Make sure all internal file descriptors are closed when spawning children

darcs-hash:20051003130937-ac50b-95fb750b3c26f1c03a2a877770bbeee536ea3b74.gz

env.c

@@ -164,11 +164,10 @@ static int get_names_show_unexported;
 
 /**
    When fishd isn't started, this function is provided to
-   env_universal as a callback, it tries to start upå fishd. It's
-   implementation is a bit of a hack, since it just calls a bit of
-   shellscript, and the shell is not properly initialized ad this
-   point. Should be changed to deferr the evaluation until fish has
-   been properly initialized.
+   env_universal as a callback, it tries to start up fishd. It's
+   implementation is a bit of a hack, since it evaluates a bit of
+   shellscript, and it might be used at times when that might not be
+   the best idea.
 */
 static void start_fishd()
 {

env_universal.c

@@ -167,6 +167,21 @@ static void check_connection()
 	}	
 }
 
+static void reconnect()
+{
+	if( get_socket_count >= RECONNECT_COUNT )
+		return 0;
+	
+	debug( 2, L"Get new fishd connection" );
+	
+	init = 0;
+	env_universal_server.fd = get_socket(1);
+	init = 1;
+	if( env_universal_server.fd >= 0 )
+	{
+		env_universal_barrier();
+	}
+}
 
 
 void env_universal_init( wchar_t * p, wchar_t *u, void (*sf)() )
@@ -223,20 +238,7 @@ int env_universal_read_all()
 
 	if( env_universal_server.fd == -1 )
 	{
-		
-		if( get_socket_count >= RECONNECT_COUNT )
-			return 0;
-
-		debug( 2, L"Get new fishd connection" );
-		
-		init = 0;
-		env_universal_server.fd = get_socket(1);
-		init = 1;
-
-		if( env_universal_server.fd >= 0 )
-		{
-			env_universal_barrier();
-		}
+		reconnect();		
 	}
 	
 	if( env_universal_server.fd != -1 )
@@ -296,6 +298,13 @@ void env_universal_barrier()
 		
 		if( q_empty( &env_universal_server.unsent ) )
 			break;
+		
+		if( env_universal_server.fd == -1 )
+		{
+			reconnect();
+			return;			
+		}
+		
 		FD_ZERO( &fds );
 		FD_SET( env_universal_server.fd, &fds );
 		select( env_universal_server.fd+1, 0, &fds, 0, 0 );
@@ -307,6 +316,11 @@ void env_universal_barrier()
 	debug( 3, L"Sent barrier request" );
 	while( !barrier_reply )
 	{
+		if( env_universal_server.fd == -1 )
+		{
+			reconnect();
+			return;			
+		}		
 		FD_ZERO( &fds );
         FD_SET( env_universal_server.fd, &fds );		
         select( env_universal_server.fd+1, &fds, 0, 0, 0 );

exec.c

@@ -61,9 +61,21 @@ pid_t getpgid( pid_t pid );
 */
 #define FORK_ERROR L"Could not create child process - exiting"
 
+/**
+   List of all pipes used by internal pipes. These must be closed in
+   many situations in order to make sure that stray fds aren't lying
+   around.
+*/
+array_list_t *open_fds=0;
 
