re PR fortran/14943 (read/write code generation is not thread safe)

gcc/fortran/
	PR fortran/14943
	PR fortran/21647
	* Make-lang.in (fortran/trans-io.o): Depend on fortran/ioparm.def.
	* dump-parse-tree.c (gfc_show_code_node): Dump c->block for
	EXEC_{READ,WRITE,IOLENGTH} nodes.
	* io.c (terminate_io, match_io, gfc_match_inquire): Put data
	transfer commands into EXEC_{READ,WRITE,IOLENGTH}'s code->block.
	* resolve.c (resolve_blocks): Handle EXEC_{READ,WRITE,IOLENGTH}.
	* trans-io.c (ioparm_unit, ioparm_err, ioparm_end, ioparm_eor,
	ioparm_list_format, ioparm_library_return, ioparm_iostat,
	ioparm_exist, ioparm_opened, ioparm_number, ioparm_named,
	ioparm_rec, ioparm_nextrec, ioparm_size, ioparm_recl_in,
	ioparm_recl_out, ioparm_iolength, ioparm_file, ioparm_file_len,
	ioparm_status, ioparm_status_len, ioparm_access, ioparm_access_len,
	ioparm_form, ioparm_form_len, ioparm_blank, ioparm_blank_len,
	ioparm_position, ioparm_position_len, ioparm_action,
	ioparm_action_len, ioparm_delim, ioparm_delim_len, ioparm_pad,
	ioparm_pad_len, ioparm_format, ioparm_format_len, ioparm_advance,
	ioparm_advance_len, ioparm_name, ioparm_name_len,
	ioparm_internal_unit, ioparm_internal_unit_len,
	ioparm_internal_unit_desc, ioparm_sequential, ioparm_sequential_len,
	ioparm_direct, ioparm_direct_len, ioparm_formatted,
	ioparm_formatted_len, ioparm_unformatted, ioparm_unformatted_len,
	ioparm_read, ioparm_read_len, ioparm_write, ioparm_write_len,
	ioparm_readwrite, ioparm_readwrite_len, ioparm_namelist_name,
	ioparm_namelist_name_len, ioparm_namelist_read_mode, ioparm_iomsg,
	ioparm_iomsg_len, ioparm_var): Remove.
	(enum ioparam_type, enum iofield_type, enum iofield,
	enum iocall): New enums.
	(gfc_st_parameter_field, gfc_st_parameter): New typedefs.
	(st_parameter, st_parameter_field, iocall): New variables.
	(ADD_FIELD, ADD_STRING): Remove.
	(dt_parm, dt_post_end_block): New variables.
	(gfc_build_st_parameter): New function.
	(gfc_build_io_library_fndecls): Use it.  Initialize iocall
	array rather than ioparm_*, add extra first arguments to
	the function types.
	(set_parameter_const): New function.
	(set_parameter_value): Add type argument, return a bitmask.
	Changed to set a field in automatic structure variable rather
	than set a field in a global _gfortran_ioparm variable.
	(set_parameter_ref): Likewise.  If requested var has different
	size than what field should point to, call with a temporary and
	then copy into the user variable.  Add postblock argument.
	(set_string): Remove var_len argument, add type argument, return
	a bitmask.  Changed to set fields in automatic structure variable
	rather than set a field in a global _gfortran_ioparm variable.
	(set_internal_unit): Remove iunit, iunit_len, iunit_desc arguments,
	add var argument.  Return a bitmask.  Changed to set fields in
	automatic structure variable rather than set a field in a global
	_gfortran_ioparm variable.
	(set_flag): Removed.
	(io_result): Add var argument.  Changed to read common.flags field
	from automatic structure variable and bitwise AND it with 3.
	(set_error_locus): Add var argument.  Changed to set fields in
	automatic structure variable rather than set a field in a global
	_gfortran_{filename,line} variables.
	(gfc_trans_open): Use gfc_start_block rather than gfc_init_block.
	Create a temporary st_parameter_* structure.  Adjust callers of
	all above mentioned functions.  Pass address of the temporary
	variable as first argument to the generated function call.
	Use iocall array rather than ioparm_* separate variables.
	(gfc_trans_close, build_filepos, gfc_trans_inquire): Likewise.
	(build_dt): Likewise.  Change first argument to tree from tree *.
	Don't dereference code->ext.dt if last_dt == INQUIRE.  Emit
	IOLENGTH argument setup here.  Set dt_parm/dt_post_end_block
	variables and gfc_trans_code the nested data transfer commands
	in code->block.
	(gfc_trans_iolength): Just set last_dt and call build_dt immediately.
	(transfer_namelist_element): Pass address of dt_parm variable
	to generated functions.  Use iocall array rather than ioparm_*
	separate variables.
	(gfc_trans_backspace, gfc_trans_endfile, gfc_trans_rewind,
	gfc_trans_flush, gfc_trans_read, gfc_trans_write): Use iocall array
	rather than ioparm_* separate variables.
	(gfc_trans_dt_end): Likewise.  Pass address of dt_parm variable
	as first argument to generated function.  Adjust io_result caller.
	Prepend dt_post_end_block before io_result code.
	(transfer_expr): Use iocall array rather than ioparm_* separate
	variables.  Pass address of dt_parm variables as first argument
	to generated functions.
	* ioparm.def: New file.
gcc/testsuite/
	PR fortran/24774
	* gfortran.dg/inquire_9.f90: New test.

