ogl_beamforming

ogl_beamformer_lib.c (21498B)

---

 /* See LICENSE for license details. */
 #include "../compiler.h"
 
 #define BEAMFORMER_IMPORT static
 
 #include "../beamformer.h"
 
 #include "../util.h"
 
 #include "../generated/beamformer.meta.c"
 #include "../beamformer_parameters.h"
 #include "ogl_beamformer_lib_base.h"
 
 #if OS_LINUX
 #include "../os_linux.c"
 #elif OS_WINDOWS
 #include "../os_win32.c"
 
 W32(iptr) OpenFileMappingA(u32, b32, c8 *);
 
 #else
 #error Unsupported Platform
 #endif
 
 #include "../util_os.c"
 #include "../beamformer_shared_memory.c"
 
 global struct {
 	BeamformerSharedMemory *bp;
 	i32                     timeout_ms;
 	BeamformerLibErrorKind  last_error;
 } g_beamformer_library_context;
 
 #if OS_LINUX
 
 function void *
 os_open_shared_memory_area(char *name)
 {
 	void *result = 0;
 	i32 fd = shm_open(name, O_RDWR, S_IRUSR|S_IWUSR);
 	if (fd > 0) {
 		void *new = mmap(0, BEAMFORMER_SHARED_MEMORY_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
 		if (new != MAP_FAILED) result = new;
 		close(fd);
 	}
 	return result;
 }
 
 #elif OS_WINDOWS
 
 W32(b32) UnmapViewOfFile(void *);
 
 function b32
 os_reserve_region_locks(void)
 {
 	u8 buffer[1024];
 	Stream sb = {.data = buffer, .cap = countof(buffer)};
 	stream_append_s8(&sb, s8(OS_SHARED_MEMORY_NAME "_lock_"));
 
 	i32 start_index    = sb.widx;
 	u32 reserved_count = 0;
 	for EachElement(os_w32_shared_memory_semaphores, it) {
 		stream_reset(&sb, start_index);
 		stream_append_u64(&sb, it);
 		stream_append_byte(&sb, 0);
 		os_w32_shared_memory_semaphores[it] = os_w32_create_semaphore((c8 *)sb.data, 1, 1);
 		if InvalidHandle(os_w32_shared_memory_semaphores[it])
 			break;
 		reserved_count++;
 	}
 
 	b32 result = reserved_count == countof(os_w32_shared_memory_semaphores);
 	if (!result) {
 		for (u32 i = 0; i < reserved_count; i++)
 			CloseHandle(os_w32_shared_memory_semaphores[i].value[0]);
 	}
 
 	return result;
 }
 
 function void *
 os_open_shared_memory_area(char *name)
 {
 	iptr h = OpenFileMappingA(FILE_MAP_ALL_ACCESS, 0, name);
 	void *result = 0;
 	if (h != INVALID_FILE) {
 		void *new = MapViewOfFile(h, FILE_MAP_ALL_ACCESS, 0, 0, BEAMFORMER_SHARED_MEMORY_SIZE);
 		if (new && os_reserve_region_locks())
 			result = new;
 		if (new && !result)
 			UnmapViewOfFile(new);
 		CloseHandle(h);
 	}
 	return result;
 }
 
 #endif
 
 #define lib_error_check(c, e) lib_error_check_(c, BeamformerLibErrorKind_##e)
 function b32
 lib_error_check_(b32 condition, BeamformerLibErrorKind error_kind)
 {
 	b32 result = condition;
 	if (!result) g_beamformer_library_context.last_error = error_kind;
 	assert(result);
 	return result;
 }
 
 function b32
 check_shared_memory(void)
 {
 	if unlikely(!g_beamformer_library_context.bp) {
 		g_beamformer_library_context.bp = os_open_shared_memory_area(OS_SHARED_MEMORY_NAME);
 		if (lib_error_check(g_beamformer_library_context.bp != 0, SharedMemory)) {
 			u32 version = g_beamformer_library_context.bp->version;
 			lib_error_check(version == BEAMFORMER_SHARED_MEMORY_VERSION, VersionMismatch);
 		}
 	}
 
 	b32 result = 0;
 	if likely(g_beamformer_library_context.bp)
 		result = lib_error_check(likely(!g_beamformer_library_context.bp->invalid), InvalidAccess);
 	return result;
 }
 
