mempool: Introduce optional stride parameter

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ic7119bb33f86cf72c73c2d50dbe55e4769ce0b22

diff --git a/include/rseq/compiler.h b/include/rseq/compiler.h
index 3df18cdbf84082417dd1725abd94e21df7b7bf5a..9a202cde9246291ec831e216c808d3905867c707 100644 (file)
--- a/include/rseq/compiler.h
+++ b/include/rseq/compiler.h
@@ -92,4 +92,15 @@
        )
 #endif
 
+/*
+ * RSEQ_PARAM_SELECT_ARG1
+ *
+ * Select second argument. Use inside macros to implement optional last
+ * macro argument, such as:
+ *
+ * #define macro(_a, _b, _c, _optional...) \
+ *     RSEQ_PARAM_SELECT_ARG1(_, ##_optional, do_default_macro())
+ */
+#define RSEQ_PARAM_SELECT_ARG1(_arg0, _arg1, ...) _arg1
+
 #endif  /* _RSEQ_COMPILER_H */

diff --git a/include/rseq/mempool.h b/include/rseq/mempool.h
index 58ebbac27aafb876bc37c85b1ef839e45132a347..f321313a112b4ec3e09bde9cd0e764529f38e26d 100644 (file)
--- a/include/rseq/mempool.h
+++ b/include/rseq/mempool.h
@@ -31,9 +31,9 @@ extern "C" {
  * The stride *must* match for all objects belonging to a given pool
  * between arguments to:
  *
- * - rseq_percpu_pool_create(),
- * - __rseq_percpu_free(),
- * - __rseq_percpu_ptr().
+ * - rseq_mempool_create(),
+ * - rseq_percpu_ptr().
+ * - rseq_percpu_free(),
  */
 #if RSEQ_BITS_PER_LONG == 64
 # define RSEQ_PERCPU_STRIDE    (1U << 24)      /* 64-bit stride: 16MB */
@@ -153,15 +153,16 @@ void __rseq_percpu *rseq_percpu_zmalloc(struct rseq_mempool *pool);
  * - rseq_percpu_pool_set_malloc(),
  * - rseq_percpu_pool_set_zmalloc().
  *
- * The @stride argument to __rseq_percpu_free() is a configurable
+ * The @stride optional argument to rseq_percpu_free() is a configurable
  * stride, which must match the stride received by pool creation.
- * rseq_percpu_free() uses the default RSEQ_PERCPU_STRIDE stride.
+ * If the argument is not present, use the default RSEQ_PERCPU_STRIDE.
  *
  * This API is MT-safe.
  */
-void __rseq_percpu_free(void __rseq_percpu *ptr, size_t percpu_stride);
+void librseq_percpu_free(void __rseq_percpu *ptr, size_t percpu_stride);
 
-#define rseq_percpu_free(ptr)  __rseq_percpu_free(ptr, RSEQ_PERCPU_STRIDE)
+#define rseq_percpu_free(_ptr, _stride...)             \
+       librseq_percpu_free(_ptr, RSEQ_PARAM_SELECT_ARG1(_, ##_stride, RSEQ_PERCPU_STRIDE))
 
 /*
  * rseq_percpu_ptr: Offset a per-cpu pointer for a given CPU.
@@ -175,20 +176,19 @@ void __rseq_percpu_free(void __rseq_percpu *ptr, size_t percpu_stride);
  * - rseq_percpu_pool_set_malloc(),
  * - rseq_percpu_pool_set_zmalloc().
  *
- * The macros rseq_percpu_ptr() and __rseq_percpu_ptr() preserve the
- * type of the @ptr parameter for the returned pointer, but removes the
- * __rseq_percpu annotation.
+ * The macro rseq_percpu_ptr() preserves the type of the @ptr parameter
+ * for the returned pointer, but removes the __rseq_percpu annotation.
  *
- * The macro __rseq_percpu_ptr() takes a configurable @stride argument,
- * whereas rseq_percpu_ptr() uses the RSEQ_PERCPU_STRIDE default stride.
+ * The macro rseq_percpu_ptr() takes an optional @stride argument. If
+ * the argument is not present, use the default RSEQ_PERCPU_STRIDE.
  * This must match the stride used for pool creation.
  *
  * This API is MT-safe.
  */
-#define __rseq_percpu_ptr(ptr, cpu, stride) \
-       ((__typeof__(*(ptr)) *) ((uintptr_t) (ptr) + ((unsigned int) (cpu) * (uintptr_t) (stride))))
-
-#define rseq_percpu_ptr(ptr, cpu) __rseq_percpu_ptr(ptr, cpu, RSEQ_PERCPU_STRIDE)
+#define rseq_percpu_ptr(_ptr, _cpu, _stride...)                \
+       ((__typeof__(*(_ptr)) *) ((uintptr_t) (_ptr) +  \
+               ((unsigned int) (_cpu) *                \
+                       (uintptr_t) RSEQ_PARAM_SELECT_ARG1(_, ##_stride, RSEQ_PERCPU_STRIDE))))
 
 /*
  * rseq_mempool_set_create: Create a pool set.

diff --git a/src/rseq-mempool.c b/src/rseq-mempool.c
index 1681f74591b04f0ece7741456b8bebcd0668ff98..1ece00e7f71d0c28e9a26ca02eaab377132e98d9 100644 (file)
--- a/src/rseq-mempool.c
+++ b/src/rseq-mempool.c
@@ -655,7 +655,7 @@ void clear_alloc_slot(struct rseq_mempool *pool, size_t item_offset)
        bitmap[k] &= ~mask;
 }
 
-void __rseq_percpu_free(void __rseq_percpu *_ptr, size_t percpu_stride)
+void librseq_percpu_free(void __rseq_percpu *_ptr, size_t percpu_stride)
 {
        uintptr_t ptr = (uintptr_t) _ptr;
        void *range_base = (void *) (ptr & (~(percpu_stride - 1)));

diff --git a/tests/mempool_test.c b/tests/mempool_test.c
index 119c18cd9054fd69dadc26fa4a2d35ac2f4cc72a..39d5b3b84cb7edae2e4a863446bd6de7a07c1ddc 100644 (file)
--- a/tests/mempool_test.c
+++ b/tests/mempool_test.c
@@ -57,7 +57,7 @@ static void test_mempool_fill(size_t stride)
                if (!ptr)
                        break;
                /* Link items in cpu 0. */
-               cpuptr = __rseq_percpu_ptr(ptr, 0, stride);
+               cpuptr = rseq_percpu_ptr(ptr, 0, stride);
                cpuptr->backref = ptr;
                /* Randomize items in list. */
                if (count & 1)
@@ -72,7 +72,7 @@ static void test_mempool_fill(size_t stride)
        list_for_each_entry(iter, &list, node) {
                ptr = iter->backref;
                for (i = 0; i < CPU_SETSIZE; i++) {
-                       struct test_data *cpuptr = __rseq_percpu_ptr(ptr, i, stride);
+                       struct test_data *cpuptr = rseq_percpu_ptr(ptr, i, stride);
 
                        if (cpuptr->value != 0)
                                abort();
@@ -84,7 +84,7 @@ static void test_mempool_fill(size_t stride)
 
        list_for_each_entry_safe(iter, tmp, &list, node) {
                ptr = iter->backref;
-               __rseq_percpu_free(ptr, stride);
+               rseq_percpu_free(ptr, stride);
        }
        ret = rseq_mempool_destroy(mempool);
        ok(ret == 0, "Destroy mempool");