进程间，有时候想共用硬件内存。如下代码，服务端分配了硬件内存，客户端共享逻辑内存得到一些信息，再读取硬件内存。 sharedMemoryCreate是对shm_open的封装。

服务端

#include <cstdio>
#include <cuda_runtime_api.h>
#include <nvbufsurface.h>
#include "string.h"
#include <unistd.h>
#include "helper_multiprocess.h"
#include "stdlib.h"
#include "helper_cuda.h"static const char shmName[] = "simpleIPCshm";typedef struct shmStruct_st {cudaIpcMemHandle_t memHandle;cudaIpcEventHandle_t eventHandle;int device;int bufLen;
} shmStruct;int main() {cudaIpcMemHandle_t handle;void* ptr = NULL, *ptrDev = NULL;char* pbuf = NULL;sharedMemoryInfo info;cudaStream_t stream;cudaEvent_t event;volatile shmStruct *shm = NULL;int bufLen = 10;if (sharedMemoryCreate(shmName, sizeof(*shm), &info) != 0) {printf("Failed to create shared memory slab\n");exit(EXIT_FAILURE);}shm = (volatile shmStruct *)info.addr;memset((void *)shm, 0, sizeof(*shm));/* create memory */pbuf = new char[bufLen];memset(pbuf, 10, bufLen);cudaMalloc(&ptr, bufLen);if (cudaMemcpy (ptr, pbuf, bufLen, cudaMemcpyHostToDevice) != cudaSuccess) {printf("cudaMemcpy failed\n");}shm->device = 0;shm->bufLen = bufLen;checkCudaErrors(cudaSetDevice(shm->device));cudaError_t err = cudaIpcGetMemHandle((cudaIpcMemHandle_t *)&shm->memHandle, ptr);/*checkCudaErrors(cudaEventCreate(&event));printf("event:%d\n", event);checkCudaErrors(cudaIpcGetEventHandle((cudaIpcEventHandle_t *)&shm->eventHandle, event));cudaSetDevice(shm->device);
*/while(1){sleep(3);}/* checkCudaErrors(cudaEventSynchronize(event));printf("a checkCudaErrors\n");checkCudaErrors(cudaEventDestroy(event)); */checkCudaErrors(cudaFree(ptr));sharedMemoryClose(&info);return 0;
}

客户端

#include <cstdio>
#include <cuda_runtime_api.h>
#include <nvbufsurface.h>
#include "string.h"
#include <unistd.h>
#include "helper_multiprocess.h"
#include "stdlib.h"
#include "helper_cuda.h"static const char shmName[] = "simpleIPCshm";typedef struct shmStruct_st {cudaIpcMemHandle_t memHandle;cudaIpcEventHandle_t eventHandle;int device;int bufLen;
} shmStruct;int main() {cudaIpcMemHandle_t* cuda_shm_handle;sharedMemoryInfo info;volatile shmStruct *shm = NULL;checkCudaErrors(cudaSetDevice(0));if (sharedMemoryOpen(shmName, sizeof(shmStruct), &info) != 0) {printf("Failed to create shared memory slab\n");exit(EXIT_FAILURE);}printf("sharedMemoryOpen suc\n");shm = (volatile shmStruct *)info.addr;int bufLen = shm->bufLen;printf("bufLen:%d\n", bufLen);void *ptr = NULL;cudaError_t err = cudaIpcOpenMemHandle(&ptr, *(cudaIpcMemHandle_t *)&shm->memHandle, cudaIpcMemLazyEnablePeerAccess);printf("err:%d\n", err);char* pbuf = new char[bufLen];memset(pbuf, 10, bufLen);if (cudaMemcpy (pbuf, ptr, bufLen, cudaMemcpyDeviceToHost ) != cudaSuccess) {printf("cudaMemcpy failed\n");}for(int i = 0; i < bufLen; i++){printf("v:%d\n", pbuf[i]);}return 0;
}

Makefile

CUDA_VER=12.2
ifeq ($(CUDA_VER),)$(error "CUDA_VER is not set")
endifCXX=g++ -std=c++14APP:= ipc_serverTARGET_DEVICE = $(shell gcc -dumpmachine | cut -f1 -d -)CUDA_HOME:= /usr/local/cuda-$(CUDA_VER)
DEEPSTREAM_HOME:= /opt/nvidia/deepstream/deepstreamLIB_INSTALL_DIR?=$(DEEPSTREAM_HOME)/lib/
APP_INSTALL_DIR?=$(DEEPSTREAM_HOME)/bin/ifeq ($(TARGET_DEVICE),aarch64)CFLAGS:= -DPLATFORM_TEGRA
endifSRCS:= $(wildcard *.cpp)INCS:= $(wildcard *.h)PKGS:= gstreamer-1.0 gstreamer-video-1.0 x11 json-glib-1.0OBJS:= $(patsubst %.c,%.o, $(patsubst %.cpp,%.o, $(SRCS)))CFLAGS+= \-I$(CUDA_HOME)/include \-I$(DEEPSTREAM_HOME)/sources/includes 
LIBS+= \-L$(CUDA_HOME)/lib64 -lcudart -lcuda \-lpthread -lm -ldl -Wl,-rpathCFLAGS+= $(shell pkg-config --cflags $(PKGS))LIBS+= $(shell pkg-config --libs $(PKGS))debug: CXXFLAGS += -DDEBUG -ggdb
debug: CCFLAGS += -DDEBUG -ggdb
debug: CFLAGS += -DDEBUG -ggdb
debug: $(APP)%.o: %.c $(INCS) Makefile$(CC) -c -o $@ $(CFLAGS) $<%.o: %.cpp $(INCS) Makefile$(CXX) -c -o $@ $(CFLAGS) $<$(APP): $(OBJS) Makefile$(CXX) -o $(APP) $(OBJS) $(LIBS)install: $(APP)cp -rv $(APP) $(APP_INSTALL_DIR)clean:rm -rf $(OBJS) $(APP)