Merge tag 'v1.8.2' into parse-bytecode

Thread support, ESP8266 memory improvements, btree module, improved docs

This release brings multi-threading support in the form of the _thread
module, which closely matches the semantics of the corresponding CPython
module.  There is support for GIL and non-GIL builds; without the GIL
enabled one must protect concurrent access to mutable Python state at the
Python level using Lock objects.  Threading with the GIL is enabled in
the cc3200 port on the WiPy.  Threading without the GIL is enabled on the
unix port.  The ESP8266 port has support for frozen bytecode (for scripts
in the modules/ subdirectory), as well as optimisations for reduced
memory usage and decreased memory fragmentation.  The ESP8266 RTC also
resumes correctly after a deepsleep.  An initial "btree" module has been
implemented for database support (unix port only), and the documentation
has been further improved, with pre-built PDF versions of the docs now
available.

py core:
- parse: treat constants that start with underscore as private
- objdict: implemented OrderedDict equality check
- support to build berkeley db 1.85 and "btree" module
- mpconfig.h: MP_NOINLINE is universally useful, move from unix port
- makeqstrdefs.py: remove restriction that source path can't be absolute
- mkrules.mk: define "lib" outside conditional block
- rename __QSTR_EXTRACT flag to NO_QSTR
- objtype: instance: inherit protocol vtable from a base class
- mphal.h: if virtpin API is used, automagically include its header
- objtype: inherit protocol vtable from base class only if it exists
- add MP_STATE_THREAD to hold state specific to a given thread
- add basic _thread module, with ability to start a new thread
- modthread: properly cast concrete exception pointer to an object
- modthread: add stack_size() function
- modthread: add exit() function
- modthread: implement lock object, for creating a mutex
- modthread: add with-context capabilities to lock object
- gc: make memory manager and garbage collector thread safe
- modthread: satisfy unused-args warning
- gc: fix 2 cases of concurrent access to ATB and FTB
- modthread: be more careful with root pointers when creating a thread
- modthread: call mp_thread_start/mp_thread_finish around threads
- gc: fix GC+thread bug where ptr gets lost because it's not computed
- make interning of qstrs thread safe
- implement a simple global interpreter lock (GIL)
- don't use gc or qstr mutex when the GIL is enabled, there is no need
- modthread: make Lock objects work when GIL is enabled
- mpthread.h: move GIL macros outside MICROPY_PY_THREAD block
- modthread: allow to properly set the stack limit of a thread
- nlrthumb: convert NLR thumb funcs from asm to C with inline-asm
- nlrsetjmp: update to take into account new location of nlr_top
- mpthread: include mpstate.h when defining GIL macros
- gc: be sure to count last allocated block at heap end in stats
- gc: calculate (and report) maximum contiguous free block size
- builtinimport: disable "imported as namespace package" warning
- mpconfig.h: mention MICROPY_PY_BTREE config option
- objarray: split out header to allow direct access to object
- rename mp_obj_type_t::stream_p to "protocol"

extmod:
- modbtree: initial implementation of "btree" module based on BerkeleyDB
- modbtree: handle default value and error check
- modbtree: implement .items() iterator
- modbtree: actually implement end key support for .items()
- modbtree: items(): Implement "end key inclusive" flag
- modbtree: items(): Implement DESC flag
- modbtree: __getitem__() should raise KeyError for non-existing key
- modbtree: open(): Support "in-memory" database with filename=None
- machine_pinbase: implementation of PinBase class
- machine_pinbase: fix nanbox build
- modlwip: store a chain of incoming pbufs, instead of only one
- modbtree: implement keys(), values(), items() iterators
- modbtree: cleverly implement "for key in btree:" syntax
- modwebsocket: add readinto() method
- modwebrepl: add readinto() method
- modbtree: fix unused argument warning
- modbtree: fixes for nanbox build
- moduos_dupterm: reserve buffer bytearray object for dupterm
- moduos_dupterm: reuse dupterm_arr_obj for write operations

lib:
- berkeley-db-1.xx: add Berkeley DB 1.85 as a submodule
- berkeley-db-1.xx: update to upstream which builds for uPy
- fatfs/option/ccsbcs: follow uPy optional features model
- libm: format code to pass gcc v6.1.1 warning
- libm: remove unused definition of "one"

drivers:
- display/ssd1306: add width arg and support 64px wide displays

tests:
- recursive_iternext: clang/Linux is even more stack-frugal than MacOS
- bench: add testcase to compare bytes(N) vs b"\0" * N
- add testcase for OrderedDict equality
- add a testcase for machine.PinBase class
- extmod: add "btree" module test
- btree1: add testcase for iterating btree object directly
- add tests for _thread module
- add 3 more tests for _thread module
- thread: remove need to sleep to wait for completion in some tests
- thread: add tests for running GC within a thread, and heap stress
- thread: rename thread_stress_XXX.py to stress_XXX.py
- thread: add tests that mutate shared objects
- thread: add test for concurrent interning of strings
- thread: add test for concurrent mutating of user instance
- thread: make stack-size test run correctly and reliable on uPy
- thread: make sure that thread tests don't rely on floating point
- thread: allow thread_sleep1 to run without floating point
- thread: allow some tests to run on ports with not much heap
- meminfo: update for addition of "max free sz" output
- run-tests: If running thread tests on unix, don't run mutate ones

unix port:
- unbreak "minimal" target by disabling FatFs
- mpconfigport_minimal.h: clearly mark where user-define config ends
- deprecate support for GNU Readline (MICROPY_USE_READLINE=2)
- time to build with --gc-sections
- move "utime" module config to C level instead of make level
- Makefile: libffi: Build with -Os
- alloc: add option to use uPy's alloc-exec implementation even for libffi
- alloc: make coverage build and its overzealous warnings happy
- disable FatFs VFS for normal build, keep enabled for coverage
- modmachine: include PinBase class
- modmachine: enable time_pulse_us() function
- fix Makefile to handle gc-sections linker flags on Mac OS
- add basic thread support using pthreads
- file: if write syscall returns because of EINTR then try again
- implement garbage collection with threading
- mpthreadport: use SA_SIGINFO for GC signal handler
- gccollect: provide declaration of exported function
- mpthreadport: suppress compiler warning about unused arguments
- modtime: release the GIL when sleeping
- enable btree module
- Makefile: make "minimal" build be minimal again
- mpconfigport_minimal.h: allow to print a string within 1KB of heap
- main: error out on unknown value of suffix in -X heapsize= option
- main: improve help for -X options a bit
- main: when preparing sys.path, allocate exact strings on uPy heap
- disable the GIL to improve performance of non-thread code