	PR fortran/21647
	* gfortran.fortran-torture/execute/inquire_5.f90: New test.
libgfortran/
	PR fortran/24774
	PR fortran/14943
	PR fortran/21647
	* Makefile.am (AM_CPPFLAGS): Add gcc directories as -I paths,
	add -D_GNU_SOURCE.
	* Makefile.in: Regenerated.
	* acinclude.m4 (LIBGFOR_CHECK_SYNC_FETCH_AND_ADD,
	LIBGFOR_CHECK_GTHR_DEFAULT, LIBGFOR_CHECK_PRAGMA_WEAK): New macros.
	* configure.ac: Add them.
	* configure: Rebuilt.
	* config.h.in: Rebuilt.
	* libtool-version: Bump libgfortran.so SONAME to libgfortran.so.1.
	* libgfortran.h (library_start, show_locus, internal_error,
	generate_error, find_option): Add st_parameter_common * argument.
	(library_end): Change into a dummy macro.
	* io/io.h: Include gthr.h.
	(SUPPORTS_WEAK): Define if HAVE_PRAGMA_WEAK.
	(CHARACTER): Remove define.
	(st_parameter, global_t): Remove typedef.
	(ioparm, g, ionml, current_unit): Remove variables.
	(init_error_stream): Remove prototype.
	(CHARACTER1, CHARACTER2): Define.
	(st_parameter_common, st_parameter_open, st_parameter_close,
	st_parameter_filepos, st_parameter_inquire, st_parameter_dt): New
	typedefs.
	(IOPARM_LIBRETURN_MASK, IOPARM_LIBRETURN_OK, IOPARM_LIBRETURN_ERROR,
	IOPARM_LIBRETURN_END, IOPARM_LIBRETURN_EOR, IOPARM_ERR, IOPARM_END,
	IOPARM_EOR, IOPARM_HAS_IOSTAT, IOPARM_HAS_IOMSG, IOPARM_COMMON_MASK,
	IOPARM_OPEN_HAS_RECL_IN, IOPARM_OPEN_HAS_FILE, IOPARM_OPEN_HAS_STATUS,
	IOPARM_OPEN_HAS_ACCESS, IOPARM_OPEN_HAS_FORM, IOPARM_OPEN_HAS_BLANK,
	IOPARM_OPEN_HAS_POSITION, IOPARM_OPEN_HAS_ACTION,
	IOPARM_OPEN_HAS_DELIM, IOPARM_OPEN_HAS_PAD, IOPARM_CLOSE_HAS_STATUS,
	IOPARM_INQUIRE_HAS_EXIST, IOPARM_INQUIRE_HAS_OPENED,
	IOPARM_INQUIRE_HAS_NUMBER, IOPARM_INQUIRE_HAS_NAMED,
	IOPARM_INQUIRE_HAS_NEXTREC, IOPARM_INQUIRE_HAS_RECL_OUT,
	IOPARM_INQUIRE_HAS_FILE, IOPARM_INQUIRE_HAS_ACCESS,
	IOPARM_INQUIRE_HAS_FORM, IOPARM_INQUIRE_HAS_BLANK,
	IOPARM_INQUIRE_HAS_POSITION, IOPARM_INQUIRE_HAS_ACTION,
	IOPARM_INQUIRE_HAS_DELIM, IOPARM_INQUIRE_HAS_PAD,
	IOPARM_INQUIRE_HAS_NAME, IOPARM_INQUIRE_HAS_SEQUENTIAL,
	IOPARM_INQUIRE_HAS_DIRECT, IOPARM_INQUIRE_HAS_FORMATTED,
	IOPARM_INQUIRE_HAS_UNFORMATTED, IOPARM_INQUIRE_HAS_READ,
	IOPARM_INQUIRE_HAS_WRITE, IOPARM_INQUIRE_HAS_READWRITE,
	IOPARM_DT_LIST_FORMAT, IOPARM_DT_NAMELIST_READ_MODE,
	IOPARM_DT_HAS_REC, IOPARM_DT_HAS_SIZE, IOPARM_DT_HAS_IOLENGTH,
	IOPARM_DT_HAS_FORMAT, IOPARM_DT_HAS_ADVANCE,
	IOPARM_DT_HAS_INTERNAL_UNIT, IOPARM_DT_HAS_NAMELIST_NAME,
	IOPARM_DT_IONML_SET): Define.
	(gfc_unit): Add lock, waiting and close fields.  Change file
	from flexible array member into pointer to char.
	(open_external): Add st_parameter_open * argument.
	(find_file, file_exists): Add file and file_len arguments.
	(flush_all_units): New prototype.
	(max_offset, unit_root, unit_lock): New variable.
	(is_internal_unit, is_array_io, next_array_record,
	parse_format, next_format, unget_format, format_error,
	read_block, write_block, next_record, convert_real,
