Add 8052 IRQ test; Fix places where IDLE task could try to wait on semaphoresnuttx-1.1

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@61 42af7a65-404d-4744-a932-0658087f49c3
author: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> 2007-03-14 18:58:21 +0000
committer: patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> 2007-03-14 18:58:21 +0000
commit: 78cbcfd2a16c0cf3763173ce0a14d656bede0135 (patch)
tree: 5fd6d76721ba77adb12c7fc265befb5cf264329f
parent: 9daf318dc8fbefa6d41c739fa53baa155b31887f (diff)
download: nuttx-78cbcfd2a16c0cf3763173ce0a14d656bede0135.tar.gz
nuttx-78cbcfd2a16c0cf3763173ce0a14d656bede0135.tar.bz2
nuttx-78cbcfd2a16c0cf3763173ce0a14d656bede0135.zip
19 files changed, 570 insertions, 93 deletions
diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index 9678148ca..a14dc11e2 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -4,13 +4,16 @@
 	* Support for Linux user mode simulation and TI
 	  TMS320C5471 (Arm7) provided
 
-0.1.1 2007-xx-xx  Gregory Nutt <spudmonkey@racsa.co.cr>
+0.1.1 2007-03-14  Gregory Nutt <spudmonkey@racsa.co.cr>
 
 	* Corrected an error in interrupt level context switching
 	  for C5471
 	* Added fgets() and gets() logic; verified c5471 console read.
-	* Corrected error in reading from serial port.  Improper
-	  use of semaphore can cause deadlock.
+	* Corrected error in reading from the C5471 serial port:
+          Improper use of semaphore can cause deadlock.
+	* Fixed an error in the memory cleanup:  The idle task
+	  cannot take sempahores (because it must always be ready
+	  to run).
 	* Tasks can now accept a configurable maximum number of
 	  input parameters (argc)
 	* _task_init() was divided into separate functions that
@@ -24,5 +27,7 @@
 	  were calling printf-like functions.
 	* Added strtok() and strtok_r()
 	* Added a simple shell called nsh (see examples/nsh).
-	* Many changes as part of 8052 bringup
+	* Platform support for 8052 is complete but not stable
+	  when the timer interrupt is enabled.  Seems to be an
+	  issue when SP enters indirect address space.
 	* Documentation updates
diff --git a/nuttx/Documentation/NuttX.html b/nuttx/Documentation/NuttX.html
index c048fe472..99753437e 100644
--- a/nuttx/Documentation/NuttX.html
+++ b/nuttx/Documentation/NuttX.html
@@ -3,12 +3,22 @@
 <title>NuttX</title>
 </head>
 <body background="backgd.gif">
-<hr>
-<hr>
-<center><h1><i>Under Construction</i></h1></center>
-<hr>
-<hr>
-<h1>Overview</h1>
+<center>
+  <hr><hr>
+  <h1><big><i>NuttX RTOS</i></big></h1>
+  <p>Last Updated: March 14, 2007</p>
+  <hr><hr>
+  <h1>Table of Contents</h1>
+</center>
+<li><a href="#overview">Overview</a></li>
+<li><a href="#downloads">Downloads</a></li>
+<li><a href="#platforms">Supported Platforms</a></li>
+<li><a href="#footprint">Memory Footprint</a></li>
+<li><a href="#licensing">Licensing</a></li>
+<li><a href="#history">Release History</a></li>
+<li><a href="#documentation">Other Documentation</a></li>
+
+<a name="overview"><h1>Overview</h1></a>
 <p>
   <b>Goals</b>.
   Nuttx is a real timed embedded operating system (RTOS).
@@ -60,7 +70,7 @@
     </p>
 </ol>
 
-<h1>Downloads</h1>
+<a name="downloads"><h1>Downloads</h1></a>
 
 <p>
    The initial release of NuttX (nuttx-0.1.0) is avalable for download
@@ -68,7 +78,7 @@
    website.
 </p>
 
-<h1>Supported Platforms</h1>
+<a name="platforms"><h1>Supported Platforms</h1></a>
 
 <ul>
   <li><b>Linux User Mode</b></li>
@@ -95,7 +105,9 @@
       and the <a href="http://sdcc.sourceforge.net/">SDCC</a> toolchain.
     </p>
     <p>
-      STATUS: This port will require a few more weeks before it is ready for prime time.
+      STATUS: This port is complete but not stable with timer interrupts enabled.
+      There seems to be some issue when the stack pointer enters into the indirect IRAM
+      address space during interrupt handling.
     </p>
   <li><b>Other ports</b></li>
     <p>
@@ -106,7 +118,7 @@
 <blockquote>* A highly modified <a href="http://buildroot.uclibc.org/">buildroot</a>
 is available that be used to build a NuttX-compatible arm-elf toolchain.</blockquote>
 