windows port:
- follow unix port changes regarding "utime" module
- msvc: include machine_pinbase.c in build and enable umachine module

stmhal port:
- add board definition files for Olimex STM32-E407
- port of f4 hal commit 1d7fb82 to l4 hal (SD card modifications)
- correct DMA to allow SD card on L4 MCUs
- enable SD card on L4 MCUs

cc3200 port:
- update FreeRTOS to v9.0.0
- define our own FreeRTOS heap so it can go in a special segment
- add basic threading capabilities
- fix call to new exception to be _msg instead of _arg1
- use xTaskCreateStatic instead of osi_TaskCreate
- mpthreadport: make mutex statically allocated
- mpthreadport: properly initialise the main thread's data
- gccollect: use MP_STATE_THREAD(stack_top) to get top of stack
- mpthreadport: scan more root pointers from thread data
- mpthreadport: move mem alloc outside the thread_mutex lock
- enable the GIL
- in FreeRTOSConfig.h, comment on configSUPPORT_STATIC_ALLOCATION
- remove .boot section attribute from osi_TaskCreate function
- start the simplelink spawn task using the static task creator
- shrink the FreeRTOS heap and place TCB+stack in freed location
- allow to compile bootloader with threading enabled
- remove obsolete singleton heart-beat object

teensy port:
- update the README with OSX specific information and tips

esp8266 port:
- modnetwork: use struct bss_info::ssid_len for ESSID length
- let RTC work correctly after deepsleep
- switch floating-point arith routines to BootROM
- Makefile: enable --verify option for esptool.py write_flash
- use RTC to set date & time stamps for files
- main.c: clear the command line history when (re)booting
- enable frozen bytecode, with scripts in modules/ subdir
- README: describe how to build mpy-cross
- websocket_helper.py: avoid extra string allocations
- websocket_helper.py: fix typo in debug output
- modpybuart: allow setting baudrate and other params
- explicitly collect garbage in bootstrap scripts
- switch webrepl_setup to use frozen bytecode
- switch webrepl to use frozen bytecode
- README: promote from "highly experimental" to "experimental"
- main: init recently added dupterm_arr_obj port state var
- esp_mphal: call_dupterm_read: Use readinto() method
- esp_mphal: properly handle dupterm EOF after switching to readinto()

qemu-arm port:
- disable gcc LTO option for nlrthumb.c

docs:
- esp8266/tutorial/network_basics: minor typo fix, ap becomes ap_if
- add link to PDF version of docs in sidebar
- library/network: wipy: fix literal block indentation
- esp.socket: remove unused file
- ure: typo fix
- usocket: there must be empty line after .only::
- library/machine.Pin: mention GPIO and cross-link .value() function
- machine.*: add "currentmodule:: machine" directive
- pyb.*: add "currentmodule:: pyb" directive
- machine.Pin: remove explicit target
- machine.UART: cleanup pyboard section
- machine.*: use proper class case in method headers
- machine.Pin: add class designator to all constants
- pyb.CAN: mark CAN.initfilterbanks() as classmethod explicitly
- pyb.Pin: af_list() is a normal method, not a class method
- pyb.ExtInt,pyb.Pin: mark up class methods as such
- pyb.*: use proper class case in method headers
- pyb.Pin: sort .af() and .af_list() methods together
- builtins: enumerate all builtin functions implemented
- library/index: add builtins.rst
- machine.Pin: disambiguate object call method
- machine*: remove explicit targets and "machine." prefixes on classes
- uctypes: improve documentation
- sys: detailed description of print_exception() diff from traceback module
- add sphinx_selective_exclude extension suite
- conf.py: active sphinx_selective_exclude extensions
- rebuild docs from scratch, as required for proper only:: handling
- select: add an article
- sys: print_exception: Fixes/clarifications
- conf.py: exclude cmath from modindex for wipy
- library: fix typo in docs for usocket.listen()

examples:
- unix/ffi_example.py: update for current "ffi" module API
- unix/ffi_example.py: remove TODO, make output more clear

1 files changed, 432 insertions, 101 deletions

diff --git a/cc3200/FreeRTOS/Source/include/semphr.h b/cc3200/FreeRTOS/Source/include/semphr.h
index 5275895438..a674b02a41 100644
--- a/cc3200/FreeRTOS/Source/include/semphr.h
+++ b/cc3200/FreeRTOS/Source/include/semphr.h
@@ -1,60 +1,64 @@
 /*
-    FreeRTOS V8.1.2 - Copyright (C) 2014 Real Time Engineers Ltd.
+    FreeRTOS V9.0.0 - Copyright (C) 2016 Real Time Engineers Ltd.
     All rights reserved
 
     VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
 
-    ***************************************************************************
-     *                                                                       *
-     *    FreeRTOS provides completely free yet professionally developed,    *
-     *    robust, strictly quality controlled, supported, and cross          *
-     *    platform software that has become a de facto standard.             *
-     *                                                                       *
-     *    Help yourself get started quickly and support the FreeRTOS         *
-     *    project by purchasing a FreeRTOS tutorial book, reference          *
-     *    manual, or both from: http://www.FreeRTOS.org/Documentation        *
-     *                                                                       *
-     *    Thank you!                                                         *
-     *                                                                       *
-    ***************************************************************************
-
     This file is part of the FreeRTOS distribution.
 
     FreeRTOS is free software; you can redistribute it and/or modify it under
     the terms of the GNU General Public License (version 2) as published by the
-    Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
+    Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.
 