 function b32
 valid_parameter_block(u32 block)
 {
 	b32 result = check_shared_memory();
 	if (result) {
 		result = lib_error_check(block < g_beamformer_library_context.bp->reserved_parameter_blocks,
 		                         ParameterBlockUnallocated);
 	}
 	return result;
 }
 
 function BeamformWork *
 try_push_work_queue(void)
 {
 	BeamformWork *result = beamform_work_queue_push(&g_beamformer_library_context.bp->external_work_queue);
 	lib_error_check(result != 0, WorkQueueFull);
 	return result;
 }
 
 function b32
 lib_try_lock(i32 lock, i32 timeout_ms)
 {
 	b32 result = beamformer_shared_memory_take_lock(g_beamformer_library_context.bp, lock, (u32)timeout_ms);
 	lib_error_check(result, SyncVariable);
 	return result;
 }
 
 function void
 lib_release_lock(i32 lock)
 {
 	beamformer_shared_memory_release_lock(g_beamformer_library_context.bp, lock);
 }
 
 u32
 beamformer_get_api_version(void)
 {
 	return BEAMFORMER_SHARED_MEMORY_VERSION;
 }
 
 const char *
 beamformer_error_string(BeamformerLibErrorKind kind)
 {
 	#define X(type, num, string) string,
 	local_persist const char *error_string_table[] = {BEAMFORMER_LIB_ERRORS "invalid error kind"};
 	#undef X
 	return error_string_table[MIN(kind, countof(error_string_table) - 1)];
 }
 
 BeamformerLibErrorKind
 beamformer_get_last_error(void)
 {
 	return g_beamformer_library_context.last_error;
 }
 
 const char *
 beamformer_get_last_error_string(void)
 {
 	return beamformer_error_string(beamformer_get_last_error());
 }
 
 void
 beamformer_set_global_timeout(u32 timeout_ms)
 {
 	g_beamformer_library_context.timeout_ms = timeout_ms;
 }
 
 b32
 beamformer_reserve_parameter_blocks(uint32_t count)
 {
 	b32 result = 0;
 	if (check_shared_memory() &&
 	    lib_error_check(count <= BeamformerMaxParameterBlockSlots, ParameterBlockOverflow))
 	{
 		g_beamformer_library_context.bp->reserved_parameter_blocks = count;
 		result = 1;
 	}
 	return result;
 }
 
 function b32
 validate_pipeline(i32 *shaders, u32 shader_count, BeamformerDataKind data_kind)
 {
 	b32 result = lib_error_check(shader_count <= BeamformerMaxComputeShaderStages, ComputeStageOverflow);
 	if (result) {
 		for (u32 i = 0; i < shader_count; i++)
 			result &= BETWEEN(shaders[i], BeamformerShaderKind_ComputeFirst, BeamformerShaderKind_ComputeLast);
 		if (!result) {
 			g_beamformer_library_context.last_error = BeamformerLibErrorKind_InvalidComputeStage;
 		} else if (shaders[0] != BeamformerShaderKind_Demodulate &&
 		           shaders[0] != BeamformerShaderKind_Decode)
 		{
 			g_beamformer_library_context.last_error = BeamformerLibErrorKind_InvalidStartShader;
 			result = 0;
 		} else if (shaders[0] == BeamformerShaderKind_Demodulate &&
 		           !(data_kind == BeamformerDataKind_Int16 || data_kind == BeamformerDataKind_Float32))
 		{
 			g_beamformer_library_context.last_error = BeamformerLibErrorKind_InvalidDemodulationDataKind;
 			result = 0;
 		}
 	}
 	return result;
 }
 
 function b32
 validate_simple_parameters(BeamformerSimpleParameters *bp)
 {
 	b32 result = check_shared_memory();
 	if (result) {
 		result &= bp->channel_count <= BeamformerMaxChannelCount;
 		if (!result)
 			g_beamformer_library_context.last_error = BeamformerLibErrorKind_InvalidSimpleParameters;
 	}
 	return result;
 }
 
 function b32
 parameter_block_region_upload(void *data, u32 size, u32 block, BeamformerParameterBlockRegions region_id,
                               u32 block_offset, i32 timeout_ms)
 {
 	i32 lock   = BeamformerSharedMemoryLockKind_Count + (i32)block;
 	b32 result = valid_parameter_block(block) && lib_try_lock(lock, timeout_ms);
 	if (result) {
 		mem_copy((u8 *)beamformer_parameter_block(g_beamformer_library_context.bp, block) + block_offset,
 		         data, size);
 		mark_parameter_block_region_dirty(g_beamformer_library_context.bp, block, region_id);
 		lib_release_lock(lock);
 	}
 	return result;
 }
 
