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Diffstat (limited to 'nuttx/sched/env_dup.c')
-rw-r--r-- | nuttx/sched/env_dup.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/nuttx/sched/env_dup.c b/nuttx/sched/env_dup.c new file mode 100644 index 000000000..033348411 --- /dev/null +++ b/nuttx/sched/env_dup.c @@ -0,0 +1,132 @@ +/**************************************************************************** + * sched/env_dup.c + * + * Copyright (C) 2007, 2009, 2011 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 <sys/types.h> +#include <sched.h> +#include <string.h> +#include <errno.h> + +#include <nuttx/kmalloc.h> + +#include "os_internal.h" +#include "env_internal.h" + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: env_dup + * + * Description: + * Copy the internal environment structure of a task. This is the action + * that is performed when a new task is created: The new task has a private, + * exact duplicate of the parent task's environment. + * + * Parameters: + * ptcb The tcb to receive the newly allocated copy of the parspecifiedent + * TCB's environment structure with reference count equal to one + * + * Return Value: + * zero on success + * + * Assumptions: + * Not called from an interrupt handler. + * + ****************************************************************************/ + +int env_dup(FAR _TCB *ptcb) +{ + int ret = OK; + if (!ptcb ) + { + ret = -EINVAL; + } + else + { + FAR _TCB *parent = (FAR _TCB*)g_readytorun.head; + environ_t *envp = NULL; + + /* Pre-emption must be disabled throughout the following because the + * environment may be shared. + */ + + sched_lock(); + + /* Does the parent task have an environment? */ + + if (parent->envp) + { + /* Yes..The parent task has an environment, duplicate it */ + + size_t envlen = parent->envp->ev_alloc; + envp = (environ_t*)kmalloc(SIZEOF_ENVIRON_T( envlen )); + if (!envp) + { + ret = -ENOMEM; + } + else + { + envp->ev_crefs = 1; + envp->ev_alloc = envlen; + memcpy( envp->ev_env, parent->envp->ev_env, envlen ); + } + } + + /* Save the cloned environment in the new TCB */ + + ptcb->envp = envp; + sched_unlock(); + } + + return ret; +} + +#endif /* CONFIG_DISABLE_ENVIRON */ + + + |