Implement `chReadProcessEvents` and `chProcessEvents` to read events from event monitor FIFO file and parse them accordingly. Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi(a)linux.microsoft.com&gt; Co-authored-by: Vineeth Pillai <viremana(a)linux.microsoft.com&gt; --- po/POTFILES | 1 + src/ch/ch_events.c | 141 +++++++++++++++++++++++++++++++++++++++++++- src/ch/ch_events.h | 2 + src/ch/ch_monitor.h | 6 ++ 4 files changed, 147 insertions(+), 3 deletions(-) diff --git a/po/POTFILES b/po/POTFILES index 484b34c3df..d4b3de781b 100644 --- a/po/POTFILES +++ b/po/POTFILES @@ -22,6 +22,7 @@ src/bhyve/bhyve_process.c src/ch/ch_conf.c src/ch/ch_domain.c src/ch/ch_driver.c +src/ch/ch_events.c src/ch/ch_hostdev.c src/ch/ch_interface.c src/ch/ch_monitor.c diff --git a/src/ch/ch_events.c b/src/ch/ch_events.c index b6bbce2db0..c5c703ded7 100644 --- a/src/ch/ch_events.c +++ b/src/ch/ch_events.c @@ -20,8 +20,6 @@ #include <config.h> -#include <fcntl.h> - #include "ch_domain.h" #include "ch_events.h" #include "ch_process.h" @@ -31,6 +29,137 @@ VIR_LOG_INIT("ch.ch_events"); +/** + * virCHProcessEvents: + * @mon: the CH monitor object + * + * Parse the events from the event buffer and process them + * Example event: + * { + * "timestamp": { + * "secs": 0, + * "nanos": 29228206 + * }, + * "source": "vm", + * "event": "booted", + * "properties": null + * } + * + * Returns: 0 on success, -1 on failure + */ +static int virCHProcessEvents(virCHMonitor *mon) +{ + virDomainObj *vm = mon->vm; + char *buf = mon->event_buffer.buffer; + ssize_t sz = mon->event_buffer.buf_fill_sz; + virJSONValue *obj = NULL; + int blocks = 0; + size_t i = 0; + char *json_start; + ssize_t start_index = -1; + ssize_t end_index = -1; + char tmp; + + while (i < sz) { + if (buf[i] == '{') { + blocks++; + if (blocks == 1) + start_index = i; + } else if (buf[i] == '}' && blocks > 0) { + blocks--; + if (blocks == 0) { + /* valid json document */ + end_index = i; + + /* temporarily null terminate the JSON doc */ + tmp = buf[end_index + 1]; + buf[end_index + 1] = '\0'; + json_start = buf + start_index; + + if ((obj = virJSONValueFromString(json_start))) { + /* Process the event string (obj) here */ + virJSONValueFree(obj); + } else { + VIR_ERROR(_("%1$s: Invalid JSON event doc: %2$s"), + vm->def->name, json_start); + return -1; + } + + /* replace the original character */ + buf[end_index + 1] = tmp; + start_index = -1; + } + } + + i++; + } + + if (start_index == -1) { + /* We have processed all the JSON docs in the buffer */ + mon->event_buffer.buf_fill_sz = 0; + } else if (start_index > 0) { + /* We have an incomplete JSON doc at the end of the buffer + * Move it to the start of the buffer + */ + mon->event_buffer.buf_fill_sz = sz - start_index; + memmove(buf, buf+start_index, mon->event_buffer.buf_fill_sz); + } + + return 0; +} + +static int virCHReadProcessEvents(virCHMonitor *mon) +{ + /* Event json string must always terminate with null char. + * So, reserve one byte for '\0' at the end. + */ + size_t max_sz = CH_EVENT_BUFFER_SZ - 1; + char *buf = mon->event_buffer.buffer; + virDomainObj *vm = mon->vm; + bool incomplete = false; + size_t sz = 0; + int event_monitor_fd = mon->eventmonitorfd; + + memset(buf, 0, max_sz); + do { + ssize_t ret; + + ret = read(event_monitor_fd, buf + sz, max_sz - sz); + if (ret == 0 || (ret < 0 && errno == EINTR)) { + g_usleep(G_USEC_PER_SEC); + continue; + } else if (ret < 0) { + /* We should never reach here. read(2) says possible errors + * are EINTR, EAGAIN, EBADF, EFAULT, EINVAL, EIO, EISDIR + * We handle EINTR gracefully. There is some serious issue + * if we encounter any of the other errors(either in our code + * or in the system). + */ + VIR_ERROR(_("%1$s: Failed to read ch events!: %2$s"), + vm->def->name, g_strerror(errno)); + return -1; + } + + sz += ret; + mon->event_buffer.buf_fill_sz = sz; + + if (virCHProcessEvents(mon) < 0) { + VIR_ERROR(_("%1$s: Failed to parse and process events"), + vm->def->name); + return -1; + } + + if (mon->event_buffer.buf_fill_sz != 0) + incomplete = true; + else + incomplete = false; + sz = mon->event_buffer.buf_fill_sz; + + } while (virDomainObjIsActive(vm) && (sz < max_sz) && incomplete); + + return 0; +} + static void virCHEventHandlerLoop(void *data) { virCHMonitor *mon = data; @@ -41,11 +170,17 @@ static void virCHEventHandlerLoop(void *data) VIR_DEBUG("%s: Event handler loop thread starting", vm->def->name); + mon->event_buffer.buffer = g_malloc_n(sizeof(char), CH_EVENT_BUFFER_SZ); + mon->event_buffer.buf_fill_sz = 0; + while (g_atomic_int_get(&mon->event_handler_stop) == 0) { VIR_DEBUG("%s: Reading events from event monitor file", vm->def->name); - /* Read and process events here */ + if (virCHReadProcessEvents(mon) < 0) { + virCHStopEventHandler(mon); + } } + g_clear_pointer(&mon->event_buffer.buffer, g_free); virObjectUnref(vm); VIR_DEBUG("%s: Event handler loop thread exiting", vm->def->name); return; diff --git a/src/ch/ch_events.h b/src/ch/ch_events.h index 4c8a48231d..2e9cdf03bb 100644 --- a/src/ch/ch_events.h +++ b/src/ch/ch_events.h @@ -22,5 +22,7 @@ #include "ch_monitor.h" +#define CH_EVENT_BUFFER_SZ PIPE_BUF + int virCHStartEventHandler(virCHMonitor *mon); void virCHStopEventHandler(virCHMonitor *mon); diff --git a/src/ch/ch_monitor.h b/src/ch/ch_monitor.h index b9092f22b8..185de0dbfd 100644 --- a/src/ch/ch_monitor.h +++ b/src/ch/ch_monitor.h @@ -101,6 +101,12 @@ struct _virCHMonitor { virThread event_handler_thread; int event_handler_stop; + struct { + /* Buffer to hold the data read from pipe */ + char *buffer; + /* Size of the data read from pipe into buffer */ + size_t buf_fill_sz; + } event_buffer; pid_t pid; -- 2.34.1