1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef APR_THREAD_PROC_H
18 #define APR_THREAD_PROC_H
21 * @file apr_thread_proc.h
22 * @brief APR Thread and Process Library
26 #include "apr_file_io.h"
27 #include "apr_pools.h"
28 #include "apr_errno.h"
29 #include "apr_perms_set.h"
31 #if APR_HAVE_STRUCT_RLIMIT
33 #include <sys/resource.h>
38 #endif /* __cplusplus */
41 * @defgroup apr_thread_proc Threads and Process Functions
47 APR_SHELLCMD, /**< use the shell to invoke the program */
48 APR_PROGRAM, /**< invoke the program directly, no copied env */
49 APR_PROGRAM_ENV, /**< invoke the program, replicating our environment */
50 APR_PROGRAM_PATH, /**< find program on PATH, use our environment */
51 APR_SHELLCMD_ENV /**< use the shell to invoke the program,
52 * replicating our environment
57 APR_WAIT, /**< wait for the specified process to finish */
58 APR_NOWAIT /**< do not wait -- just see if it has finished */
61 /* I am specifically calling out the values so that the macros below make
62 * more sense. Yes, I know I don't need to, but I am hoping this makes what
63 * I am doing more clear. If you want to add more reasons to exit, continue
67 APR_PROC_EXIT = 1, /**< process exited normally */
68 APR_PROC_SIGNAL = 2, /**< process exited due to a signal */
69 APR_PROC_SIGNAL_CORE = 4 /**< process exited and dumped a core file */
72 /** did we exit the process */
73 #define APR_PROC_CHECK_EXIT(x) (x & APR_PROC_EXIT)
74 /** did we get a signal */
75 #define APR_PROC_CHECK_SIGNALED(x) (x & APR_PROC_SIGNAL)
76 /** did we get core */
77 #define APR_PROC_CHECK_CORE_DUMP(x) (x & APR_PROC_SIGNAL_CORE)
79 /** @see apr_procattr_io_set */
81 /** @see apr_procattr_io_set and apr_file_pipe_create_ex */
82 #define APR_FULL_BLOCK 1
83 /** @see apr_procattr_io_set and apr_file_pipe_create_ex */
84 #define APR_FULL_NONBLOCK 2
85 /** @see apr_procattr_io_set */
86 #define APR_PARENT_BLOCK 3
87 /** @see apr_procattr_io_set */
88 #define APR_CHILD_BLOCK 4
89 /** @see apr_procattr_io_set */
92 /** @see apr_file_pipe_create_ex */
93 #define APR_READ_BLOCK 3
94 /** @see apr_file_pipe_create_ex */
95 #define APR_WRITE_BLOCK 4
97 /** @see apr_procattr_io_set
98 * @note Win32 only effective with version 1.2.12, portably introduced in 1.3.0
100 #define APR_NO_FILE 8
102 /** @see apr_procattr_limit_set */
103 #define APR_LIMIT_CPU 0
104 /** @see apr_procattr_limit_set */
105 #define APR_LIMIT_MEM 1
106 /** @see apr_procattr_limit_set */
107 #define APR_LIMIT_NPROC 2
108 /** @see apr_procattr_limit_set */
109 #define APR_LIMIT_NOFILE 3
112 * @defgroup APR_OC Other Child Flags
115 #define APR_OC_REASON_DEATH 0 /**< child has died, caller must call
116 * unregister still */
117 #define APR_OC_REASON_UNWRITABLE 1 /**< write_fd is unwritable */
118 #define APR_OC_REASON_RESTART 2 /**< a restart is occurring, perform
119 * any necessary cleanup (including
120 * sending a special signal to child)
122 #define APR_OC_REASON_UNREGISTER 3 /**< unregister has been called, do
123 * whatever is necessary (including
125 #define APR_OC_REASON_LOST 4 /**< somehow the child exited without
126 * us knowing ... buggy os? */
127 #define APR_OC_REASON_RUNNING 5 /**< a health check is occurring,
128 * for most maintainence functions
133 /** The APR process type */
134 typedef struct apr_proc_t {
135 /** The process ID */
137 /** Parent's side of pipe to child's stdin */
139 /** Parent's side of pipe to child's stdout */
141 /** Parent's side of pipe to child's stdouterr */
143 #if APR_HAS_PROC_INVOKED || defined(DOXYGEN)
144 /** Diagnositics/debugging string of the command invoked for
145 * this process [only present if APR_HAS_PROC_INVOKED is true]
146 * @remark Only enabled on Win32 by default.