+    ***************************************************************************
     >>!   NOTE: The modification to the GPL is included to allow you to     !<<
     >>!   distribute a combined work that includes FreeRTOS without being   !<<
     >>!   obliged to provide the source code for proprietary components     !<<
     >>!   outside of the FreeRTOS kernel.                                   !<<
+    ***************************************************************************
 
     FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
-    FOR A PARTICULAR PURPOSE.  Full license text is available from the following
+    FOR A PARTICULAR PURPOSE.  Full license text is available on the following
     link: http://www.freertos.org/a00114.html
 
-    1 tab == 4 spaces!
-
     ***************************************************************************
      *                                                                       *
-     *    Having a problem?  Start by reading the FAQ "My application does   *
-     *    not run, what could be wrong?"                                     *
+     *    FreeRTOS provides completely free yet professionally developed,    *
+     *    robust, strictly quality controlled, supported, and cross          *
+     *    platform software that is more than just the market leader, it     *
+     *    is the industry's de facto standard.                               *
      *                                                                       *
-     *    http://www.FreeRTOS.org/FAQHelp.html                               *
+     *    Help yourself get started quickly while simultaneously helping     *
+     *    to support the FreeRTOS project by purchasing a FreeRTOS           *
+     *    tutorial book, reference manual, or both:                          *
+     *    http://www.FreeRTOS.org/Documentation                              *
      *                                                                       *
     ***************************************************************************
 
-    http://www.FreeRTOS.org - Documentation, books, training, latest versions,
-    license and Real Time Engineers Ltd. contact details.
+    http://www.FreeRTOS.org/FAQHelp.html - Having a problem?  Start by reading
+    the FAQ page "My application does not run, what could be wrong?".  Have you
+    defined configASSERT()?
+
+    http://www.FreeRTOS.org/support - In return for receiving this top quality
+    embedded software for free we request you assist our global community by
+    participating in the support forum.
+
+    http://www.FreeRTOS.org/training - Investing in training allows your team to
+    be as productive as possible as early as possible.  Now you can receive
+    FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
+    Ltd, and the world's leading authority on the world's leading RTOS.
 
     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
     including FreeRTOS+Trace - an indispensable productivity tool, a DOS
     compatible FAT file system, and our tiny thread aware UDP/IP stack.
 
-    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
-    Integrity Systems to sell under the OpenRTOS brand.  Low cost OpenRTOS
-    licenses offer ticketed support, indemnification and middleware.
+    http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
+    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
+
+    http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
+    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS
+    licenses offer ticketed support, indemnification and commercial middleware.
 
     http://www.SafeRTOS.com - High Integrity Systems also provide a safety
     engineered and independently SIL3 certified version for use in safety and
@@ -83,6 +87,10 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * semphr. h
  * <pre>vSemaphoreCreateBinary( SemaphoreHandle_t xSemaphore )</pre>
  *
+ * In many usage scenarios it is faster and more memory efficient to use a
+ * direct to task notification in place of a binary semaphore!
+ * http://www.freertos.org/RTOS-task-notifications.html
+ *
  * This old vSemaphoreCreateBinary() macro is now deprecated in favour of the
  * xSemaphoreCreateBinary() function.  Note that binary semaphores created using
  * the vSemaphoreCreateBinary() macro are created in a state such that the
@@ -124,19 +132,37 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * \defgroup vSemaphoreCreateBinary vSemaphoreCreateBinary
  * \ingroup Semaphores
  */
-#define vSemaphoreCreateBinary( xSemaphore )																							\
-	{																																	\
-		( xSemaphore ) = xQueueGenericCreate( ( UBaseType_t ) 1, semSEMAPHORE_QUEUE_ITEM_LENGTH, queueQUEUE_TYPE_BINARY_SEMAPHORE );	\
-		if( ( xSemaphore ) != NULL )																									\
-		{																																\
-			( void ) xSemaphoreGive( ( xSemaphore ) );																					\
-		}																																\
-	}
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
+	#define vSemaphoreCreateBinary( xSemaphore )																							\
+		{																																	\
+			( xSemaphore ) = xQueueGenericCreate( ( UBaseType_t ) 1, semSEMAPHORE_QUEUE_ITEM_LENGTH, queueQUEUE_TYPE_BINARY_SEMAPHORE );	\
+			if( ( xSemaphore ) != NULL )																									\
+			{																																\
+				( void ) xSemaphoreGive( ( xSemaphore ) );																					\
+			}																																\
+		}
+#endif
 
 /**
  * semphr. h
  * <pre>SemaphoreHandle_t xSemaphoreCreateBinary( void )</pre>
  *
+ * Creates a new binary semaphore instance, and returns a handle by which the
+ * new semaphore can be referenced.
+ *
+ * In many usage scenarios it is faster and more memory efficient to use a
+ * direct to task notification in place of a binary semaphore!
+ * http://www.freertos.org/RTOS-task-notifications.html
+ *
+ * Internally, within the FreeRTOS implementation, binary semaphores use a block
+ * of memory, in which the semaphore structure is stored.  If a binary semaphore
+ * is created using xSemaphoreCreateBinary() then the required memory is
+ * automatically dynamically allocated inside the xSemaphoreCreateBinary()
+ * function.  (see http://www.freertos.org/a00111.html).  If a binary semaphore
+ * is created using xSemaphoreCreateBinaryStatic() then the application writer
+ * must provide the memory.  xSemaphoreCreateBinaryStatic() therefore allows a
+ * binary semaphore to be created without using any dynamic memory allocation.
+ *
  * The old vSemaphoreCreateBinary() macro is now deprecated in favour of this
  * xSemaphoreCreateBinary() function.  Note that binary semaphores created using
  * the vSemaphoreCreateBinary() macro are created in a state such that the
@@ -144,11 +170,6 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * created using xSemaphoreCreateBinary() are created in a state such that the
  * the semaphore must first be 'given' before it can be 'taken'.
  *
- * Function that creates a semaphore by using the existing queue mechanism.
- * The queue length is 1 as this is a binary semaphore.  The data size is 0
- * as nothing is actually stored - all that is important is whether the queue is
- * empty or full (the binary semaphore is available or not).
- *
  * This type of semaphore can be used for pure synchronisation between tasks or
  * between an interrupt and a task.  The semaphore need not be given back once
  * obtained, so one task/interrupt can continuously 'give' the semaphore while
@@ -156,7 +177,8 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * semaphore does not use a priority inheritance mechanism.  For an alternative
  * that does use priority inheritance see xSemaphoreCreateMutex().
  *
- * @return Handle to the created semaphore.
+ * @return Handle to the created semaphore, or NULL if the memory required to
+ * hold the semaphore's data structures could not be allocated.
  *
  * Example usage:
  <pre>
@@ -164,7 +186,7 @@ typedef QueueHandle_t SemaphoreHandle_t;
 
  void vATask( void * pvParameters )
  {
-    // Semaphore cannot be used before a call to vSemaphoreCreateBinary ().
+    // Semaphore cannot be used before a call to xSemaphoreCreateBinary().
     // This is a macro so pass the variable in directly.
     xSemaphore = xSemaphoreCreateBinary();
 
