diff options
author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2009-11-06 13:43:21 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2009-11-06 13:43:21 +0000 |
commit | 0054d8d2513e6988bf92809e6f065e920e6aedd5 (patch) | |
tree | c251b6d03e75081410e96a59b77a8c63ef1694a1 /nuttx/drivers/rwbuffer.c | |
parent | 13712e46ce30b5ad84a30994d03fedfbab2a3820 (diff) | |
download | px4-nuttx-0054d8d2513e6988bf92809e6f065e920e6aedd5.tar.gz px4-nuttx-0054d8d2513e6988bf92809e6f065e920e6aedd5.tar.bz2 px4-nuttx-0054d8d2513e6988bf92809e6f065e920e6aedd5.zip |
Fix confusion between byte and block transfers
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2235 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/drivers/rwbuffer.c')
-rw-r--r-- | nuttx/drivers/rwbuffer.c | 183 |
1 files changed, 100 insertions, 83 deletions
diff --git a/nuttx/drivers/rwbuffer.c b/nuttx/drivers/rwbuffer.c index e495660f3..59817f0ba 100644 --- a/nuttx/drivers/rwbuffer.c +++ b/nuttx/drivers/rwbuffer.c @@ -111,16 +111,16 @@ static void rwb_semtake(sem_t *sem) * Name: rwb_overlap ****************************************************************************/ -static inline boolean rwb_overlap(off_t bufferstart1, size_t buffersize1, - off_t bufferstart2, size_t buffersize2) +static inline boolean rwb_overlap(off_t blockstart1, size_t nblocks1, + off_t blockstart2, size_t nblocks2) { - off_t bufferend1 = bufferstart1 + buffersize1; - off_t bufferend2 = bufferstart2 + buffersize2; + off_t blockend1 = blockstart1 + nblocks1; + off_t blockend2 = blockstart2 + nblocks2; /* If the buffer 1 is wholly outside of buffer 2, return false */ - if ((bufferend1 < bufferstart2) || /* Wholly "below" */ - (bufferstart1 > bufferend2)) /* Wholly "above" */ + if ((blockend1 < blockstart2) || /* Wholly "below" */ + (blockstart1 > blockend2)) /* Wholly "above" */ { return FALSE; } @@ -139,7 +139,7 @@ static inline void rwb_resetwrbuffer(struct rwbuffer_s *rwb) { /* We assume that the caller holds the wrsem */ - rwb->wrnbytes = 0; + rwb->wrnblocks = 0; rwb->wrblockstart = (off_t)-1; rwb->wrexpectedblock = (off_t)-1; } @@ -154,17 +154,17 @@ static void rwb_wrflush(struct rwbuffer_s *rwb) { int ret; - fvdbg("Timeout!"); + fvdbg("Timeout!\n"); rwb_semtake(&rwb->wrsem); - if (rwb->wrnbytes) + if (rwb->wrnblocks) { - fvdbg("Flushing: blockstart=0x%08lx nbytes=%d from buffer=%p", - (long)rwb->wrblockstart, (long)rwb->wrnbytes, (long)rwb->wrbuffer); + fvdbg("Flushing: blockstart=0x%08lx nblocks=%d from buffer=%p\n", + (long)rwb->wrblockstart, rwb->wrnblocks, rwb->wrbuffer); /* Flush cache */ - ret = rwb->wrflush(rwb->dev, rwb->wrbuffer, rwb->wrblockstart, rwb->wrnbytes); + ret = rwb->wrflush(rwb->dev, rwb->wrbuffer, rwb->wrblockstart, rwb->wrnblocks); if (ret < 0) { fdbg("ERROR: Error flushing write buffer: %d\n", -ret); @@ -225,7 +225,7 @@ static inline void rwb_wrcanceltimeout(struct rwbuffer_s *rwb) #ifdef CONFIG_FS_WRITEBUFFER static ssize_t rwb_writebuffer(FAR struct rwbuffer_s *rwb, - off_t startblock, uint32 nbytes, + off_t startblock, uint32 nblocks, FAR const ubyte *wrbuffer) { int ret; @@ -234,17 +234,20 @@ static ssize_t rwb_writebuffer(FAR struct rwbuffer_s *rwb, rwb_wrcanceltimeout(rwb); - /* First: Should we flush out our cache? */ + /* First: Should we flush out our cache? We would do that if (1) we already + * buffering blocks and the next block writing is not in the same sequence, + * or (2) the number of blocks would exceed our allocated buffer capacity + */ - if (((startblock != rwb->wrexpectedblock) && (rwb->wrnbytes)) || - ((rwb->wrnbytes + nbytes) > rwb->wrallocsize)) + if (((startblock != rwb->wrexpectedblock) && (rwb->wrnblocks)) || + ((rwb->wrnblocks + nblocks) > rwb->wrmaxblocks)) { - fvdbg("writebuffer miss, expected: 0x%08x, given: 0x%08x", - rwb->wrexpectedblock, startblock); + fvdbg("writebuffer miss, expected: %08x, given: %08x\n", + rwb->wrexpectedblock, startblock); - /* Flush cache */ + /* Flush the write buffer */ - ret = rwb->wrflush(rwb, rwb->wrbuffer, rwb->wrblockstart, rwb->wrnbytes); + ret = rwb->wrflush(rwb, rwb->wrbuffer, rwb->wrblockstart, rwb->wrnblocks); if (ret < 0) { fdbg("ERROR: Error writing multiple from cache: %d\n", -ret); @@ -254,24 +257,26 @@ static ssize_t rwb_writebuffer(FAR struct rwbuffer_s *rwb, rwb_resetwrbuffer(rwb); } - /* writebuffer is clear? Then initialize it */ + /* writebuffer is empty? Then initialize it */ - if (!rwb->wrnbytes) + if (!rwb->wrnblocks) { - fvdbg("Fresh cache starting at block: 0x%08x",startblock); + fvdbg("Fresh cache starting at block: 0x%08x\n", startblock); rwb->wrblockstart = startblock; } /* Add data to cache */ - fvdbg("writebuffer: copying from 0x%p to 0x%p", - wrbuffer, &rwb->wrbuffer[rwb->wrnbytes]); - memcpy(&rwb->wrbuffer[rwb->wrnbytes], wrbuffer, nbytes); + fvdbg("writebuffer: copying %d bytes from %p to %p\n", + nblocks * wrb->blocksize, wrbuffer, + &rwb->wrbuffer[rwb->wrnblocks * rwb->blocksize]); + memcpy(&rwb->wrbuffer[rwb->wrnblocks * rwb->blocksize], + wrbuffer, nblocks * rwb->blocksize); - rwb->wrnbytes += nbytes; - rwb->wrexpectedblock = rwb->wrblockstart + rwb->wrnbytes; + rwb->wrnblocks += nblocks; + rwb->wrexpectedblock = rwb->wrblockstart + rwb->wrnblocks; rwb_wrstarttimeout(rwb); - return nbytes; + return nblocks; } #endif @@ -284,7 +289,7 @@ static inline void rwb_resetrhbuffer(struct rwbuffer_s *rwb) { /* We assume that the caller holds the readAheadBufferSemphore */ - rwb->rhnbytes = 0; + rwb->rhnblocks = 0; rwb->rhblockstart = (off_t)-1; } #endif @@ -305,21 +310,21 @@ rwb_bufferread(struct rwbuffer_s *rwb, off_t startblock, /* Convert the units from blocks to bytes */ - uint32 dwStartBlockOffset = startblock - rwb->rhblockstart; - uint32 dwStartByteOffset = rwb->blocksize * dwStartBlockOffset; - uint32 dwByteCount = rwb->blocksize * nblocks; + off_t blockoffset = startblock - rwb->rhblockstart; + off_t byteoffset = rwb->blocksize * blockoffset; + size_t nbytes = rwb->blocksize * nblocks; /* Get the byte address in the read-ahead buffer */ - ubyte *pchBuffer = rwb->rhbuffer + dwStartByteOffset; + ubyte *rhbuffer = rwb->rhbuffer + byteoffset; /* Copy the data from the read-ahead buffer into the IO buffer */ - memcpy(*rdbuffer, pchBuffer, dwByteCount); + memcpy(*rdbuffer, rhbuffer, nbytes); /* Update the caller's copy for the next address */ - *rdbuffer += dwByteCount; + *rdbuffer += nbytes; } #endif @@ -330,12 +335,13 @@ rwb_bufferread(struct rwbuffer_s *rwb, off_t startblock, #ifdef CONFIG_FS_READAHEAD static int rwb_rhreload(struct rwbuffer_s *rwb, off_t startblock) { - /* Get the maximum number of blocks that will fit in the read-ahead buffer */ + /* Get the block number +1 of the last block that will fit in the + * read-ahead buffer + */ - size_t maxblocks = rwb->rhallocsize / rwb->blocksize; - off_t endblock = startblock + maxblocks; + off_t endblock = startblock + rwb->rhmaxblocks; size_t nblocks; - int ret; + int ret; /* Reset the read buffer */ @@ -356,7 +362,7 @@ static int rwb_rhreload(struct rwbuffer_s *rwb, off_t startblock) { /* Update information about