From b120a91a3d917207b092f898128600e3a3f7fdb3 Mon Sep 17 00:00:00 2001 From: Alexander Wenzel Date: Tue, 18 Oct 2011 16:58:57 +0200 Subject: [GSW-43] Performance improvement for bulk data over DLT. Implemented recovery of SHM. --- src/shared/dlt_shm.c | 203 ++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 154 insertions(+), 49 deletions(-) (limited to 'src/shared/dlt_shm.c') diff --git a/src/shared/dlt_shm.c b/src/shared/dlt_shm.c index 11993d7..cfa961d 100644 --- a/src/shared/dlt_shm.c +++ b/src/shared/dlt_shm.c @@ -97,7 +97,7 @@ void dlt_shm_pv(int id,int operation) semaphor.sem_flg = SEM_UNDO; if(semop(id, &semaphor,1) == -1) { - perror("semop"); + perror("SHM: semop"); } } @@ -113,32 +113,32 @@ int dlt_shm_init_server(DltShm *buf,int key,int size) { // Create the segment. if ((buf->shmid = shmget(key, size, IPC_CREAT | 0666)) < 0) { - perror("shmget"); + perror("SHM: shmget"); return -1; /* ERROR */ } // get the size of shm if (shmctl(buf->shmid, IPC_STAT, &shm_buf)) { - perror("shmctl"); + perror("SHM: shmctl"); return -1; /* ERROR */ } // Now we attach the segment to our data space. if ((buf->shm = shmat(buf->shmid, NULL, 0)) == (char *) -1) { - perror("shmat"); + perror("SHM: shmat"); return -1; /* ERROR */ } // Init semaphore if( (buf->semid = semget(DLT_SHM_SEM,1,S_IRWXU|S_IRWXG|IPC_CREAT|IPC_EXCL)) == -1 ) { if( (buf->semid = semget(DLT_SHM_SEM,1,S_IRWXU|S_IRWXG|IPC_EXCL)) == -1 ) { - perror("semget"); + perror("SHM: semget"); return -1; /* ERROR */ } } if( semctl(buf->semid,0,SETVAL,(int)1) == -1 ) { - perror("semctl"); + perror("SHM: semctl"); return -1; /* ERROR */ } @@ -171,14 +171,14 @@ int dlt_shm_init_client(DltShm *buf,int key) { // Create the segment. if ((buf->shmid = shmget(key, 0, 0666)) < 0) { - perror("shmget"); + perror("SHM: shmget"); return -1; /* ERROR */ } // get the size of shm if (shmctl(buf->shmid, IPC_STAT, &shm_buf)) { - perror("shmctl"); + perror("SHM: shmctl"); return -1; /* ERROR */ } @@ -190,7 +190,7 @@ int dlt_shm_init_client(DltShm *buf,int key) { // Init semaphore if( (buf->semid = semget(DLT_SHM_SEM,0,0)) == -1 ) { - perror("semget"); + perror("SHM: semget"); return -1; /* ERROR */ } DLT_SHM_SEM_FREE(buf->semid); @@ -208,10 +208,10 @@ int dlt_shm_init_client(DltShm *buf,int key) { void dlt_shm_info(DltShm *buf) { - printf("SHM id: %d\n",buf->shmid); - printf("Available size: %d\n",buf->size); - printf("SHM full start address: %lX\n",(unsigned long)buf->shm); - printf("SHM start address: %lX\n",(unsigned long)buf->mem); + printf("SHM: SHM id: %d\n",buf->shmid); + printf("SHM: Available size: %d\n",buf->size); + printf("SHM: SHM full start address: %lX\n",(unsigned long)buf->shm); + printf("SHM: SHM start address: %lX\n",(unsigned long)buf->mem); } @@ -223,9 +223,9 @@ void dlt_shm_status(DltShm *buf) read = ((int*)(buf->shm))[1]; count = ((int*)(buf->shm))[2]; - printf("Write: %d\n",write); - printf("Read: %d\n",read); - printf("Count: %d\n",count); + printf("SHM: Write: %d\n",write); + printf("SHM: Read: %d\n",read); + printf("SHM: Count: %d\n",count); } @@ -259,10 +259,14 @@ int dlt_shm_get_message_count(DltShm *buf) int dlt_shm_push(DltShm *buf,const unsigned char *data1,unsigned int size1,const unsigned char *data2,unsigned int size2,const unsigned char *data3,unsigned int size3) { int write, read, count; + char head[] = DLT_SHM_HEAD; + + // initialise head + head[3] = 0x01; if(!buf->mem) { // shm not initialised - printf("SHM not initialised\n"); + printf("SHM: SHM not initialised\n"); return -1; /* ERROR */ } @@ -282,7 +286,7 @@ int dlt_shm_push(DltShm *buf,const unsigned char *data1,unsigned int size1,const return -1; // ERROR } else if(write >= buf->size) { - if((size1+size2+size3+sizeof(unsigned char)+sizeof(int)) > read) { + if((size1+size2+size3+sizeof(head)+sizeof(unsigned char)+sizeof(int)) > read) { DLT_SHM_SEM_FREE(buf->semid); //printf("SHM is full at start\n"); return -1; // ERROR @@ -290,7 +294,7 @@ int dlt_shm_push(DltShm *buf,const unsigned char *data1,unsigned int size1,const write = 0; } else if(read > write) { - if((write + size1+size2+size3+sizeof(unsigned char)+sizeof(int)) > read) { + if((write + size1+size2+size3+sizeof(head)+sizeof(unsigned char)+sizeof(int)) > read) { DLT_SHM_SEM_FREE(buf->semid); //printf("SHM is full at end\n"); return -1; // ERROR @@ -298,10 +302,10 @@ int dlt_shm_push(DltShm *buf,const unsigned char *data1,unsigned int size1,const } else // read <= write { - if((write+size1+size2+size3+sizeof(unsigned char)+sizeof(int)) > buf->size) { + if((write+size1+size2+size3+sizeof(head)+sizeof(unsigned char)+sizeof(int)) > buf->size) { // data does not fit at end of buffer // try write at beginning - if((size1+size2+size3+sizeof(unsigned char)+sizeof(int)) > read) { + if((size1+size2+size3+sizeof(head)+sizeof(unsigned char)+sizeof(int)) > read) { DLT_SHM_SEM_FREE(buf->semid); //printf("SHM is full at start\n"); return -1; // ERROR @@ -317,23 +321,24 @@ int dlt_shm_push(DltShm *buf,const unsigned char *data1,unsigned int size1,const } // update global shm pointers - ((int*)(buf->shm))[0] = write+sizeof(unsigned char)+sizeof(int)+size1+size2+size3; // set new write pointer + ((int*)(buf->shm))[0] = write+sizeof(unsigned char)+sizeof(int)+size1+size2+size3+sizeof(head); // set new write pointer ((int*)(buf->shm))[2] += 1; // increase counter // update buffer pointers *((unsigned char*)(buf->mem+write)) = 1; // set write status - *((int*)(buf->mem+write+sizeof(unsigned char))) = size1+size2+size3; // set write size + *((int*)(buf->mem+write+sizeof(unsigned char))) = size1+size2+size3+sizeof(head); // set write size // free semaphore DLT_SHM_SEM_FREE(buf->semid); // write data + memcpy(buf->mem+write+sizeof(unsigned char)+sizeof(int),head,sizeof(head)); if(data1) - memcpy(buf->mem+write+sizeof(unsigned char)+sizeof(int),data1,size1); + memcpy(buf->mem+write+sizeof(head)+sizeof(unsigned char)+sizeof(int),data1,size1); if(data2) - memcpy(buf->mem+write+sizeof(unsigned char)+sizeof(int)+size1,data2,size2); + memcpy(buf->mem+write+sizeof(head)+sizeof(unsigned char)+sizeof(int)+size1,data2,size2); if(data3) - memcpy(buf->mem+write+sizeof(unsigned char)+sizeof(int)+size1+size2,data3,size3); + memcpy(buf->mem+write+sizeof(head)+sizeof(unsigned char)+sizeof(int)+size1+size2,data3,size3); // update write status *((unsigned char*)(buf->mem+write)) = 2; @@ -345,10 +350,15 @@ int dlt_shm_pull(DltShm *buf,unsigned char *data, int max_size) { int write, read, count, size; unsigned char status; + char head[] = DLT_SHM_HEAD; + char head_compare[] = DLT_SHM_HEAD; + + // initialise head + head[3] = 0x01; if(!buf->mem) { // shm not initialised - printf("SHM not initialised\n"); + printf("SHM: SHM not initialised\n"); return -1; /* ERROR */ } @@ -361,7 +371,10 @@ int dlt_shm_pull(DltShm *buf,unsigned char *data, int max_size) // check if data is in there if(count<=0) { - //printf("SHM is empty\n"); + if((write!