-<h1>Memory Footprint</h1>
+<a name="footprint"><h1>Memory Footprint</h1></a>
 
 <p><b>C5471 (Arm7)</b>
   The build for this ARM7 target that includes most of the OS features and
@@ -118,11 +130,21 @@ is available that be used to build a NuttX-compatible arm-elf toolchain.</blockq
   53272     428    3568   57268    dfb4 nuttx
 </pre>
 <p><b>87C52</b>
-  A reduced functionality OS test for the 8051 target requires only
-  about 18Kb (see <a href="codesize-070301.xls">spreadsheet</a> for details).
+  A reduced functionality OS test for the 8052 target requires only
+  about 18-19Kb:
 </p>
+<pre>
+Stack starts at: 0x21 (sp set to 0x20) with 223 bytes available.
+
+Other memory:
+   Name             Start    End      Size     Max
+   ---------------- -------- -------- -------- --------
+   PAGED EXT. RAM                         0      256
+   EXTERNAL RAM     0x0100   0x02fd     510     7936
+   ROM/EPROM/FLASH  0x2100   0x6e55   19798    24384
+</pre>
 
-<h1>Licensing</h1>
+<a name="licensing"><h1>Licensing</h1></a>
 
 <p>NuttX is available under the highly permissive
   <a href="http://en.wikipedia.org/wiki/BSD_license">BSD license</a>.
@@ -131,7 +153,45 @@ is available that be used to build a NuttX-compatible arm-elf toolchain.</blockq
   without any concern for jeopardizing any proprietary software that
   you may link with it.</p>
 
-<h1>Other Documentation</h1>
+<a name="history"><h1>Release History</h1></a>
+
+<pre>
+0.1.0 2007-03-09  Gregory Nutt <spudmonkey@racsa.co.cr>
+
+	* Initial Release
+	* Support for Linux user mode simulation and TI
+	  TMS320C5471 (Arm7) provided
+
+0.1.1 2007-03-14  Gregory Nutt <spudmonkey@racsa.co.cr>
+
+	* Corrected an error in interrupt level context switching
+	  for C5471
+	* Added fgets() and gets() logic; verified c5471 console read.
+	* Corrected error in reading from the C5471 serial port:
+          Improper use of semaphore can cause deadlock.
+	* Fixed an error in the memory cleanup:  The idle task
+	  cannot take sempahores (because it must always be ready
+	  to run).
+	* Tasks can now accept a configurable maximum number of
+	  input parameters (argc)
+	* _task_init() was divided into separate functions that
+	  require fewer parameters.  This was necessary to keep
+	  the stack usage down for the 8051/2 (which has only
+	  256 bytes of stack).
+	* Attempts to use C5471 console from interrupt handlers
+	  can casue errors. Added a special path for this case.
+	* Refuse calls to sem_wait and sem_trywait from interrupt
+	  handlers.  This was happening because interrupt handlers
+	  were calling printf-like functions.
+	* Added strtok() and strtok_r()
+	* Added a simple shell called nsh (see examples/nsh).
+	* Platform support for 8052 is complete but not stable
+	  when the timer interrupt is enabled.  Seems to be an
+	  issue when SP enters indirect address space.
+	* Documentation updates
+</pre>
+
+<a name="documentation"><h1>Other Documentation</h1></a>
 
 <li><a href="NuttxUserGuide.html">User Guide</li>
 <li><a href="NuttxPortingGuide.html">Porting Guide</li>
diff --git a/nuttx/Documentation/codesize-070301.xls b/nuttx/Documentation/codesize-070301.xls
deleted file mode 100644
index 22fed5abf..000000000
--- a/nuttx/Documentation/codesize-070301.xls
+++ /dev/null
diff --git a/nuttx/ReleaseNotes b/nuttx/ReleaseNotes
index 9dec8b03e..1ae536fb3 100644
--- a/nuttx/ReleaseNotes
+++ b/nuttx/ReleaseNotes
@@ -1,12 +1,19 @@
-Nuttx-0.1.0
+Nuttx-0.1.1
 ^^^^^^^^^^^
 
-This is the initial.  This initial includes the complete NuttX RTOS
-with support for the Linux user mode simulation and the TI TMS320C5471
-(Arm7) processor.  Partial support for the 87C52 is included.
+This is the second release of NuttX.  This release includes the
+following.  See the ChangeLog for more detailed description of
+the changes.
 