+/**
+   Loops over close until thesyscall was run without beeing
+   interrupted. Thenremoves the fd from the open_fds list.
+*/
 static void close_loop( int fd )
 {
+	int i;
+	
 	while( close(fd) == -1 )
 	{
 		if( errno != EINTR )
@@ -72,6 +84,115 @@ static void close_loop( int fd )
 			wperror( L"close" );
 		}
 	}
+
+	if( open_fds )
+	{
+		for( i=0; i<al_get_count( open_fds ); i++ )
+		{
+			int n = (int)(long)al_get( open_fds, i );
+			if( n == fd )
+			{
+				al_set( open_fds,
+						i,
+						al_get( open_fds,
+								al_get_count( open_fds ) -1 ) );
+				al_truncate( open_fds, 
+							 al_get_count( open_fds ) -1 );
+				break;
+			}
+		}
+	}
+
+}
+
+/**
+   Call pipe(), and add resulting fds to open_fds, the list of opend
+   file descriptors for pipes.
+*/
+static int internal_pipe( int fd[2])
+{
+	int res = pipe( fd );
+	if( open_fds == 0 )
+	{
+		open_fds = malloc( sizeof( array_list_t ) );
+		if(!open_fds )
+			die_mem();
+		al_init( open_fds );
+	}
+	
+	if( res != -1 )
+	{
+		debug( 1, L"Created pipe using fds %d and %d", fd[0], fd[1]);
+		
+		al_push( open_fds, (void *)(long)fd[0] );
+		al_push( open_fds, (void *)(long)fd[1] );		
+	}
+	return res;
+}
+
+/**
+   Check if the specified fd is used as a part of a pipeline in the
+   specidied set of IO redirections.
+
+   \param fd the fd to search for
+   \param io the set of io redirections to search in
+*/
+static int use_fd_in_pipe( int fd, io_data_t *io )
+{	
+	if( !io )
+		return 0;
+	
+	if( (io->io_mode == IO_PIPE) || 
+		(io->io_mode == IO_BUFFER) )
+	{
+		if( io->pipe_fd[0] == fd ||
+			io->pipe_fd[1] == fd )
+			return 1;
+	}
+	
+	return use_fd_in_pipe( fd, io->next );
+}
+
+
+/**
+   Close all fds in open_fds, except for those that are mentioned in
+   the redirection list io
+
+   \param io the list of io redirections for this job. Pipes mentioned here should not be closed.
+*/
+static void close_unused_internal_pipes( io_data_t *io )
+{
+	int i=0;
+	
+	if( open_fds )
+	{
+		for( ;i<al_get_count( open_fds ); i++ )
+		{
+			int n = (int)(long)al_get( open_fds, i );
+			if( !use_fd_in_pipe( n, io) )
+			{
+				debug( 1, L"Close fd %d, used in other context", n );
+				close_loop( n );
+				i--;
+			}
+			else
+				debug( 1, L"Don't close fd %d, used in this context", n );
+		}
+	}
+}
+
+void exec_init()
+{
+	
+}
+
+void exec_destroy()
+{
+	if( open_fds )
+	{
+		al_destroy( open_fds );
+		free( open_fds );
+	}
 }
 
 
@@ -115,6 +236,8 @@ void free_fd( io_data_t *io, int fd )
 static void handle_child_io( io_data_t *io )
 {
 
+	close_unused_internal_pipes( io );
+	
 	if( env_universal_server.fd >= 0 )
 		close_loop( env_universal_server.fd );
 
@@ -309,7 +432,8 @@ static void launch_process( process_t *p )
 
 
 /**
-   Check if the IO redirection chains contains redirections for the specified file descriptor
+   Check if the IO redirection chains contains redirections for the
+   specified file descriptor
 */
 
 static int has_fd( io_data_t *d, int fd )
@@ -328,13 +452,12 @@ void exec_read_io_buffer( io_data_t *d )
 	
 	if( d->io_mode == IO_BUFFER )
 	{		
-/*		if( fcntl( d->pipe_fd[0], F_SETFL, 0 ) )
+		if( fcntl( d->pipe_fd[0], F_SETFL, 0 ) )
 		{
 			wperror( L"fcntl" );
 			return;
-		}
-*/	
-		debug( 3, L"exec_read_io_buffer: blocking read on fd %d", d->pipe_fd[0] );
+		}	
+		debug( 1, L"exec_read_io_buffer: blocking read on fd %d", d->pipe_fd[0] );
 		
 		while(1)
 		{
@@ -384,7 +507,7 @@ io_data_t *exec_make_io_buffer()
 	buffer_redirect->fd=1;
 
 
-	if( pipe( buffer_redirect->pipe_fd ) == -1 )
+	if( internal_pipe( buffer_redirect->pipe_fd ) == -1 )
 	{
 		debug( 1, PIPE_ERROR );
 		wperror (L"pipe");
@@ -411,7 +534,8 @@ void exec_free_io_buffer( io_data_t *io_buffer )
 	close_loop( io_buffer->pipe_fd[0] );
 