 b32
 beamformer_set_pipeline_stage_parameters_at(u32 stage_index, i32 parameter, u32 block)
 {
 	u32 offset  = BeamformerParameterBlockRegionOffsets[BeamformerParameterBlockRegion_ComputePipeline];
 	offset     += offsetof(BeamformerComputePipeline, parameters);
 	offset     += (stage_index % BeamformerMaxComputeShaderStages) * sizeof(BeamformerShaderParameters);
 	b32 result  = parameter_block_region_upload(&parameter, sizeof(BeamformerShaderParameters), block,
 	                                            BeamformerParameterBlockRegion_ComputePipeline, offset,
 	                                            g_beamformer_library_context.timeout_ms);
 	return result;
 }
 
 b32
 beamformer_set_pipeline_stage_parameters(u32 stage_index, i32 parameter)
 {
 	b32 result = beamformer_set_pipeline_stage_parameters_at(stage_index, parameter, 0);
 	return result;
 }
 
 b32
 beamformer_push_pipeline_at(i32 *shaders, u32 shader_count, BeamformerDataKind data_kind, u32 block)
 {
 	b32 result = 0;
 	if (check_shared_memory() && validate_pipeline(shaders, shader_count, data_kind)) {
 		i32 lock = BeamformerSharedMemoryLockKind_Count + (i32)block;
 		if (valid_parameter_block(block) && lib_try_lock(lock, g_beamformer_library_context.timeout_ms)) {
 			BeamformerParameterBlock *b = beamformer_parameter_block(g_beamformer_library_context.bp, block);
 			mem_copy(&b->pipeline.shaders, shaders, shader_count * sizeof(*shaders));
 			mark_parameter_block_region_dirty(g_beamformer_library_context.bp, block,
 			                                  BeamformerParameterBlockRegion_ComputePipeline);
 			b->pipeline.shader_count = shader_count;
 			b->pipeline.data_kind    = data_kind;
 			lib_release_lock(lock);
 			result = 1;
 		}
 	}
 	return result;
 }
 
 b32
 beamformer_push_pipeline(i32 *shaders, u32 shader_count, BeamformerDataKind data_kind)
 {
 	b32 result = beamformer_push_pipeline_at(shaders, shader_count, data_kind, 0);
 	return result;
 }
 
 function b32
 beamformer_create_filter_base(BeamformerFilterParameters params, u8 filter_slot, u8 parameter_block)
 {
 	b32 result = 0;
 	if (check_shared_memory()) {
 		BeamformWork *work = try_push_work_queue();
 		if (work) {
 			BeamformerCreateFilterContext *ctx = &work->create_filter_context;
 			work->kind = BeamformerWorkKind_CreateFilter;
 			ctx->parameters      = params;
 			ctx->filter_slot     = filter_slot     % BeamformerFilterSlots;
 			ctx->parameter_block = parameter_block % BeamformerMaxParameterBlockSlots;
 			beamform_work_queue_push_commit(&g_beamformer_library_context.bp->external_work_queue);
 			result = 1;
 		}
 	}
 	return result;
 }
 
 b32
 beamformer_create_filter(BeamformerFilterKind kind, void *filter_parameters, u32 filter_size,
                          f32 sampling_frequency, b32 complex, u8 filter_slot, u8 parameter_block)
 {
 	b32 result = 0;
 	if (lib_error_check(kind >= 0 && kind < BeamformerFilterKind_Count, InvalidFilterKind)) {
 		BeamformerFilterParameters fp = {0};
 		/* NOTE(rnp): any parameter struct works as base offset */
 		filter_size = MIN(filter_size, sizeof(fp) - offsetof(BeamformerFilterParameters, kaiser));
 		mem_copy(&fp.kaiser, filter_parameters, filter_size);
 		fp.kind               = kind;
 		fp.complex            = complex != 0;
 		fp.sampling_frequency = sampling_frequency;
 		result = beamformer_create_filter_base(fp, filter_slot, parameter_block);
 	}
 	return result;
 }
 
 function void
 beamformer_flush_commands(void)
 {
 	i32 lock = BeamformerSharedMemoryLockKind_DispatchCompute;
 	beamformer_shared_memory_take_lock(g_beamformer_library_context.bp, lock, 0);
 }
 
