EventPipeBufferManager *buffer_manager,
EventPipeBuffer *buffer);
+// Attempt to reserve space for a buffer
+static
+bool
+buffer_manager_try_reserve_buffer(
+ EventPipeBufferManager *buffer_manager,
+ uint32_t request_size);
+
+// Release a reserved buffer budget
+static
+void
+buffer_manager_release_buffer(
+ EventPipeBufferManager *buffer_manager,
+ uint32_t size);
+
// An iterator that can enumerate all the events which have been written into this buffer manager.
// Initially the iterator starts uninitialized and get_current_event () returns NULL. Calling move_next_xxx ()
// attempts to advance the cursor to the next event. If there is no event prior to stop_timestamp then
return ret_buffer;
}
+bool
+buffer_manager_try_reserve_buffer(
+ EventPipeBufferManager *buffer_manager,
+ uint32_t request_size)
+{
+ uint64_t iters = 0;
+ size_t old_size_of_all_buffers;
+ size_t new_size_of_all_buffers;
+ do {
+ old_size_of_all_buffers = buffer_manager->size_of_all_buffers;
+ new_size_of_all_buffers = old_size_of_all_buffers + request_size;
+ iters++;
+ if (iters % 64 == 0) {
+ ep_rt_thread_sleep (0); // yield the thread to the scheduler in case we're in high contention
+ }
+ } while (new_size_of_all_buffers <= buffer_manager->max_size_of_all_buffers && ep_rt_atomic_compare_exchange_size_t (&buffer_manager->size_of_all_buffers, old_size_of_all_buffers, new_size_of_all_buffers) != old_size_of_all_buffers);
+
+ return new_size_of_all_buffers <= buffer_manager->max_size_of_all_buffers;
+}
+
+void
+buffer_manager_release_buffer(
+ EventPipeBufferManager *buffer_manager,
+ uint32_t size)
+{
+ uint64_t iters = 0;
+ size_t old_size_of_all_buffers;
+ size_t new_size_of_all_buffers;
+ do {
+ old_size_of_all_buffers = buffer_manager->size_of_all_buffers;
+ new_size_of_all_buffers = old_size_of_all_buffers - size;
+ iters++;
+ if (iters % 64 == 0) {
+ ep_rt_thread_sleep (0); // yield the thread to the scheduler in case we're in high contention
+ }
+ } while (new_size_of_all_buffers >= 0 && ep_rt_atomic_compare_exchange_size_t (&buffer_manager->size_of_all_buffers, old_size_of_all_buffers, new_size_of_all_buffers) != old_size_of_all_buffers);
+}
+
#ifdef EP_CHECKED_BUILD
bool
ep_buffer_list_ensure_consistency (EventPipeBufferList *buffer_list)
EventPipeBuffer *new_buffer = NULL;
EventPipeBufferList *thread_buffer_list = NULL;
EventPipeSequencePoint* sequence_point = NULL;
- bool allocate_new_buffer = false;
+ uint32_t sequence_number = 0;
+
+ // Pick a buffer size by multiplying the base buffer size by the number of buffers already allocated for this thread.
+ uint32_t size_multiplier = ep_thread_session_state_get_buffer_count_estimate(thread_session_state) + 1;
+ EP_ASSERT(size_multiplier > 0);
+
+ // Pick the base buffer size. Checked builds have a smaller size to stress the allocate path more.
+#ifdef EP_CHECKED_BUILD
+ uint32_t base_buffer_size = 30 * 1024; // 30K
+#else
+ uint32_t base_buffer_size = 100 * 1024; // 100K
+#endif
+ uint32_t buffer_size = base_buffer_size * size_multiplier;
+ EP_ASSERT(buffer_size > 0);
+
+
+ buffer_size = EP_MAX (request_size, buffer_size);
+
+ // Don't allow the buffer size to exceed 1MB.
+ const uint32_t max_buffer_size = 1024 * 1024;
+ buffer_size = EP_MIN (buffer_size, max_buffer_size);
+
+
+ // Make sure that buffer size >= request size so that the buffer size does not
+ // determine the max event size.
+ EP_ASSERT (request_size <= buffer_size);
+
+ // Make the buffer size fit into with pagesize-aligned block, since ep_rt_valloc0 expects page-aligned sizes to be passed as arguments
+ buffer_size = (buffer_size + ep_rt_system_get_alloc_granularity () - 1) & ~(uint32_t)(ep_rt_system_get_alloc_granularity () - 1);
+
+ // Attempt to reserve the necessary buffer size
+ EP_ASSERT(buffer_size > 0);
+ ep_return_null_if_nok(buffer_manager_try_reserve_buffer(buffer_manager, buffer_size));
// Allocating a buffer requires us to take the lock.