147 * @bug This should either always or never be present in release
148 * builds - since it breaks binary compatibility. We may enable
149 * it always in APR 1.0 yet leave it undefined in most cases.
153 #if defined(WIN32) || defined(DOXYGEN)
154 /** (Win32 only) Creator's handle granting access to the process
155 * @remark This handle is closed and reset to NULL in every case
156 * corresponding to a waitpid() on Unix which returns the exit status.
157 * Therefore Win32 correspond's to Unix's zombie reaping characteristics
158 * and avoids potential handle leaks.
165 * The prototype for APR child errfn functions. (See the description
166 * of apr_procattr_child_errfn_set() for more information.)
167 * It is passed the following parameters:
168 * @param pool Pool associated with the apr_proc_t. If your child
169 * error function needs user data, associate it with this
171 * @param err APR error code describing the error
172 * @param description Text description of type of processing which failed
174 typedef void (apr_child_errfn_t)(apr_pool_t *proc, apr_status_t err,
175 const char *description);
177 /** Opaque Thread structure. */
178 typedef struct apr_thread_t apr_thread_t;
180 /** Opaque Thread attributes structure. */
181 typedef struct apr_threadattr_t apr_threadattr_t;
183 /** Opaque Process attributes structure. */
184 typedef struct apr_procattr_t apr_procattr_t;
186 /** Opaque control variable for one-time atomic variables. */
187 typedef struct apr_thread_once_t apr_thread_once_t;
189 /** Opaque thread private address space. */
190 typedef struct apr_threadkey_t apr_threadkey_t;
192 /** Opaque record of child process. */
193 typedef struct apr_other_child_rec_t apr_other_child_rec_t;
196 * The prototype for any APR thread worker functions.
198 typedef void *(APR_THREAD_FUNC *apr_thread_start_t)(apr_thread_t*, void*);
201 APR_KILL_NEVER, /**< process is never killed (i.e., never sent
202 * any signals), but it will be reaped if it exits
203 * before the pool is cleaned up */
204 APR_KILL_ALWAYS, /**< process is sent SIGKILL on apr_pool_t cleanup */
205 APR_KILL_AFTER_TIMEOUT, /**< SIGTERM, wait 3 seconds, SIGKILL */
206 APR_JUST_WAIT, /**< wait forever for the process to complete */
207 APR_KILL_ONLY_ONCE /**< send SIGTERM and then wait */
208 } apr_kill_conditions_e;
210 /* Thread Function definitions */
215 * Create and initialize a new threadattr variable
216 * @param new_attr The newly created threadattr.
217 * @param cont The pool to use
219 APR_DECLARE(apr_status_t) apr_threadattr_create(apr_threadattr_t **new_attr,
223 * Set if newly created threads should be created in detached state.
224 * @param attr The threadattr to affect
225 * @param on Non-zero if detached threads should be created.
227 APR_DECLARE(apr_status_t) apr_threadattr_detach_set(apr_threadattr_t *attr,
231 * Get the detach state for this threadattr.
232 * @param attr The threadattr to reference
233 * @return APR_DETACH if threads are to be detached, or APR_NOTDETACH
234 * if threads are to be joinable.
236 APR_DECLARE(apr_status_t) apr_threadattr_detach_get(apr_threadattr_t *attr);
239 * Set the stack size of newly created threads.
240 * @param attr The threadattr to affect
241 * @param stacksize The stack size in bytes
243 APR_DECLARE(apr_status_t) apr_threadattr_stacksize_set(apr_threadattr_t *attr,
244 apr_size_t stacksize);
247 * Set the stack guard area size of newly created threads.
248 * @param attr The threadattr to affect
249 * @param guardsize The stack guard area size in bytes
250 * @note Thread library implementations commonly use a "guard area"
251 * after each thread's stack which is not readable or writable such that
252 * stack overflows cause a segfault; this consumes e.g. 4K of memory
253 * and increases memory management overhead. Setting the guard area
254 * size to zero hence trades off reliable behaviour on stack overflow
255 * for performance. */
256 APR_DECLARE(apr_status_t) apr_threadattr_guardsize_set(apr_threadattr_t *attr,
257 apr_size_t guardsize);
260 * Create a new thread of execution
261 * @param new_thread The newly created thread handle.
