diff options
Diffstat (limited to 'src/util')
-rw-r--r-- | src/util/mutex.c | 20 | ||||
-rw-r--r-- | src/util/mutex.h | 15 |
2 files changed, 35 insertions, 0 deletions
diff --git a/src/util/mutex.c b/src/util/mutex.c new file mode 100644 index 0000000..86ffcf5 --- /dev/null +++ b/src/util/mutex.c @@ -0,0 +1,20 @@ +#include "../util/mutex.h" + +unsigned char lock_mutex(struct Mutex* m, unsigned long pid) { + if (m->pid == NULL_PID) { + m->pid = pid; + return 0; + } + return 1; +} + +// Eventually, there will need to be a hook into the scheduling mechanism +// that checks the currently running process and check that against the +// mutex's pid lock +unsigned char release_mutex(struct Mutex* m, unsigned long pid) { + if (m->pid == pid) { + m->pid = NULL_PID; + return 0; + } + return 1; +} diff --git a/src/util/mutex.h b/src/util/mutex.h new file mode 100644 index 0000000..8c9a097 --- /dev/null +++ b/src/util/mutex.h @@ -0,0 +1,15 @@ +#ifndef SYS_MUTEX_H +#define SYS_MUTEX_H + +#define NULL_PID 0 +#define SCHED_PID 1 + +struct Mutex { + unsigned long* addr; + unsigned long pid; +}; + +unsigned char lock_mutex(struct Mutex*, unsigned long); +unsigned char release_mutex(struct Mutex*, unsigned long); + +#endif |