	read_a, read_f, read_l, read_x, read_radix, read_decimal,
	list_formatted_read, finish_list_read, namelist_read,
	namelist_write, write_a, write_b, write_d, write_e, write_en,
	write_es, write_f, write_i, write_l, write_o, write_x, write_z,
	list_formatted_write, get_unit): Add st_parameter_dt * argument.
	(insert_unit): Remove prototype.
	(find_or_create_unit, unlock_unit): New prototype.
	(new_unit): Return gfc_unit *.  Add st_parameter_open *
	and gfc_unit * arguments.
	(free_fnodes): Remove prototype.
	(free_format_data): New prototype.
	(scratch): Remove.
	(init_at_eol): Remove prototype.
	(free_ionml): New prototype.
	(inc_waiting_locked, predec_waiting_locked, dec_waiting_unlocked):
	New inline functions.
	* io/unit.c (max_offset, unit_root, unit_lock): New variables.
	(insert): Adjust os_error caller.
	(insert_unit): Made static.  Allocate memory here, initialize
	lock and after inserting it return it, locked.
	(delete_unit): Adjust for deletion of g.
	(find_unit_1): New function.
	(find_unit): Use it.
	(find_or_create_unit): New function.
	(get_unit): Add dtp argument, change meaning of the int argument
	as creation request flag.  Adjust for different st_* calling
	conventions, lock internal unit's lock before returning it
	and removal of g.  Call find_unit_1 instead of find_unit.
	(is_internal_unit, is_array_io): Add dtp argument, adjust for
	removal of most of global variables.
	(init_units): Initialize unit_lock.  Adjust insert_unit callers
	and adjust for g removal.
	(close_unit_1): New function.
	(close_unit): Use it.
	(unlock_unit): New function.
	(close_units): Lock unit_lock, use close_unit_1 rather than
	close_unit.
	* io/close.c (st_close): Add clp argument.  Adjust for new
	st_* calling conventions and internal function API changes.
	* io/file_pos.c (st_backspace, st_endfile, st_rewind, st_flush):
	Add fpp argument.  Adjust for new st_* calling conventions and
	internal function API changes.
	(formatted_backspace, unformatted_backspace): Likewise.  Add
	u argument.
	* io/open.c (edit_modes, st_open): Add opp argument.  Adjust for
	new st_* calling conventions and internal function API changes.
	(already_open): Likewise.  If not HAVE_UNLINK_OPEN_FILE, unlink
	scratch file.  Instead of calling close_unit just call sclose,
	free u->file if any and clear a few u fields before calling
	new_unit.
	(new_unit): Return gfc_unit *.  Add opp and u arguments.
	Adjust for new st_* calling conventions and internal function
	API changes.  Don't allocate unit here, rather than work with
	already created unit u already locked on entry.  In case
	of failure, close_unit it.
	* io/unix.c: Include unix.h.
	(BUFFER_SIZE, unix_stream): Moved to unix.h.
	(unit_to_fd): Add unlock_unit call.
	(tempfile): Add opp argument, use its fields rather than ioparm.
	(regular_file): Likewise.
	(open_external): Likewise.  Only unlink file if fd >= 0.
	(init_error_stream): Add error argument, set structure it points