EP_SPIN_LOCK_ENTER (&buffer_manager->rt_lock, section1)
thread_buffer_list = NULL;
}
- // Determine if policy allows us to allocate another buffer
- size_t available_buffer_size;
- available_buffer_size = buffer_manager->max_size_of_all_buffers - buffer_manager->size_of_all_buffers;
- if (request_size <= available_buffer_size)
- allocate_new_buffer = true;
-
- if (allocate_new_buffer) {
- // Pick a buffer size by multiplying the base buffer size by the number of buffers already allocated for this thread.
- uint32_t size_multiplier = ep_thread_session_state_get_buffer_list (thread_session_state)->buffer_count + 1;
-
- // Pick the base buffer size based. Checked builds have a smaller size to stress the allocate/steal path more.
-#ifdef EP_CHECKED_BUILD
- uint32_t base_buffer_size = 30 * 1024; // 30K
-#else
- uint32_t base_buffer_size = 100 * 1024; // 100K
-#endif
- uint32_t buffer_size = base_buffer_size * size_multiplier;
-
- // Make sure that buffer size >= request size so that the buffer size does not
- // determine the max event size.
- EP_ASSERT (request_size <= available_buffer_size);
-
- buffer_size = EP_MAX (request_size, buffer_size);
- buffer_size = EP_MIN ((uint32_t)buffer_size, (uint32_t)available_buffer_size);
-
- // Don't allow the buffer size to exceed 1MB.
- const uint32_t max_buffer_size = 1024 * 1024;
- buffer_size = EP_MIN (buffer_size, max_buffer_size);
-
- // Make the buffer size fit into with pagesize-aligned block, since ep_rt_valloc0 expects page-aligned sizes to be passed as arguments
- buffer_size = (buffer_size + ep_rt_system_get_alloc_granularity () - 1) & ~(uint32_t)(ep_rt_system_get_alloc_granularity () - 1);
-
- // The sequence counter is exclusively mutated on this thread so this is a thread-local read.
- uint32_t sequence_number = ep_thread_session_state_get_volatile_sequence_number (thread_session_state);
- new_buffer = ep_buffer_alloc (buffer_size, ep_thread_session_state_get_thread (thread_session_state), sequence_number);
- ep_raise_error_if_nok_holding_spin_lock (new_buffer != NULL, section1);
-
- buffer_manager->size_of_all_buffers += buffer_size;
- if (buffer_manager->sequence_point_alloc_budget != 0) {
- // sequence point bookkeeping
- if (buffer_size >= buffer_manager->remaining_sequence_point_alloc_budget) {
- sequence_point = ep_sequence_point_alloc ();
- if (sequence_point) {
- buffer_manager_init_sequence_point_thread_list (buffer_manager, sequence_point);
- ep_raise_error_if_nok_holding_spin_lock (buffer_manager_enqueue_sequence_point (buffer_manager, sequence_point), section1);
- sequence_point = NULL;
- }
- buffer_manager->remaining_sequence_point_alloc_budget = buffer_manager->sequence_point_alloc_budget;
- } else {
- buffer_manager->remaining_sequence_point_alloc_budget -= buffer_size;
+ // The sequence counter is exclusively mutated on this thread so this is a thread-local read.
+ sequence_number = ep_thread_session_state_get_volatile_sequence_number (thread_session_state);
+ new_buffer = ep_buffer_alloc (buffer_size, ep_thread_session_state_get_thread (thread_session_state), sequence_number);
+ ep_raise_error_if_nok_holding_spin_lock (new_buffer != NULL, section1);
+
+ if (buffer_manager->sequence_point_alloc_budget != 0) {
+ // sequence point bookkeeping
+ if (buffer_size >= buffer_manager->remaining_sequence_point_alloc_budget) {
+ sequence_point = ep_sequence_point_alloc ();
+ if (sequence_point) {
+ buffer_manager_init_sequence_point_thread_list (buffer_manager, sequence_point);
+ ep_raise_error_if_nok_holding_spin_lock (buffer_manager_enqueue_sequence_point (buffer_manager, sequence_point), section1);
+ sequence_point = NULL;
}
+ buffer_manager->remaining_sequence_point_alloc_budget = buffer_manager->sequence_point_alloc_budget;
+ } else {
+ buffer_manager->remaining_sequence_point_alloc_budget -= buffer_size;
}
+ }
#ifdef EP_CHECKED_BUILD
- buffer_manager->num_buffers_allocated++;
+ buffer_manager->num_buffers_allocated++;
#endif // EP_CHECKED_BUILD
- }
// Set the buffer on the thread.
if (new_buffer != NULL)
ep_buffer_free (new_buffer);
new_buffer = NULL;
+ buffer_manager_release_buffer(buffer_manager, buffer_size);
+
ep_exit_error_handler ();
}
EP_ASSERT (buffer_manager != NULL);
if (buffer) {
- buffer_manager->size_of_all_buffers -= ep_buffer_get_size (buffer);
+ buffer_manager_release_buffer(buffer_manager, ep_buffer_get_size (buffer));
ep_buffer_free (buffer);
#ifdef EP_CHECKED_BUILD
buffer_manager->num_buffers_allocated--;
projects / platform / upstream / dotnet / runtime.git / commitdiff