T: simplify

Don't use shm anymore. Use mmap directly.

common/utils/T/T.c

@@ -91,7 +91,7 @@ static void new_thread(void *(*f)(void *), void *data)
 
 /* defined in local_tracer.c */
 void T_local_tracer_main(int remote_port, int wait_for_tracer,
-    int local_socket, char *shm_file);
+    int local_socket, void *shm_array);
 
 /* We monitor the tracee and the local tracer processes.
  * When one dies we forcefully kill the other.
@@ -114,22 +114,31 @@ void T_init(int remote_port, int wait_for_tracer, int dont_fork)
 {
   int socket_pair[2];
   int s;
-  int T_shm_fd;
   int child1, child2;
-  char shm_file[128];
-
-  sprintf(shm_file, "/%s%d", T_SHM_FILENAME, getpid());
+  int i;
 
   if (socketpair(AF_UNIX, SOCK_STREAM, 0, socket_pair))
     { perror("socketpair"); abort(); }
 
+  /* setup shared memory */
+  T_cache = mmap(NULL, T_CACHE_SIZE * sizeof(T_cache_t),
+                 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+  if (T_cache == MAP_FAILED)
+    { perror("mmap"); abort(); }
+
+  /* let's garbage the memory to catch some potential problems
+   * (think multiprocessor sync issues, barriers, etc.)
+   */
+  memset(T_cache, 0x55, T_CACHE_SIZE * sizeof(T_cache_t));
+  for (i = 0; i < T_CACHE_SIZE; i++) T_cache[i].busy = 0;
+
   /* child1 runs the local tracer and child2 (or main) runs the tracee */
 
   child1 = fork(); if (child1 == -1) abort();
   if (child1 == 0) {
     close(socket_pair[1]);
     T_local_tracer_main(remote_port, wait_for_tracer, socket_pair[0],
-                        shm_file);
+                        T_cache);
     exit(0);
   }
   close(socket_pair[0]);
@@ -138,6 +147,7 @@ void T_init(int remote_port, int wait_for_tracer, int dont_fork)
     child2 = fork(); if (child2 == -1) abort();
     if (child2 != 0) {
       close(socket_pair[1]);
+      munmap(T_cache, T_CACHE_SIZE * sizeof(T_cache_t));
       monitor_and_kill(child1, child2);
     }
   }
@@ -148,34 +158,29 @@ void T_init(int remote_port, int wait_for_tracer, int dont_fork)
 
   T_socket = s;
 
-  /* setup shared memory */
-  T_shm_fd = shm_open(shm_file, O_RDWR /*| O_SYNC*/, 0666);
-  shm_unlink(shm_file);
-  if (T_shm_fd == -1) { perror(shm_file); abort(); }
-  T_cache = mmap(NULL, T_CACHE_SIZE * sizeof(T_cache_t),
-                 PROT_READ | PROT_WRITE, MAP_SHARED, T_shm_fd, 0);
-  if (T_cache == MAP_FAILED)
-    { perror(shm_file); abort(); }
-  close(T_shm_fd);
-
   new_thread(T_receive_thread, NULL);
 }
 
 void T_Config_Init(void)
 {
-int T_port;            /* by default we wait for the tracer */
-int T_nowait;	      /* default port to listen to to wait for the tracer */
-int T_dont_fork;       /* default is to fork, see 'T_init' to understand */
+  int T_port;         /* by default we wait for the tracer */
+  int T_nowait;	      /* default port to listen to to wait for the tracer */
+  int T_dont_fork;    /* default is to fork, see 'T_init' to understand */
 
-paramdef_t ttraceparams[] = CMDLINE_TTRACEPARAMS_DESC ;
+  paramdef_t ttraceparams[] = CMDLINE_TTRACEPARAMS_DESC;
 
-/* for a cleaner config file, TTracer params should be defined in a specific section... */
-  config_get( ttraceparams,sizeof(ttraceparams)/sizeof(paramdef_t),TTRACER_CONFIG_PREFIX);
+  /* for a cleaner config file, TTracer params should be defined in a
+   * specific section...
+   */
+  config_get(ttraceparams,
+             sizeof(ttraceparams) / sizeof(paramdef_t),
+             TTRACER_CONFIG_PREFIX);
 
-/* compatibility: look for TTracer command line options in root section */
-  config_process_cmdline( ttraceparams,sizeof(ttraceparams)/sizeof(paramdef_t),NULL);
+  /* compatibility: look for TTracer command line options in root section */
+  config_process_cmdline(ttraceparams,
+                         sizeof(ttraceparams) / sizeof(paramdef_t),
+                         NULL);
 
-  if (T_stdout == 0) {
+  if (T_stdout == 0)
     T_init(T_port, 1-T_nowait, T_dont_fork);
-  }
 }

common/utils/T/T_defs.h

@@ -36,8 +36,6 @@ typedef struct {
   int length;
 } T_cache_t;
 
-#define T_SHM_FILENAME "/T_shm_segment"
-
 /* number of VCD functions (to be kept up to date! see in T_messages.txt) */
 #define VCD_NUM_FUNCTIONS 190
 

common/utils/T/local_tracer.c

@@ -340,51 +340,31 @@ static void wait_message(void)
   while (T_local_cache[T_busylist_head].busy == 0) usleep(1000);
 }
 
-static void init_shm(char *shm_file)
-{
-  int i;
-  int s = shm_open(shm_file, O_RDWR | O_CREAT /*| O_SYNC*/, 0666);
-  if (s == -1) { perror(shm_file); abort(); }
-  if (ftruncate(s, T_CACHE_SIZE * sizeof(T_cache_t)))
-    { perror(shm_file); abort(); }
-  T_local_cache = mmap(NULL, T_CACHE_SIZE * sizeof(T_cache_t),
-                       PROT_READ | PROT_WRITE, MAP_SHARED, s, 0);
-  if (T_local_cache == MAP_FAILED)
-    { perror(shm_file); abort(); }
-  close(s);
-
-  /* let's garbage the memory to catch some potential problems
-   * (think multiprocessor sync issues, barriers, etc.)
-   */
-  memset(T_local_cache, 0x55, T_CACHE_SIZE * sizeof(T_cache_t));
-  for (i = 0; i < T_CACHE_SIZE; i++) T_local_cache[i].busy = 0;
-}
-
 void T_local_tracer_main(int remote_port, int wait_for_tracer,
-    int local_socket, char *shm_file)
+    int local_socket, void *shm_array)
 {
   int s;
   int port = remote_port;
   int dont_wait = wait_for_tracer ? 0 : 1;
   void *f;
-  printf("local tracer starting\n");
+
   /* write on a socket fails if the other end is closed and we get SIGPIPE */
-  if (signal(SIGPIPE, SIG_IGN) == SIG_ERR){
+  if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
        printf("local tracer received SIGPIPE\n");
        abort();
   }
 
-  init_shm(shm_file);
+  T_local_cache = shm_array;
+
   s = local_socket;
-  printf("local tracer starting step 2\n");
+
   if (dont_wait) {
     char t = 2;
-  printf("local tracer in no wait mode \n");
     if (write(s, &t, 1) != 1) abort();
   }
-  printf("local tracer starting step 3\n");
+
   f = forwarder(port, s);
-  printf("local tracer main loop.... \n");
+
   /* read messages */
   while (1) {
     wait_message();