	to rather than filling static variable and returning its address.
	(FIND_FILE0_DECL, FIND_FILE0_ARGS): Define.
	(find_file0): Use them.  Don't crash if u->s == NULL.
	(find_file): Add file and file_len arguments, use them instead
	of ioparm.  Add locking.  Pass either an array of 2 struct stat
	or file and file_len pair to find_file0.
	(flush_all_units_1, flush_all_units): New functions.
	(file_exists): Add file and file_len arguments, use them instead
	of ioparm.
	* io/unix.h: New file.
	* io/lock.c (ioparm, g, ionml): Remove variables.
	(library_start): Add cmp argument, adjust for new st_* calling
	conventions.
	(library_end): Remove.
	(free_ionml): New function.
	* io/inquire.c (inquire_via_unit, inquire_via_filename,
	st_inquire): Add iqp argument, adjust for new st_* calling
	conventions and internal function API changes.
	* io/format.c (FARRAY_SIZE): Decrease to 64.
	(fnode_array, format_data): New typedefs.
	(avail, array, format_string, string, error, saved_token, value,
	format_string_len, reversion_ok, saved_format): Remove variables.
	(colon_node): Add const.
	(free_fnode, free_fnodes): Remove.
	(free_format_data): New function.
	(next_char, unget_char, get_fnode, format_lex, parse_format_list,
	format_error, parse_format, revert, unget_format, next_test): Add
	fmt or dtp arguments, pass it all around, adjust for internal
	function API changes and adjust for removal of global variables.
	(next_format): Likewise.  Constify return type.
	(next_format0): Constify return type.
	* io/transfer.c (current_unit, sf_seen_eor, eor_condition, max_pos,
	skips, pending_spaces, scratch, line_buffer, advance_status,
	transfer): Remove variables.
	(transfer_integer, transfer_real, transfer_logical,
	transfer_character, transfer_complex, transfer_array, current_mode,
	read_sf, read_block, read_block_direct, write_block,
	write_block_direct, unformatted_read, unformatted_write,
	type_name, write_constant_string, require_type,
	formatted_transfer_scalar, us_read, us_write, pre_position,
	data_transfer_init, next_record_r, next_record_w, next_record,
	finalize_transfer, iolength_transfer, iolength_transfer_init,
	st_iolength, st_iolength_done, st_read, st_read_done, st_write,
	st_write_done, st_set_nml_var, st_set_nml_var_dim,
	next_array_record): Add dtp argument, pass it all around, adjust for
	internal function API changes and removal of global variables.
	* io/list_read.c (repeat_count, saved_length, saved_used,
	input_complete, at_eol, comma_flag, last_char, saved_string,
	saved_type, namelist_mode, nml_read_error, value, parse_err_msg,
	nml_err_msg, prev_nl): Remove variables.
	(push_char, free_saved, next_char, unget_char, eat_spaces,
	eat_separator, finish_separator, nml_bad_return, convert_integer,
	parse_repeat, read_logical, read_integer, read_character,
	parse_real, read_complex, read_real, check_type,
	list_formatted_read_scalar, list_formatted_read, finish_list_read,
