Current File : //opt/alt/ruby32/include/ruby/internal/intern/process.h
#ifndef RBIMPL_INTERN_PROCESS_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_INTERN_PROCESS_H
/**
* @file
* @author Ruby developers <ruby-core@ruby-lang.org>
* @copyright This file is a part of the programming language Ruby.
* Permission is hereby granted, to either redistribute and/or
* modify this file, provided that the conditions mentioned in the
* file COPYING are met. Consult the file for details.
* @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are
* implementation details. Don't take them as canon. They could
* rapidly appear then vanish. The name (path) of this header file
* is also an implementation detail. Do not expect it to persist
* at the place it is now. Developers are free to move it anywhere
* anytime at will.
* @note To ruby-core: remember that this header can be possibly
* recursively included from extension libraries written in C++.
* Do not expect for instance `__VA_ARGS__` is always available.
* We assume C99 for ruby itself but we don't assume languages of
* extension libraries. They could be written in C++98.
* @brief Public APIs related to ::rb_mProcess.
*/
#include "ruby/internal/attr/nonnull.h"
#include "ruby/internal/attr/noreturn.h"
#include "ruby/internal/config.h" /* rb_pid_t is defined here. */
#include "ruby/internal/dllexport.h"
#include "ruby/internal/value.h"
RBIMPL_SYMBOL_EXPORT_BEGIN()
/* process.c */
/**
* Sets the "last status", or the `$?`.
*
* @param[in] status The termination status, as defined in `waitpid(3posix)`.
* @param[in] pid The last child of the current process.
* @post `$?` is updated.
*/
void rb_last_status_set(int status, rb_pid_t pid);
/**
* Queries the "last status", or the `$?`.
*
* @retval RUBY_Qnil The current thread has no dead children.
* @retval otherwise An instance of Process::Status describing the status of
* the child that was most recently `wait`-ed.
*/
VALUE rb_last_status_get(void);
RBIMPL_ATTR_NONNULL(())
/**
* Executes a shell command.
*
* @warning THIS FUNCTION RETURNS on error!
* @param[in] cmd Passed to the shell.
* @retval -1 Something prevented the command execution.
* @post Upon successful execution this function doesn't return.
* @post In case it returns the `errno` is set properly.
*/
int rb_proc_exec(const char *cmd);
RBIMPL_ATTR_NORETURN()
/**
* Replaces the current process by running the given external command. This is
* the implementation of `Kernel#exec`.
*
* @param[in] argc Number of objects in `argv`.
* @param[in] argv Command and its options to execute.
* @exception rb_eTypeError Invalid options e.g. non-String argv.
* @exception rb_eArgError Invalid options e.g. redirection cycle.
* @exception rb_eNotImpError Not implemented e.g. no `setuid(2)`.
* @exception rb_eRuntimeError `Process::UID.switch` in operation.
* @exception rb_eSystemCallError `execve(2)` failed.
* @warning This function doesn't return.
* @warning On failure it raises. On success the process is replaced.
*
* @internal
*
* @shyouhei have to say that the rdoc for `Kernel#exec` is fairly incomplete.
* AFAIK this function ultimately takes the following signature:
*
* ```rbs
* type boolx = bool | nil # != `boolish`
*
* type rlim_t = Integer # rlim_cur
* | [ Integer, Integer ] # rlim_cur, rlim_max
*
* type uid_t = String # e.g. "root"
* | Integer # e.g. 0
*
* type gid_t = String # e.g. "wheel"
* | Integer # e.g. 0
*
* type fmode = String # e.g. "rb"
* | Integer # e.g. O_RDONLY | O_BINARY
*
* type mode_t = Integer # e.g. 0644
*
* type pgrp = true # Creates a dedicated pgroup
* | 0 # ditto
* | nil # Uses the current one
* | Integer # Uses this specific pgroup
*
* type fd = :in # STDIN
* | :out # STDOUT
* | :err # STDERR
* | IO # This specific IO
* | Integer # A file descriptor of this #
*
* type src = fd | [ fd ]
* type dst = :close # Intuitive
* | fd # Intuitive
* | String # Open a file at this path
* | [ String ] # ... using O_RDONLY
* | [ String, fmode ] # ... using this mode
* | [ String, fmode, mode_t ] # ... with a permission
* | [ :child, fd ] # fd of child side
*
* type redir = Hash[ src, dst ]
*
* # ----
*
* # Key-value pair of environment variables
* type envp = Hash[ String, String ]
*
* # Actual name (and the name passed to the subprocess if any)
* type arg0 = String | [ String, String ]
*
* # Arbitrary string parameters
* type argv = String
*
* # Exec options:
* type argh = redir | {
* chdir: String, # Working directory
* close_others: boolx, # O_CLOEXEC like behaviour
* gid: gid_t, # setegid(2)
* pgrooup: pgrp, # setpgrp(2)
* rlimit_as: rlim_t, # setrlimit(2)
* rlimit_core: rlim_t, # ditto
* rlimit_cpu: rlim_t, # ditto
* rlimit_data: rlim_t, # ditto
* rlimit_fsize: rlim_t, # ditto
* rlimit_memlock: rlim_t, # ditto
* rlimit_msgqueue: rlim_t, # ditto
* rlimit_nice: rlim_t, # ditto
* rlimit_nofile: rlim_t, # ditto
* rlimit_nproc: rlim_t, # ditto
* rlimit_rss: rlim_t, # ditto
* rlimit_rtprio: rlim_t, # ditto
* rlimit_rttime: rlim_t, # ditto
* rlimit_sbsize: rlim_t, # ditto
* rlimit_sigpending: rlim_t, # ditto
* rlimit_stack: rlim_t, # ditto
* uid: uid_t, # seteuid(2)
* umask: mode_t, # umask(2)
* unsetenv_others: boolx # Unset everything except the passed envp
* }
*
* # ====
*
* class Kernel
* def self?.exec
* : ( arg0 cmd, *argv args ) -> void
* | ( arg0 cmd, *argv args, argh opts) -> void
* | (envp env, arg0 cmd, *argv args ) -> void
* | (envp env, arg0 cmd, *argv args, argh opts) -> void
* end
* ```
*/
VALUE rb_f_exec(int argc, const VALUE *argv);
/**
* Waits for a process, with releasing GVL.