262 * @param attr The threadattr to use to determine how to create the thread
263 * @param func The function to start the new thread in
264 * @param data Any data to be passed to the starting function
265 * @param cont The pool to use
267 APR_DECLARE(apr_status_t) apr_thread_create(apr_thread_t **new_thread,
268 apr_threadattr_t *attr,
269 apr_thread_start_t func,
270 void *data, apr_pool_t *cont);
273 * stop the current thread
274 * @param thd The thread to stop
275 * @param retval The return value to pass back to any thread that cares
277 APR_DECLARE(apr_status_t) apr_thread_exit(apr_thread_t *thd,
278 apr_status_t retval);
281 * block until the desired thread stops executing.
282 * @param retval The return value from the dead thread.
283 * @param thd The thread to join
285 APR_DECLARE(apr_status_t) apr_thread_join(apr_status_t *retval,
289 * force the current thread to yield the processor
291 APR_DECLARE(void) apr_thread_yield(void);
294 * Initialize the control variable for apr_thread_once. If this isn't
295 * called, apr_initialize won't work.
296 * @param control The control variable to initialize
297 * @param p The pool to allocate data from.
299 APR_DECLARE(apr_status_t) apr_thread_once_init(apr_thread_once_t **control,
303 * Run the specified function one time, regardless of how many threads
305 * @param control The control variable. The same variable should
306 * be passed in each time the function is tried to be
307 * called. This is how the underlying functions determine
308 * if the function has ever been called before.
309 * @param func The function to call.
311 APR_DECLARE(apr_status_t) apr_thread_once(apr_thread_once_t *control,
316 * @param thd The thread to detach
318 APR_DECLARE(apr_status_t) apr_thread_detach(apr_thread_t *thd);
321 * Return user data associated with the current thread.
322 * @param data The user data associated with the thread.
323 * @param key The key to associate with the data
324 * @param thread The currently open thread.
326 APR_DECLARE(apr_status_t) apr_thread_data_get(void **data, const char *key,
327 apr_thread_t *thread);
330 * Set user data associated with the current thread.
331 * @param data The user data to associate with the thread.
332 * @param key The key to use for associating the data with the thread
333 * @param cleanup The cleanup routine to use when the thread is destroyed.
334 * @param thread The currently open thread.
336 APR_DECLARE(apr_status_t) apr_thread_data_set(void *data, const char *key,
337 apr_status_t (*cleanup) (void *),
338 apr_thread_t *thread);
341 * Create and initialize a new thread private address space
342 * @param key The thread private handle.
343 * @param dest The destructor to use when freeing the private memory.
344 * @param cont The pool to use
346 APR_DECLARE(apr_status_t) apr_threadkey_private_create(apr_threadkey_t **key,
347 void (*dest)(void *),
351 * Get a pointer to the thread private memory
352 * @param new_mem The data stored in private memory
353 * @param key The handle for the desired thread private memory
355 APR_DECLARE(apr_status_t) apr_threadkey_private_get(void **new_mem,
356 apr_threadkey_t *key);
359 * Set the data to be stored in thread private memory
360 * @param priv The data to be stored in private memory
361 * @param key The handle for the desired thread private memory
363 APR_DECLARE(apr_status_t) apr_threadkey_private_set(void *priv,
364 apr_threadkey_t *key);
367 * Free the thread private memory
368 * @param key The handle for the desired thread private memory
370 APR_DECLARE(apr_status_t) apr_threadkey_private_delete(apr_threadkey_t *key);
373 * Return the pool associated with the current threadkey.
374 * @param data The user data associated with the threadkey.
375 * @param key The key associated with the data
376 * @param threadkey The currently open threadkey.
378 APR_DECLARE(apr_status_t) apr_threadkey_data_get(void **data, const char *key,
379 apr_threadkey_t *threadkey);
382 * Return the pool associated with the current threadkey.
383 * @param data The data to set.
384 * @param key The key to associate with the data.
385 * @param cleanup The cleanup routine to use when the file is destroyed.
386 * @param threadkey The currently open threadkey.
388 APR_DECLARE(apr_status_t) apr_threadkey_data_set(void *data, const char *key,
389 apr_status_t (*cleanup) (void *),
390 apr_threadkey_t *threadkey);
395 * Create and initialize a new procattr variable
396 * @param new_attr The newly created procattr.
