617305ddb21c497c64b2da3fc2cee5326ce445df

Expose the size specified as a constant

Signed-off-by: Michel Pollet <buserror@gmail.com>

diff --git a/simavr/sim/fifo_declare.h b/simavr/sim/fifo_declare.h
index 081fcf8df0112a70ec337c467897a564362b1bc1..44deb390286a881d9d2808e7d012a0f38f33d515 100644 (file)
--- a/simavr/sim/fifo_declare.h
+++ b/simavr/sim/fifo_declare.h
@@ -1,7 +1,7 @@
 /*
        fifo_declare.h
 
-       Copyright 2008, 2009 Michel Pollet <buserror@gmail.com>
+       Copyright 2008, 2012 Michel Pollet <buserror@gmail.com>
 
        This file is part of simavr.
 
@@ -19,10 +19,13 @@
        along with simavr.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/* Licensed to Vidiactive by Michel Pollet under the terms of the VECL */
+
 /*
  * FIFO helpers, aka circular buffers
  *
- * these macros define accessory for fifos of any name and any size (power of two)
+ * these macros define accessories for FIFOs of any name, type and
+ * any (power of two) size
  */
 
 #ifndef __FIFO_DECLARE__
@@ -30,7 +33,7 @@
 
 /*
        doing a :
-       DEFINE_FIFO(uint8_t, myfifo, 128);
+       DECLARE_FIFO(uint8_t, myfifo, 128);
 
        will declare :
        enum : myfifo_overflow_f
@@ -49,6 +52,8 @@
                // write b at offset o compared to current write cursor, no cursor advance
                void myfifo_write_at(myfifo_t *c, uint16_t o, uint8_t b);
 
+       In your .c you need to 'implement' the fifo:
+       DEFINE_FIFO(uint8_t, myfifo)
 
        To use the fifo, you must declare at least one :
        myfifo_t fifo = FIFO_NULL;
@@ -77,22 +82,26 @@
 #define FIFO_INLINE    inline
 #endif
 
-#define FIFO_NULL { {0}, 0, 0, 0 }
+#ifndef FIFO_ZERO_INIT
+#define FIFO_ZERO_INIT {0}
+#endif
+#define FIFO_NULL { FIFO_ZERO_INIT, 0, 0, 0 }
 
 #define DECLARE_FIFO(__type, __name, __size) \
 enum { __name##_overflow_f = (1 << 0) }; \
+enum { __name##_fifo_size = (__size) }; \
 typedef struct __name##_t {                    \
-       __type          buffer[__size];         \
+       __type          buffer[__name##_fifo_size];             \
        volatile FIFO_CURSOR_TYPE       read;           \
        volatile FIFO_CURSOR_TYPE       write;          \
        volatile uint8_t        flags;          \
 } __name##_t
 
-#define DEFINE_FIFO(__type, __name, __size) \
+#define DEFINE_FIFO(__type, __name) \
 static FIFO_INLINE FIFO_BOOL_TYPE __name##_write(__name##_t * c, __type b)\
 {\
        FIFO_CURSOR_TYPE now = c->write;\
-       FIFO_CURSOR_TYPE next = (now + 1) & (__size-1);\
+       FIFO_CURSOR_TYPE next = (now + 1) & (__name##_fifo_size-1);\
        if (c->read != next) {  \
                c->buffer[now] = b;\
                c->write = next;\
@@ -100,45 +109,46 @@ static FIFO_INLINE FIFO_BOOL_TYPE __name##_write(__name##_t * c, __type b)\
        }\
        return 0;\
 }\
-static inline FIFO_BOOL_TYPE __name##_isfull(__name##_t *c)\
+static FIFO_INLINE FIFO_BOOL_TYPE __name##_isfull(__name##_t *c)\
 {\
-       FIFO_CURSOR_TYPE next = (c->write + 1) & (__size-1);\
+       FIFO_CURSOR_TYPE next = (c->write + 1) & (__name##_fifo_size-1);\
        return c->read == next;\
 }\
-static inline FIFO_BOOL_TYPE __name##_isempty(__name##_t * c)\
+static FIFO_INLINE FIFO_BOOL_TYPE __name##_isempty(__name##_t * c)\
 {\
        return c->read == c->write;\
 }\
 static FIFO_INLINE __type __name##_read(__name##_t * c)\
 {\
+       __type res = FIFO_ZERO_INIT; \
        if (c->read == c->write)\
-               return 0;\
+               return res;\
        FIFO_CURSOR_TYPE read = c->read;\
-       __type res = c->buffer[read];\
-       c->read = (read + 1) & (__size-1);\
+       res = c->buffer[read];\
+       c->read = (read + 1) & (__name##_fifo_size-1);\
        return res;\
 }\
-static inline FIFO_CURSOR_TYPE __name##_get_read_size(__name##_t *c)\
+static FIFO_INLINE FIFO_CURSOR_TYPE __name##_get_read_size(__name##_t *c)\
 {\
-       return c->write > c->read ? c->write - c->read : __size - 1 - c->read + c->write;\
+       return c->write > c->read ? c->write - c->read : __name##_fifo_size - 1 - c->read + c->write;\
 }\
-static inline void __name##_read_offset(__name##_t *c, FIFO_CURSOR_TYPE o)\
+static FIFO_INLINE void __name##_read_offset(__name##_t *c, FIFO_CURSOR_TYPE o)\
 {\
-       c->read = (c->read + o) & (__size-1);\
+       c->read = (c->read + o) & (__name##_fifo_size-1);\
 }\
-static inline __type __name##_read_at(__name##_t *c, FIFO_CURSOR_TYPE o)\
+static FIFO_INLINE __type __name##_read_at(__name##_t *c, FIFO_CURSOR_TYPE o)\
 {\
-       return c->buffer[(c->read + o) & (__size-1)];\
+       return c->buffer[(c->read + o) & (__name##_fifo_size-1)];\
 }\
-static inline void __name##_write_at(__name##_t *c, FIFO_CURSOR_TYPE o, __type b)\
+static FIFO_INLINE void __name##_write_at(__name##_t *c, FIFO_CURSOR_TYPE o, __type b)\
 {\
-       c->buffer[(c->write + o) & (__size-1)] = b;\
+       c->buffer[(c->write + o) & (__name##_fifo_size-1)] = b;\
 }\
-static inline void __name##_write_offset(__name##_t *c, FIFO_CURSOR_TYPE o)\
+static FIFO_INLINE void __name##_write_offset(__name##_t *c, FIFO_CURSOR_TYPE o)\
 {\
-       c->write = (c->write + o) & (__size-1);\
+       c->write = (c->write + o) & (__name##_fifo_size-1);\
 }\
-static inline void __name##_reset(__name##_t *c)\
+static FIFO_INLINE void __name##_reset(__name##_t *c)\
 {\
        c->read = c->write = c->flags = 0;\
 }\