*
* @param[in] pid Process ID.
* @param[out] status The wait status is filled back.
* @param[in] flags Wait options.
* @retval -1 System call failed, errno set.
* @retval 0 WNOHANG but no waitable children.
* @retval otherwise A process ID that was `wait()`-ed.
* @post Upon successful return `status` is updated to have the process'
* status.
* @note `status` can be NULL.
* @note The arguments are passed through to underlying system call(s).
* Can have special meanings. For instance passing `(rb_pid_t)-1`
* to `pid` means it waits for any processes, under
* POSIX-compliant situations.
*/
rb_pid_t rb_waitpid(rb_pid_t pid, int *status, int flags);
/**
* This is a shorthand of rb_waitpid without status and flags. It has been
* like this since the very beginning. The initial revision already did the
* same thing. Not sure why, then, it has been named `syswait`. AFAIK this is
* different from how `wait(3posix)` works.
*
* @param[in] pid Passed to rb_waitpid().
*/
void rb_syswait(rb_pid_t pid);
/**
* Identical to rb_f_exec(), except it spawns a child process instead of
* replacing the current one.
*
* @param[in] argc Number of objects in `argv`.
* @param[in] argv Command and its options to execute.
* @exception rb_eTypeError Invalid options e.g. non-String argv.
* @exception rb_eArgError Invalid options e.g. redirection cycle.
* @exception rb_eNotImpError Not implemented e.g. no `setuid(2)`.
* @exception rb_eRuntimeError `Process::UID.switch` in operation.
* @retval -1 Child process died for some reason.
* @retval otherwise The ID of the born child.
*
* @internal
*
* This is _really_ identical to rb_f_exec() until ultimately calling the
* system call. Almost everything are shared among these two (and
* rb_f_system()).
*/
rb_pid_t rb_spawn(int argc, const VALUE *argv);
/**
* Identical to rb_spawn(), except you can additionally know the detailed
* situation in case of abnormal parturitions.
*
* @param[in] argc Number of objects in `argv`.
* @param[in] argv Command and its options to execute.
* @param[out] errbuf Error description write-back buffer.
* @param[in] buflen Number of bytes of `errbuf`, including NUL.
* @exception rb_eTypeError Invalid options e.g. non-String argv.
* @exception rb_eArgError Invalid options e.g. redirection cycle.
* @exception rb_eNotImpError Not implemented e.g. no `setuid(2)`.
* @exception rb_eRuntimeError `Process::UID.switch` in operation.
* @retval -1 Child process died for some reason.
* @retval otherwise The ID of the born child.
* @post In case of `-1`, at most `buflen` bytes of the reason why is
* written back to `errbuf`.
*/
rb_pid_t rb_spawn_err(int argc, const VALUE *argv, char *errbuf, size_t buflen);
/**
* Gathers info about resources consumed by the current process.
*
* @param[in] _ Not used. Pass anything.
* @return An instance of `Process::Tms`.
*
* @internal
*
* This function might or might not exist depending on `./confiugre` result.
* It must be a portability hell. Better not use.
*/
VALUE rb_proc_times(VALUE _);
/**
* "Detaches" a subprocess. In POSIX systems every child processes that a
* process creates must be `wait(2)`-ed. A child process that died yet has not
* been waited so far is called a "zombie", which more or less consumes
* resources. This function automates reclamation of such processes. Once
* after this function successfully returns you can basically forget about the
* child process.
*
* @param[in] pid Process to wait.
* @return An instance of ::rb_cThread which is `waitpid(2)`-ing `pid`.
* @post You can just forget about the return value. GC reclaims it.
* @post You can know the exit status by querying `#value` of the
* return value (which is a blocking operation).
*/
VALUE rb_detach_process(rb_pid_t pid);
RBIMPL_SYMBOL_EXPORT_END()
#endif /* RBIMPL_INTERN_PROCESS_H */