397 * @param cont The pool to use
399 APR_DECLARE(apr_status_t) apr_procattr_create(apr_procattr_t **new_attr,
403 * Determine if any of stdin, stdout, or stderr should be linked to pipes
404 * when starting a child process.
405 * @param attr The procattr we care about.
406 * @param in Should stdin be a pipe back to the parent?
407 * @param out Should stdout be a pipe back to the parent?
408 * @param err Should stderr be a pipe back to the parent?
409 * @note If APR_NO_PIPE, there will be no special channel, the child
410 * inherits the parent's corresponding stdio stream. If APR_NO_FILE is
411 * specified, that corresponding stream is closed in the child (and will
412 * be INVALID_HANDLE_VALUE when inspected on Win32). This can have ugly
413 * side effects, as the next file opened in the child on Unix will fall
414 * into the stdio stream fd slot!
416 APR_DECLARE(apr_status_t) apr_procattr_io_set(apr_procattr_t *attr,
417 apr_int32_t in, apr_int32_t out,
421 * Set the child_in and/or parent_in values to existing apr_file_t values.
422 * @param attr The procattr we care about.
423 * @param child_in apr_file_t value to use as child_in. Must be a valid file.
424 * @param parent_in apr_file_t value to use as parent_in. Must be a valid file.
425 * @remark This is NOT a required initializer function. This is
426 * useful if you have already opened a pipe (or multiple files)
427 * that you wish to use, perhaps persistently across multiple
428 * process invocations - such as a log file. You can save some
429 * extra function calls by not creating your own pipe since this
430 * creates one in the process space for you.
431 * @bug Note that calling this function with two NULL files on some platforms
432 * creates an APR_FULL_BLOCK pipe, but this behavior is neither portable nor
433 * is it supported. @see apr_procattr_io_set instead for simple pipes.
435 APR_DECLARE(apr_status_t) apr_procattr_child_in_set(struct apr_procattr_t *attr,
436 apr_file_t *child_in,
437 apr_file_t *parent_in);
440 * Set the child_out and parent_out values to existing apr_file_t values.
441 * @param attr The procattr we care about.
442 * @param child_out apr_file_t value to use as child_out. Must be a valid file.
443 * @param parent_out apr_file_t value to use as parent_out. Must be a valid file.
444 * @remark This is NOT a required initializer function. This is
445 * useful if you have already opened a pipe (or multiple files)
446 * that you wish to use, perhaps persistently across multiple
447 * process invocations - such as a log file.
448 * @bug Note that calling this function with two NULL files on some platforms
449 * creates an APR_FULL_BLOCK pipe, but this behavior is neither portable nor
450 * is it supported. @see apr_procattr_io_set instead for simple pipes.
452 APR_DECLARE(apr_status_t) apr_procattr_child_out_set(struct apr_procattr_t *attr,
453 apr_file_t *child_out,
454 apr_file_t *parent_out);
457 * Set the child_err and parent_err values to existing apr_file_t values.
458 * @param attr The procattr we care about.
459 * @param child_err apr_file_t value to use as child_err. Must be a valid file.
460 * @param parent_err apr_file_t value to use as parent_err. Must be a valid file.
461 * @remark This is NOT a required initializer function. This is
462 * useful if you have already opened a pipe (or multiple files)
463 * that you wish to use, perhaps persistently across multiple
464 * process invocations - such as a log file.
465 * @bug Note that calling this function with two NULL files on some platforms
466 * creates an APR_FULL_BLOCK pipe, but this behavior is neither portable nor
467 * is it supported. @see apr_procattr_io_set instead for simple pipes.
469 APR_DECLARE(apr_status_t) apr_procattr_child_err_set(struct apr_procattr_t *attr,
470 apr_file_t *child_err,
471 apr_file_t *parent_err);
474 * Set which directory the child process should start executing in.
475 * @param attr The procattr we care about.
476 * @param dir Which dir to start in. By default, this is the same dir as
477 * the parent currently resides in, when the createprocess call
480 APR_DECLARE(apr_status_t) apr_procattr_dir_set(apr_procattr_t *attr,
484 * Set what type of command the child process will call.
485 * @param attr The procattr we care about.