-This release has been verified on both the Linux user-mode and C5471
-platforms using the test program under examples/ostest.  Test results
-for the C5471 can be found in arch/c5471/doc/test-results.txt.
+(1) General OS bugfixes (see the ChangeLog for details),
+(2) bugfixes for the TI TMS320C5471 (Arm7) platform (see the
+    ChangeLog)
+(3) Complete support for the 87C52. (However, the 87C52 release
+    is not stable enough for general usage).
+(4) Added the beginning of a shell call NuttShell (nsh)
 
-This tarball contains a complete CVS snapshot from March 9,2007.
+This release has been verified on the Linux user-mode platform,
+the  Spectrum Digital TMS320C5471 EVM, and the PJRC 87C52 development
+board using the test program under examples/ostest.
+
+This tarball contains a complete CVS snapshot from March 14, 2007.
diff --git a/nuttx/arch/c5471/src/up_serial.c b/nuttx/arch/c5471/src/up_serial.c
index 022befd38..4b70ca4e2 100644
--- a/nuttx/arch/c5471/src/up_serial.c
+++ b/nuttx/arch/c5471/src/up_serial.c
@@ -837,15 +837,19 @@ static ssize_t up_write(struct file *filep, const char *buffer, size_t buflen)
   ssize_t       ret      = buflen;
 
   /* We may receive console writes through this path from
-   * interrupt handlers!  In this case, we will need to do
-   * things a little differently.
+   * interrupt handlers and from debug output in the IDLE task!
+   * In these cases, we will need to do things a little
+   * differently.
    */
 
-  if (up_interrupt_context())
+  if (up_interrupt_context() || getpid() == 0)
     {
       if (dev->isconsole)
         {
-          return up_irqwrite(dev, buffer, buflen);
+          irqstate_t flags = irqsave();
+          ret = up_irqwrite(dev, buffer, buflen);
+          irqrestore(flags);
+          return ret;
         }
       else
         {
diff --git a/nuttx/arch/pjrc-8051/defconfig b/nuttx/arch/pjrc-8051/defconfig
index 8e122c065..789bd79c9 100644
--- a/nuttx/arch/pjrc-8051/defconfig
+++ b/nuttx/arch/pjrc-8051/defconfig
@@ -68,10 +68,10 @@ CONFIG_ARCH_LEDS=y
 CONFIG_8052_TIMER2=y
 
 CONFIG_ARCH_BRINGUP=y
-CONFIG_FRAME_DUMP=y
+CONFIG_FRAME_DUMP=n
 CONFIG_FRAME_DUMP_SHORT=n
 CONFIG_SUPPRESS_INTERRUPTS=y
-CONFIG_SWITCH_FRAME_DUMP=y
+CONFIG_SWITCH_FRAME_DUMP=n
 CONFIG_INTERRUPT_FRAME_DUMP=n
 CONFIG_LED_DEBUG=n
 
diff --git a/nuttx/arch/pjrc-8051/include/irq.h b/nuttx/arch/pjrc-8051/include/irq.h
index 45891986a..e41ba9687 100644
--- a/nuttx/arch/pjrc-8051/include/irq.h
+++ b/nuttx/arch/pjrc-8051/include/irq.h
@@ -65,7 +65,11 @@
  */
 
 #define IRAM_BASE    0x0000
-#define IRAM_SIZE    0x0100
+#ifdef CONFIG_ARCH_8052
+# define IRAM_SIZE   0x0100
+#else
+# define IRAM_SIZE   0x0080
+#endif
 
 #define STACK_BASE   0x0024
 #define STACK_SIZE   (IRAM_SIZE - STACK_BASE)
diff --git a/nuttx/arch/pjrc-8051/src/Makefile b/nuttx/arch/pjrc-8051/src/Makefile
index 628d239a2..51eaf269b 100644
--- a/nuttx/arch/pjrc-8051/src/Makefile
+++ b/nuttx/arch/pjrc-8051/src/Makefile
@@ -65,6 +65,11 @@ LINKLIBS	=
 LDPATHES	= $(addprefix -L$(TOPDIR)/,$(dir $(LINKLIBS)))
 LDLIBS		= $(addprefix -l,$(notdir $(LINKLIBS)))
 
+TESTSRCS	= up_irqtest.c
+TESTOBJS	= $(TESTSRCS:.c=$(OBJEXT))
+TESTLINKOBJS	= up_head$(OBJEXT)
+TESTEXTRAOBJS	= up_savecontext$(OBJEXT) up_restorecontext$(OBJEXT)
+
 IRAM_SIZE	= 0x100
 DEF_STACK_BASE	= 0x24
 LDFLAGS		= --model-large --nostdlib \
@@ -108,7 +113,7 @@ $(ASRCS) $(LINKASRCS): %$(ASMEXT): %.S
 $(AOBJS) $(LINKOBJS): $(ASRCS) $(LINKASRCS)
 	$(AS) $(ASFLAGS) $<
 
-$(COBJS): %$(OBJEXT): %.c
+$(COBJS) $(TESTOBJS): %$(OBJEXT): %.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
 # Create a header file that contains addressing information needed by the code
@@ -174,6 +179,15 @@ nuttx$(EXEEXT): pass1.ihx nuttx.ihx
 	packihx nuttx.ihx > $(TOPDIR)/nuttx$(EXEEXT)
 	@cp -f nuttx.map $(TOPDIR)/.
 