what is in the read-ahead buffer */ - rwb->rhnbytes = nblocks; + rwb->rhnblocks = nblocks; rwb->rhblockstart = startblock; } return ret; @@ -372,6 +378,8 @@ static int rwb_rhreload(struct rwbuffer_s *rwb, off_t startblock) int rwb_initialize(FAR struct rwbuffer_s *rwb) { + uint32 allocsize; + /* Sanity checking */ DEBUGASSERT(rwb != NULL); @@ -382,18 +390,16 @@ int rwb_initialize(FAR struct rwbuffer_s *rwb) /* Setup so that rwb_uninitialize can handle a failure */ #ifdef CONFIG_FS_WRITEBUFFER - DEBUGASSERT(rwb->wrblocks > 0); DEBUGASSERT(rwb->wrflush!= NULL); rwb->wrbuffer = NULL; #endif #ifdef CONFIG_FS_READAHEAD - DEBUGASSERT(rwb->rhblocks > 0); DEBUGASSERT(rwb->rhreload != NULL); rwb->rhbuffer = NULL; #endif #ifdef CONFIG_FS_WRITEBUFFER - fvdbg("Initialize the write buffer"); + fvdbg("Initialize the write buffer\n"); /* Initialize the write buffer access semaphore */ @@ -405,19 +411,23 @@ int rwb_initialize(FAR struct rwbuffer_s *rwb) /* Allocate the write buffer */ - rwb->wrallocsize = rwb->wrblocks * rwb->blocksize; - rwb->wrbuffer = malloc(rwb->wrallocsize); - if (!rwb->wrbuffer) + rwb->wrbuffer = NULL; + if (rwb->wrmaxblocks > 0) { - fdbg("Write buffer malloc(%ld) failed\n", (long)rwb->wrallocsize); - return -ENOMEM; + allocsize = rwb->wrmaxblocks * rwb->blocksize; + rwb->wrbuffer = malloc(allocsize); + if (!rwb->wrbuffer) + { + fdbg("Write buffer malloc(%d) failed\n", allocsizee); + return -ENOMEM; + } } - fvdbg("Write buffer size: %d bytes\n", rwb->wrallocsize); + fvdbg("Write buffer size: %d bytes\n", allocsize); #endif /* CONFIG_FS_WRITEBUFFER */ #ifdef CONFIG_FS_READAHEAD - fvdbg("Initialize the read-ahead buffer"); + fvdbg("Initialize the read-ahead buffer\n"); /* Initialize the read-ahead buffer access semaphore */ @@ -429,15 +439,19 @@ int rwb_initialize(FAR struct rwbuffer_s *rwb) /* Allocate the read-ahead buffer */ - rwb->rhallocsize = rwb->rhblocks * rwb->blocksize; - rwb->rhbuffer = malloc(rwb->rhallocsize); - if (!rwb->rhbuffer) + rwb->rhbuffer = NULL; + if (rwb->rhmaxblocks > 0) { - fdbg("Read-ahead buffer malloc(%ld) failed\n", (long)rwb->rhallocsize); - return -ENOMEM; + allocsize = rwb->rhmaxblocks * rwb->blocksize; + rwb->rhbuffer = malloc(allocsize); + if (!rwb->rhbuffer) + { + fdbg("Read-ahead buffer malloc(%d) failed\n", allocsize); + return -ENOMEM; + } } - fvdbg("Read-ahead buffer size: %d bytes\n", rwb->rhallocsize); + fvdbg("Read-ahead buffer size: %d bytes\n", allocsize); #endif /* CONFIG_FS_READAHEAD */ return 0; } @@ -470,11 +484,11 @@ void rwb_uninitialize(FAR struct rwbuffer_s *rwb) * Name: ****************************************************************************/ -int rwb_read(FAR struct rwbuffer_s *rwb, off_t startblock, uint32 blockcount, +int rwb_read(FAR struct rwbuffer_s *rwb, off_t startblock, uint32 nblocks, FAR ubyte *rdbuffer) { - fvdbg("startblock=%ld blockcount=%ld rdbuffer=%p", - (long)startblock, (long)blockcount, rdbuffer); + fvdbg("startblock=%ld nblocks=%ld rdbuffer=%p\n", + (long)startblock, (long)nblocks, rdbuffer); #ifdef CONFIG_FS_WRITEBUFFER /* If the new read data overlaps any part of the write buffer, then @@ -483,27 +497,30 @@ int rwb_read(FAR struct rwbuffer_s *rwb, off_t startblock, uint32 blockcount, * is well-suited for simple streaming applications. */ - /* If the write buffer overlaps the block(s) requested, then flush the - * write buffer. - */ - - rwb_semtake(&rwb->wrsem); - if (rwb_overlap(rwb->wrblockstart, rwb->wrnbytes, startblock, blockcount)) + if (rwb->wrmaxblocks > 0) { - rwb_wrflush(rwb); + /* If