doc: Terminology change - signalling -> synchronization

The kernel's services previously referred to as "signalling services",
which include object types such as semaphores, events, and mutexes,
are now referred to as "synchronization services". This term more
clearly conveys their use as a means to synchronize the operation
of two or more entities within the kernel.

Change-Id: Id24b96f2daf7d866a2d134c222e3d0b6fc568f5a
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>

doc/about_zephyr.rst

@@ -27,7 +27,7 @@ which are summarized below.
 * Interrupt services, including both compile-time and run-time registration
   of interrupt handlers, which can be written in C or assembly language.
 
-* Inter-thread signalling services, including binary sempahores,
+* Inter-thread synchronization services, including binary sempahores,
   counting semaphores, and mutex semaphores.
 
 * Inter-thread data passing services, including basic message queues,

doc/kernel/microkernel/microkernel.rst

@@ -13,6 +13,6 @@ nanokernel applications.
    microkernel_tasks
    microkernel_timers
    microkernel_memory
-   microkernel_signaling
+   microkernel_synchronization
    microkernel_data
    microkernel_task_irqs.rst

doc/kernel/microkernel/microkernel_signaling.rst

@@ -1,13 +0,0 @@
-.. _microkernel_signaling:
-
-Signaling Services
-##################
-
-This section contains the information about all signaling services available in the microkernel.
-
-.. toctree::
-   :maxdepth: 2
-
-   microkernel_semaphores
-   microkernel_events
-   microkernel_mutexes

doc/kernel/microkernel/microkernel_synchronization.rst

@@ -0,0 +1,14 @@
+.. _microkernel_synchronization:
+
+Synchronization Services
+########################
+
+This section contains the information about the synchronization services
+available in the microkernel.
+
+.. toctree::
+   :maxdepth: 2
+
+   microkernel_semaphores
+   microkernel_events
+   microkernel_mutexes

doc/kernel/nanokernel/nanokernel.rst

@@ -12,6 +12,6 @@ nanokernel applications.
 
    nanokernel_fibers
    nanokernel_timers
-   nanokernel_signaling
+   nanokernel_synchronization
    nanokernel_data
-   nanokernel_interrupts
+   nanokernel_interrupts

doc/kernel/nanokernel/nanokernel_synchronization.rst

@@ -1,9 +1,9 @@
-.. _nanokernel_signaling:
+.. _nanokernel_synchronization:
 
-Signaling Services
-##################
+Synchronization Services
+########################
 
-This section describes the signalling services provided by the nanokernel.
+This section describes the synchronization services provided by the nanokernel.
 Currently, only a single service is provided.
 
 Nanokernel Semaphores

doc/kernel/overview/kernel_fundamentals.rst

@@ -90,8 +90,8 @@ be registered with the kernel at compile time, but can also be registered
 dynamically once the kernel is up and running. Zephyr supports ISRs that
 are written entirely in C, but also permits the use of assembly language.
 
-In situations where an ISR cannot complete the processing of an interrupt
-in a timely manner by itself the kernel's signalling and data passing mechanisms
+In situations where an ISR cannot complete the processing of an interrupt in a
+timely manner by itself the kernel's synchronization and data passing mechanisms
 can be used to hand off the remaining processing to a fiber or task.
 In addition, the microkernel provides a *task IRQ* object type that streamlines
 the handoff to a task in a manner that does not require the device driver
@@ -127,8 +127,8 @@ Related sections:
 * :ref:`Nanokernel Timer Services <nanokernel_timers>`
 * :ref:`Microkernel Timers Services <microkernel_timers>`
 
-Signalling
-**********
+Synchronization
+***************
 
 The Zephyr kernel provides four types of objects that allow different
 contexts to synchronize their execution.
@@ -162,8 +162,8 @@ for each specific object type.
 
 Related sections:
 
-* :ref:`Microkernel Signalling Services <microkernel_signaling>`
-* :ref:`Nanokernel Signalling Services <nanokernel_signaling>`
+* :ref:`Microkernel Synchronization Services <microkernel_synchronization>`
+* :ref:`Nanokernel Synchronization Services <nanokernel_synchronization>`
 
 Data Passing
 ************