+# This target builds a test program to verify interrupt context switching.  irqtest is
+# a PHONY target that just sets upt the up_irqtest build correctly
+
+up_irqtest.ihx: $(TESTOBJS)
+	$(CC) $(LDFLAGS) -L. $(SDCCPATH) $(TESTLINKOBJS) $(TESTOBJS) $(TESTEXTRAOBJS) $(SDCCLIBS) -o $@
+
+irqtest:
+	$(MAKE) TOPDIR=../../.. up_irqtest.ihx
+
 # Build dependencies
 
 .depend: Makefile up_mem.h $(DEPSRCS)
diff --git a/nuttx/arch/pjrc-8051/src/up_irqtest.c b/nuttx/arch/pjrc-8051/src/up_irqtest.c
new file mode 100644
index 000000000..944e70594
--- /dev/null
+++ b/nuttx/arch/pjrc-8051/src/up_irqtest.c
@@ -0,0 +1,269 @@
+/************************************************************
+ * up_putc.c
+ *
+ *   Copyright (C) 2007 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name Gregory Nutt nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************/
+
+/************************************************************
+ * Included Files
+ ************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+#include <nuttx/arch.h>
+#include <8052.h>
+#include "up_internal.h"
+
+/************************************************************
+ * Definitions
+ ************************************************************/
+
+#define up_extint0 ((vector_t)PM2_VECTOR_EXTINT0)
+#define up_timer0  ((vector_t)PM2_VECTOR_TIMER0)
+#define up_extint1 ((vector_t)PM2_VECTOR_EXTINT1)
+#define up_timer1  ((vector_t)PM2_VECTOR_TIMER1)
+#define up_uart    ((vector_t)PM2_VECTOR_UART)
+#define up_timer2  ((vector_t)PM2_VECTOR_TIMER2)
+
+/************************************************************
+ * Private Types
+ ************************************************************/
+
+typedef void (*vector_t)(void);
+
+/************************************************************
+ * Public Variables
+ ************************************************************/
+
+boolean g_irqtest;
+ubyte g_irqtos;
+ubyte g_irqregs[REGS_SIZE];
+int g_nirqs;
+FAR struct xcptcontext *g_irqcontext; 
+
+/************************************************************
+ * Private Functions
+ ************************************************************/
+
+/************************************************************
+ * Name: utility functions
+ ************************************************************/
+
+static void _up_putc(ubyte ch) __naked
+{
+  ch; /* To avoid unreferenced argument warning */
+  _asm
+        mov     a, dpl
+        ljmp    PM2_ENTRY_COUT
+  _endasm;
+}
+
+void _up_puthex(ubyte hex) __naked
+{
+  hex; /* To avoid unreferenced argument warning */
+  _asm
+        mov     a, dpl
+        ljmp    PM2_ENTRY_PHEX
+  _endasm;
+}
+
+void _up_puthex16(int hex) __naked
+{
+  hex; /* To avoid unreferenced argument warning */
+  _asm
+        ljmp    PM2_ENTRY_PHEX16
+  _endasm;
+}
+
+void _up_putnl(void) __naked
+{
+  _asm
+	ljmp	PM2_ENTRY_NEWLINE
+  _endasm;
+}
+
+void _up_puts(__code char *ptr)
+{
+  for (; *ptr; ptr++)
+    {
+       _up_putc(*ptr);
+    }
+}
+
+void _up_delay(ubyte milliseconds) __naked
+{
+  _asm
+	mov	r0, dpl
+00001$: mov	r1, #230
+00002$: nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	djnz	r1, 00002$
+	djnz	r0, 00001$
+	ret
+  _endasm;
+}
+
+/************************************************************
+ * Public Functions
+ ************************************************************/
+
+/************************************************************
+ * Name: os_start
+ *
+ * Description:
+ *   "Fake" OS entry point.
+ *
+ ************************************************************/
+
+void os_start(void)
+{
+  int i;
+
+  /* Disable all interrupts */
+
+  IE = 0;
+
+  /* Then verify all of the interrupt */
+
+  g_irqtest = FALSE;
+
+  up_extint0();
+  up_timer0();
+#ifndef CONFIG_8052_TIMER2
+  up_timer0();
+#endif
+  up_extint1();
+  up_timer1();
+  up_uart();
+  up_timer2();
+
+  /* Now a real interrupt ... */
+
+  /* Configure timer 0 */
+
+  TR0   = 0;     /* Make sure timer 0 is stopped */
+  TF0   = 0;     /* Clear the overflow flag */
+  TMOD &= 0xF0;  /* Set to mode 0 (without changing timer1) */
+  TL0   = 0;     /* Clear timer 0 value */
+  TH0   = 0;
+  TR0    = 1;    /* Start the timer */
+
+  /* Start timer interrupts */
+
+  g_irqtest = TRUE;
+  g_nirqs   = 0;
+  IE        = 0x82;    /* Enable interrupts */
+
+  /* Wait a about 500 MS */
+
+  _up_delay(500);
+
+  /* Disable the timer */
+
+  TR0 = 0;     /* Stop timer 0 */
+  IE  = 0;     /* Disable interrupts */
+
+  _up_puts("IRQs in 500 MS=");
+  _up_puthex16(g_nirqs);
+  _up_putnl();
+
+  /* end of test */
+
+  _up_puts("Test complete");
+  _up_putnl();
+  for(;;);
+}
+
+/************************************************************
+ * Name: irq_dispatch
+ *
+ * Description:
+ *   "Fake" IRQ dispatcher
+ *
+ ***********************************************************/
+
+void irq_dispatch(int irq, FAR void *context)
+{
+  context;
+  if (g_irqtest)
+    {
+      g_nirqs++;
+    }
+  else
+    {
+      _up_puts("Dispatch IRQ=");
+      _up_puthex(irq);
+      _up_putnl();
+    }
+}
+
+/************************************************************
+ * Name: up_dumpstack / up_dumpframe
+ *
+ * Description:
+ *   "Fake" debug routines if needed.
+ *
+ ************************************************************/
+
+void up_dumpstack(void)
+{
+}
+
+void up_dumpframe(FAR struct xcptcontext *context)
+{
+}
+
+/************************************************************
+ * Name: up_ledinit, up_ledon, up_ledoff
+ *
+ * Description:
+ *   "Fake" LED routines if needed
+ *
+ ************************************************************/
+
+void up_ledinit(void)
+{
+}
+
+void up_ledon(ubyte led)
+{
+  led;
+}
+
+void up_ledoff(ubyte led)
+{
+  led;
+}
diff --git a/nuttx/arch/pjrc-8051/src/up_savecontext.c b/nuttx/arch/pjrc-8051/src/up_savecontext.c
index 83310534c..1c4b26898 100644
--- a/nuttx/arch/pjrc-8051/src/up_savecontext.c
+++ b/nuttx/arch/pjrc-8051/src/up_savecontext.c
@@ -274,7 +274,7 @@ ubyte up_savecontext(FAR struct xcptcontext *context) _naked
 