=read) || (count<0)) + { + dlt_shm_reset(buf); + } return -1; // ERROR } @@ -390,50 +403,65 @@ int dlt_shm_pull(DltShm *buf,unsigned char *data, int max_size) // plausibility check of buffer size if( (read+size) > buf->size) { - printf("Buffers size bigger than shm buffer\n"); + printf("SHM: Buffers size bigger than shm buffer\n"); return -1; // ERROR } // check max read size if(size > max_size) { - printf("Buffer is bigger than max size\n"); + printf("SHM: Buffer is bigger than max size\n"); return -1; // ERROR } + // check head + memcpy(head_compare,buf->mem+read+sizeof(unsigned char)+sizeof(int),sizeof(head)); + if(memcmp(head,head_compare,sizeof(head))!=0) + { + /* SHM message header is not correct */ + } + // copy data - memcpy(data,buf->mem+read+sizeof(unsigned char)+sizeof(int),size); + memcpy(data,buf->mem+read+sizeof(unsigned char)+sizeof(int)+sizeof(head),size-sizeof(head)); // update buffer pointers ((int*)(buf->shm))[1] = read+sizeof(unsigned char)+sizeof(int)+size; // set new read pointer ((int*)(buf->shm))[2] -= 1; // decrease counter - return size; // OK + return size-sizeof(head); // OK } int dlt_shm_copy(DltShm *buf,unsigned char *data, int max_size) { int write, read, count, size; unsigned char status; + char head[] = DLT_SHM_HEAD; + + // initialise head + head[3] = 0x01; if(!buf->mem) { // shm not initialised - printf("SHM not initialised\n"); + printf("SHM: SHM not initialised\n"); return -1; /* ERROR */ } + DLT_SHM_SEM_FREE(buf->semid); // get current write pointer DLT_SHM_SEM_GET(buf->semid); write = ((int*)(buf->shm))[0]; read = ((int*)(buf->shm))[1]; count = ((int*)(buf->shm))[2]; - DLT_SHM_SEM_FREE(buf->semid); // check if data is in there if(count<=0) { - //printf("SHM is empty\n"); + if((write!=read) || (count<0)) + { + dlt_shm_reset(buf); + } return -1; // ERROR } + // check if end of buffer is reached and read status and size if((read+sizeof(unsigned char)+sizeof(int)) <= buf->size) { status = *((unsigned char*)(buf->mem+read)); @@ -459,20 +487,20 @@ int dlt_shm_copy(DltShm *buf,unsigned char *data, int max_size) // plausibility check of buffer size if( (read+size) > buf->size) { - printf("Buffers size bigger than shm buffer\n"); + printf("SHM: Buffers size bigger than shm buffer\n"); return -1; // ERROR } // check max read size - if(size > max_size) { - printf("Buffer is bigger than max size\n"); + if((size-sizeof(head)) > max_size) { + printf("SHM: Buffer is bigger than max size\n"); return -1; // ERROR } // copy data - memcpy(data,buf->mem+read+sizeof(unsigned char)+sizeof(int),size); + memcpy(data,buf->mem+read+sizeof(unsigned char)+sizeof(int)+sizeof(head),size-sizeof(head)); - return size; // OK + return size-sizeof(head); // OK } int dlt_shm_remove(DltShm *buf) @@ -482,7 +510,7 @@ int dlt_shm_remove(DltShm *buf) if(!buf->mem) { // shm not initialised - printf("SHM not initialised\n"); + printf("SHM: SHM not initialised\n"); return -1; /* ERROR */ } @@ -495,10 +523,14 @@ int dlt_shm_remove(DltShm *buf) // check if data is in there if(count<=0) { - //printf("SHM is empty\n"); + if((write!