486 * @param cmd The type of command. One of:
488 * APR_SHELLCMD -- Anything that the shell can handle
489 * APR_PROGRAM -- Executable program (default)
490 * APR_PROGRAM_ENV -- Executable program, copy environment
491 * APR_PROGRAM_PATH -- Executable program on PATH, copy env
494 APR_DECLARE(apr_status_t) apr_procattr_cmdtype_set(apr_procattr_t *attr,
498 * Determine if the child should start in detached state.
499 * @param attr The procattr we care about.
500 * @param detach Should the child start in detached state? Default is no.
502 APR_DECLARE(apr_status_t) apr_procattr_detach_set(apr_procattr_t *attr,
505 #if APR_HAVE_STRUCT_RLIMIT
507 * Set the Resource Utilization limits when starting a new process.
508 * @param attr The procattr we care about.
509 * @param what Which limit to set, one of:
516 * @param limit Value to set the limit to.
518 APR_DECLARE(apr_status_t) apr_procattr_limit_set(apr_procattr_t *attr,
520 struct rlimit *limit);
524 * Specify an error function to be called in the child process if APR
525 * encounters an error in the child prior to running the specified program.
526 * @param attr The procattr describing the child process to be created.
527 * @param errfn The function to call in the child process.
528 * @remark At the present time, it will only be called from apr_proc_create()
529 * on platforms where fork() is used. It will never be called on other
530 * platforms, on those platforms apr_proc_create() will return the error
531 * in the parent process rather than invoke the callback in the now-forked
534 APR_DECLARE(apr_status_t) apr_procattr_child_errfn_set(apr_procattr_t *attr,
535 apr_child_errfn_t *errfn);
538 * Specify that apr_proc_create() should do whatever it can to report
539 * failures to the caller of apr_proc_create(), rather than find out in
541 * @param attr The procattr describing the child process to be created.
542 * @param chk Flag to indicate whether or not extra work should be done
543 * to try to report failures to the caller.
544 * @remark This flag only affects apr_proc_create() on platforms where
545 * fork() is used. This leads to extra overhead in the calling
546 * process, but that may help the application handle such
547 * errors more gracefully.
549 APR_DECLARE(apr_status_t) apr_procattr_error_check_set(apr_procattr_t *attr,
553 * Determine if the child should start in its own address space or using the
554 * current one from its parent
555 * @param attr The procattr we care about.
556 * @param addrspace Should the child start in its own address space? Default
557 * is no on NetWare and yes on other platforms.
559 APR_DECLARE(apr_status_t) apr_procattr_addrspace_set(apr_procattr_t *attr,
560 apr_int32_t addrspace);
563 * Set the username used for running process
564 * @param attr The procattr we care about.
565 * @param username The username used
566 * @param password User password if needed. Password is needed on WIN32
567 * or any other platform having
568 * APR_PROCATTR_USER_SET_REQUIRES_PASSWORD set.
570 APR_DECLARE(apr_status_t) apr_procattr_user_set(apr_procattr_t *attr,
571 const char *username,
572 const char *password);
575 * Set the group used for running process
576 * @param attr The procattr we care about.
577 * @param groupname The group name used
579 APR_DECLARE(apr_status_t) apr_procattr_group_set(apr_procattr_t *attr,
580 const char *groupname);
584 * Register permission set function
585 * @param attr The procattr we care about.
586 * @param perms_set_fn Permission set callback
587 * @param data Data to pass to permission callback function
588 * @param perms Permissions to set
590 APR_DECLARE(apr_status_t) apr_procattr_perms_set_register(apr_procattr_t *attr,
591 apr_perms_setfn_t *perms_set_fn,
593 apr_fileperms_t perms);
597 * This is currently the only non-portable call in APR. This executes
598 * a standard unix fork.
599 * @param proc The resulting process handle.
600 * @param cont The pool to use.
601 * @remark returns APR_INCHILD for the child, and APR_INPARENT for the parent
604 APR_DECLARE(apr_status_t) apr_proc_fork(apr_proc_t *proc, apr_pool_t *cont);
608 * Create a new process and execute a new program within that process.
609 * @param new_proc The resulting process handle.
610 * @param progname The program to run
611 * @param args the arguments to pass to the new program. The first
612 * one should be the program name.
613 * @param env The new environment table for the new process. This
614 * should be a list of NULL-terminated strings. This argument
615 * is ignored for APR_PROGRAM_ENV, APR_PROGRAM_PATH, and
616 * APR_SHELLCMD_ENV types of commands.
