-/**
- * \brief Determine if a short spinlock is locked
- * \param Lock Lock pointer
- */
-static inline int IS_LOCKED(struct sShortSpinlock *Lock) {
- return !!Lock->Lock;
-}
-
-/**
- * \brief Check if the current CPU has the lock
- * \param Lock Lock pointer
- */
-static inline int CPU_HAS_LOCK(struct sShortSpinlock *Lock) {
- extern int GetCPUNum(void);
- return Lock->Lock == GetCPUNum() + 1;
-}
-
-/**
- * \brief Acquire a Short Spinlock
- * \param Lock Lock pointer
- *
- * This type of mutex should only be used for very short sections of code,
- * or in places where a Mutex_* would be overkill, such as appending
- * an element to linked list (usually two assignement lines in C)
- *
- * \note This type of lock halts interrupts, so ensure that no timing
- * functions are called while it is held. As a matter of fact, spend as
- * little time as possible with this lock held
- */
-static inline void SHORTLOCK(struct sShortSpinlock *Lock) {
- int v = 1;
- #if LOCK_DISABLE_INTS
- int IF;
- #endif
- #if STACKED_LOCKS
- extern int GetCPUNum(void);
- int cpu = GetCPUNum() + 1;
- #endif
-
- #if LOCK_DISABLE_INTS
- // Save interrupt state and clear interrupts
- __ASM__ ("pushf;\n\tpop %%eax\n\tcli" : "=a"(IF));
- IF &= 0x200; // AND out all but the interrupt flag
- #endif
-
- #if STACKED_LOCKS
- if( Lock->Lock == cpu ) {
- Lock->Depth ++;
- return ;
- }
- #endif
-
- // Wait for another CPU to release
- while(v) {
- #if STACKED_LOCKS
- // CMPXCHG:
- // If r/m32 == EAX, set ZF and set r/m32 = r32
- // Else, clear ZF and set EAX = r/m32
- __ASM__("lock cmpxchgl %2, (%3)"
- : "=a"(v)
- : "a"(0), "r"(cpu), "r"(&Lock->Lock)
- );
- #else
- __ASM__("xchgl %%eax, (%%edi)":"=a"(v):"a"(1),"D"(&Lock->Lock));
- #endif
- }
-
- #if LOCK_DISABLE_INTS
- Lock->IF = IF;
- #endif
-}
-/**
- * \brief Release a short lock
- * \param Lock Lock pointer
- */
-static inline void SHORTREL(struct sShortSpinlock *Lock) {
- #if STACKED_LOCKS
- if( Lock->Depth ) {
- Lock->Depth --;
- return ;
- }
- #endif
-
- #if LOCK_DISABLE_INTS
- // Lock->IF can change anytime once Lock->Lock is zeroed
- if(Lock->IF) {
- Lock->Lock = 0;
- __ASM__ ("sti");
- }
- else {
- Lock->Lock = 0;
- }
- #else
- Lock->Lock = 0;
- #endif
-}