[Emacs-diffs] test-concurrency 19bc430: Documentation and commentary improvements

[Eli Zaretskii]

branch: test-concurrency
commit 19bc43020d6afa2265447e2dad43ad617812ab38
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Documentation and commentary improvements
    
    * src/lisp.h:
    * src/regex.c:
    * src/xgselect.c (xg_select): Improve commentary and formatting.
    
    * doc/lispref/objects.texi (Thread Type, Mutex Type)
    (Condition Variable Type): New subsections.
    (Type Predicates): Add thread-related predicates.
    * doc/lispref/objects.texi (Editing Types):
    * doc/lispref/elisp.texi (Top): Update higher-level menus.
---
 doc/lispref/elisp.texi   |    3 ++
 doc/lispref/objects.texi |   69 ++++++++++++++++++++++++++++++++++++++++++++++
 src/lisp.h               |    2 ++
 src/regex.c              |    1 +
 src/xgselect.c           |    3 ++
 5 files changed, 78 insertions(+)

diff --git a/doc/lispref/elisp.texi b/doc/lispref/elisp.texi
index 415dbe6..4a53a0c 100644
--- a/doc/lispref/elisp.texi
+++ b/doc/lispref/elisp.texi
@@ -349,6 +349,9 @@ Editing Types
 * Window Configuration Type::  Recording the way a frame is subdivided.
 * Frame Configuration Type::   Recording the status of all frames.
 * Process Type::            A subprocess of Emacs running on the underlying OS.
+* Thread Type::             A thread of Emacs Lisp execution.
+* Mutex Type::              An exclusive lock for thread synchronization.
+* Condition Variable Type::    Condition variable for thread synchronization.
 * Stream Type::             Receive or send characters.
 * Keymap Type::             What function a keystroke invokes.
 * Overlay Type::            How an overlay is represented.
diff --git a/doc/lispref/objects.texi b/doc/lispref/objects.texi
index a76fbb1..5e608bc 100644
--- a/doc/lispref/objects.texi
+++ b/doc/lispref/objects.texi
@@ -1410,6 +1410,9 @@ editing.
 * Window Configuration Type::   Recording the way a frame is subdivided.
 * Frame Configuration Type::    Recording the status of all frames.
 * Process Type::        A subprocess of Emacs running on the underlying OS.
+* Thread Type::         A thread of Emacs Lisp execution.
+* Mutex Type::          An exclusive lock for thread synchronization.
+* Condition Variable Type::     Condition variable for thread synchronization.
 * Stream Type::         Receive or send characters.
 * Keymap Type::         What function a keystroke invokes.
 * Overlay Type::        How an overlay is represented.
@@ -1625,6 +1628,63 @@ giving the name of the process:
 return information about, send input or signals to, and receive output
 from processes.
 
address@hidden Thread Type
address@hidden Thread Type
+
+  A @dfn{thread} in Emacs represents a separate thread of Emacs Lisp
+execution.  It runs its own Lisp program, has its own current buffer,
+and can have subprocesses locked to it, i.e.@: subprocesses whose
+output only this thread can accept.  @xref{Threads}.
+
+  Thread objects have no read syntax.  They print in hash notation,
+giving the name of the thread (if it has been given a name) or its
+address in core:
+
address@hidden
address@hidden
+(all-threads)
+    @result{} (#<thread 0176fc40>)
address@hidden group
address@hidden example
+
address@hidden Mutex Type
address@hidden Mutex Type
+
+  A @dfn{mutex} is an exclusive lock that threads can own and disown,
+in order to synchronize between them.  @xref{Mutexes}.
+
+  Mutex objects have no read syntax.  They print in hash notation,
+giving the name of the mutex (if it has been given a name) or its
+address in core:
+
address@hidden
address@hidden
+(make-mutex "my-mutex")
+    @result{} #<mutex my-mutex>
+(make-mutex)
+    @result{} #<mutex 01c7e4e0>
address@hidden group
address@hidden example
+
address@hidden Condition Variable Type
address@hidden Condition Variable Type
+
+  A @dfn{condition variable} is a device for a more complex thread
+synchronization than the one supported by a mutex.  A thread can wait
+on a condition variable, to be woken up when some other thread
+notifies the condition.
+
+  Condition variable objects have no read syntax.  They print in hash
+notation, giving the name of the condition variable (if it has been
+given a name) or its address in core:
+
address@hidden
address@hidden
+(make-condition-variable (make-mutex))
+    @result{} #<condvar 01c45ae8>
address@hidden group
address@hidden example
+
 @node Stream Type
 @subsection Stream Type
 
@@ -1830,6 +1890,9 @@ with references to further information.
 @item commandp
 @xref{Interactive Call, commandp}.
 
address@hidden condition-variable-p
address@hidden Variables, condition-variable-p}.
+
 @item consp
 @xref{List-related Predicates, consp}.
 
@@ -1875,6 +1938,9 @@ with references to further information.
 @item markerp
 @xref{Predicates on Markers, markerp}.
 
address@hidden mutexp
address@hidden, mutexp}.
+
 @item wholenump
 @xref{Predicates on Numbers, wholenump}.
 
@@ -1908,6 +1974,9 @@ with references to further information.
 @item syntax-table-p
 @xref{Syntax Tables, syntax-table-p}.
 
address@hidden threadp
address@hidden Thread Functions, threadp}.
+
 @item vectorp
 @xref{Vectors, vectorp}.
 
diff --git a/src/lisp.h b/src/lisp.h
index 72ea50d..3c7c3dd 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -845,6 +845,7 @@ enum pvec_type
   PVEC_THREAD,
   PVEC_MUTEX,
   PVEC_CONDVAR,
+
   /* These should be last, check internal_equal to see why.  */
   PVEC_COMPILED,
   PVEC_CHAR_TABLE,
@@ -3229,6 +3230,7 @@ union specbinding
     } bt;
   };
 
+/* These 3 are defined as macros in thread.h.  */
 /* extern union specbinding *specpdl; */
 /* extern union specbinding *specpdl_ptr; */
 /* extern ptrdiff_t specpdl_size; */
diff --git a/src/regex.c b/src/regex.c
index e7231d3..f1686cf 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -1140,6 +1140,7 @@ print_double_string (re_char *where, re_char *string1, 
ssize_t size1,
 #endif /* not DEBUG */
 
 #ifndef emacs
+
 /* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
    also be assigned to arbitrarily: each pattern buffer stores its own
    syntax, so it can be changed between regex compilations.  */
diff --git a/src/xgselect.c b/src/xgselect.c
index e418e1a..2f23764 100644
--- a/src/xgselect.c
+++ b/src/xgselect.c
@@ -76,6 +76,9 @@ xg_select (int fds_lim, fd_set *rfds, fd_set *wfds, fd_set 
*efds,
 
   if (gfds_size < n_gfds)
     {
+      /* Avoid using SAFE_NALLOCA, as that implicitly refers to the
+        current thread.  Using xnmalloc avoids thread-switching
+        problems here.  */
       gfds = xnmalloc (n_gfds, sizeof *gfds);
       must_free = 1;
       gfds_size = n_gfds;