617 * @param attr the procattr we should use to determine how to create the new
619 * @param pool The pool to use.
620 * @note This function returns without waiting for the new process to terminate;
621 * use apr_proc_wait for that.
623 APR_DECLARE(apr_status_t) apr_proc_create(apr_proc_t *new_proc,
624 const char *progname,
625 const char * const *args,
626 const char * const *env,
627 apr_procattr_t *attr,
631 * Wait for a child process to die
632 * @param proc The process handle that corresponds to the desired child process
633 * @param exitcode The returned exit status of the child, if a child process
634 * dies, or the signal that caused the child to die.
635 * On platforms that don't support obtaining this information,
636 * the status parameter will be returned as APR_ENOTIMPL.
637 * @param exitwhy Why the child died, the bitwise or of:
639 * APR_PROC_EXIT -- process terminated normally
640 * APR_PROC_SIGNAL -- process was killed by a signal
641 * APR_PROC_SIGNAL_CORE -- process was killed by a signal, and
642 * generated a core dump.
644 * @param waithow How should we wait. One of:
646 * APR_WAIT -- block until the child process dies.
647 * APR_NOWAIT -- return immediately regardless of if the
648 * child is dead or not.
650 * @remark The child's status is in the return code to this process. It is one of:
652 * APR_CHILD_DONE -- child is no longer running.
653 * APR_CHILD_NOTDONE -- child is still running.
656 APR_DECLARE(apr_status_t) apr_proc_wait(apr_proc_t *proc,
657 int *exitcode, apr_exit_why_e *exitwhy,
658 apr_wait_how_e waithow);
661 * Wait for any current child process to die and return information
663 * @param proc Pointer to NULL on entry, will be filled out with child's
665 * @param exitcode The returned exit status of the child, if a child process
666 * dies, or the signal that caused the child to die.
667 * On platforms that don't support obtaining this information,
668 * the status parameter will be returned as APR_ENOTIMPL.
669 * @param exitwhy Why the child died, the bitwise or of:
671 * APR_PROC_EXIT -- process terminated normally
672 * APR_PROC_SIGNAL -- process was killed by a signal
673 * APR_PROC_SIGNAL_CORE -- process was killed by a signal, and
674 * generated a core dump.
676 * @param waithow How should we wait. One of:
678 * APR_WAIT -- block until the child process dies.
679 * APR_NOWAIT -- return immediately regardless of if the
680 * child is dead or not.
682 * @param p Pool to allocate child information out of.
683 * @bug Passing proc as a *proc rather than **proc was an odd choice
684 * for some platforms... this should be revisited in 1.0
686 APR_DECLARE(apr_status_t) apr_proc_wait_all_procs(apr_proc_t *proc,
688 apr_exit_why_e *exitwhy,
689 apr_wait_how_e waithow,
692 #define APR_PROC_DETACH_FOREGROUND 0 /**< Do not detach */
693 #define APR_PROC_DETACH_DAEMONIZE 1 /**< Detach */
696 * Detach the process from the controlling terminal.
697 * @param daemonize set to non-zero if the process should daemonize
698 * and become a background process, else it will
699 * stay in the foreground.
701 APR_DECLARE(apr_status_t) apr_proc_detach(int daemonize);
704 * Register an other_child -- a child associated to its registered
705 * maintence callback. This callback is invoked when the process
706 * dies, is disconnected or disappears.
707 * @param proc The child process to register.
708 * @param maintenance maintenance is a function that is invoked with a
709 * reason and the data pointer passed here.
710 * @param data Opaque context data passed to the maintenance function.
711 * @param write_fd An fd that is probed for writing. If it is ever unwritable
712 * then the maintenance is invoked with reason
713 * OC_REASON_UNWRITABLE.
714 * @param p The pool to use for allocating memory.
715 * @bug write_fd duplicates the proc->out stream, it's really redundant
716 * and should be replaced in the APR 1.0 API with a bitflag of which
717 * proc->in/out/err handles should be health checked.
718 * @bug no platform currently tests the pipes health.
720 APR_DECLARE(void) apr_proc_other_child_register(apr_proc_t *proc,
721 void (*maintenance) (int reason,
724 void *data, apr_file_t *write_fd,
728 * Stop watching the specified other child.
729 * @param data The data to pass to the maintenance function. This is
730 * used to find the process to unregister.