	find_nml_node, nml_untouch_nodes, nml_match_name, nml_query,
	namelist_read): Add dtp argument, pass it all around, adjust for
	internal function API changes and removal of global variables.
	(nml_parse_qualifier): Likewise.  Add parse_err_msg argument.
	(nml_read_obj): Likewise.  Add pprev_nl, nml_err_msg, clow and
	chigh arguments.
	(nml_get_obj_data): Likewise.  Add pprev_nl and nml_err_msg
	arguments.
	(init_at_eol): Removed.
	* io/read.c (convert_real, read_l, read_a, next_char, read_decimal,
	read_radix, read_f, read_x): Add dtp argument, pass it all around,
	adjust for internal function API changes and removal of global
	variables.
	(set_integer): Adjust internal_error caller.
	* io/write.c (no_leading_blank, nml_delim): Remove variables.
	(write_a, calculate_sign, calculate_G_format, output_float,
	write_l, write_float, write_int, write_decimal, write_i, write_b,
	write_o, write_z, write_d, write_e, write_f, write_en, write_es,
	write_x, write_char, write_logical, write_integer, write_character,
	write_real, write_complex, write_separator,
	list_formatted_write_scalar, list_formatted_write, nml_write_obj,
	namelist_write): Add dtp argument, pass it all around, adjust for
	internal function API changes and removal of global variables.
	(extract_int, extract_uint, extract_real): Adjust internal_error
	callers.
	* runtime/fpu.c (_GNU_SOURCE): Don't define here.
	* runtime/error.c: Include ../io/unix.h.
	(filename, line): Remove variables.
	(st_printf): Pass address of a local variable to init_error_stream.
	(show_locus): Add cmp argument.  Use fields it points to rather than
	filename and line variables.
	(os_error, runtime_error): Remove show_locus calls.
	(internal_error): Add cmp argument.  Pass it down to show_locus.
	(generate_error): Likewise.  Use flags bitmask instead of non-NULL
	check for iostat and iomsg parameter presence, adjust for st_*
	calling convention changes.
	* runtime/stop.c (stop_numeric, stop_string): Remove show_locus
	calls.
	* runtime/pause.c (pause_numeric, pause_string): Likewise.
	* runtime/string.c: Include ../io/io.h.
	(find_option): Add cmp argument.  Pass it down to generate_error.
	* intrinsics/flush.c (recursive_flush): Remove.
	(flush_i4, flush_i8): Use flush_all_units.  Add unlock_unit
	call.
	* intrinsics/rand.c: Include ../io/io.h.
	(rand_seed_lock): New variable.
	(srand, irand): Add locking.
	(init): New constructor function.
	* intrinsics/random.c: Include ../io/io.h.
	(random_lock): New variable.
	(random_r4, random_r8, arandom_r4, arandom_r8): Add locking.
	(random_seed): Likewise.  open failed if fd < 0.  Set i correctly.
	(init): New constructor function.
	* intrinsics/system_clock.c (tp0, t0): Remove.
	(system_clock_4, system_clock_8): Don't subtract tp0/t0 from current
	time, use just integer arithmetics.
	* intrinsics/tty.c (isatty_l4, isatty_l8, ttynam_sub): Add
	unlock_unit calls.