@@ -175,10 +197,71 @@ typedef QueueHandle_t SemaphoreHandle_t;
     }
  }
  </pre>
- * \defgroup vSemaphoreCreateBinary vSemaphoreCreateBinary
+ * \defgroup xSemaphoreCreateBinary xSemaphoreCreateBinary
  * \ingroup Semaphores
  */
-#define xSemaphoreCreateBinary() xQueueGenericCreate( ( UBaseType_t ) 1, semSEMAPHORE_QUEUE_ITEM_LENGTH, queueQUEUE_TYPE_BINARY_SEMAPHORE )
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
+	#define xSemaphoreCreateBinary() xQueueGenericCreate( ( UBaseType_t ) 1, semSEMAPHORE_QUEUE_ITEM_LENGTH, queueQUEUE_TYPE_BINARY_SEMAPHORE )
+#endif
+
+/**
+ * semphr. h
+ * <pre>SemaphoreHandle_t xSemaphoreCreateBinaryStatic( StaticSemaphore_t *pxSemaphoreBuffer )</pre>
+ *
+ * Creates a new binary semaphore instance, and returns a handle by which the
+ * new semaphore can be referenced.
+ *
+ * NOTE: In many usage scenarios it is faster and more memory efficient to use a
+ * direct to task notification in place of a binary semaphore!
+ * http://www.freertos.org/RTOS-task-notifications.html
+ *
+ * Internally, within the FreeRTOS implementation, binary semaphores use a block
+ * of memory, in which the semaphore structure is stored.  If a binary semaphore
+ * is created using xSemaphoreCreateBinary() then the required memory is
+ * automatically dynamically allocated inside the xSemaphoreCreateBinary()
+ * function.  (see http://www.freertos.org/a00111.html).  If a binary semaphore
+ * is created using xSemaphoreCreateBinaryStatic() then the application writer
+ * must provide the memory.  xSemaphoreCreateBinaryStatic() therefore allows a
+ * binary semaphore to be created without using any dynamic memory allocation.
+ *
+ * This type of semaphore can be used for pure synchronisation between tasks or
+ * between an interrupt and a task.  The semaphore need not be given back once
+ * obtained, so one task/interrupt can continuously 'give' the semaphore while
+ * another continuously 'takes' the semaphore.  For this reason this type of
+ * semaphore does not use a priority inheritance mechanism.  For an alternative
+ * that does use priority inheritance see xSemaphoreCreateMutex().
+ *
+ * @param pxSemaphoreBuffer Must point to a variable of type StaticSemaphore_t,
+ * which will then be used to hold the semaphore's data structure, removing the
+ * need for the memory to be allocated dynamically.
+ *
+ * @return If the semaphore is created then a handle to the created semaphore is
+ * returned.  If pxSemaphoreBuffer is NULL then NULL is returned.
+ *
+ * Example usage:
+ <pre>
+ SemaphoreHandle_t xSemaphore = NULL;
+ StaticSemaphore_t xSemaphoreBuffer;
+
+ void vATask( void * pvParameters )
+ {
+    // Semaphore cannot be used before a call to xSemaphoreCreateBinary().
+    // The semaphore's data structures will be placed in the xSemaphoreBuffer
+    // variable, the address of which is passed into the function.  The
+    // function's parameter is not NULL, so the function will not attempt any
+    // dynamic memory allocation, and therefore the function will not return
+    // return NULL.
+    xSemaphore = xSemaphoreCreateBinary( &xSemaphoreBuffer );
+
+    // Rest of task code goes here.
+ }
+ </pre>
+ * \defgroup xSemaphoreCreateBinaryStatic xSemaphoreCreateBinaryStatic
+ * \ingroup Semaphores
+ */
+#if( configSUPPORT_STATIC_ALLOCATION == 1 )
+	#define xSemaphoreCreateBinaryStatic( pxStaticSemaphore ) xQueueGenericCreateStatic( ( UBaseType_t ) 1, semSEMAPHORE_QUEUE_ITEM_LENGTH, NULL, pxStaticSemaphore, queueQUEUE_TYPE_BINARY_SEMAPHORE )
+#endif /* configSUPPORT_STATIC_ALLOCATION */
 
 /**
  * semphr. h
@@ -188,7 +271,7 @@ typedef QueueHandle_t SemaphoreHandle_t;
  *               )</pre>
  *
  * <i>Macro</i> to obtain a semaphore.  The semaphore must have previously been
- * created with a call to vSemaphoreCreateBinary(), xSemaphoreCreateMutex() or
+ * created with a call to xSemaphoreCreateBinary(), xSemaphoreCreateMutex() or
  * xSemaphoreCreateCounting().
  *
  * @param xSemaphore A handle to the semaphore being taken - obtained when
@@ -211,7 +294,7 @@ typedef QueueHandle_t SemaphoreHandle_t;
  void vATask( void * pvParameters )
  {
     // Create the semaphore to guard a shared resource.
-    vSemaphoreCreateBinary( xSemaphore );
+    xSemaphore = xSemaphoreCreateBinary();
  }
 