 	/* Push the top of frame stack pointer.  We need to
 	 * decrement the current SP value by three to account
-	 * for dpst+IE on the stack above the end of the frame.
+	 * for dptr+IE on the stack above the end of the frame.
 	 */
 
 	mov	a, sp
diff --git a/nuttx/arch/pjrc-8051/src/up_timerisr.c b/nuttx/arch/pjrc-8051/src/up_timerisr.c
index 8f139d89a..c4575273b 100644
--- a/nuttx/arch/pjrc-8051/src/up_timerisr.c
+++ b/nuttx/arch/pjrc-8051/src/up_timerisr.c
@@ -139,7 +139,6 @@ void up_timerinit(void)
   TR0 = 1;       /* Start the timer */
   up_enable_irq(TIMER0_IRQ);
 
-# warning "No support for timer 0 as the system timer"
 #endif
 }
 
diff --git a/nuttx/fs/fs_files.c b/nuttx/fs/fs_files.c
index 8d300b8ce..88f905ef4 100644
--- a/nuttx/fs/fs_files.c
+++ b/nuttx/fs/fs_files.c
@@ -122,11 +122,17 @@ int files_addreflist(FAR struct filelist *list)
 {
   if (list)
     {
-       /* Increment the reference count on the list */
+       /* Increment the reference count on the list.
+        * NOTE: that we disable interrupts to do this
+        * (vs. taking the list semaphore).  We do this
+        * because file cleanup operations often must be
+        * done from the IDLE task which cannot wait
+        * on semaphores.
+        */
 
-       _files_semtake(list);
+       register irqstate_t flags = irqsave();
        list->fl_crefs++;
-       _files_semgive(list);
+       irqrestore(flags);
     }
   return OK;
 }
@@ -138,14 +144,22 @@ int files_releaselist(FAR struct filelist *list)
   int crefs;
   if (list)
     {
-       /* Decrement the reference count */
+       /* Decrement the reference count on the list.
+        * NOTE: that we disable interrupts to do this
+        * (vs. taking the list semaphore).  We do this
+        * because file cleanup operations often must be
+        * done from the IDLE task which cannot wait
+        * on semaphores.
+        */
 
-       _files_semtake(list);
+       register irqstate_t flags = irqsave();
        crefs = --(list->fl_crefs);
-       _files_semgive(list);
+       irqrestore(flags);
 
        /* If the count decrements to zero, then there is no reference
-        * to the structure and it should be deallocated.
+        * to the structure and it should be deallocated.  Since there
+        * are references, it would be an error if any task still held
+        * a reference to the list's semaphore.
         */
 
        if (crefs <= 0)
diff --git a/nuttx/include/nuttx/os_external.h b/nuttx/include/nuttx/os_external.h
index 48ee8e440..6c81b9874 100644
--- a/nuttx/include/nuttx/os_external.h
+++ b/nuttx/include/nuttx/os_external.h
@@ -78,6 +78,11 @@ EXTERN void   os_start(void); /* OS entry point called by boot logic */
 EXTERN void   mm_initialize(FAR void *heap_start, size_t heap_size);
 EXTERN void   mm_addregion(FAR void *heapstart, size_t heapsize);
 
