Adds fetch_sub/decrement to AtomicUint32

Test: Sanity check by using methods
Change-Id: Ica1a41f4cfd8e541f49b907600c8911e77921bc1

3 files changed, 34 insertions, 0 deletions

diff --git a/platform/include/chre/platform/atomic.h b/platform/include/chre/platform/atomic.h
index b01fd811..753c94df 100644
--- a/platform/include/chre/platform/atomic.h
+++ b/platform/include/chre/platform/atomic.h
@@ -98,6 +98,22 @@ class AtomicUint32 : public AtomicUint32Base,
    * @return The previous value of the object.
    */
   uint32_t fetch_increment();
+
+  /**
+   * Atomically subtracts the argument from the current value of the object.
+   *
+   * @param The amount which the object should be decreased by.
+   *
+   * @return The previous value of the object.
+   */
+  uint32_t fetch_sub(uint32_t arg);
+
+  /**
+   * Atomically decrements the value stored in the atomic object by 1.
+   *
+   * @return The previous value of the object.
+   */
+  uint32_t fetch_decrement();
 };
 
 }  // namespace chre
diff --git a/platform/linux/include/chre/target_platform/atomic_base_impl.h b/platform/linux/include/chre/target_platform/atomic_base_impl.h
index 850085d5..68c1f84c 100644
--- a/platform/linux/include/chre/target_platform/atomic_base_impl.h
+++ b/platform/linux/include/chre/target_platform/atomic_base_impl.h
@@ -53,6 +53,14 @@ inline uint32_t AtomicUint32::fetch_increment() {
   return mAtomic.fetch_add(1);
 }
 
+inline uint32_t AtomicUint32::fetch_sub(uint32_t arg) {
+  return mAtomic.fetch_sub(arg);
+}
+
+inline uint32_t AtomicUint32::fetch_decrement() {
+  return mAtomic.fetch_sub(1);
+}
+
 }  // namespace chre
 
 #endif  // CHRE_PLATFORM_LINUX_ATOMIC_BASE_IMPL_H_
diff --git a/platform/slpi/include/chre/target_platform/atomic_base_impl.h b/platform/slpi/include/chre/target_platform/atomic_base_impl.h
index 6b734ef8..46f9d725 100644
--- a/platform/slpi/include/chre/target_platform/atomic_base_impl.h
+++ b/platform/slpi/include/chre/target_platform/atomic_base_impl.h
@@ -66,6 +66,16 @@ inline uint32_t AtomicUint32::fetch_increment() {
   return qurt_atomic_add_return(&mValue, 1);
 }
 
+inline uint32_t AtomicUint32::fetch_sub(uint32_t arg) {
+  qurt_atomic_barrier();
+  return qurt_atomic_sub_return(&mValue, arg);
+}
+
+inline uint32_t AtomicUint32::fetch_decrement() {
+  qurt_atomic_barrier();
+  return qurt_atomic_sub_return(&mValue, 1);
+}
+
 }  // namespace chre
 
 #endif  // CHRE_PLATFORM_SLPI_ATOMIC_BASE_IMPL_H_