# HG changeset patch
# User Olaf Hering <olaf@xxxxxxxxx>
# Date 1319708351 -7200
# Node ID a3000b1c0fab28d663ebc7fc7533109bd69766d2
# Parent feee3cb40887d43e3de301324655c7655311cfbd
libxl: document spawn related functions
Group spawn related prototypes and add some documentation.
Remove unused prototype for libxl__log_child_exitstatus
Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>
Acked-by: Ian Jackson <ian.jackson.citrix.com>
Committed-by: Ian Jackson <ian.jackson.citrix.com>
---
diff -r feee3cb40887 -r a3000b1c0fab tools/libxl/libxl_internal.h
--- a/tools/libxl/libxl_internal.h Thu Oct 27 11:23:29 2011 +0200
+++ b/tools/libxl/libxl_internal.h Thu Oct 27 11:39:11 2011 +0200
@@ -273,6 +273,121 @@
libxl__spawn_starting *for_spawn;
} libxl__spawner_starting;
+/*
+ * libxl__spawn_spawn - Create a new process
+ * gc: allocation pool
+ * for_spawn: malloc'd pointer to libxl__spawn_starting (optional)
+ * what: string describing the spawned process
+ * intermediate_hook: helper to record pid, such as libxl_spawner_record_pid
+ * hook_data: data to pass to the hook function
+ *
+ * Logs errors. A copy of "what" is taken.
+ * Return values:
+ * < 0 error, for_spawn need not be detached
+ * +1 caller is the parent, must call detach on *for_spawn eventually
+ * 0 caller is now the inner child, should probably call libxl__exec
+ * Caller, may pass 0 for for_spawn, in which case no need to detach.
+ */
+_hidden int libxl__spawn_spawn(libxl__gc *gc,
+ libxl__spawn_starting *for_spawn,
+ const char *what,
+ void (*intermediate_hook)(void *for_spawn, pid_t
innerchild),
+ void *hook_data);
+
+/*
+ * libxl_spawner_record_pid - Record given pid in xenstore
+ * for_spawn: malloc'd pointer to libxl__spawn_starting (optional)
+ * innerchild: pid of the child
+ *
+ * This function is passed as intermediate_hook to libxl__spawn_spawn.
+ */
+_hidden void libxl_spawner_record_pid(void *for_spawn, pid_t innerchild);
+
+/*
+ * libxl__spawn_confirm_offspring_startup - Wait for child state
+ * gc: allocation pool
+ * timeout: how many seconds to wait for the child
+ * what: string describing the spawned process
+ * path: path to the state file in xenstore
+ * state: expected string to wait for in path (optional)
+ * starting: malloc'd pointer to libxl__spawner_starting
+ *
+ * Returns 0 on success, and < 0 on error.
+ *
+ * This function waits the given timeout for the given path to appear
+ * in xenstore, and optionally for state in path.
+ * The intermediate process created in libxl__spawn_spawn is killed.
+ * The memory referenced by starting->for_spawn and starting is free'd.
+ */
+_hidden int libxl__spawn_confirm_offspring_startup(libxl__gc *gc,
+ uint32_t timeout, char *what,
+ char *path, char *state,
+ libxl__spawner_starting *starting);
+
+/*
+ * libxl__wait_for_offspring - Wait for child state
+ * gc: allocation pool
+ * domid: guest to work with
+ * timeout: how many seconds to wait for the state to appear
+ * what: string describing the spawned process
+ * path: path to the state file in xenstore
+ * state: expected string to wait for in path (optional)
+ * spawning: malloc'd pointer to libxl__spawn_starting (optional)
+ * check_callback: (optional)
+ * check_callback_userdata: data to pass to the callback function
+ *
+ * Returns 0 on success, and < 0 on error.
+ *
+ * This function waits the given timeout for the given path to appear
+ * in xenstore, and optionally for state in path.
+ * If path appears and state matches, check_callback is called.
+ * If check_callback returns > 0, waiting for path or state continues.
+ * Otherwise libxl__wait_for_offspring returns.
+ */
+_hidden int libxl__wait_for_offspring(libxl__gc *gc,
+ uint32_t domid,
+ uint32_t timeout, char *what,
+ char *path, char *state,
+ libxl__spawn_starting *spawning,
+ int (*check_callback)(libxl__gc *gc,
+ uint32_t domid,
+ const char *state,
+ void *userdata),
+ void *check_callback_userdata);
+
+/*
+ * libxl__spawn_detach - Kill intermediate process from spawn_spawn
+ * gc: allocation pool
+ * for_spawn: malloc'd pointer to libxl__spawn_starting (optional)
+ *
+ * Returns 0 on success, and < 0 on error.