=read) || (count<0)) + { + dlt_shm_reset(buf); + } return -1; // ERROR } + // check if end of buffer is reached and read status and size if((read+sizeof(unsigned char)+sizeof(int)) <= buf->size) { status = *((unsigned char*)(buf->mem+read)); @@ -524,7 +556,7 @@ int dlt_shm_remove(DltShm *buf) // plausibility check of buffer size if( (read+size) > buf->size) { - printf("Buffers size bigger than shm buffer\n"); + printf("SHM: Buffers size bigger than shm buffer\n"); return -1; // ERROR } @@ -535,25 +567,98 @@ int dlt_shm_remove(DltShm *buf) return size; // OK } +int dlt_shm_reset(DltShm *buf) { + + printf("SHM: Pointer corrupted; reset triggered.\n"); + + /* reset pointers and counters */ + DLT_SHM_SEM_GET(buf->semid); + ((int*)(buf->shm))[0] = 0; // pointer to write memory + ((int*)(buf->shm))[1] = 0; // pointer to read memory + ((int*)(buf->shm))[2] = 0; // number of packets + DLT_SHM_SEM_FREE(buf->semid); + + return 0; /* OK */ +} + +int dlt_shm_recover(DltShm *buf) { + int write, read, count; + char head[] = DLT_SHM_HEAD; + int num; + + // initialise head + head[3] = 0x01; + + printf("SHM: Head not found; try to recover.\n"); + + /* try to find next valid message */ + DLT_SHM_SEM_GET(buf->semid); + + write = ((int*)(buf->shm))[0]; + read = ((int*)(buf->shm))[1]; + count = ((int*)(buf->shm))[2]; + + while(1) { + if(memcmp(buf->mem+read,head,sizeof(head))==0) { + /* HEAD found */ + if(read>=(sizeof(unsigned char)+sizeof(int))) { + /* HEAD not at beginning, recover */ + count--; + break; + } + else { + /* HEAD at beginning, cannot recover */ + count--; + } + } + read++; + if(read==write) { + /* nothing found */ + break; + } + if(read>=buf->size) { + /* end reached, continue at beginning */ + read = 0; + } + } + + if(read==write) { + ((int*)(buf->shm))[0] = 0; // pointer to write memory + ((int*)(buf->shm))[1] = 0; // pointer to read memory + ((int*)(buf->shm))[2] = 0; // number of packets + } + else { + ((int*)(buf->shm))[1] = read - sizeof(unsigned char)+sizeof(int); // set new read pointer + if(count<0) + ((int*)(buf->shm))[2] = 0; // decrease counter + else + ((int*)(buf->shm))[2] = count; // decrease counter + } + + DLT_SHM_SEM_FREE(buf->semid); + + return 0; /* OK */ +} + int dlt_shm_free_server(DltShm *buf) { if(!buf->shm) { - printf("Shared memory segment not attached\n"); + printf("SHM: Shared memory segment not attached\n"); return -1; /* ERROR */ } if(shmdt(buf->shm)) { - perror("shmdt"); + perror("SHM: shmdt"); return -1; /* ERROR */ } if(shmctl(buf->shmid,IPC_RMID,NULL) == -1) { - perror("shmdt"); + perror("SHM: shmdt"); return -1; /* ERROR */ } if(semctl(buf->semid,0,IPC_RMID,(int)0) == -1) { - perror("shmdt"); + perror("SHM: shmdt"); return -1; /* ERROR */ } @@ -570,12 +675,12 @@ int dlt_shm_free_server(DltShm *buf) { int dlt_shm_free_client(DltShm *buf) { if(!buf->shm) { - printf("Shared memory segment not attached\n"); + printf("SHM: Shared memory segment not attached\n"); return -1; /* ERROR */ } if(shmdt(buf->shm)) { - perror("shmdt"); + perror("SHM: shmdt"); return -1; /* ERROR */ } -- cgit v1.2.1