  // A task that uses the semaphore.
@@ -338,29 +421,16 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * \defgroup xSemaphoreTakeRecursive xSemaphoreTakeRecursive
  * \ingroup Semaphores
  */
-#define xSemaphoreTakeRecursive( xMutex, xBlockTime )	xQueueTakeMutexRecursive( ( xMutex ), ( xBlockTime ) )
-
-
-/*
- * xSemaphoreAltTake() is an alternative version of xSemaphoreTake().
- *
- * The source code that implements the alternative (Alt) API is much
- * simpler	because it executes everything from within a critical section.
- * This is	the approach taken by many other RTOSes, but FreeRTOS.org has the
- * preferred fully featured API too.  The fully featured API has more
- * complex	code that takes longer to execute, but makes much less use of
- * critical sections.  Therefore the alternative API sacrifices interrupt
- * responsiveness to gain execution speed, whereas the fully featured API
- * sacrifices execution speed to ensure better interrupt responsiveness.
- */
-#define xSemaphoreAltTake( xSemaphore, xBlockTime )		xQueueAltGenericReceive( ( QueueHandle_t ) ( xSemaphore ), NULL, ( xBlockTime ), pdFALSE )
+#if( configUSE_RECURSIVE_MUTEXES == 1 )
+	#define xSemaphoreTakeRecursive( xMutex, xBlockTime )	xQueueTakeMutexRecursive( ( xMutex ), ( xBlockTime ) )
+#endif
 
 /**
  * semphr. h
  * <pre>xSemaphoreGive( SemaphoreHandle_t xSemaphore )</pre>
  *
  * <i>Macro</i> to release a semaphore.  The semaphore must have previously been
- * created with a call to vSemaphoreCreateBinary(), xSemaphoreCreateMutex() or
+ * created with a call to xSemaphoreCreateBinary(), xSemaphoreCreateMutex() or
  * xSemaphoreCreateCounting(). and obtained using sSemaphoreTake().
  *
  * This macro must not be used from an ISR.  See xSemaphoreGiveFromISR () for
@@ -384,7 +454,7 @@ typedef QueueHandle_t SemaphoreHandle_t;
  void vATask( void * pvParameters )
  {
     // Create the semaphore to guard a shared resource.
-    vSemaphoreCreateBinary( xSemaphore );
+    xSemaphore = vSemaphoreCreateBinary();
 
     if( xSemaphore != NULL )
     {
@@ -500,21 +570,9 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * \defgroup xSemaphoreGiveRecursive xSemaphoreGiveRecursive
  * \ingroup Semaphores
  */
-#define xSemaphoreGiveRecursive( xMutex )	xQueueGiveMutexRecursive( ( xMutex ) )
-
-/*
- * xSemaphoreAltGive() is an alternative version of xSemaphoreGive().
- *
- * The source code that implements the alternative (Alt) API is much
- * simpler	because it executes everything from within a critical section.
- * This is	the approach taken by many other RTOSes, but FreeRTOS.org has the
- * preferred fully featured API too.  The fully featured API has more
- * complex	code that takes longer to execute, but makes much less use of
- * critical sections.  Therefore the alternative API sacrifices interrupt
- * responsiveness to gain execution speed, whereas the fully featured API
- * sacrifices execution speed to ensure better interrupt responsiveness.
- */
-#define xSemaphoreAltGive( xSemaphore )		xQueueAltGenericSend( ( QueueHandle_t ) ( xSemaphore ), NULL, semGIVE_BLOCK_TIME, queueSEND_TO_BACK )
+#if( configUSE_RECURSIVE_MUTEXES == 1 )
+	#define xSemaphoreGiveRecursive( xMutex )	xQueueGiveMutexRecursive( ( xMutex ) )
+#endif
 
 /**
  * semphr. h
@@ -525,7 +583,7 @@ typedef QueueHandle_t SemaphoreHandle_t;
                       )</pre>
  *
  * <i>Macro</i> to  release a semaphore.  The semaphore must have previously been
- * created with a call to vSemaphoreCreateBinary() or xSemaphoreCreateCounting().
+ * created with a call to xSemaphoreCreateBinary() or xSemaphoreCreateCounting().
  *
  * Mutex type semaphores (those created using a call to xSemaphoreCreateMutex())
  * must not be used with this macro.
@@ -605,7 +663,7 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * \defgroup xSemaphoreGiveFromISR xSemaphoreGiveFromISR
  * \ingroup Semaphores
  */
-#define xSemaphoreGiveFromISR( xSemaphore, pxHigherPriorityTaskWoken )	xQueueGenericSendFromISR( ( QueueHandle_t ) ( xSemaphore ), NULL, ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
+#define xSemaphoreGiveFromISR( xSemaphore, pxHigherPriorityTaskWoken )	xQueueGiveFromISR( ( QueueHandle_t ) ( xSemaphore ), ( pxHigherPriorityTaskWoken ) )
 
