Avoid to stick on event loop

When working synchronously, waiting continuously
to an event can make deadlocks. This commit
enforce threads that wait for some job completion
to wait for a fixed amount of time.

An alternative management with signals should
be studied in future.

Change-Id: Idcfadc60f8c14d73d7fa32e937c6ea0f552cc09b
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

diff --git a/src/jobs.c b/src/jobs.c
index fa94ef1..1ed20fc 100644 (file)
--- a/src/jobs.c
+++ b/src/jobs.c
@@ -18,6 +18,7 @@
 #define _GNU_SOURCE
 
 #include <stdlib.h>
+#include <stdint.h>
 #include <unistd.h>
 #include <signal.h>
 #include <time.h>
@@ -39,6 +40,9 @@
 #define sig_monitor(to,cb,arg)       (cb(0,arg))
 #endif
 
+#define EVENT_TIMEOUT_TOP      ((uint64_t)-1)
+#define EVENT_TIMEOUT_CHILD    ((uint64_t)10000)
+
 /** Internal shortcut for callback */
 typedef void (*job_cb_t)(int, void*, void *, void*);
 
@@ -61,6 +65,7 @@ struct events
 {
        struct events *next;
        struct sd_event *event;
+       uint64_t timeout;
        unsigned runs: 1;
 };
 
@@ -276,7 +281,7 @@ static void events_call(int signum, void *arg)
 {
        struct events *events = arg;
        if (!signum)
-               sd_event_run(events->event, (uint64_t) -1);
+               sd_event_run(events->event, events->timeout);
 }
 
 /**
@@ -291,6 +296,7 @@ static void thread_run(volatile struct thread *me)
        struct thread **prv;
        struct job *job;
        struct events *events;
+       uint64_t evto;
 
        /* initialize description of itself and link it in the list */
        me->tid = pthread_self();
@@ -300,9 +306,11 @@ static void thread_run(volatile struct thread *me)
        me->upper = current;
        if (current) {
                current->lowered = 1;
+               evto = EVENT_TIMEOUT_CHILD;
        } else {
                started++;
                sig_monitor_init_timeouts();
+               evto = EVENT_TIMEOUT_TOP;
        }
        me->next = threads;
        threads = (struct thread*)me;
@@ -341,6 +349,7 @@ static void thread_run(volatile struct thread *me)
                        if (events) {
                                /* run the events */
                                events->runs = 1;
+                               events->timeout = evto;
                                me->events = events;
                                pthread_mutex_unlock(&mutex);
                                sig_monitor(0, events_call, events);