 #define BEAMFORMER_UPLOAD_FNS \
 	X(channel_mapping,               i16, 1, ChannelMapping) \
 	X(focal_vectors,                 f32, 2, FocalVectors)   \
 	X(sparse_elements,               i16, 1, SparseElements) \
 	X(transmit_receive_orientations, u8,  1, TransmitReceiveOrientations)
 
 #define X(name, dtype, elements, region_name) \
 b32 beamformer_push_##name ##_at(dtype *data, u32 count, u32 block) { \
 	b32 result = 0; \
 	if (lib_error_check(count <= countof(((BeamformerParameterBlock *)0)->name), BufferOverflow)) { \
 		result = parameter_block_region_upload(data, count * elements * sizeof(dtype), block, \
 		                                       BeamformerParameterBlockRegion_##region_name,  \
 		                                       offsetof(BeamformerParameterBlock, name),      \
 		                                       g_beamformer_library_context.timeout_ms);      \
 	} \
 	return result; \
 }
 BEAMFORMER_UPLOAD_FNS
 #undef X
 
 #define X(name, dtype, ...) \
 b32 beamformer_push_##name (dtype *data, u32 count) { \
 	b32 result = beamformer_push_##name ##_at(data, count, 0); \
 	return result; \
 }
 BEAMFORMER_UPLOAD_FNS
 #undef X
 
 function b32
 beamformer_push_data_base(void *data, u32 data_size, i32 timeout_ms, u32 block)
 {
 	b32 result = 0;
 	Arena scratch = beamformer_shared_memory_scratch_arena(g_beamformer_library_context.bp);
 	BeamformerParameterBlock *b  = beamformer_parameter_block(g_beamformer_library_context.bp, block);
 	BeamformerParameters     *bp = &b->parameters;
 	BeamformerDataKind data_kind = b->pipeline.data_kind;
 
 	u32 size     = bp->acquisition_count * bp->sample_count * bp->channel_count * beamformer_data_kind_byte_size[data_kind];
 	u32 raw_size = bp->raw_data_dimensions.x * bp->raw_data_dimensions.y * beamformer_data_kind_byte_size[data_kind];
 
 	if (lib_error_check(size <= arena_capacity(&scratch, u8), BufferOverflow) &&
 	    lib_error_check(size <= data_size && data_size == raw_size, DataSizeMismatch))
 	{
 		if (lib_try_lock(BeamformerSharedMemoryLockKind_UploadRF, timeout_ms)) {
 			if (lib_try_lock(BeamformerSharedMemoryLockKind_ScratchSpace, 0)) {
 				u32 channel_count      = bp->channel_count;
 				u32 out_channel_stride = beamformer_data_kind_byte_size[data_kind] * bp->sample_count * bp->acquisition_count;
 				u32 in_channel_stride  = beamformer_data_kind_byte_size[data_kind] * bp->raw_data_dimensions.x;
 
 				for (u32 channel = 0; channel < channel_count; channel++) {
 					u16 data_channel = (u16)b->channel_mapping[channel];
 					u32 out_off = out_channel_stride * channel;
 					u32 in_off  = in_channel_stride  * data_channel;
 					/* TODO(rnp): it would be better to do non temporal copy here, but we can't ensure
 					 * 64 byte boundaries. */
 					mem_copy(scratch.beg + out_off, (u8 *)data + in_off, out_channel_stride);
 				}
 
 				lib_release_lock(BeamformerSharedMemoryLockKind_ScratchSpace);
 				/* TODO(rnp): need a better way to communicate this */
 				u64 rf_block_rf_size = (u64)block << 32ULL | (u64)size;
 				atomic_store_u64(&g_beamformer_library_context.bp->rf_block_rf_size, rf_block_rf_size);
 				result = 1;
 			}
 		}
 	}
 	return result;
 }
 
 b32
 beamformer_push_data_with_compute(void *data, u32 data_size, u32 image_plane_tag, u32 parameter_slot)
 {
 	b32 result = 0;
 	if (check_shared_memory()) {
 		u32 reserved_blocks = g_beamformer_library_context.bp->reserved_parameter_blocks;
 		if (lib_error_check(image_plane_tag < BeamformerViewPlaneTag_Count, InvalidImagePlane) &&
 		    lib_error_check(parameter_slot < reserved_blocks, ParameterBlockUnallocated) &&
 		    beamformer_push_data_base(data, data_size, g_beamformer_library_context.timeout_ms, parameter_slot))
 		{
 			BeamformWork *work = try_push_work_queue();
 			if (work) {
 				work->kind = BeamformerWorkKind_ComputeIndirect;
 				work->compute_indirect_context.view_plane      = image_plane_tag;
 				work->compute_indirect_context.parameter_block = parameter_slot;
 				beamform_work_queue_push_commit(&g_beamformer_library_context.bp->external_work_queue);
 				beamformer_flush_commands();
 				result = 1;
 			}
 		}
 	}
 	return result;
 }
 