 /**
  * semphr. h
@@ -616,7 +674,7 @@ typedef QueueHandle_t SemaphoreHandle_t;
                       )</pre>
  *
  * <i>Macro</i> to  take a semaphore from an ISR.  The semaphore must have
- * previously been created with a call to vSemaphoreCreateBinary() or
+ * previously been created with a call to xSemaphoreCreateBinary() or
  * xSemaphoreCreateCounting().
  *
  * Mutex type semaphores (those created using a call to xSemaphoreCreateMutex())
@@ -645,12 +703,21 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * semphr. h
  * <pre>SemaphoreHandle_t xSemaphoreCreateMutex( void )</pre>
  *
- * <i>Macro</i> that implements a mutex semaphore by using the existing queue
- * mechanism.
+ * Creates a new mutex type semaphore instance, and returns a handle by which
+ * the new mutex can be referenced.
  *
- * Mutexes created using this macro can be accessed using the xSemaphoreTake()
+ * Internally, within the FreeRTOS implementation, mutex semaphores use a block
+ * of memory, in which the mutex structure is stored.  If a mutex is created
+ * using xSemaphoreCreateMutex() then the required memory is automatically
+ * dynamically allocated inside the xSemaphoreCreateMutex() function.  (see
+ * http://www.freertos.org/a00111.html).  If a mutex is created using
+ * xSemaphoreCreateMutexStatic() then the application writer must provided the
+ * memory.  xSemaphoreCreateMutexStatic() therefore allows a mutex to be created
+ * without using any dynamic memory allocation.
+ *
+ * Mutexes created using this function can be accessed using the xSemaphoreTake()
  * and xSemaphoreGive() macros.  The xSemaphoreTakeRecursive() and
- * xSemaphoreGiveRecursive() macros should not be used.
+ * xSemaphoreGiveRecursive() macros must not be used.
  *
  * This type of semaphore uses a priority inheritance mechanism so a task
  * 'taking' a semaphore MUST ALWAYS 'give' the semaphore back once the
@@ -658,13 +725,14 @@ typedef QueueHandle_t SemaphoreHandle_t;
  *
  * Mutex type semaphores cannot be used from within interrupt service routines.
  *
- * See vSemaphoreCreateBinary() for an alternative implementation that can be
+ * See xSemaphoreCreateBinary() for an alternative implementation that can be
  * used for pure synchronisation (where one task or interrupt always 'gives' the
  * semaphore and another always 'takes' the semaphore) and from within interrupt
  * service routines.
  *
- * @return xSemaphore Handle to the created mutex semaphore.  Should be of type
- *		SemaphoreHandle_t.
+ * @return If the mutex was successfully created then a handle to the created
+ * semaphore is returned.  If there was not enough heap to allocate the mutex
+ * data structures then NULL is returned.
  *
  * Example usage:
  <pre>
@@ -683,22 +751,96 @@ typedef QueueHandle_t SemaphoreHandle_t;
     }
  }
  </pre>
- * \defgroup vSemaphoreCreateMutex vSemaphoreCreateMutex
+ * \defgroup xSemaphoreCreateMutex xSemaphoreCreateMutex
  * \ingroup Semaphores
  */
-#define xSemaphoreCreateMutex() xQueueCreateMutex( queueQUEUE_TYPE_MUTEX )
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
+	#define xSemaphoreCreateMutex() xQueueCreateMutex( queueQUEUE_TYPE_MUTEX )
+#endif
+
+/**
+ * semphr. h
+ * <pre>SemaphoreHandle_t xSemaphoreCreateMutexStatic( StaticSemaphore_t *pxMutexBuffer )</pre>
+ *
+ * Creates a new mutex type semaphore instance, and returns a handle by which
+ * the new mutex can be referenced.
+ *
+ * Internally, within the FreeRTOS implementation, mutex semaphores use a block
+ * of memory, in which the mutex structure is stored.  If a mutex is created
+ * using xSemaphoreCreateMutex() then the required memory is automatically
+ * dynamically allocated inside the xSemaphoreCreateMutex() function.  (see
+ * http://www.freertos.org/a00111.html).  If a mutex is created using
+ * xSemaphoreCreateMutexStatic() then the application writer must provided the
+ * memory.  xSemaphoreCreateMutexStatic() therefore allows a mutex to be created
+ * without using any dynamic memory allocation.
+ *
+ * Mutexes created using this function can be accessed using the xSemaphoreTake()
+ * and xSemaphoreGive() macros.  The xSemaphoreTakeRecursive() and
+ * xSemaphoreGiveRecursive() macros must not be used.
+ *
+ * This type of semaphore uses a priority inheritance mechanism so a task
+ * 'taking' a semaphore MUST ALWAYS 'give' the semaphore back once the
+ * semaphore it is no longer required.
+ *
+ * Mutex type semaphores cannot be used from within interrupt service routines.
+ *
+ * See xSemaphoreCreateBinary() for an alternative implementation that can be
+ * used for pure synchronisation (where one task or interrupt always 'gives' the
+ * semaphore and another always 'takes' the semaphore) and from within interrupt
+ * service routines.
+ *
+ * @param pxMutexBuffer Must point to a variable of type StaticSemaphore_t,
+ * which will be used to hold the mutex's data structure, removing the need for
+ * the memory to be allocated dynamically.
+ *
+ * @return If the mutex was successfully created then a handle to the created
+ * mutex is returned.  If pxMutexBuffer was NULL then NULL is returned.
+ *
+ * Example usage:
+ <pre>
+ SemaphoreHandle_t xSemaphore;
+ StaticSemaphore_t xMutexBuffer;
+
+ void vATask( void * pvParameters )
+ {
+    // A mutex cannot be used before it has been created.  xMutexBuffer is
+    // into xSemaphoreCreateMutexStatic() so no dynamic memory allocation is
+    // attempted.
+    xSemaphore = xSemaphoreCreateMutexStatic( &xMutexBuffer );
+
+    // As no dynamic memory allocation was performed, xSemaphore cannot be NULL,
+    // so there is no need to check it.
+ }
+ </pre>
+ * \defgroup xSemaphoreCreateMutexStatic xSemaphoreCreateMutexStatic
+ * \ingroup Semaphores
+ */
+ #if( configSUPPORT_STATIC_ALLOCATION == 1 )
+	#define xSemaphoreCreateMutexStatic( pxMutexBuffer ) xQueueCreateMutexStatic( queueQUEUE_TYPE_MUTEX, ( pxMutexBuffer ) )
+#endif /* configSUPPORT_STATIC_ALLOCATION */
 
