Added new semaphore API chSemSetCounterI().

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2569 35acf78f-673a-0410-8e92-d51de3d6d3f4

os/kernel/include/chsem.h

@@ -51,6 +51,7 @@ extern "C" {
   msg_t chSemWaitTimeoutS(Semaphore *sp, systime_t time);
   void chSemSignal(Semaphore *sp);
   void chSemSignalI(Semaphore *sp);
+  void chSemSetCounterI(Semaphore *sp, cnt_t n);
 #if CH_USE_SEMSW
   msg_t chSemSignalWait(Semaphore *sps, Semaphore *spw);
 #endif

os/kernel/src/chsem.c

@@ -311,6 +311,38 @@ void chSemSignalI(Semaphore *sp) {
   }
 }
 
+/**
+ * @brief   Sets the semaphore counter to the specified value.
+ * @post    After invoking this function all the threads waiting on the
+ *          semaphore, if any, are released and the semaphore counter is set
+ *          to the specified, non negative, value.
+ * @post    This function does not reschedule so a call to a rescheduling
+ *          function must be performed before unlocking the kernel. Note that
+ *          interrupt handlers always reschedule on exit so an explicit
+ *          reschedule must not be performed in ISRs.
+ *
+ * @param[in] sp        pointer to a @p Semaphore structure
+ * @param[in] n         the new value of the semaphore counter. The value must
+ *                      be non-negative.
+ *
+ * @iclass
+ */
+void chSemSetCounterI(Semaphore *sp, cnt_t n) {
+  cnt_t cnt;
+
+  chDbgCheck((sp != NULL) && (n >= 0), "chSemSetCounterI");
+
+  chDbgAssert(((sp->s_cnt >= 0) && isempty(&sp->s_queue)) ||
+              ((sp->s_cnt < 0) && notempty(&sp->s_queue)),
+              "chSemSetCounterI(), #1",
+              "inconsistent semaphore");
+
+  cnt = sp->s_cnt;
+  sp->s_cnt = n;
+  while (++cnt <= 0)
+    chSchReadyI(lifo_remove(&sp->s_queue))->p_u.rdymsg = RDY_OK;
+}
+
 #if CH_USE_SEMSW
 /**
  * @brief   Performs atomic signal and wait operations on two semaphores.

readme.txt

@@ -74,6 +74,7 @@
 - NEW: Integrated the STM32 GCC, IAR and RVCT demos in a single demo with
   multiple project files, the code is exactly the same.
 - NEW: Added an USB clock configuration in the STM32 HAL driver (LD, MD, HD).
+- NEW: New semaphore API chSemSetCounterI().
 - CHANGE: Modified the ADC and CAN drivers to allow a NULL pointer for
   the configuration structure if it is not required by the implementation.
 - CHANGE: Modified the MMC_SPI driver to *require* a NULL as pointer to

todo.txt

@@ -62,18 +62,11 @@ X Support for not just Makefiles (Ride7, Crossworks etc).
 ? Make thread functions return void.
 - Introduce a "THREAD" function prefix in order to hide compiler-specific
   optimizations for thread functions.
-- Move I/O queues out of the kernel into an new "oslib" category.
-- Add an I/O buffers mechanism to the oslib category.
-- Move MemStreams to the oslib category.
-- Move iochannels and file interfaces to the oslib category.
-? Evaluate moving mailboxes to the oslib category.
-- Make the oslib category appear in the general documentation and the various
-  kernel reference manuals.
-- IAR port for Cortex-Mx, add demos for all the supported families.
-- Keil port for Cortex-Mx, add demos for all the supported families.
-- Add an USB abstract device driver class.
-- USB driver implementation for STM32F103/STM32F102.
-- Add a Serial over USB generic device driver implementing a USB Communication
+X IAR port for Cortex-Mx, add demos for all the supported families.
+X Keil port for Cortex-Mx, add demos for all the supported families.
+X Add an USB abstract device driver class.
+X USB driver implementation for STM32F103/STM32F102.
+X Add a Serial over USB generic device driver implementing a USB Communication
   Device Class and offering a Serial-like interface to the applications.
 X Except for the above, bug fixing only until the 2.2.0 release.
 
@@ -87,7 +80,7 @@ X I2C device driver class support and at least one implementation.
 - Serial over UART complex driver driver, evaluate from the performance
   results if to make obsolete the current dedicated Serial driver.
 X Shared DMA channels support in the STM32/STM8L HALs.
-X New device driver models: Clock, Systick, RTC, WDG, DAC, USB, Power Monitor.
+X New device driver models: Clock, Systick, RTC, WDG, DAC, Power Monitor.
 - MAC driver for STM32F107 (hardware missing).
 - Device drivers for STM8/STM8L (ADC, PWM, bring them on par with STM32).
 - Batch testing of the ARM7/ARMCMx port using OpenOCD, with reports.