From-SVN: r107328

1 files changed, 144 insertions, 71 deletions

diff --git a/libgfortran/io/unix.c b/libgfortran/io/unix.c
index 2f08aad..d1833f3 100644
--- a/libgfortran/io/unix.c
+++ b/libgfortran/io/unix.c
@@ -45,6 +45,7 @@ Boston, MA 02110-1301, USA.  */
 
 #include "libgfortran.h"
 #include "io.h"
+#include "unix.h"
 
 #ifndef SSIZE_MAX
 #define SSIZE_MAX SHRT_MAX
@@ -116,35 +117,6 @@ Boston, MA 02110-1301, USA.  */
  * 'where' parameter and use the current file pointer. */
 
 
-#define BUFFER_SIZE 8192
-
-typedef struct
-{
-  stream st;
-
-  int fd;
-  gfc_offset buffer_offset;	/* File offset of the start of the buffer */
-  gfc_offset physical_offset;	/* Current physical file offset */
-  gfc_offset logical_offset;	/* Current logical file offset */
-  gfc_offset dirty_offset;	/* Start of modified bytes in buffer */
-  gfc_offset file_length;	/* Length of the file, -1 if not seekable. */
-
-  char *buffer;
-  int len;			/* Physical length of the current buffer */
-  int active;			/* Length of valid bytes in the buffer */
-
-  int prot;
-  int ndirty;			/* Dirty bytes starting at dirty_offset */
-
-  int special_file;		/* =1 if the fd refers to a special file */
-
-  unsigned unbuffered:1;
-
-  char small_buffer[BUFFER_SIZE];
-
-}
-unix_stream;
-
 /*move_pos_offset()--  Move the record pointer right or left
  *relative to current position */
 
@@ -998,15 +970,18 @@ fd_to_stream (int fd, int prot)
 /* Given the Fortran unit number, convert it to a C file descriptor.  */
 
 int
-unit_to_fd(int unit)
+unit_to_fd (int unit)
 {
   gfc_unit *us;
+  int fd;
 
-  us = find_unit(unit);
+  us = find_unit (unit);
   if (us == NULL)
     return -1;
 
-  return ((unix_stream *) us->s)->fd;
+  fd = ((unix_stream *) us->s)->fd;
+  unlock_unit (us);
+  return fd;
 }
 
 
@@ -1032,11 +1007,11 @@ unpack_filename (char *cstring, const char *fstring, int len)
  * open it.  mkstemp() opens the file for reading and writing, but the
  * library mode prevents anything that is not allowed.  The descriptor
  * is returned, which is -1 on error.  The template is pointed to by 
- * ioparm.file, which is copied into the unit structure
+ * opp->file, which is copied into the unit structure
  * and freed later. */
 
 static int
-tempfile (void)
+tempfile (st_parameter_open *opp)
 {
   const char *tempdir;
   char *template;
@@ -1078,8 +1053,8 @@ tempfile (void)
     free_mem (template);
   else
     {
-      ioparm.file = template;
-      ioparm.file_len = strlen (template);	/* Don't include trailing nul */
+      opp->file = template;
+      opp->file_len = strlen (template);	/* Don't include trailing nul */
     }
 
   return fd;
@@ -1092,7 +1067,7 @@ tempfile (void)
  * Returns the descriptor, which is less than zero on error. */
 
 static int
-regular_file (unit_flags *flags)
+regular_file (st_parameter_open *opp, unit_flags *flags)
 {
   char path[PATH_MAX + 1];
   int mode;
@@ -1100,7 +1075,7 @@ regular_file (unit_flags *flags)
   int crflag;
   int fd;
 
-  if (unpack_filename (path, ioparm.file, ioparm.file_len))
+  if (unpack_filename (path, opp->file, opp->file_len))
     {
       errno = ENOENT;		/* Fake an OS error */
       return -1;
@@ -1124,7 +1099,7 @@ regular_file (unit_flags *flags)
       break;
 
     default:
-      internal_error ("regular_file(): Bad action");
+      internal_error (&opp->common, "regular_file(): Bad action");
     }
 
   switch (flags->status)
@@ -1147,7 +1122,7 @@ regular_file (unit_flags *flags)
       break;
 
     default:
-      internal_error ("regular_file(): Bad status");
+      internal_error (&opp->common, "regular_file(): Bad status");
     }
 
