Better phrasing from TIP 509

1 files changed, 7 insertions, 7 deletions

diff --git a/doc/Thread.3 b/doc/Thread.3
index 59bf488..2005c93 100644
--- a/doc/Thread.3
+++ b/doc/Thread.3
@@ -137,17 +137,17 @@ Tcl provides \fBTcl_ThreadQueueEvent\fR and \fBTcl_ThreadAlert\fR
 for handling event queuing in multithreaded applications.  See
 the \fBNotifier\fR manual page for more information on these procedures.
 .PP
-A mutex is a
-.VS TIP509
-recursive
-.VE TIP509
-lock that is used to serialize all threads through a piece
+A mutex is a lock that is used to serialize all threads through a piece
 of code by calling \fBTcl_MutexLock\fR and \fBTcl_MutexUnlock\fR.
 If one thread holds a mutex, any other thread calling \fBTcl_MutexLock\fR will
 block until \fBTcl_MutexUnlock\fR is called.
 A mutex can be destroyed after its use by calling \fBTcl_MutexFinalize\fR.
-The result of locking a mutex twice from the same thread is undefined.
-On some platforms it will result in a deadlock.
+.VS TIP509
+Mutexes are reentrant: they can be locked several times from the same
+thread. However there must be exactly one call to
+\fBTcl_MutexUnlock\fR for each call to \fBTcl_MutexLock\fR in order
+for a thread to release a mutex completely.
+.VE TIP509
 The \fBTcl_MutexLock\fR, \fBTcl_MutexUnlock\fR and \fBTcl_MutexFinalize\fR
 procedures are defined as empty macros if not compiling with threads enabled.
 For declaration of mutexes the \fBTCL_DECLARE_MUTEX\fR macro should be used.