+ *
+ * Logs errors. Idempotent, but only permitted after successful
+ * call to libxl__spawn_spawn, and no point calling it again if it fails.
+ */
+_hidden int libxl__spawn_detach(libxl__gc *gc,
+ libxl__spawn_starting *for_spawn);
+
+/*
+ * libxl__spawn_check - Check intermediate child process
+ * gc: allocation pool
+ * for_spawn: malloc'd pointer to libxl__spawn_starting (optional)
+ *
+ * Returns 0 on success, and < 0 on error.
+ *
+ * Logs errors but also returns them.
+ * for_spawn must actually be a libxl__spawn_starting* but
+ * we take void* so you can pass this function directly to
+ * libxl__wait_for_offspring. Caller must still call detach.
+ */
+_hidden int libxl__spawn_check(libxl__gc *gc,
+ void *for_spawn);
+
+ /* low-level stuff, for synchronous subprocesses etc. */
+
+_hidden void libxl__exec(int stdinfd, int stdoutfd, int stderrfd,
+ const char *arg0, char **args); // logs errors, never returns
+
/* from xl_create */
_hidden int libxl__domain_make(libxl__gc *gc, libxl_domain_create_info *info,
uint32_t *domid);
_hidden int libxl__domain_build(libxl__gc *gc,
@@ -299,7 +414,7 @@
int nr_disks, libxl_device_disk *disks);
/* Caller must either: pass starting_r==0, or on successful
* return pass *starting_r (which will be non-0) to
- * libxl_confirm_device_model or libxl_detach_device_model. */
+ * libxl__confirm_device_model_startup or libxl__detach_device_model. */
_hidden int libxl__confirm_device_model_startup(libxl__gc *gc,
libxl__spawner_starting *starting);
_hidden int libxl__detach_device_model(libxl__gc *gc, libxl__spawner_starting
*starting);
@@ -312,55 +427,8 @@
void *userdata),
void *check_callback_userdata);
-_hidden int libxl__spawn_spawn(libxl__gc *gc,
- libxl__spawn_starting *starting,
- const char *what,
- void (*intermediate_hook)(void *for_spawn, pid_t
innerchild),
- void *hook_data);
_hidden int libxl__destroy_device_model(libxl__gc *gc, uint32_t domid);
-_hidden void libxl_spawner_record_pid(void *for_spawn, pid_t innerchild);
-
-_hidden int libxl__wait_for_offspring(libxl__gc *gc,
- uint32_t domid,
- uint32_t timeout, char *what,
- char *path, char *state,
- libxl__spawn_starting *spawning,
- int (*check_callback)(libxl__gc *gc,
- uint32_t domid,
- const char *state,
- void *userdata),
- void *check_callback_userdata);
-
-_hidden int libxl__spawn_confirm_offspring_startup(libxl__gc *gc,
- uint32_t timeout, char *what,
- char *path, char *state,
- libxl__spawner_starting *starting);
-
- /* Logs errors. A copy of "what" is taken. Return values:
- * < 0 error, for_spawn need not be detached
- * +1 caller is the parent, must call detach on *for_spawn eventually
- * 0 caller is now the inner child, should probably call libxl__exec
- * Caller, may pass 0 for for_spawn, in which case no need to detach.
- */
-_hidden int libxl__spawn_detach(libxl__gc *gc,
- libxl__spawn_starting *for_spawn);
- /* Logs errors. Idempotent, but only permitted after successful
- * call to libxl__spawn_spawn, and no point calling it again if it fails. */
-_hidden int libxl__spawn_check(libxl__gc *gc,
- void *for_spawn);
- /* Logs errors but also returns them.
- * for_spawn must actually be a libxl__spawn_starting* but
- * we take void* so you can pass this function directly to
- * libxl__wait_for_offspring. Caller must still call detach. */
-
- /* low-level stuff, for synchronous subprocesses etc. */
-
-_hidden void libxl__exec(int stdinfd, int stdoutfd, int stderrfd,
- const char *arg0, char **args); // logs errors, never returns
-_hidden void libxl__log_child_exitstatus(libxl__gc *gc,
- const char *what, pid_t pid, int status);
-
_hidden char *libxl__abs_path(libxl__gc *gc, const char *s, const char *path);
#define LIBXL__LOG_DEBUG XTL_DEBUG
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