usertrace fast work
[lttv.git] / usertrace-fast / ltt-usertrace-fast.c
index cb1316951f101692dd6a71e6353a0c7859662e0e..9e9596d55675b9fd32911ea4b2311dfd17b37dec 100644 (file)
 
 #include "ltt-usertrace-fast.h"
 
-/* TLS for the trace buffer
- * http://www.dis.com/gnu/gcc/C--98-Thread-Local-Edits.html
- *
- * Add after paragraph 4
- *
- *     The storage for an object of thread storage duration shall be statically
- *     initialized before the first statement of the thread startup function. An
- *     object of thread storage duration shall not require dynamic
- *     initialization.
- */
-#if 0
-__thread struct ltt_trace_info ltt_trace_info =
-{
-       .init = 0,
-       .filter = 0,
-       .nesting = ATOMIC_INIT(0),
-       .channel.facilities = 
-               {       ATOMIC_INIT(0),
-                       ATOMIC_INIT(0),
-                       ATOMIC_INIT(0),
-                       ATOMIC_INIT(0)
-               },
-       .channel.cpu = 
-               { ATOMIC_INIT(0),
-                       ATOMIC_INIT(0),
-                       ATOMIC_INIT(0),
-                       ATOMIC_INIT(0)
-               },
-};
-#endif //0
 
-__thread struct ltt_trace_info *thread_trace_info = NULL;
+/* Writer (the traced application) */
 
+__thread struct ltt_trace_info *thread_trace_info = NULL;
 
-/* signal handling */
+void ltt_usertrace_fast_buffer_switch(void)
+{
+       kill(thread_trace_info->daemon_id, SIGUSR1);
+}
 
-static void handler(int signo)
+static void ltt_usertrace_fast_cleanup(void *arg)
 {
-       printf("Signal %d received\n", signo);
+       kill(thread_trace_info->daemon_id, SIGUSR2);
 }
 
+/* Reader (the disk dumper daemon) */
 
+static pid_t ppid = 0;
+static int parent_exited = 0;
 
-void ltt_usertrace_fast_buffer_switch(void)
+/* signal handling */
+static void handler_sigusr1(int signo)
 {
-       kill(thread_trace_info->daemon_id, SIGUSR1);
+       printf("LTT Signal %d received : parent buffer switch.\n", signo);
+}
+
+static void handler_sigusr2(int signo)
+{
+       printf("LTT Signal %d received : parent exited.\n", signo);
+       parent_exited = 1;
 }
 
+static void handler_sigalarm(int signo)
+{
+       printf("LTT Signal %d received\n", signo);
+
+       if(getppid() != ppid) {
+               /* Parent died */
+               printf("LTT Parent %lu died, cleaning up\n", ppid);
+               ppid = 0;
+       }
+       alarm(3);
+}
+
+
+/* This function is called by ltt_thread_init which has signals blocked */
 static void ltt_usertrace_fast_daemon(struct ltt_trace_info *shared_trace_info,
                sigset_t oldset)
 {
        struct sigaction act;
        int ret;
 
-       printf("ltt_usertrace_fast_daemon : init is %d, pid is %lu\n",
+       ppid = getppid();
+
+       printf("LTT ltt_usertrace_fast_daemon : init is %d, pid is %lu\n",
                        shared_trace_info->init, getpid());
 
-       act.sa_handler = handler;
+       act.sa_handler = handler_sigusr1;
        act.sa_flags = 0;
        sigemptyset(&(act.sa_mask));
        sigaddset(&(act.sa_mask), SIGUSR1);
        sigaction(SIGUSR1, &act, NULL);
+
+       act.sa_handler = handler_sigusr2;
+       act.sa_flags = 0;
+       sigemptyset(&(act.sa_mask));
+       sigaddset(&(act.sa_mask), SIGUSR2);
+       sigaction(SIGUSR2, &act, NULL);
+
+       act.sa_handler = handler_sigalarm;
+       act.sa_flags = 0;
+       sigemptyset(&(act.sa_mask));
+       sigaddset(&(act.sa_mask), SIGALRM);
+       sigaction(SIGALRM, &act, NULL);
+
        /* Enable signals */
        ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
        if(ret) {
-               printf("Error in pthread_sigmask\n");
+               printf("LTT Error in pthread_sigmask\n");
        }
 
+       alarm(3);
+
        while(1) {
                pause();
-               printf("Doing a buffer switch read. pid is : %lu\n", getpid());
+               if(ppid == 0) break; /* parent died */
+               if(parent_exited) break;
+               printf("LTT Doing a buffer switch read. pid is : %lu\n", getpid());
+               //printf("Test parent. pid is : %lu, ppid is %lu\n", getpid(), getppid());
        }
 
+       /* Buffer force switch (flush) */
+       //TODO
+       
+       /* The parent thread is dead and we have finished with the buffer */
+       munmap(shared_trace_info, sizeof(*shared_trace_info));
+       
+       exit(0);
 }
 
-void ltt_thread_init(void)
+
+/* Reader-writer initialization */
+
+static enum ltt_process_role { LTT_ROLE_WRITER, LTT_ROLE_READER }
+       role = LTT_ROLE_WRITER;
+
+
+void ltt_rw_init(void)
 {
        pid_t pid;
        struct ltt_trace_info *shared_trace_info;
@@ -141,13 +173,13 @@ void ltt_thread_init(void)
        /* Disable signals */
   ret = sigfillset(&set);
   if(ret) {
-    printf("Error in sigfillset\n");
+    printf("LTT Error in sigfillset\n");
   } 
        
        
   ret = pthread_sigmask(SIG_BLOCK, &set, &oldset);
   if(ret) {
-    printf("Error in pthread_sigmask\n");
+    printf("LTT Error in pthread_sigmask\n");
   }
        
        pid = fork();
@@ -158,29 +190,40 @@ void ltt_thread_init(void)
                /* Enable signals */
                ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
                if(ret) {
-                       printf("Error in pthread_sigmask\n");
+                       printf("LTT Error in pthread_sigmask\n");
                }
        } else if(pid == 0) {
                /* Child */
+               role = LTT_ROLE_READER;
                ltt_usertrace_fast_daemon(shared_trace_info, oldset);
                /* Should never return */
                exit(-1);
        } else if(pid < 0) {
                /* fork error */
-               perror("Error in forking ltt-usertrace-fast");
+               perror("LTT Error in forking ltt-usertrace-fast");
        }
 }
 
+static __thread struct _pthread_cleanup_buffer cleanup_buffer;
+
+void ltt_thread_init(void)
+{
+       _pthread_cleanup_push(&cleanup_buffer, ltt_usertrace_fast_cleanup, NULL);
+       ltt_rw_init();
+}
+       
 void __attribute__((constructor)) __ltt_usertrace_fast_init(void)
 {
   printf("LTT usertrace-fast init\n");
 
-       ltt_thread_init();
+       ltt_rw_init();
 }
 
 void __attribute__((destructor)) __ltt_usertrace_fast_fini(void)
 {
-  printf("LTT usertrace-fast fini\n");
-
+       if(role == LTT_ROLE_WRITER) {
+         printf("LTT usertrace-fast fini\n");
+               ltt_usertrace_fast_cleanup(NULL);
+       }
 }
 
This page took 0.031941 seconds and 4 git commands to generate.