   /* rwflag |= O_LARGEFILE; */
@@ -1198,26 +1173,27 @@ regular_file (unit_flags *flags)
  * Returns NULL on operating system error. */
 
 stream *
-open_external (unit_flags *flags)
+open_external (st_parameter_open *opp, unit_flags *flags)
 {
   int fd, prot;
 
   if (flags->status == STATUS_SCRATCH)
     {
-      fd = tempfile ();
+      fd = tempfile (opp);
       if (flags->action == ACTION_UNSPECIFIED)
         flags->action = ACTION_READWRITE;
 
 #if HAVE_UNLINK_OPEN_FILE
       /* We can unlink scratch files now and it will go away when closed. */
-      unlink (ioparm.file);
+      if (fd >= 0)
+	unlink (opp->file);
 #endif
     }
   else
     {
       /* regular_file resets flags->action if it is ACTION_UNSPECIFIED and
        * if it succeeds */
-      fd = regular_file (flags);
+      fd = regular_file (opp, flags);
     }
 
   if (fd < 0)
@@ -1239,7 +1215,7 @@ open_external (unit_flags *flags)
       break;
 
     default:
-      internal_error ("open_external(): Bad action");
+      internal_error (&opp->common, "open_external(): Bad action");
     }
 
   return fd_to_stream (fd, prot);
@@ -1281,21 +1257,19 @@ error_stream (void)
  * corrupted. */
 
 stream *
-init_error_stream (void)
+init_error_stream (unix_stream *error)
 {
-  static unix_stream error;
-
-  memset (&error, '\0', sizeof (error));
+  memset (error, '\0', sizeof (*error));
 
-  error.fd = options.use_stderr ? STDERR_FILENO : STDOUT_FILENO;
+  error->fd = options.use_stderr ? STDERR_FILENO : STDOUT_FILENO;
 
-  error.st.alloc_w_at = (void *) fd_alloc_w_at;
-  error.st.sfree = (void *) fd_sfree;
+  error->st.alloc_w_at = (void *) fd_alloc_w_at;
+  error->st.sfree = (void *) fd_sfree;
 
-  error.unbuffered = 1;
-  error.buffer = error.small_buffer;
+  error->unbuffered = 1;
+  error->buffer = error->small_buffer;
 
-  return (stream *) & error;
+  return (stream *) error;
 }
 
 
@@ -1332,33 +1306,39 @@ compare_file_filename (gfc_unit *u, const char *name, int len)
 }
 
 
+#ifdef HAVE_WORKING_STAT
+# define FIND_FILE0_DECL struct stat *st
+# define FIND_FILE0_ARGS st
+#else
+# define FIND_FILE0_DECL const char *file, gfc_charlen_type file_len
+# define FIND_FILE0_ARGS file, file_len
+#endif
+
 /* find_file0()-- Recursive work function for find_file() */
 
 static gfc_unit *
-find_file0 (gfc_unit * u, struct stat *st1)
+find_file0 (gfc_unit *u, FIND_FILE0_DECL)
 {
-#ifdef HAVE_WORKING_STAT
-  struct stat st2;
-#endif
   gfc_unit *v;
 
   if (u == NULL)
     return NULL;
 
 #ifdef HAVE_WORKING_STAT
-  if (fstat (((unix_stream *) u->s)->fd, &st2) >= 0 &&
-      st1->st_dev == st2.st_dev && st1->st_ino == st2.st_ino)
+  if (u->s != NULL
+      && fstat (((unix_stream *) u->s)->fd, &st[1]) >= 0 &&
+      st[0].st_dev == st[1].st_dev && st[0].st_ino == st[1].st_ino)
     return u;
 #else
-  if (compare_string(u->file_len, u->file, ioparm.file_len, ioparm.file) == 0)
+  if (compare_string (u->file_len, u->file, file_len, file) == 0)
     return u;
 #endif
 
-  v = find_file0 (u->left, st1);
+  v = find_file0 (u->left, FIND_FILE0_ARGS);
   if (v != NULL)
     return v;
 