 
 /**
  * semphr. h
  * <pre>SemaphoreHandle_t xSemaphoreCreateRecursiveMutex( void )</pre>
  *
- * <i>Macro</i> that implements a recursive mutex by using the existing queue
- * mechanism.
+ * Creates a new recursive mutex type semaphore instance, and returns a handle
+ * by which the new recursive mutex can be referenced.
+ *
+ * Internally, within the FreeRTOS implementation, recursive mutexs use a block
+ * of memory, in which the mutex structure is stored.  If a recursive mutex is
+ * created using xSemaphoreCreateRecursiveMutex() then the required memory is
+ * automatically dynamically allocated inside the
+ * xSemaphoreCreateRecursiveMutex() function.  (see
+ * http://www.freertos.org/a00111.html).  If a recursive mutex is created using
+ * xSemaphoreCreateRecursiveMutexStatic() then the application writer must
+ * provide the memory that will get used by the mutex.
+ * xSemaphoreCreateRecursiveMutexStatic() therefore allows a recursive mutex to
+ * be created without using any dynamic memory allocation.
  *
  * Mutexes created using this macro can be accessed using the
  * xSemaphoreTakeRecursive() and xSemaphoreGiveRecursive() macros.  The
- * xSemaphoreTake() and xSemaphoreGive() macros should not be used.
+ * xSemaphoreTake() and xSemaphoreGive() macros must not be used.
  *
  * A mutex used recursively can be 'taken' repeatedly by the owner. The mutex
  * doesn't become available again until the owner has called
@@ -713,13 +855,13 @@ typedef QueueHandle_t SemaphoreHandle_t;
  *
  * Mutex type semaphores cannot be used from within interrupt service routines.
  *
- * See vSemaphoreCreateBinary() for an alternative implementation that can be
+ * See xSemaphoreCreateBinary() for an alternative implementation that can be
  * used for pure synchronisation (where one task or interrupt always 'gives' the
  * semaphore and another always 'takes' the semaphore) and from within interrupt
  * service routines.
  *
  * @return xSemaphore Handle to the created mutex semaphore.  Should be of type
- *		SemaphoreHandle_t.
+ * SemaphoreHandle_t.
  *
  * Example usage:
  <pre>
@@ -738,17 +880,107 @@ typedef QueueHandle_t SemaphoreHandle_t;
     }
  }
  </pre>
- * \defgroup vSemaphoreCreateMutex vSemaphoreCreateMutex
+ * \defgroup xSemaphoreCreateRecursiveMutex xSemaphoreCreateRecursiveMutex
  * \ingroup Semaphores
  */
-#define xSemaphoreCreateRecursiveMutex() xQueueCreateMutex( queueQUEUE_TYPE_RECURSIVE_MUTEX )
+#if( ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) && ( configUSE_RECURSIVE_MUTEXES == 1 ) )
+	#define xSemaphoreCreateRecursiveMutex() xQueueCreateMutex( queueQUEUE_TYPE_RECURSIVE_MUTEX )
+#endif
+
+/**
+ * semphr. h
+ * <pre>SemaphoreHandle_t xSemaphoreCreateRecursiveMutexStatic( StaticSemaphore_t *pxMutexBuffer )</pre>
+ *
+ * Creates a new recursive mutex type semaphore instance, and returns a handle
+ * by which the new recursive mutex can be referenced.
+ *
+ * Internally, within the FreeRTOS implementation, recursive mutexs use a block
+ * of memory, in which the mutex structure is stored.  If a recursive mutex is
+ * created using xSemaphoreCreateRecursiveMutex() then the required memory is
+ * automatically dynamically allocated inside the
+ * xSemaphoreCreateRecursiveMutex() function.  (see
+ * http://www.freertos.org/a00111.html).  If a recursive mutex is created using
+ * xSemaphoreCreateRecursiveMutexStatic() then the application writer must
+ * provide the memory that will get used by the mutex.
+ * xSemaphoreCreateRecursiveMutexStatic() therefore allows a recursive mutex to
+ * be created without using any dynamic memory allocation.
+ *
+ * Mutexes created using this macro can be accessed using the
+ * xSemaphoreTakeRecursive() and xSemaphoreGiveRecursive() macros.  The
+ * xSemaphoreTake() and xSemaphoreGive() macros must not be used.
+ *
+ * A mutex used recursively can be 'taken' repeatedly by the owner. The mutex
+ * doesn't become available again until the owner has called
+ * xSemaphoreGiveRecursive() for each successful 'take' request.  For example,
+ * if a task successfully 'takes' the same mutex 5 times then the mutex will
+ * not be available to any other task until it has also  'given' the mutex back
+ * exactly five times.
+ *
+ * This type of semaphore uses a priority inheritance mechanism so a task
+ * 'taking' a semaphore MUST ALWAYS 'give' the semaphore back once the
+ * semaphore it is no longer required.
+ *
+ * Mutex type semaphores cannot be used from within interrupt service routines.
+ *
+ * See xSemaphoreCreateBinary() for an alternative implementation that can be
+ * used for pure synchronisation (where one task or interrupt always 'gives' the
+ * semaphore and another always 'takes' the semaphore) and from within interrupt
+ * service routines.
+ *
+ * @param pxMutexBuffer Must point to a variable of type StaticSemaphore_t,
+ * which will then be used to hold the recursive mutex's data structure,
+ * removing the need for the memory to be allocated dynamically.
+ *
+ * @return If the recursive mutex was successfully created then a handle to the
+ * created recursive mutex is returned.  If pxMutexBuffer was NULL then NULL is
+ * returned.
+ *
+ * Example usage:
+ <pre>
+ SemaphoreHandle_t xSemaphore;
+ StaticSemaphore_t xMutexBuffer;
+
+ void vATask( void * pvParameters )
+ {
+    // A recursive semaphore cannot be used before it is created.  Here a
+    // recursive mutex is created using xSemaphoreCreateRecursiveMutexStatic().
+    // The address of xMutexBuffer is passed into the function, and will hold
+    // the mutexes data structures - so no dynamic memory allocation will be
+    // attempted.
+    xSemaphore = xSemaphoreCreateRecursiveMutexStatic( &xMutexBuffer );
+
+    // As no dynamic memory allocation was performed, xSemaphore cannot be NULL,
+    // so there is no need to check it.
+ }
+ </pre>
+ * \defgroup xSemaphoreCreateRecursiveMutexStatic xSemaphoreCreateRecursiveMutexStatic
+ * \ingroup Semaphores
+ */
+#if( ( configSUPPORT_STATIC_ALLOCATION == 1 ) && ( configUSE_RECURSIVE_MUTEXES == 1 ) )
+	#define xSemaphoreCreateRecursiveMutexStatic( pxStaticSemaphore ) xQueueCreateMutexStatic( queueQUEUE_TYPE_RECURSIVE_MUTEX, pxStaticSemaphore )
+#endif /* configSUPPORT_STATIC_ALLOCATION */
 