+/* Functions contained in mm_sem.c **************************/
+
+EXTERN int mm_trysemaphore(void);
+EXTERN void mm_givesemaphore(void);
+
 #undef EXTERN
 #ifdef __cplusplus
 }
diff --git a/nuttx/lib/lib_init.c b/nuttx/lib/lib_init.c
index d6eb5f0a4..0527f921b 100644
--- a/nuttx/lib/lib_init.c
+++ b/nuttx/lib/lib_init.c
@@ -145,11 +145,17 @@ void lib_addreflist(FAR struct streamlist *list)
 {
   if (list)
     {
-       /* Increment the reference count on the list */
+       /* Increment the reference count on the list.
+        * NOTE: that we disable interrupts to do this
+        * (vs. taking the list semaphore).  We do this
+        * because file cleanup operations often must be
+        * done from the IDLE task which cannot wait
+        * on semaphores.
+        */
 
-       _lib_semtake(list);
+       register irqstate_t flags = irqsave();
        list->sl_crefs++;
-       _lib_semgive(list);
+       irqrestore(flags);
     }
 }
 
@@ -163,14 +169,22 @@ void lib_releaselist(FAR struct streamlist *list)
   int crefs;
   if (list)
     {
-       /* Decrement the reference count */
+       /* Decrement the reference count on the list.
+        * NOTE: that we disable interrupts to do this
+        * (vs. taking the list semaphore).  We do this
+        * because file cleanup operations often must be
+        * done from the IDLE task which cannot wait
+        * on semaphores.
+        */
 
-       _lib_semtake(list);
+       register irqstate_t flags = irqsave();
        crefs = --(list->sl_crefs);
-       _lib_semgive(list);
+       irqrestore(flags);
 
        /* If the count decrements to zero, then there is no reference
-        * to the structure and it should be deallocated.
+        * to the structure and it should be deallocated.  Since there
+        * are references, it would be an error if any task still held
+        * a reference to the list's semaphore.
         */
 
        if (crefs <= 0)
diff --git a/nuttx/mm/mm_sem.c b/nuttx/mm/mm_sem.c
index 3a790de1e..66c667061 100644
--- a/nuttx/mm/mm_sem.c
+++ b/nuttx/mm/mm_sem.c
@@ -78,7 +78,11 @@ static  int   g_counts_held;
  ************************************************************/
 
 /************************************************************
- * mm_seminitialize
+ * Name: mm_seminitialize
+ *
+ * Description:
+ *   Initialize the MM mutex
+ *
  ************************************************************/
 
 void mm_seminitialize(void)
@@ -94,7 +98,56 @@ void mm_seminitialize(void)
 }
 
 /************************************************************
- * mm_takesemaphore
+ * Name: mm_trysemaphore
+ *
+ * Description:
+ *   Try to take the MM mutex.  This is called only from the
+ *   OS in certain conditions when it is necessary to have
+ *   exclusive access to the memory manager but it is
+ *   impossible to wait on a semaphore (e.g., the idle process
+ *   when it performs its background memory cleanup).
+ *
+ ************************************************************/
+
+#ifndef MM_TEST
+int mm_trysemaphore(void)
+{
+  pid_t my_pid = getpid();
+
+  /* Do I already have the semaphore? */
+
+  if (g_holder == my_pid)
+    {
+      /* Yes, just increment the number of references that I have */
+
+      g_counts_held++;
+      return OK;
+    }
+  else
+    {
+      /* Try to tak the semaphore (perhaps waiting) */
+
+      if (sem_trywait(&g_mm_semaphore) != 0)
+       {
+         return ERROR;
+       }
+
+      /* We have it.  Claim the stak and return */
+
+      g_holder      = my_pid;
+      g_counts_held = 1;
+      return OK;
+    }
+}
+#endif
+
+/************************************************************
+ * Name: mm_takesemaphore
+ *
+ * Description:
+ *   Take the MM mutex.  This is the normal action before all
+ *   memory management actions.
+ *
  ************************************************************/
 
 void mm_takesemaphore(void)
@@ -134,7 +187,11 @@ void mm_takesemaphore(void)
 }
 
 /************************************************************
- * mm_givesemaphore
+ * Name: mm_givesemaphore
+ *
+ * Description:
+ *   Release the MM mutex when it is not longer needed.
+ *
  ************************************************************/
 
 void mm_givesemaphore(void)
@@ -160,12 +217,21 @@ void mm_givesemaphore(void)
       /* Nope, this is the last reference I have */
 
       msemdbg("PID=%d giving\n", my_pid);
-      g_holder = -1;
+      g_holder      = -1;
       g_counts_held = 0;
       ASSERT(sem_post(&g_mm_semaphore) == 0);
     }
 }
 
