[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] libxl: introduce asynchronous execution API
1.introduce asynchronous execution API: libxl__async_exec_init libxl__async_exec_start libxl__async_exec_inuse 2.use the async exec API to execute device hotplug scripts Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx> Signed-off-by: Yang Hongyang <yanghy@xxxxxxxxxxxxxx> --- tools/libxl/libxl_aoutils.c | 89 ++++++++++++++++++++++++++++++++++++++++++++ tools/libxl/libxl_device.c | 78 +++++++++++--------------------------- tools/libxl/libxl_internal.h | 32 ++++++++++++++-- 3 files changed, 139 insertions(+), 60 deletions(-) diff --git a/tools/libxl/libxl_aoutils.c b/tools/libxl/libxl_aoutils.c index 1c9eb9e..6215a3d 100644 --- a/tools/libxl/libxl_aoutils.c +++ b/tools/libxl/libxl_aoutils.c @@ -451,3 +451,92 @@ int libxl__openptys(libxl__openpty_state *op, return rc; } +static void async_exec_timeout(libxl__egc *egc, + libxl__ev_time *ev, + const struct timeval *requested_abs) +{ + libxl__async_exec_state *aes = CONTAINER_OF(ev, *aes, time); + STATE_AO_GC(aes->ao); + + libxl__ev_time_deregister(gc, &aes->time); + + assert(libxl__ev_child_inuse(&aes->child)); + LOG(DEBUG, "killing execution of %s because of timeout", aes->what); + + if (kill(aes->child.pid, SIGKILL)) { + LOGEV(ERROR, errno, "unable to kill %s [%ld]", + aes->what, (unsigned long)aes->child.pid); + } + + return; +} + +static void async_exec_done(libxl__egc *egc, + libxl__ev_child *child, + pid_t pid, int status) +{ + libxl__async_exec_state *aes = CONTAINER_OF(child, *aes, child); + STATE_AO_GC(aes->ao); + + libxl__ev_time_deregister(gc, &aes->time); + + if (status) { + libxl_report_child_exitstatus(CTX, LIBXL__LOG_ERROR, + aes->what, pid, status); + } + + aes->callback(egc, aes, status); +} + +void libxl__async_exec_init(libxl__async_exec_state *aes) +{ + libxl__ev_time_init(&aes->time); + libxl__ev_child_init(&aes->child); +} + +int libxl__async_exec_start(libxl__gc *gc, libxl__async_exec_state *aes) +{ + pid_t pid; + + /* Convenience aliases */ + libxl__ev_child *const child = &aes->child; + char ** const args = aes->args; + + /* Set execution timeout */ + if (libxl__ev_time_register_rel(gc, &aes->time, + async_exec_timeout, + aes->timeout_ms)) { + LOG(ERROR, "unable to register timeout for executing: %s", aes->what); + goto errout; + } + + LOG(DEBUG, "asynchronously execute: %s ", aes->what); + + /* Fork and exec */ + pid = libxl__ev_child_fork(gc, child, async_exec_done); + if (pid == -1) { + LOG(ERROR, "unable to fork"); + goto errout; + } + + if (!pid) { + /* child */ + libxl__exec(gc, aes->stdfds[0], aes->stdfds[1], + aes->stdfds[2], args[0], args, aes->env); + /* notreached */ + abort(); + } + + return 0; + +errout: + return ERROR_FAIL; +} + +bool libxl__async_exec_inuse(const libxl__async_exec_state *aes) +{ + bool time_inuse = libxl__ev_time_isregistered(&aes->time); + bool child_inuse = libxl__ev_child_inuse(&aes->child); + assert(time_inuse == child_inuse); + return child_inuse; +} diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c index fa99f77..90ae564 100644 --- a/tools/libxl/libxl_device.c +++ b/tools/libxl/libxl_device.c @@ -430,7 +430,7 @@ void libxl__prepare_ao_device(libxl__ao *ao, libxl__ao_device *aodev) aodev->rc = 0; aodev->dev = NULL; aodev->num_exec = 0; - /* Initialize timer for QEMU Bodge and hotplug execution */ + /* Initialize timer for QEMU Bodge */ libxl__ev_time_init(&aodev->timeout); /* * Initialize xs_watch, because it's not used on all possible @@ -440,7 +440,7 @@ void libxl__prepare_ao_device(libxl__ao *ao, libxl__ao_device *aodev) aodev->active = 1; /* We init this here because we might call device_hotplug_done * without actually calling any hotplug script */ - libxl__ev_child_init(&aodev->child); + libxl__async_exec_init(&aodev->aes); } /* multidev */ @@ -707,12 +707,9 @@ static void device_backend_cleanup(libxl__gc *gc, static void device_hotplug(libxl__egc *egc, libxl__ao_device *aodev); -static void device_hotplug_timeout_cb(libxl__egc *egc, libxl__ev_time *ev, - const struct timeval *requested_abs); - static void device_hotplug_child_death_cb(libxl__egc *egc, - libxl__ev_child *child, - pid_t pid, int status); + libxl__async_exec_state *aes, + int status); static void device_destroy_be_timeout_cb(libxl__egc *egc, libxl__ev_time *ev, const struct timeval *requested_abs); @@ -953,11 +950,11 @@ static void device_backend_cleanup(libxl__gc *gc, libxl__ao_device *aodev) static void device_hotplug(libxl__egc *egc, libxl__ao_device *aodev) { STATE_AO_GC(aodev->ao); + libxl__async_exec_state *aes = &aodev->aes; char *be_path = libxl__device_backend_path(gc, aodev->dev); char **args = NULL, **env = NULL; int rc = 0; int hotplug, nullfd = -1; - pid_t pid; uint32_t domid; /* @@ -1009,16 +1006,6 @@ static void device_hotplug(libxl__egc *egc, libxl__ao_device *aodev) goto out; } - /* Set hotplug timeout */ - rc = libxl__ev_time_register_rel(gc, &aodev->timeout, - device_hotplug_timeout_cb, - LIBXL_HOTPLUG_TIMEOUT * 1000); - if (rc) { - LOG(ERROR, "unable to register timeout for hotplug device %s", be_path); - goto out; - } - - aodev->what = GCSPRINTF("%s %s", args[0], args[1]); LOG(DEBUG, "calling hotplug script: %s %s", args[0], args[1]); nullfd = open("/dev/null", O_RDONLY); @@ -1028,23 +1015,22 @@ static void device_hotplug(libxl__egc *egc, libxl__ao_device *aodev) goto out; } - /* fork and execute hotplug script */ - pid = libxl__ev_child_fork(gc, &aodev->child, device_hotplug_child_death_cb); - if (pid == -1) { - LOG(ERROR, "unable to fork"); - rc = ERROR_FAIL; + aes->ao = ao; + aes->what = GCSPRINTF("%s %s", args[0], args[1]); + aes->env = env; + aes->args = args; + aes->callback = device_hotplug_child_death_cb; + aes->timeout_ms = LIBXL_HOTPLUG_TIMEOUT * 1000; + aes->stdfds[0] = nullfd; + aes->stdfds[1] = 2; + aes->stdfds[2] = -1; + + rc = libxl__async_exec_start(gc, aes); + if (rc) goto out; - } - - if (!pid) { - /* child */ - libxl__exec(gc, nullfd, 2, -1, args[0], args, env); - /* notreached */ - abort(); - } close(nullfd); - assert(libxl__ev_child_inuse(&aodev->child)); + assert(libxl__async_exec_inuse(&aodev->aes)); return; @@ -1055,29 +1041,11 @@ out: return; } -static void device_hotplug_timeout_cb(libxl__egc *egc, libxl__ev_time *ev, - const struct timeval *requested_abs) -{ - libxl__ao_device *aodev = CONTAINER_OF(ev, *aodev, timeout); - STATE_AO_GC(aodev->ao); - - libxl__ev_time_deregister(gc, &aodev->timeout); - - assert(libxl__ev_child_inuse(&aodev->child)); - LOG(DEBUG, "killing