src/ecmascript/spidermonkey/heartbeat.c

   1 /* The SpiderMonkey ECMAScript backend heartbeat fuctionality. */
   2
   3 #ifdef HAVE_CONFIG_H
   4 #include "config.h"
   5 #endif
   6
   7 #include <sys/time.h>    /* setitimer(2) */
   8
   9 #include "elinks.h"
  10
  11 #include "ecmascript/spidermonkey/util.h"
  12
  13 #include "config/options.h"
  14 #include "document/view.h"
  15 #include "ecmascript/ecmascript.h"
  16 #include "ecmascript/spidermonkey.h"
  17 #include "ecmascript/spidermonkey/heartbeat.h"
  18 #include "osdep/signals.h"
  19 #include "session/session.h"
  20 #include "util/lists.h"
  21 #include "util/math.h"   /* int_upper_bound */
  22 #include "util/memory.h"
  23 #include "viewer/text/vs.h"
  24
  25
  26
  27 static INIT_LIST_OF(struct heartbeat, heartbeats);
  28
  29 static struct itimerval heartbeat_timer = { { 1, 0 }, { 1, 0 } };
  30
  31
  32 /* This callback is installed by JS_SetOperationCallback and triggered
  33  * by JS_TriggerOperationCallback in the heartbeat code below.  Returning
  34  * JS_FALSE terminates script execution immediately. */
  35 JSBool
  36 heartbeat_callback(JSContext *ctx)
  37 {
  38         return JS_FALSE;
  39 }
  40
  41 /* Callback for SIGVTALRM.  Go through all heartbeats, decrease each
  42  * one's TTL, and call JS_TriggerOperationCallback if a heartbeat's TTL
  43  * goes to 0. */
  44 static void
  45 check_heartbeats(void *data)
  46 {
  47         struct heartbeat *hb;
  48
  49         foreach (hb, heartbeats) {
  50                 assert(hb->interpreter);
  51
  52                 --hb->ttl;
  53
  54                 if (hb->ttl <= 0) {
  55                         if (hb->interpreter->vs
  56                             && hb->interpreter->vs->doc_view
  57                             && hb->interpreter->vs->doc_view->session
  58                             && hb->interpreter->vs->doc_view->session->tab
  59                             && hb->interpreter->vs->doc_view->session->tab->term) {
  60                                 struct session *ses = hb->interpreter->vs->doc_view->session;
  61                                 struct terminal *term = ses->tab->term;
  62                                 int max_exec_time = get_opt_int("ecmascript.max_exec_time", ses);
  63
  64                                 ecmascript_timeout_dialog(term, max_exec_time);
  65                         }
  66
  67                         JS_TriggerOperationCallback(hb->interpreter->backend_data);
  68                 }
  69         }
  70
  71         install_signal_handler(SIGVTALRM, check_heartbeats, NULL, 1);
  72 }
  73
  74 /* Create a new heartbeat for the given interpreter. */
  75 struct heartbeat *
  76 add_heartbeat(struct ecmascript_interpreter *interpreter)
  77 {
  78         struct session *ses;
  79         struct heartbeat *hb;
  80
  81         assert(interpreter);
  82
  83         if (!interpreter->vs || !interpreter->vs->doc_view)
  84                 ses = NULL;
  85         else
  86                 ses = interpreter->vs->doc_view->session;
  87
  88         hb = mem_alloc(sizeof(struct heartbeat));
  89         if (!hb) return NULL;
  90
  91         hb->ttl = get_opt_int("ecmascript.max_exec_time", ses);
  92         hb->interpreter = interpreter;
  93
  94         add_to_list(heartbeats, hb);
  95
  96         /* Update the heartbeat timer. */
  97         if (list_is_singleton(*hb)) {
  98                 heartbeat_timer.it_value.tv_sec = 1;
  99                 setitimer(ITIMER_VIRTUAL, &heartbeat_timer, NULL);
 100         }
 101
 102         /* We install the handler every call to add_heartbeat instead of only on
 103          * module initialisation because other code may set other handlers for
 104          * the signal.  */
 105         install_signal_handler(SIGVTALRM, check_heartbeats, NULL, 1);
 106
 107         return hb;
 108 }
 109
 110 /* Destroy the given heartbeat. */
 111 void
 112 done_heartbeat(struct heartbeat *hb)
 113 {
 114         if (!hb) return; /* add_heartbeat returned NULL */
 115         assert(hb->interpreter);
 116
 117         /* Stop the heartbeat timer if this heartbeat is the only one. */
 118         if (list_is_singleton(*hb)) {
 119                 heartbeat_timer.it_value.tv_sec = 0;
 120                 setitimer(ITIMER_VIRTUAL, &heartbeat_timer, NULL);
 121         }
 122
 123         del_from_list(hb);
 124         hb->interpreter->heartbeat = NULL;
 125         mem_free(hb);
 126 }