diff options
Diffstat (limited to 'src/lib9/lock-pthread.c')
-rw-r--r-- | src/lib9/lock-pthread.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/src/lib9/lock-pthread.c b/src/lib9/lock-pthread.c new file mode 100644 index 00000000..689261f6 --- /dev/null +++ b/src/lib9/lock-pthread.c @@ -0,0 +1,54 @@ +#include <u.h> +#include <unistd.h> +#include <sys/time.h> +#include <sched.h> +#include <libc.h> + +static pthread_mutex_t initmutex = PTHREAD_MUTEX_INITIALIZER; + +static void +lockinit(Lock *lk) +{ + pthread_mutexattr_t attr; + + pthread_mutex_lock(&initmutex); + if(lk->init == 0){ + pthread_mutexattr_init(&attr); + pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL); + pthread_mutex_init(&lk->mutex, &attr); + pthread_mutexattr_destroy(&attr); + lk->init = 1; + } + pthread_mutex_unlock(&initmutex); +} + +void +lock(Lock *lk) +{ + if(!lk->init) + lockinit(lk); + if(pthread_mutex_lock(&lk->mutex) != 0) + abort(); +} + +int +canlock(Lock *lk) +{ + int r; + + if(!lk->init) + lockinit(lk); + r = pthread_mutex_trylock(&lk->mutex); + if(r == 0) + return 1; + if(r == EBUSY) + return 0; + abort(); +} + +void +unlock(Lock *lk) +{ + if(pthread_mutex_unlock(&lk->mutex) != 0) + abort(); +} |