROCESS " PROC_FMT + " finished executing\n", PROC_DBG ( process ) ); + ref_put ( process->refcnt ); /* Allow destruction */ + } +} + +/** + * Initialise processes + * + */ +static void init_processes ( void ) { + struct process *process; + + for_each_table_entry ( process, PERMANENT_PROCESSES ) + process_add ( process ); +} + +/** Process initialiser */ +struct init_fn process_init_fn __init_fn ( INIT_NORMAL ) = { + .initialise = init_processes, +}; |