 	/*
-	  Dont free fd for writing. This should already be free'd before calling exec_read_io_buffer on the buffer
+	  Dont free fd for writing. This should already be free'd before
+	  calling exec_read_io_buffer on the buffer
 	*/
 	
 	b_destroy( io_buffer->out_buffer );
@@ -655,14 +779,12 @@ void exec( job_t *j )
 	sigaddset( &chldset, SIGCHLD );
 	int skip_fork;
 	
-	/* This call is used so the global environment variable array is regenerated, if needed, before the fork. That way, we avoid a lot of duplicate work where EVERY child would need to generate it */
-
 	io_data_t pipe_read, pipe_write;
 	io_data_t *tmp;
 
 	io_data_t *io_buffer =0;
 		
-	debug( 3, L"Exec job %ls with id %d", j->command, j->job_id );	
+	debug( 1, L"Exec job %ls with id %d", j->command, j->job_id );	
 	
 	if( j->first_process->type==INTERNAL_EXEC )
 	{
@@ -702,9 +824,16 @@ void exec( job_t *j )
 		mypipe[1]=-1;
 		skip_fork=0;
 
+		/* 
+		   This call is used so the global environment variable array is
+		   regenerated, if needed, before the fork. That way, we avoid a
+		   lot of duplicate work where EVERY child would need to generate
+		   it
+		*/
 		if( p->type == EXTERNAL )
 			env_export_arr( 1 );
 		
+		
 		/*
 		  Set up fd:s that will be used in the pipe 
 		*/
@@ -716,7 +845,7 @@ void exec( job_t *j )
 		
 		if (p->next)
 		{
-			if (pipe( mypipe ) == -1)
+			if (internal_pipe( mypipe ) == -1)
 			{
 				debug( 1, PIPE_ERROR );
 				wperror (L"pipe");
@@ -1233,4 +1362,3 @@ int exec_subshell( const wchar_t *cmd,
 	exec_free_io_buffer( io_buffer );
 	return status;	
 }
-

exec.h

@@ -2,6 +2,17 @@
 	Prototypes for functions for executing a program
 */
 
+/**
+   Initialize the exec library
+*/
+void exec_init();
+
+/*
+  Destroy dynamically allocated data and other resources used by the
+  exec library
+*/
+void exec_destroy();
+
 /**
   Execute the processes specified by j. 
 

fish_tests.c

@@ -614,13 +614,14 @@ int main( int argc, char **argv )
 
 	say( L"Testing low-level functionality");
 	say( L"Lines beginning with 'fish:' are not errors, they are warning messages\ngenerated by the fish parser library when given broken input, and can be\nignored. All errors begin with 'Error:'." );
-	
+
+	exec_init();	
 	parser_init();
 	function_init();
 	builtin_init();
-	env_init();
 	complete_init();
 	reader_init();
+	env_init();
 	
 	test_util();
 	test_tok();
@@ -635,13 +636,13 @@ int main( int argc, char **argv )
 //	say( L"Testing performance" );
 //	perf_complete();
 		
-	reader_destroy();
-	
+	env_destroy();
+	reader_destroy();	
 	parser_destroy();
 	function_destroy();
 	builtin_destroy();
-	env_destroy();
 	complete_destroy();
 	wutil_destroy();
+	exec_destroy();
 	
 }

main.c

@@ -205,7 +205,8 @@ int main( int argc, char **argv )
 
 	if( force_interactive )
 		is_interactive_session=1;	
-	
+
+	exec_init();	
 	parser_init();
 	builtin_init();
 	function_init();
@@ -299,6 +300,7 @@ int main( int argc, char **argv )
 	parser_destroy();
 	wutil_destroy();
 	common_destroy();
+	exec_destroy();	
 	
 	intern_free_all();
 

parser.h

@@ -117,7 +117,7 @@ extern block_t *current_block;
 extern int error_code;
 
 /**
-   Current block level redirections 
+   Current block level io redirections 
 */
 extern io_data_t *block_io;