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-rw-r--r--src/library/std/mutex.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/src/library/std/mutex.c b/src/library/std/mutex.c
new file mode 100644
index 0000000..ac0ee8f
--- /dev/null
+++ b/src/library/std/mutex.c
@@ -0,0 +1,22 @@
+#include <mutex.h>
+
+static uint32_t atomic_exchange(uint32_t* ptr, uint32_t newval) {
+ uint32_t r;
+ asm volatile("xchg (%%ecx), %%eax" : "=a"(r) : "c"(ptr), "a"(newval));
+ return r;
+}
+
+void mutex_lock(uint32_t* mutex) {
+ while (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) {
+ thread_sleep(1);
+ }
+}
+
+int mutex_lockE(uint32_t* mutex) {
+ if (atomic_exchange(mutex, MUTEX_LOCKED) == MUTEX_LOCKED) return 0;
+ return 1;
+}
+
+void mutex_unlock(uint32_t* mutex) {
+ *mutex = MUTEX_UNLOCKED;
+}