Merge pull request #716 from hexluthor/isr-safe-pt-sem

Make protothread semaphores interrupt-safe.
This commit is contained in:
Simon Duquennoy 2015-09-28 13:20:24 +02:00
commit ef176bad33

View File

@ -162,9 +162,11 @@ PT_THREAD(driver_thread(struct pt *pt))
#include "sys/pt.h"
struct pt_sem {
unsigned int count;
unsigned int head, tail;
};
#define PT_SEM_COUNT(s) ((s)->head - (s)->tail)
/**
* Initialize a semaphore
*
@ -179,7 +181,11 @@ struct pt_sem {
* \param c (unsigned int) The initial count of the semaphore.
* \hideinitializer
*/
#define PT_SEM_INIT(s, c) (s)->count = c
#define PT_SEM_INIT(s, c) \
do { \
(s)->tail = 0; \
(s)->head = (c); \
} while(0)
/**
* Wait for a semaphore
@ -199,8 +205,8 @@ struct pt_sem {
*/
#define PT_SEM_WAIT(pt, s) \
do { \
PT_WAIT_UNTIL(pt, (s)->count > 0); \
--(s)->count; \
PT_WAIT_UNTIL(pt, PT_SEM_COUNT(s) > 0); \
++(s)->tail; \
} while(0)
/**
@ -218,7 +224,7 @@ struct pt_sem {
*
* \hideinitializer
*/
#define PT_SEM_SIGNAL(pt, s) ++(s)->count
#define PT_SEM_SIGNAL(pt, s) (++(s)->head)
#endif /* PT_SEM_H_ */