disable signals in update function

git-svn-id: http://ltt.polymtl.ca/svn@1500 04897980-b3bd-0310-b5e0-8ef037075253

diff --git a/usertrace/lttng_usertrace.c b/usertrace/lttng_usertrace.c
index 3458e6d51ea37278249d7185bb2deb1bddb6b170..3a85aa9b9b1da17f37a648d669c286329b625a55 100644 (file)
--- a/usertrace/lttng_usertrace.c
+++ b/usertrace/lttng_usertrace.c
@@ -23,6 +23,17 @@
 #define MAX_TRACES 16
 
 
+/*
+ * Notes :
+ *
+ * ltt_update :
+ *
+ * it should send the information on the traces that has their status MODIFIED.
+ * It's a necessary assumption to have a correct lttng_free_trace_info, which
+ * would not be reentrant otherwise.
+ */
+
+
 /* TLS for the trace info
  * http://www.dis.com/gnu/gcc/C--98-Thread-Local-Edits.html
  *
@@ -93,12 +104,52 @@ void lttng_free_trace_info(struct lttng_trace_info *info)
 }
 
 
+static struct lttng_trace_info* find_info(unsigned long cpu_addr,
+               unsigned long fac_addr, unsigned int *first_empty)
+{
+       struct lttng_trace_info *found = NULL;
+       unsigned int i;
+
+       *first_empty = MAX_TRACES;
+
+       /* Try to find the trace */
+       for(i=0;i<MAX_TRACES;i++) {
+               if(i<*first_empty && !lttng_trace_info[i].channel.cpu.start)
+                       *first_empty = i;
+               if(cpu_addr == 
+                               (unsigned long)lttng_trace_info[i].channel.cpu.start &&
+                        fac_addr == 
+                               (unsigned long)lttng_trace_info[i].channel.facilities.start) {
+                       /* Found */
+                       found = &lttng_trace_info[i];
+                       break;
+               }
+       }
+       return found;
+}
+
+
 static void lttng_get_new_info(void)
 {
        unsigned long cpu_addr, fac_addr;
        unsigned int i, first_empty;
        int active, filter, destroy;
        int ret;
+       struct lttng_trace_info *info;
+       sigset_t set, oldset;
+
+       /* Disable signals */
+       ret = sigfillset(&set);
+       if(ret) {
+               printf("Error in sigfillset\n");
+               exit(1);
+       }
+       
+       ret = pthread_sigmask(SIG_BLOCK, &set, &oldset);
+       if(ret) {
+               printf("Error in sigprocmask\n");
+               exit(1);
+       }
 
        /* Get all the new traces */
        while(1) {
@@ -112,27 +163,14 @@ static void lttng_get_new_info(void)
                
                if(!cpu_addr || !fac_addr) break;
                
-               first_empty = MAX_TRACES;
-               /* Try to find the trace */
-               for(i=0;i<MAX_TRACES;i++) {
-                       if(i<first_empty && !lttng_trace_info[i].channel.cpu.start)
-                               first_empty = i;
-                       if(cpu_addr == 
-                                       (unsigned long)lttng_trace_info[i].channel.cpu.start &&
-                                fac_addr == 
-                                       (unsigned long)lttng_trace_info[i].channel.facilities.start) {
-                               /* Found */
-                               lttng_trace_info[i].filter = filter;
-                               lttng_trace_info[i].active = active;
-                               lttng_trace_info[i].destroy = destroy;
-                               if(destroy && !atomic_read(&lttng_trace_info[i].nesting)) {
-                                       lttng_free_trace_info(&lttng_trace_info[i]);
-                               }
-                               break;
-                       }
-
-               }
-               if(i == MAX_TRACES) {
+               info = find_info(cpu_addr, fac_addr, &first_empty);
+               if(info) {
+                       info->filter = filter;
+                       info->active = active;
+                       info->destroy = destroy;
+                       if(destroy && !atomic_read(&info->nesting))
+                               lttng_free_trace_info(info);
+               } else {
                        /* Not found. Must take an empty slot */
                        if(first_empty == MAX_TRACES) {
                                printf(
@@ -141,55 +179,41 @@ static void lttng_get_new_info(void)
                                        getpid(), MAX_TRACES);
 
                        } else {
-                               lttng_trace_info[first_empty].channel.cpu.start = (void*)cpu_addr;
-                               lttng_trace_info[first_empty].channel.cpu.length = PAGE_SIZE;
-                               lttng_trace_info[first_empty].channel.facilities.start =
-                                                                                                                                                                                                                                       (void*)fac_addr;
-                               lttng_trace_info[first_empty].channel.facilities.length = PAGE_SIZE;
-                               lttng_trace_info[first_empty].filter = filter;
-                               lttng_trace_info[first_empty].active = active;
+                               info = &lttng_trace_info[first_empty];
+                               info->channel.cpu.start = (void*)cpu_addr;
+                               info->channel.cpu.length = PAGE_SIZE;
+                               info->channel.facilities.start = (void*)fac_addr;
+                               info->channel.facilities.length = PAGE_SIZE;
+                               info->filter = filter;
+                               info->active = active;
+                               info->destroy = destroy;
+                               if(destroy && !atomic_read(&info->nesting))
+                                       lttng_free_trace_info(info);
                        }
                }
        }
+
+       /* Enable signals */
+       ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+       if(ret) {
+               printf("Error in sigprocmask\n");
+               exit(1);
+       }
 }
 
 
 /* signal handler */
 void __lttng_sig_trace_handler(int signo)
 {
-       int ret;
-       sigset_t set, oldset;
-       
   printf("LTTng signal handler : thread id : %lu, pid %lu\n", pthread_self(), getpid());
-#if 0
-       /* Disable signals */
-       ret = sigfillset(&set);
-       if(ret) {
-               printf("Error in sigfillset\n");
-               exit(1);
-       }
-       
-       ret = sigprocmask(SIG_BLOCK, &set, &oldset);
-       if(ret) {
-               printf("Error in sigprocmask\n");
-               exit(1);
-       }
-#endif //0
-#if 0
-       /* Enable signals */
-       ret = sigprocmask(SIG_SETMASK, &oldset, NULL);
-       if(ret) {
-               printf("Error in sigprocmask\n");
-               exit(1);
-       }
-#endif //0
+       lttng_get_new_info();
 }
 
 
 static void thread_init(void)
 {
-       lttng_get_new_info();
        int err;
+       lttng_get_new_info();
 
        /* Make some ltt_switch syscalls */
        err = ltt_switch((unsigned long)NULL);
@@ -225,6 +249,3 @@ void lttng_thread_init(void)
 }
 
 
-
-
-