+/************************************************************
+ * Name: mm_getsemaphore
+ *
+ * Description:
+ *   Return the current value of the MM semaphore (for test
+ *   purposes only)
+ *
+ ************************************************************/
+
 #ifdef MM_TEST
 int mm_getsemaphore(void)
 {
diff --git a/nuttx/sched/getpid.c b/nuttx/sched/getpid.c
index a68ce896a..3bd9495b6 100644
--- a/nuttx/sched/getpid.c
+++ b/nuttx/sched/getpid.c
@@ -80,5 +80,5 @@ pid_t getpid(void)
     * ready-to-run task list
     */
 
-   return ((_TCB*)g_readytorun.head)->pid;
+   return ((FAR _TCB*)g_readytorun.head)->pid;
 }
diff --git a/nuttx/sched/os_internal.h b/nuttx/sched/os_internal.h
index 0fa7172b5..85dda8c96 100644
--- a/nuttx/sched/os_internal.h
+++ b/nuttx/sched/os_internal.h
@@ -134,8 +134,8 @@ typedef struct pidhash_s  pidhash_t;
 
 struct tasklist_s
 {
-  DSEG dq_queue_t *list;        /* Pointer to the task list */
-  boolean          prioritized; /* TRUE if the list is prioritized */
+  DSEG volatile dq_queue_t *list; /* Pointer to the task list */
+  boolean prioritized;            /* TRUE if the list is prioritized */
 };
 typedef struct tasklist_s tasklist_t;
 
@@ -159,7 +159,7 @@ typedef struct tasklist_s tasklist_t;
  * list is always the idle task.
  */
 
-extern dq_queue_t g_readytorun;
+extern volatile dq_queue_t g_readytorun;
 
 /* This is the list of all tasks that are ready-to-run, but
  * cannot be placed in the g_readytorun list because:  (1) They
@@ -168,16 +168,16 @@ extern dq_queue_t g_readytorun;
  * disabled pre-emption.
  */
 
-extern dq_queue_t g_pendingtasks;
+extern volatile dq_queue_t g_pendingtasks;
 
 /* This is the list of all tasks that are blocked waiting for a semaphore */
 
-extern dq_queue_t g_waitingforsemaphore;
+extern volatile dq_queue_t g_waitingforsemaphore;
 
 /* This is the list of all tasks that are blocked waiting for a signal */
 
 #ifndef CONFIG_DISABLE_SIGNALS
-extern dq_queue_t g_waitingforsignal;
+extern volatile dq_queue_t g_waitingforsignal;
 #endif
 
 /* This is the list of all tasks that are blocked waiting for a message
@@ -185,7 +185,7 @@ extern dq_queue_t g_waitingforsignal;
  */
 
 #ifndef CONFIG_DISABLE_MQUEUE
-extern dq_queue_t g_waitingformqnotempty;
+extern volatile dq_queue_t g_waitingformqnotempty;
 #endif
 
 /* This is the list of all tasks that are blocked waiting for a message
@@ -193,14 +193,14 @@ extern dq_queue_t g_waitingformqnotempty;
  */
 
 #ifndef CONFIG_DISABLE_MQUEUE
-extern dq_queue_t g_waitingformqnotfull;
+extern volatile dq_queue_t g_waitingformqnotfull;
 #endif
 
 /* This the list of all tasks that have been initialized, but not yet
  * activated. NOTE:  This is the only list that is not prioritized.
  */
 
-extern dq_queue_t g_inactivetasks;
+extern volatile dq_queue_t g_inactivetasks;
 
 /* This is the list of dayed memory deallocations that need to be handled
  * within the IDLE loop.  These deallocations get queued by sched_free()
@@ -208,11 +208,11 @@ extern dq_queue_t g_inactivetasks;
  * handler.
  */
 
-extern sq_queue_t g_delayeddeallocations;
+extern volatile sq_queue_t g_delayeddeallocations;
 
 /* This is the value of the last process ID assigned to a task */
 
-extern pid_t g_lastpid;
+extern volatile pid_t g_lastpid;
 
 /* The following hash table is used for two things:
  *
diff --git a/nuttx/sched/os_start.c b/nuttx/sched/os_start.c
index 9036f17bd..2c5da51a2 100644
--- a/nuttx/sched/os_start.c
+++ b/nuttx/sched/os_start.c
@@ -86,7 +86,7 @@
  * list is always the idle task.
  */
 
-dq_queue_t g_readytorun;
+volatile dq_queue_t g_readytorun;
 
 /* This is the list of all tasks that are ready-to-run, but
  * cannot be placed in the g_readytorun list because:  (1) They
@@ -95,16 +95,16 @@ dq_queue_t g_readytorun;
  * disabled pre-emption.
  */
 
-dq_queue_t g_pendingtasks;
+volatile dq_queue_t g_pendingtasks;
 
 /* This is the list of all tasks that are blocked waiting for a semaphore */
 
-dq_queue_t g_waitingforsemaphore;
+volatile dq_queue_t g_waitingforsemaphore;
 