hotplug script %s because of timeout", aodev->what); - if (kill(aodev->child.pid, SIGKILL)) { - LOGEV(ERROR, errno, "unable to kill hotplug script %s [%ld]", - aodev->what, (unsigned long)aodev->child.pid); - } - - return; -} - static void device_hotplug_child_death_cb(libxl__egc *egc, - libxl__ev_child *child, - pid_t pid, int status) + libxl__async_exec_state *aes, + int status) { - libxl__ao_device *aodev = CONTAINER_OF(child, *aodev, child); + libxl__ao_device *aodev = CONTAINER_OF(aes, *aodev, aes); STATE_AO_GC(aodev->ao); char *be_path = libxl__device_backend_path(gc, aodev->dev); char *hotplug_error; @@ -1085,8 +1053,6 @@ static void device_hotplug_child_death_cb(libxl__egc *egc, device_hotplug_clean(gc, aodev); if (status) { - libxl_report_child_exitstatus(CTX, LIBXL__LOG_ERROR, - aodev->what, pid, status); hotplug_error = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("%s/hotplug-error", be_path)); if (hotplug_error) @@ -1178,7 +1144,7 @@ static void device_hotplug_clean(libxl__gc *gc, libxl__ao_device *aodev) /* Clean events and check reentrancy */ libxl__ev_time_deregister(gc, &aodev->timeout); libxl__ev_xswatch_deregister(gc, &aodev->xs_watch); - assert(!libxl__ev_child_inuse(&aodev->child)); + assert(!libxl__async_exec_inuse(&aodev->aes)); } static void devices_remove_callback(libxl__egc *egc, diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h index c2b73c4..3b9acc5 100644 --- a/tools/libxl/libxl_internal.h +++ b/tools/libxl/libxl_internal.h @@ -2030,6 +2030,31 @@ _hidden const char *libxl__xen_script_dir_path(void); _hidden const char *libxl__lock_dir_path(void); _hidden const char *libxl__run_dir_path(void); +/*----- asynchronous function -----*/ +typedef struct libxl__async_exec_state libxl__async_exec_state; + +typedef void libxl__async_exec_callback(libxl__egc *egc, + libxl__async_exec_state *aes, int status); + +struct libxl__async_exec_state { + /* caller must fill these in */ + libxl__ao *ao; + const char *what; /* for error msgs, what we're execute */ + char **env; /* execution environment */ + char **args; /* execution arguments */ + libxl__async_exec_callback *callback; + int timeout_ms; + int stdfds[3]; + + /* private */ + libxl__ev_time time; + libxl__ev_child child; +}; + +void libxl__async_exec_init(libxl__async_exec_state *aes); +int libxl__async_exec_start(libxl__gc *gc, libxl__async_exec_state *aes); +bool libxl__async_exec_inuse(const libxl__async_exec_state *aes); + /*----- device addition/removal -----*/ typedef struct libxl__ao_device libxl__ao_device; @@ -2066,14 +2091,13 @@ struct libxl__ao_device { libxl__multidev *multidev; /* reference to the containing multidev */ /* private for add/remove implementation */ libxl__ev_devstate backend_ds; - /* Bodge for Qemu devices, also used for timeout of hotplug execution */ + /* Bodge for Qemu devices */ libxl__ev_time timeout; /* xenstore watch for backend path of driver domains */ libxl__ev_xswatch xs_watch; - /* device hotplug execution */ - const char *what; int num_exec; - libxl__ev_child child; + /* for calling hotplug scripts */ + libxl__async_exec_state aes; }; /* -- 1.9.1 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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