731 * @warning Since this can be called by a maintenance function while we're
732 * scanning the other_children list, all scanners should protect
733 * themself by loading ocr->next before calling any maintenance
736 APR_DECLARE(void) apr_proc_other_child_unregister(void *data);
739 * Notify the maintenance callback of a registered other child process
740 * that application has detected an event, such as death.
741 * @param proc The process to check
742 * @param reason The reason code to pass to the maintenance function
743 * @param status The status to pass to the maintenance function
744 * @remark An example of code using this behavior;
746 * rv = apr_proc_wait_all_procs(&proc, &exitcode, &status, APR_WAIT, p);
747 * if (APR_STATUS_IS_CHILD_DONE(rv)) {
748 * \#if APR_HAS_OTHER_CHILD
749 * if (apr_proc_other_child_alert(&proc, APR_OC_REASON_DEATH, status)
751 * ; (already handled)
755 * [... handling non-otherchild processes death ...]
758 APR_DECLARE(apr_status_t) apr_proc_other_child_alert(apr_proc_t *proc,
763 * Test one specific other child processes and invoke the maintenance callback
764 * with the appropriate reason code, if still running, or the appropriate reason
765 * code if the process is no longer healthy.
766 * @param ocr The registered other child
767 * @param reason The reason code (e.g. APR_OC_REASON_RESTART) if still running
769 APR_DECLARE(void) apr_proc_other_child_refresh(apr_other_child_rec_t *ocr,
773 * Test all registered other child processes and invoke the maintenance callback
774 * with the appropriate reason code, if still running, or the appropriate reason
775 * code if the process is no longer healthy.
776 * @param reason The reason code (e.g. APR_OC_REASON_RESTART) to running processes
778 APR_DECLARE(void) apr_proc_other_child_refresh_all(int reason);
781 * Terminate a process.
782 * @param proc The process to terminate.
783 * @param sig How to kill the process.
785 APR_DECLARE(apr_status_t) apr_proc_kill(apr_proc_t *proc, int sig);
788 * Register a process to be killed when a pool dies.
789 * @param a The pool to use to define the processes lifetime
790 * @param proc The process to register
791 * @param how How to kill the process, one of:
793 * APR_KILL_NEVER -- process is never sent any signals
794 * APR_KILL_ALWAYS -- process is sent SIGKILL on apr_pool_t cleanup
795 * APR_KILL_AFTER_TIMEOUT -- SIGTERM, wait 3 seconds, SIGKILL
796 * APR_JUST_WAIT -- wait forever for the process to complete
797 * APR_KILL_ONLY_ONCE -- send SIGTERM and then wait
800 APR_DECLARE(void) apr_pool_note_subprocess(apr_pool_t *a, apr_proc_t *proc,
801 apr_kill_conditions_e how);
805 #if (APR_HAVE_SIGWAIT || APR_HAVE_SIGSUSPEND) && !defined(OS2)
808 * Setup the process for a single thread to be used for all signal handling.
809 * @warning This must be called before any threads are created
811 APR_DECLARE(apr_status_t) apr_setup_signal_thread(void);
814 * Make the current thread listen for signals. This thread will loop
815 * forever, calling a provided function whenever it receives a signal. That
816 * functions should return 1 if the signal has been handled, 0 otherwise.
817 * @param signal_handler The function to call when a signal is received
818 * apr_status_t apr_signal_thread((int)(*signal_handler)(int signum))
819 * @note Synchronous signals like SIGABRT/SIGSEGV/SIGBUS/... are ignored by
820 * apr_signal_thread() and thus can't be waited by this function (they remain
821 * handled by the operating system or its native signals interface).
822 * @remark In APR version 1.6 and ealier, SIGUSR2 was part of these ignored
823 * signals and thus was never passed in to the signal_handler. From APR 1.7
824 * this is no more the case so SIGUSR2 can be handled in signal_handler and
825 * acted upon like the other asynchronous signals.
827 APR_DECLARE(apr_status_t) apr_signal_thread(int(*signal_handler)(int signum));
829 #endif /* (APR_HAVE_SIGWAIT || APR_HAVE_SIGSUSPEND) && !defined(OS2) */
832 * Get the child-pool used by the thread from the thread info.
833 * @return apr_pool_t the pool
835 APR_POOL_DECLARE_ACCESSOR(thread);
837 #endif /* APR_HAS_THREADS */
845 #endif /* ! APR_THREAD_PROC_H */