 /* This is the list of all tasks that are blocked waiting for a signal */
 
 #ifndef CONFIG_DISABLE_SIGNALS
-dq_queue_t g_waitingforsignal;
+volatile dq_queue_t g_waitingforsignal;
 #endif
 
 /* This is the list of all tasks that are blocked waiting for a message
@@ -112,7 +112,7 @@ dq_queue_t g_waitingforsignal;
  */
 
 #ifndef CONFIG_DISABLE_MQUEUE
-dq_queue_t g_waitingformqnotempty;
+volatile dq_queue_t g_waitingformqnotempty;
 #endif
 
 /* This is the list of all tasks that are blocked waiting for a message
@@ -120,14 +120,14 @@ dq_queue_t g_waitingformqnotempty;
  */
 
 #ifndef CONFIG_DISABLE_MQUEUE
-dq_queue_t g_waitingformqnotfull;
+volatile dq_queue_t g_waitingformqnotfull;
 #endif
 
 /* This the list of all tasks that have been initialized, but not yet
  * activated. NOTE:  This is the only list that is not prioritized.
  */
 
-dq_queue_t g_inactivetasks;
+volatile dq_queue_t g_inactivetasks;
 
 /* This is the list of dayed memory deallocations that need to be handled
  * within the IDLE loop.  These deallocations get queued by sched_free()
@@ -135,11 +135,11 @@ dq_queue_t g_inactivetasks;
  * handler.
  */
 
-sq_queue_t g_delayeddeallocations;
+volatile sq_queue_t g_delayeddeallocations;
 
 /* This is the value of the last process ID assigned to a task */
 
-pid_t g_lastpid;
+volatile pid_t g_lastpid;
 
 /* The following hash table is used for two things:
  *
@@ -420,22 +420,35 @@ void os_start(void)
   dbg("Beginning Idle Loop\n");
   for (;;)
     {
-      /* Check if there is anything in the delayed deallocation list. */
-
-      while (g_delayeddeallocations.head)
-	{
-	  /* Remove the first delayed deallocation. */
-
-	  irqstate_t saved_state = irqsave();
-	  void *address = (void*)sq_remfirst(&g_delayeddeallocations);
-	  irqrestore(saved_state);
-
-	  /* Then deallocate it */
-
-	  if (address) sched_free(address);
-      }
-
-      /* Perform idle state operations */
+      /* Check if there is anything in the delayed deallocation list.
+       * If there is deallocate it now.  We must have exclusive access
+       * to the memory manager to do this BUT the idle task cannot
+       * wait on a semaphore.  So we only do the cleanup now if we
+       * can get the semaphore -- and this should be possible because
+       * since we are running, no other task is!
+       */
+
+      if (mm_trysemaphore() == 0)
+        {
+          while (g_delayeddeallocations.head)
+            {
+              /* Remove the first delayed deallocation. */
+
+              irqstate_t saved_state = irqsave();
+              void *address          = (void*)sq_remfirst(&g_delayeddeallocations);
+              irqrestore(saved_state);
+
+              /* Then deallocate it */
+
+              if (address)
+                {
+                  sched_free(address);
+                }
+            }
+          mm_givesemaphore();
+        }
+
+      /* Perform any processor-specific idle state operations */
 
       up_idle();
     }
diff --git a/nuttx/sched/sched_free.c b/nuttx/sched/sched_free.c
index 96292426e..832e71082 100644
--- a/nuttx/sched/sched_free.c
+++ b/nuttx/sched/sched_free.c
@@ -83,10 +83,12 @@
 void sched_free(FAR void *address)
 {
   /* Check if this is an attempt to deallocate memory from
-   * an exception handler.
+   * an exception handler.  If this function is called from the
+   * IDLE task, then we must have exclusive access to the memory
+   * manager to do this.
    */
 
-  if (up_interrupt_context())
+  if (up_interrupt_context() || mm_trysemaphore() != 0)
     {
       /* Yes.. Delay the deallocation until a more appropriate time. */
 
@@ -99,6 +101,7 @@ void sched_free(FAR void *address)
       /* No.. just deallocate the memory now. */
 
       kfree(address);
+      mm_givesemaphore();
     }
 }
author	patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>	2007-03-14 18:58:21 +0000
committer	patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3>	2007-03-14 18:58:21 +0000
commit	78cbcfd2a16c0cf3763173ce0a14d656bede0135 (patch)
tree	5fd6d76721ba77adb12c7fc265befb5cf264329f
parent	9daf318dc8fbefa6d41c739fa53baa155b31887f (diff)
download	nuttx-78cbcfd2a16c0cf3763173ce0a14d656bede0135.tar.gz nuttx-78cbcfd2a16c0cf3763173ce0a14d656bede0135.tar.bz2 nuttx-78cbcfd2a16c0cf3763173ce0a14d656bede0135.zip