src/lib/daemon.c in trema-0.4.3 vs src/lib/daemon.c in trema-0.4.4

@@ -32,10 +32,12 @@
 #include "wrapper.h"
 
 
 #ifdef UNIT_TESTING
 
+#define static
+
 #ifdef die
 #undef die
 #endif
 #define die mock_die
 void mock_die( const char *format, ... );
@@ -134,25 +136,22 @@
 #undef basename
 #endif // basename
 #define basename mock_basename
 extern char *mock_basename( char *path );
 
-#ifdef rename
-#undef rename
-#endif // rename
-#define rename mock_rename
-extern int mock_rename( const char *oldpath, const char *newpath );
-
 #ifdef warn
 #undef warn
 #endif // warn
 #define warn mock_warn
 extern void mock_warn( const char *format, ... );
 
 #endif // UNIT_TESTING
 
+static const char SWITCH_DAEMON[] = "switch.";
+static const char SWITCH_DAEMON_EXE_NAME[] = "switch";
 
+
 void
 daemonize( const char *home ) {
   assert( home != NULL );
 
   char buf[ 256 ];
@@ -183,35 +182,43 @@
 }
 
 
 static const int PID_STRING_LENGTH = 10;
 
+static int locked_fd = -1;
+
 void
 write_pid( const char *directory, const char *name ) {
   assert( directory != NULL );
   assert( name != NULL );
 
   char path[ PATH_MAX ];
   snprintf( path, PATH_MAX, "%s/%s.pid", directory, name );
   path[ PATH_MAX - 1 ] = '\0';
 
-  int fd = open( path, O_RDWR | O_CREAT, 0600 );
-  if ( fd == -1 ) {
+  if ( locked_fd > -1 ) {
+    close(locked_fd);
+    locked_fd = -1;
+  }
+
+  locked_fd = open( path, O_RDWR | O_CREAT, 0600 );
+  if ( locked_fd == -1 ) {
     die( "Could not create a PID file: %s", path );
   }
 
-  if ( lockf( fd, F_TLOCK, 0 ) == -1 ) {
+  if ( lockf( locked_fd, F_TLOCK, 0 ) == -1 ) {
     die( "Could not acquire a lock on a PID file: %s", path );
   }
 
   char str[ PID_STRING_LENGTH ];
   snprintf( str, sizeof( str ), "%d\n", getpid() );
   str[ sizeof( str ) - 1 ] = '\0';
-  ssize_t ret = write( fd, str, strlen( str ) );
+  ssize_t ret = write( locked_fd, str, strlen( str ) );
   if ( ret == -1 ) {
     die( "Could not write a PID file: %s", path );
   }
+  debug( "Write pid file ( file = %s, pid = %d )", path, getpid() );
 }
 
 
 void
 unlink_pid( const char *directory, const char *name ) {
@@ -222,12 +229,18 @@
   snprintf( path, PATH_MAX, "%s/%s.pid", directory, name );
   path[ PATH_MAX - 1 ] = '\0';
 
   int ret = unlink( path );
   if ( ret < 0 ) {
-    die( "Could not remove a PID file: %s", path );
+    if ( errno == ENOENT ) {
+      warn( "PID file %s does not exist", path );
+    }
+    else {
+      die( "Could not remove a PID file: %s", path );
+    }
   }
+  debug( "Unlink pid file ( file = %s, pid = %d )", path, getpid() );
 }
 
 
 pid_t
 read_pid( const char *directory, const char *name ) {
@@ -293,10 +306,15 @@
   char *exe_name = basename( exe_path );
   if ( strcmp( name, exe_name ) == 0 ) {
     return pid;
   }
 
+  if ( strncmp( name, SWITCH_DAEMON, strlen( SWITCH_DAEMON ) ) == 0 &&
+       strcmp( exe_name, SWITCH_DAEMON_EXE_NAME ) == 0 ) {
+    return pid;
+  }
+
   // check if -n (service_name) option is used
   sprintf( proc_path, "/proc/%d/cmdline", pid );
   fd = open( proc_path, O_RDONLY, 0 );
   if ( fd < 0 ) {
     warn( "Failed to open %s ( %s [%d] ).", proc_path, strerror( errno ), errno );
@@ -377,21 +395,18 @@
 rename_pid( const char *directory, const char *old, const char *new ) {
   assert( directory != NULL );
   assert( old != NULL );
   assert( new != NULL );
 
-  char old_path[ PATH_MAX ];
-  snprintf( old_path, PATH_MAX, "%s/%s.pid", directory, old );
-  old_path[ PATH_MAX - 1 ] = '\0';
-  char new_path[ PATH_MAX ];
-  snprintf( new_path, PATH_MAX, "%s/%s.pid", directory, new );
-  new_path[ PATH_MAX - 1 ] = '\0';
+  assert( locked_fd > -1 );
 
-  unlink( new_path );
-  int ret = rename( old_path, new_path );
-  if ( ret < 0 ) {
-    die( "Could not rename a PID file from %s to %s.", old_path, new_path );
-  }
+  int old_locked_fd = locked_fd;
+  locked_fd = -1;
+  write_pid( directory, new );
+  close( old_locked_fd );
+  unlink_pid( directory, old );
+
+  debug( "Rename pid file ( old name = %s, new name = %s, pid = %d )", old, new, getpid() );
 }
 
 
 /*
  * Local variables: