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Diffstat (limited to 'nuttx/sched/env_share.c')
-rw-r--r-- | nuttx/sched/env_share.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/nuttx/sched/env_share.c b/nuttx/sched/env_share.c new file mode 100644 index 000000000..5f37a0219 --- /dev/null +++ b/nuttx/sched/env_share.c @@ -0,0 +1,117 @@ +/**************************************************************************** + * sched/env_share.c + * + * Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#ifndef CONFIG_DISABLE_ENVIRON + +#include <sched.h> +#include <errno.h> + +#include "os_internal.h" +#include "env_internal.h" + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: env_share + * + * Description: + * Increment the reference count on the internal environment structure of + * a task. This is the action that is performed when a new pthread is + * created: The new pthread shares the environment with its parent. + * + * Parameters: + * ptcb The new TCB to receive the shared environment. + * + * Return Value: + * A pointer to a specified TCB's environment structure with an incremented + * reference count. + * + * Assumptions: + * Not called from an interrupt handler. + * + ****************************************************************************/ + +int env_share(FAR _TCB *ptcb) +{ + int ret = OK; + if (!ptcb) + { + ret = -EINVAL; + } + else + { + FAR _TCB *parent = (FAR _TCB*)g_readytorun.head; + environ_t *envp = parent->envp; + + /* Pre-emption must be disabled throughout the following because the + * environment is shared. + */ + + sched_lock(); + + /* Does the parent task have an environment? */ + + if (envp) + { + /* Yes.. increment the reference count on the environment */ + + envp->ev_crefs++; + } + + /* Then share the environment */ + + ptcb->envp = envp; + sched_unlock(); + } + + return ret; +} + +#endif /* CONFIG_DISABLE_ENVIRON */ + + + |