 b32
 beamformer_push_parameters_at(BeamformerParameters *bp, u32 block)
 {
 	b32 result = parameter_block_region_upload(bp, sizeof(*bp), block,
 	                                           BeamformerParameterBlockRegion_Parameters,
 	                                           offsetof(BeamformerParameterBlock, parameters),
 	                                           g_beamformer_library_context.timeout_ms);
 	return result;
 }
 
 b32
 beamformer_push_parameters(BeamformerParameters *bp)
 {
 	b32 result = beamformer_push_parameters_at(bp, 0);
 	return result;
 }
 
 b32
 beamformer_push_simple_parameters_at(BeamformerSimpleParameters *bp, u32 block)
 {
 	b32 result = validate_simple_parameters(bp);
 	if (result) {
 		alignas(64) v2 focal_vectors[countof(bp->steering_angles)];
 		for (u32 i = 0; i < countof(bp->steering_angles); i++)
 			focal_vectors[i] = (v2){{bp->steering_angles[i], bp->focal_depths[i]}};
 
 		result &= beamformer_push_parameters_at((BeamformerParameters *)bp, block);
 		result &= beamformer_push_pipeline_at(bp->compute_stages, bp->compute_stages_count, (BeamformerDataKind)bp->data_kind, block);
 		result &= beamformer_push_channel_mapping_at(bp->channel_mapping, bp->channel_count, block);
 		result &= beamformer_push_focal_vectors_at((f32 *)focal_vectors, countof(focal_vectors), block);
 		result &= beamformer_push_transmit_receive_orientations_at(bp->transmit_receive_orientations,
 		                                                           bp->acquisition_count, block);
 
 		if (bp->acquisition_kind == BeamformerAcquisitionKind_UFORCES ||
 		    bp->acquisition_kind == BeamformerAcquisitionKind_UHERCULES)
 		{
 			result &= beamformer_push_sparse_elements_at(bp->sparse_elements, bp->acquisition_count, block);
 		}
 
 		for (u32 stage = 0; stage < bp->compute_stages_count; stage++)
 			result &= beamformer_set_pipeline_stage_parameters_at(stage, bp->compute_stage_parameters[stage], block);
 	}
 	return result;
 }
 
 b32
 beamformer_push_simple_parameters(BeamformerSimpleParameters *bp)
 {
 	b32 result = beamformer_push_simple_parameters_at(bp, 0);
 	return result;
 }
 
 b32
 beamformer_push_parameters_ui(BeamformerUIParameters *bp)
 {
 	b32 result = parameter_block_region_upload(bp, sizeof(*bp), 0, BeamformerParameterBlockRegion_Parameters,
 	                                           offsetof(BeamformerParameterBlock, parameters_ui),
 	                                           g_beamformer_library_context.timeout_ms);
 	return result;
 }
 
 b32
 beamformer_push_parameters_head(BeamformerParametersHead *bp)
 {
 	b32 result = parameter_block_region_upload(bp, sizeof(*bp), 0, BeamformerParameterBlockRegion_Parameters,
 	                                           offsetof(BeamformerParameterBlock, parameters_head),
 	                                           g_beamformer_library_context.timeout_ms);
 	return result;
 }
 
 function b32
 beamformer_export_buffer(BeamformerExportContext export_context)
 {
 	BeamformWork *work = try_push_work_queue();
 	b32 result = work && lib_try_lock(BeamformerSharedMemoryLockKind_ExportSync, 0);
 	if (result) {
 		work->export_context = export_context;
 		work->kind = BeamformerWorkKind_ExportBuffer;
 		work->lock = BeamformerSharedMemoryLockKind_ScratchSpace;
 		beamform_work_queue_push_commit(&g_beamformer_library_context.bp->external_work_queue);
 	}
 	return result;
 }
 
 function b32
 beamformer_export(BeamformerExportContext export, void *out, i32 timeout_ms)
 {
 	b32 result = 0;
 	if (beamformer_export_buffer(export)) {
 		/* NOTE(rnp): if this fails it just means that the work from push_data hasn't
 		 * started yet. This is here to catch the other case where the work started
 		 * and finished before we finished queuing the export work item */
 		beamformer_flush_commands();
 