 /**
  * semphr. h
  * <pre>SemaphoreHandle_t xSemaphoreCreateCounting( UBaseType_t uxMaxCount, UBaseType_t uxInitialCount )</pre>
  *
- * <i>Macro</i> that creates a counting semaphore by using the existing
- * queue mechanism.
+ * Creates a new counting semaphore instance, and returns a handle by which the
+ * new counting semaphore can be referenced.
+ *
+ * In many usage scenarios it is faster and more memory efficient to use a
+ * direct to task notification in place of a counting semaphore!
+ * http://www.freertos.org/RTOS-task-notifications.html
+ *
+ * Internally, within the FreeRTOS implementation, counting semaphores use a
+ * block of memory, in which the counting semaphore structure is stored.  If a
+ * counting semaphore is created using xSemaphoreCreateCounting() then the
+ * required memory is automatically dynamically allocated inside the
+ * xSemaphoreCreateCounting() function.  (see
+ * http://www.freertos.org/a00111.html).  If a counting semaphore is created
+ * using xSemaphoreCreateCountingStatic() then the application writer can
+ * instead optionally provide the memory that will get used by the counting
+ * semaphore.  xSemaphoreCreateCountingStatic() therefore allows a counting
+ * semaphore to be created without using any dynamic memory allocation.
  *
  * Counting semaphores are typically used for two things:
  *
@@ -804,7 +1036,94 @@ typedef QueueHandle_t SemaphoreHandle_t;
  * \defgroup xSemaphoreCreateCounting xSemaphoreCreateCounting
  * \ingroup Semaphores
  */
-#define xSemaphoreCreateCounting( uxMaxCount, uxInitialCount ) xQueueCreateCountingSemaphore( ( uxMaxCount ), ( uxInitialCount ) )
+#if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
+	#define xSemaphoreCreateCounting( uxMaxCount, uxInitialCount ) xQueueCreateCountingSemaphore( ( uxMaxCount ), ( uxInitialCount ) )
+#endif
+
+/**
+ * semphr. h
+ * <pre>SemaphoreHandle_t xSemaphoreCreateCountingStatic( UBaseType_t uxMaxCount, UBaseType_t uxInitialCount, StaticSemaphore_t *pxSemaphoreBuffer )</pre>
+ *
+ * Creates a new counting semaphore instance, and returns a handle by which the
+ * new counting semaphore can be referenced.
+ *
+ * In many usage scenarios it is faster and more memory efficient to use a
+ * direct to task notification in place of a counting semaphore!
+ * http://www.freertos.org/RTOS-task-notifications.html
+ *
+ * Internally, within the FreeRTOS implementation, counting semaphores use a
+ * block of memory, in which the counting semaphore structure is stored.  If a
+ * counting semaphore is created using xSemaphoreCreateCounting() then the
+ * required memory is automatically dynamically allocated inside the
+ * xSemaphoreCreateCounting() function.  (see
+ * http://www.freertos.org/a00111.html).  If a counting semaphore is created
+ * using xSemaphoreCreateCountingStatic() then the application writer must
+ * provide the memory.  xSemaphoreCreateCountingStatic() therefore allows a
+ * counting semaphore to be created without using any dynamic memory allocation.
+ *
+ * Counting semaphores are typically used for two things:
+ *
+ * 1) Counting events.
+ *
+ *    In this usage scenario an event handler will 'give' a semaphore each time
+ *    an event occurs (incrementing the semaphore count value), and a handler
+ *    task will 'take' a semaphore each time it processes an event
+ *    (decrementing the semaphore count value).  The count value is therefore
+ *    the difference between the number of events that have occurred and the
+ *    number that have been processed.  In this case it is desirable for the
+ *    initial count value to be zero.
+ *
+ * 2) Resource management.
+ *
+ *    In this usage scenario the count value indicates the number of resources
+ *    available.  To obtain control of a resource a task must first obtain a
+ *    semaphore - decrementing the semaphore count value.  When the count value
+ *    reaches zero there are no free resources.  When a task finishes with the
+ *    resource it 'gives' the semaphore back - incrementing the semaphore count
+ *    value.  In this case it is desirable for the initial count value to be
+ *    equal to the maximum count value, indicating that all resources are free.
+ *
+ * @param uxMaxCount The maximum count value that can be reached.  When the
+ *        semaphore reaches this value it can no longer be 'given'.
+ *
+ * @param uxInitialCount The count value assigned to the semaphore when it is
+ *        created.
+ *
+ * @param pxSemaphoreBuffer Must point to a variable of type StaticSemaphore_t,
+ * which will then be used to hold the semaphore's data structure, removing the
+ * need for the memory to be allocated dynamically.
+ *
+ * @return If the counting semaphore was successfully created then a handle to
+ * the created counting semaphore is returned.  If pxSemaphoreBuffer was NULL
+ * then NULL is returned.
+ *
+ * Example usage:
+ <pre>
+ SemaphoreHandle_t xSemaphore;
+ StaticSemaphore_t xSemaphoreBuffer;
+
+ void vATask( void * pvParameters )
+ {
+ SemaphoreHandle_t xSemaphore = NULL;
+
+    // Counting semaphore cannot be used before they have been created.  Create
+    // a counting semaphore using xSemaphoreCreateCountingStatic().  The max
+    // value to which the semaphore can count is 10, and the initial value
+    // assigned to the count will be 0.  The address of xSemaphoreBuffer is
+    // passed in and will be used to hold the semaphore structure, so no dynamic
+    // memory allocation will be used.
+    xSemaphore = xSemaphoreCreateCounting( 10, 0, &xSemaphoreBuffer );
+
+    // No memory allocation was attempted so xSemaphore cannot be NULL, so there
+    // is no need to check its value.
+ }
+ </pre>
+ * \defgroup xSemaphoreCreateCountingStatic xSemaphoreCreateCountingStatic
+ * \ingroup Semaphores
+ */
+#if( configSUPPORT_STATIC_ALLOCATION == 1 )
+	#define xSemaphoreCreateCountingStatic( uxMaxCount, uxInitialCount, pxSemaphoreBuffer ) xQueueCreateCountingSemaphoreStatic( ( uxMaxCount ), ( uxInitialCount ), ( pxSemaphoreBuffer ) )
+#endif /* configSUPPORT_STATIC_ALLOCATION */
 
 /**
  * semphr. h
@@ -835,6 +1154,18 @@ typedef QueueHandle_t SemaphoreHandle_t;
  */
 #define xSemaphoreGetMutexHolder( xSemaphore ) xQueueGetMutexHolder( ( xSemaphore ) )
 
+/**
+ * semphr.h
+ * <pre>UBaseType_t uxSemaphoreGetCount( SemaphoreHandle_t xSemaphore );</pre>
+ *
+ * If the semaphore is a counting semaphore then uxSemaphoreGetCount() returns
+ * its current count value.  If the semaphore is a binary semaphore then
+ * uxSemaphoreGetCount() returns 1 if the semaphore is available, and 0 if the
+ * semaphore is not available.
+ *
+ */
+#define uxSemaphoreGetCount( xSemaphore ) uxQueueMessagesWaiting( ( QueueHandle_t ) ( xSemaphore ) )
+
 #endif /* SEMAPHORE_H */