Revision 9:2fe93daa2106, committed 2011-02-22

Comitter:

hlipka

Date:

Tue Feb 22 22:57:44 2011 +0000

Parent:

8:ba176eea3e40

Commit message:

fixed semaphore handling - should now be really thread safe (can be called from interrupts)

Changed in this revision

--- a/dogm_spi.cpp	Mon Jan 10 22:57:59 2011 +0000
+++ b/dogm_spi.cpp	Tue Feb 22 22:57:44 2011 +0000
@@ -50,7 +50,8 @@
 void DogmLCDSPI::character(int column, int row, int c)
 {
     int address=(row)*0x40+(column);
-    _guard->take();
+    if (!_guard->take())
+        return;
     sendCmd((char)address|0x80);
     wait_ms(1);
     sendData(c);
@@ -61,7 +62,8 @@
 void DogmLCDSPI::writeText(const unsigned int column, const unsigned int row, const char text[])
 {
     int address=(row)*0x40+(column);
-    _guard->take();
+    if (!_guard->take())
+        return;
     sendCmd((char)address|0x80);
     wait_ms(1);
     
@@ -77,7 +79,8 @@
 
 void DogmLCDSPI::clear()
 {
-    _guard->take();
+    if (!_guard->take())
+        return;
     sendCmd(1);
     _guard->release();
 }

--- a/hd44780_8bit.cpp	Mon Jan 10 22:57:59 2011 +0000
+++ b/hd44780_8bit.cpp	Tue Feb 22 22:57:44 2011 +0000
@@ -30,7 +30,8 @@
 void HD44780LCD8bit::character(int column, int row, int c)
 {
     int address=(row)*0x40+(column);
-    _guard->take();
+    if (!_guard->take())
+        return;
     sendCmd((unsigned char)address|0x80);
     wait_us(30);
     sendData(c);
@@ -42,7 +43,8 @@
 void HD44780LCD8bit::writeText(const unsigned int column, const unsigned int row, const char text[]) {
 //    printf("print to %d,%d {%s}\n",line,pos,text);
     int address=row*0x40+column;
-    _guard->take();
+    if (!_guard->take())
+        return;
     sendCmd((unsigned char)address|0x80);
     wait_us(30);
 
@@ -56,7 +58,8 @@
 }
 
 void HD44780LCD8bit::clear() {
-    _guard->take();
+    if (!_guard->take())
+        return;
     sendCmd(1);
     _guard->release();
 }

--- a/ks0108_8bit.cpp	Mon Jan 10 22:57:59 2011 +0000
+++ b/ks0108_8bit.cpp	Tue Feb 22 22:57:44 2011 +0000
@@ -39,7 +39,8 @@
 }
 
 void KS0108LCD8bit::clear() {
-    _guard->take();
+    if (!_guard->take())
+        return;
     clearHalf(_left);
     if (NULL!=_right)
         clearHalf(_right);
@@ -76,7 +77,8 @@
     if (NULL==cs)
         return;
     
-    _guard->take();
+    if (!_guard->take())
+        return;
     sendCmd(0xb8|row,cs); // set x page    
 
     unsigned int y=icolumn*8;

--- a/sed1335text.cpp	Mon Jan 10 22:57:59 2011 +0000
+++ b/sed1335text.cpp	Tue Feb 22 22:57:44 2011 +0000
@@ -38,6 +38,9 @@
     int i=0;
     
     int pos=row*getColumns()+column;
+
+    if (!_guard->take())
+        return;
     
     sendCmd(0x46); // set cursor addr
     sendData(LOW(pos)); 
@@ -48,6 +51,7 @@
         sendData(text[i]);
         i++;
     }
+    _guard->release();
 }
 
 void SED1335TextLCD::clearBank(int start, int size, int data) {

--- a/semaphore.cpp	Mon Jan 10 22:57:59 2011 +0000
+++ b/semaphore.cpp	Tue Feb 22 22:57:44 2011 +0000
@@ -5,35 +5,33 @@
 
 #include "semaphore.h"
 
-  Semaphore::Semaphore(): s(SemFree) {};
-  
-  bool Semaphore::take(bool block)
-  {
+Semaphore::Semaphore(): s(SemFree) {};
+bool Semaphore::_abort=false;
+
+bool Semaphore::take(bool block) {
+    if (_abort)
+        block=false;
     int oldval;
 #if defined(TARGET_LPC1768) // on Cortex-M3 we can use ldrex/strex
     do {
-      // read the semaphore value
-      oldval = __ldrex(&s);
-      // loop again if it is locked and we are blocking
-      // or setting it with strex failed
-    }
-    while ( (block && oldval == SemTaken) || __strex(SemTaken, &s) != 0 );
+        // read the semaphore value
+        oldval = __ldrex(&s);
+        // loop again if it is locked and we are blocking
+        // or setting it with strex failed
+    } while ( (block && oldval == SemTaken) || __strex(SemTaken, &s) != 0 );
     if ( !block ) __clrex(); // clear exclusive lock set by ldrex
 #else // on arm7 there's only swp
     do {
-      // swp sets the pointed data to the given value and returns the previous one
-      oldval = __swp(SemTaken, &s);
-      // if blocking, loop until the previous value becomes 0
-      // which would mean we have successfully taken the lock
-    }
-    while (block && oldval == SemTaken);
+        // swp sets the pointed data to the given value and returns the previous one
+        oldval = __swp(SemTaken, &s);
+        // if blocking, loop until the previous value becomes 0
+        // which would mean we have successfully taken the lock
+    } while (block && oldval == SemTaken);
 #endif
     return oldval == SemFree;
-  }
-  
-  // release the semaphore
-  void Semaphore::release()
-  {
+}
+
+// release the semaphore
+void Semaphore::release() {
     s = SemFree;
-  }
-  
\ No newline at end of file
+}

--- a/semaphore.h	Mon Jan 10 22:57:59 2011 +0000
+++ b/semaphore.h	Tue Feb 22 22:57:44 2011 +0000
@@ -18,10 +18,13 @@
   // release the semaphore
   void release();
   
+  static void setAbort(bool abort){_abort=abort;};
+  
  private:
    enum { SemFree, SemTaken };
   // semaphore value
   int s;  
+  static bool _abort;
 
 };