process changes

This changes wait_reading_process_output to handle threads better.  It
introduces a wrapper for select that releases the global lock, and it
ensures that only a single thread can select a given file descriptor
at a time.

This also adds the thread-locking feature to processes.  By default a
process can only have its output accepted by the thread that created
it.  This can be changed using set-process-thread.  (If the thread
exits, the process is again available for waiting by any thread.)

Note that thread-signal will not currently interrupt a thread blocked
on select.  I'll fix this later.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/process.h b/src/process.h
index 43cc7ea33c0..1ddfe915357 100644
--- a/src/process.h
+++ b/src/process.h
@@ -103,6 +103,9 @@ struct Lisp_Process
     Lisp_Object gnutls_cred_type;
 #endif
 
+    /* The thread a process is linked to, or nil for any thread.  */
+    Lisp_Object thread;
+
     /* After this point, there are no Lisp_Objects any more.  */
     /* alloc.c assumes that `pid' is the first such non-Lisp slot.  */
 
@@ -208,3 +211,5 @@ extern void add_read_fd (int fd, fd_callback func, void *data);
 extern void delete_read_fd (int fd);
 extern void add_write_fd (int fd, fd_callback func, void *data);
 extern void delete_write_fd (int fd);
+
+extern void update_processes_for_thread_death (Lisp_Object);