 		if (lib_try_lock(BeamformerSharedMemoryLockKind_ExportSync, timeout_ms)) {
 			if (lib_try_lock(BeamformerSharedMemoryLockKind_ScratchSpace, 0)) {
 				Arena scratch = beamformer_shared_memory_scratch_arena(g_beamformer_library_context.bp);
 				mem_copy(out, scratch.beg, export.size);
 				lib_release_lock(BeamformerSharedMemoryLockKind_ScratchSpace);
 				result = 1;
 			}
 			lib_release_lock(BeamformerSharedMemoryLockKind_ExportSync);
 		}
 	}
 	return result;
 }
 
 b32
 beamformer_beamform_data(BeamformerSimpleParameters *bp, void *data, uint32_t data_size,
                          void *out_data, int32_t timeout_ms)
 {
 	b32 result = validate_simple_parameters(bp);
 	if (result) {
 		bp->output_points.E[0] = MAX(1, bp->output_points.E[0]);
 		bp->output_points.E[1] = MAX(1, bp->output_points.E[1]);
 		bp->output_points.E[2] = MAX(1, bp->output_points.E[2]);
 
 		beamformer_push_simple_parameters(bp);
 
 		b32 complex = 0;
 		for (u32 stage = 0; stage < bp->compute_stages_count; stage++) {
 			BeamformerShaderKind shader = (BeamformerShaderKind)bp->compute_stages[stage];
 			complex |= shader == BeamformerShaderKind_Demodulate || shader == BeamformerShaderKind_CudaHilbert;
 		}
 
 		iz output_size = bp->output_points.x * bp->output_points.y * bp->output_points.z * (i32)sizeof(f32);
 		if (complex) output_size *= 2;
 
 		Arena scratch = beamformer_shared_memory_scratch_arena(g_beamformer_library_context.bp);
 		if (out_data) result = lib_error_check(output_size <= arena_capacity(&scratch, u8), ExportSpaceOverflow);
 
 		if (result) {
 			result = beamformer_push_data_with_compute(data, data_size, 0, 0);
 			if (result && out_data) {
 				BeamformerExportContext export;
 				export.kind = BeamformerExportKind_BeamformedData;
 				export.size = (u32)output_size;
 				result = beamformer_export(export, out_data, timeout_ms);
 			}
 		}
 	}
 	return result;
 }
 
 b32
 beamformer_compute_timings(BeamformerComputeStatsTable *output, i32 timeout_ms)
 {
 	static_assert(sizeof(*output) <= BEAMFORMER_SHARED_MEMORY_MAX_SCRATCH_SIZE,
 	              "timing table size exceeds scratch space");
 
 	b32 result = 0;
 	if (check_shared_memory()) {
 		Arena scratch = beamformer_shared_memory_scratch_arena(g_beamformer_library_context.bp);
 		if (lib_error_check((iz)sizeof(*output) <= arena_capacity(&scratch, u8), ExportSpaceOverflow)) {
 			BeamformerExportContext export;
 			export.kind = BeamformerExportKind_Stats;
 			export.size = sizeof(*output);
 			result = beamformer_export(export, output, timeout_ms);
 		}
 	}
 	return result;
 }
 
 i32
 beamformer_live_parameters_get_dirty_flag(void)
 {
 	i32 result = -1;
 	if (check_shared_memory()) {
 		u32 flag = ctz_u32(g_beamformer_library_context.bp->live_imaging_dirty_flags);
 		if (flag != 32) {
 			atomic_and_u32(&g_beamformer_library_context.bp->live_imaging_dirty_flags, ~(1u << flag));
 			result = (i32)flag;
 		}
 	}
 	return result;
 }
 
 BeamformerLiveImagingParameters *
 beamformer_get_live_parameters(void)
 {
 	BeamformerLiveImagingParameters *result = 0;
 	if (check_shared_memory()) result = &g_beamformer_library_context.bp->live_imaging_parameters;
 	return result;
 }
 
 b32
 beamformer_set_live_parameters(BeamformerLiveImagingParameters *new)
 {
 	b32 result = 0;
 	if (check_shared_memory()) {
 		mem_copy(&g_beamformer_library_context.bp->live_imaging_parameters, new, sizeof(*new));
 		store_fence();
 		result = 1;
 	}
 	return result;
 }