-  v = find_file0 (u->right, st1);
+  v = find_file0 (u->right, FIND_FILE0_ARGS);
   if (v != NULL)
     return v;
 
@@ -1370,18 +1350,111 @@ find_file0 (gfc_unit * u, struct stat *st1)
  * that has the file already open.  Returns a pointer to the unit if so. */
 
 gfc_unit *
-find_file (void)
+find_file (const char *file, gfc_charlen_type file_len)
 {
   char path[PATH_MAX + 1];
-  struct stat statbuf;
+  struct stat st[2];
+  gfc_unit *u;
 
-  if (unpack_filename (path, ioparm.file, ioparm.file_len))
+  if (unpack_filename (path, file, file_len))
     return NULL;
 
-  if (stat (path, &statbuf) < 0)
+  if (stat (path, &st[0]) < 0)
     return NULL;
 
-  return find_file0 (g.unit_root, &statbuf);
+  __gthread_mutex_lock (&unit_lock);
+retry:
+  u = find_file0 (unit_root, FIND_FILE0_ARGS);
+  if (u != NULL)
+    {
+      /* Fast path.  */
+      if (! __gthread_mutex_trylock (&u->lock))
+	{
+	  /* assert (u->closed == 0); */
+	  __gthread_mutex_unlock (&unit_lock);
+	  return u;
+	}
+
+      inc_waiting_locked (u);
+    }
+  __gthread_mutex_unlock (&unit_lock);
+  if (u != NULL)
+    {
+      __gthread_mutex_lock (&u->lock);
+      if (u->closed)
+	{
+	  __gthread_mutex_lock (&unit_lock);
+	  __gthread_mutex_unlock (&u->lock);
+	  if (predec_waiting_locked (u) == 0)
+	    free_mem (u);
+	  goto retry;
+	}
+
+      dec_waiting_unlocked (u);
+    }
+  return u;
+}
+
+static gfc_unit *
+flush_all_units_1 (gfc_unit *u, int min_unit)
+{
+  while (u != NULL)
+    {
+      if (u->unit_number > min_unit)
+	{
+	  gfc_unit *r = flush_all_units_1 (u->left, min_unit);
+	  if (r != NULL)
+	    return r;
+	}
+      if (u->unit_number >= min_unit)
+	{
+	  if (__gthread_mutex_trylock (&u->lock))
+	    return u;
+	  if (u->s)
+	    flush (u->s);
+	  __gthread_mutex_unlock (&u->lock);
+	}
+      u = u->right;
+    }
+  return NULL;
+}
+
+void
+flush_all_units (void)
+{
+  gfc_unit *u;
+  int min_unit = 0;
+
+  __gthread_mutex_lock (&unit_lock);
+  do
+    {
+      u = flush_all_units_1 (unit_root, min_unit);
+      if (u != NULL)
+	inc_waiting_locked (u);
+      __gthread_mutex_unlock (&unit_lock);
+      if (u == NULL)
+	return;
+
+      __gthread_mutex_lock (&u->lock);
+
+      min_unit = u->unit_number + 1;
+
+      if (u->closed == 0)
+	{
+	  flush (u->s);
+	  __gthread_mutex_lock (&unit_lock);
+	  __gthread_mutex_unlock (&u->lock);
+	  (void) predec_waiting_locked (u);
+	}
+      else
+	{
+	  __gthread_mutex_lock (&unit_lock);
+	  __gthread_mutex_unlock (&u->lock);
+	  if (predec_waiting_locked (u) == 0)
+	    free_mem (u);
+	}
+    }
+  while (1);
 }
 
 
@@ -1441,12 +1514,12 @@ delete_file (gfc_unit * u)
  * the system */
 
 int
-file_exists (void)
+file_exists (const char *file, gfc_charlen_type file_len)
 {
   char path[PATH_MAX + 1];
   struct stat statbuf;
 
-  if (unpack_filename (path, ioparm.file, ioparm.file_len))
+  if (unpack_filename (path, file, file_len))
     return 0;
 
   if (stat (path, &statbuf) < 0)