ust: be able to list markers using ust

[lttng-ust.git] / libtracectl / tracectl.c

diff --git a/libtracectl/tracectl.c b/libtracectl/tracectl.c
index aca3abc207ae81ad60067778e717a7c11b3ebe92..04de9f39be695194187f7c7b816091990aed67c1 100644 (file)
--- a/libtracectl/tracectl.c
+++ b/libtracectl/tracectl.c
@@ -4,6 +4,10 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <sched.h>
+
+#include "marker.h"
+
 #define UNIX_PATH_MAX 108
 
 //#define SOCKETDIR "/var/run/ust/socks"
@@ -16,14 +20,46 @@
 #define ERR(fmt, args...) fprintf(stderr, "usertrace: ERROR: " fmt "\n", ## args)
 #define PERROR(call) perror("usertrace: ERROR: " call)
 
+#define MAX_MSG_SIZE (100)
+#define MSG_NOTIF 1
+#define MSG_REGISTER_NOTIF 2
+
 struct tracecmd { /* no padding */
        uint32_t size;
        uint16_t command;
 };
 
+//struct listener_arg {
+//     int pipe_fd;
+//};
+
+struct trctl_msg {
+       /* size: the size of all the fields except size itself */
+       uint32_t size;
+       uint16_t type;
+       /* Only the necessary part of the payload is transferred. It
+         * may even be none of it.
+         */
+       char payload[94];
+};
 
 pid_t mypid;
 char mysocketfile[UNIX_PATH_MAX] = "";
+int pfd = -1;
+
+
+static void print_markers(void)
+{
+       struct marker_iter iter;
+
+       marker_iter_reset(&iter);
+       marker_iter_start(&iter);
+
+       while(iter.marker) {
+               fprintf(stderr, "marker: %s_%s \"%s\"\n", iter.marker->channel, iter.marker->name, iter.marker->format);
+               marker_iter_next(&iter);
+       }
+}
 
 void do_command(struct tracecmd *cmd)
 {
@@ -33,22 +69,102 @@ void receive_commands()
 {
 }
 
+int fd_notif = -1;
+void notif_cb(void)
+{
+       int result;
+       struct trctl_msg msg;
+
+       /* FIXME: fd_notif should probably be protected by a spinlock */
+
+       if(fd_notif == -1)
+               return;
+
+       msg.type = MSG_NOTIF;
+       msg.size = sizeof(msg.type);
+
+       /* FIXME: don't block here */
+       result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
+       if(result == -1) {
+               PERROR("write");
+               return;
+       }
+}
+
+char recvbuf[10000];
+
+int listener_main(void *p)
+{
+       int result;
+
+       for(;;) {
+               uint32_t size;
+               struct sockaddr_un addr;
+               socklen_t addrlen = sizeof(addr);
+
+               for(;;) {
+                       struct trctl_msg msg;
+                       int len;
+
+                       result = len = recvfrom(pfd, recvbuf, sizeof(recvbuf), 0, &addr, &addrlen);
+                       if(result == -1) {
+                               PERROR("recvfrom");
+                               continue;
+                       }
+
+                       if(recvbuf[len-2] == '\n')
+                               recvbuf[len-2] = '\0';
+
+                       fprintf(stderr, "received a message! it's: %s\n", recvbuf);
+
+
+                       if(!strcmp(recvbuf, "print_markers")) {
+                               print_markers();
+                       }
+                       else if(!strcmp(recvbuf, "trace_setup")) {
+                               DBG("trace setup");
+                       }
+                       else if(!strcmp(recvbuf, "trace_alloc")) {
+                               DBG("trace alloc");
+                       }
+                       else if(!strcmp(recvbuf, "trace_start")) {
+                               DBG("trace start");
+                       }
+                       else if(!strcmp(recvbuf, "trace_stop")) {
+                               DBG("trace stop");
+                       }
+               }
+               next_conn:;
+       }
+}
+
+void create_listener(void)
+{
+       int result;
+       static char listener_stack[16384];
+
+       result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
+       if(result == -1) {
+               perror("clone");
+       }
+}
+
 /* The signal handler itself. */
 
 void sighandler(int sig)
 {
        DBG("sighandler");
-       receive_commands();
+       create_listener();
 }
 
 /* Called by the app signal handler to chain it to us. */
 
-void chain_signal()
+void chain_signal(void)
 {
        sighandler(USTSIGNAL);
 }
 
-int init_socket()
+static int init_socket(void)
 {
        int result;
        int fd;
@@ -57,7 +173,7 @@ int init_socket()
 
        struct sockaddr_un addr;
        
-       result = fd = socket(PF_UNIX, SOCK_SEQPACKET, 0);
+       result = fd = socket(PF_UNIX, SOCK_DGRAM, 0);
        if(result == -1) {
                PERROR("socket");
                return -1;
@@ -80,13 +196,16 @@ int init_socket()
 
        strcpy(mysocketfile, addr.sun_path);
 
+       pfd = fd;
+       return 0;
+
        close_sock:
        close(fd);
 
        return -1;
 }
 
-void destroy_socket()
+static void destroy_socket(void)
 {
        int result;
 
@@ -99,7 +218,7 @@ void destroy_socket()
        }
 }
 
-int init_signal_handler(void)
+static int init_signal_handler(void)
 {
        /* Attempt to handler SIGIO. If the main program wants to
         * handle it, fine, it'll override us. They it'll have to
@@ -130,15 +249,25 @@ int init_signal_handler(void)
        return 0;
 }
 
-void __attribute__((constructor)) init()
+static void __attribute__((constructor)) init()
 {
        int result;
 
        mypid = getpid();
 
-       /* if using instead seperate thread, then should create thread */
-       result = init_signal_handler();
+       /* Must create socket before signal handler to prevent races
+         * on pfd variable.
+         */
        result = init_socket();
+       if(result == -1) {
+               ERR("init_socket error");
+               return;
+       }
+       result = init_signal_handler();
+       if(result == -1) {
+               ERR("init_signal_handler error");
+               return;
+       }
 
        return;
 
@@ -149,7 +278,7 @@ void __attribute__((constructor)) init()
 /* This is only called if we terminate normally, not with an unhandled signal,
  * so we cannot rely on it. */
 
-void __attribute__((destructor)) fini()
+static void __attribute__((destructor)) fini()
 {
        destroy_socket();
 }