the write buffer overlaps the block(s) requested, then flush the + * write buffer. + */ + + rwb_semtake(&rwb->wrsem); + if (rwb_overlap(rwb->wrblockstart, rwb->wrnblocks, startblock, nblocks)) + { + rwb_wrflush(rwb); + } + rwb_semgive(&rwb->wrsem); } - rwb_semgive(&rwb->wrsem); #endif #ifdef CONFIG_FS_READAHEAD /* Loop until we have read all of the requested blocks */ rwb_semtake(&rwb->rhsem); - while (blockcount > 0) + while (nblocks > 0) { /* Is there anything in the read-ahead buffer? */ - if (rwb->rhnbytes > 0) + if (rwb->rhnblocks > 0) { off_t startblock = startblock; size_t nblocks = 0; @@ -513,11 +530,11 @@ int rwb_read(FAR struct rwbuffer_s *rwb, off_t startblock, uint32 blockcount, * number of buffers that we can read from read-ahead buffer. */ - bufferend = rwb->rhblockstart + rwb->rhnbytes; + bufferend = rwb->rhblockstart + rwb->rhnblocks; while ((startblock >= rwb->rhblockstart) && (startblock < bufferend) && - (blockcount > 0)) + (nblocks > 0)) { /* This is one more that we will read from the read ahead buffer */ @@ -526,7 +543,7 @@ int rwb_read(FAR struct rwbuffer_s *rwb, off_t startblock, uint32 blockcount, /* And one less that we will read from the media */ startblock++; - blockcount--; + nblocks--; } /* Then read the data from the read-ahead buffer */ @@ -538,12 +555,12 @@ int rwb_read(FAR struct rwbuffer_s *rwb, off_t startblock, uint32 blockcount, * the buffer and try again. */ - if (blockcount > 0) + if (nblocks > 0) { int ret = rwb_rhreload(rwb, startblock); if (ret < 0) { - fdbg("ERROR: Failed to fill the read-ahead buffer: %d", -ret); + fdbg("ERROR: Failed to fill the read-ahead buffer: %d\n", -ret); return ret; } } @@ -552,7 +569,7 @@ int rwb_read(FAR struct rwbuffer_s *rwb, off_t startblock, uint32 blockcount, rwb_semgive(&rwb->rhsem); return 0; #else - return rwb->rhreload(rwb->dev, startblock, blockcount, rdbuffer); + return rwb->rhreload(rwb->dev, startblock, nblocks, rdbuffer); #endif } @@ -561,7 +578,7 @@ int rwb_read(FAR struct rwbuffer_s *rwb, off_t startblock, uint32 blockcount, ****************************************************************************/ int rwb_write(FAR struct rwbuffer_s *rwb, off_t startblock, - size_t blockcount, FAR const ubyte *wrbuffer) + size_t nblocks, FAR const ubyte *wrbuffer) { int ret; @@ -573,7 +590,7 @@ int rwb_write(FAR struct rwbuffer_s *rwb, off_t startblock, */ rwb_semtake(&rwb->rhsem); - if (rwb_overlap(rwb->rhblockstart, rwb->rhnbytes, startblock, blockcount)) + if (rwb_overlap(rwb->rhblockstart, rwb->rhnblocks, startblock, nblocks)) { rwb_resetrhbuffer(rwb); } @@ -581,11 +598,11 @@ int rwb_write(FAR struct rwbuffer_s *rwb, off_t startblock, #endif #ifdef CONFIG_FS_WRITEBUFFER - fvdbg("startblock=%d wrbuffer=%p", startblock, wrbuffer); + fvdbg("startblock=%d wrbuffer=%p\n", startblock, wrbuffer); /* Use the block cache unless the buffer size is bigger than block cache */ - if (blockcount > rwb->wrallocsize) + if (nblocks > rwb->wrmaxblocks) { /* First flush the cache */ @@ -595,19 +612,19 @@ int rwb_write(FAR struct rwbuffer_s *rwb, off_t startblock, /* Then transfer the data directly to the media */ - ret = rwb->wrflush(rwb->dev, startblock, blockcount, wrbuffer); + ret = rwb->wrflush(rwb->dev, startblock, nblocks, wrbuffer); } else { /* Buffer the data in the write buffer */ - ret = rwb_writebuffer(rwb, startblock, blockcount, wrbuffer); + ret = rwb_writebuffer(rwb, startblock, nblocks, wrbuffer); } return ret; #else - return rwb->wrflush(rwb->dev, startblock, blockcount, wrbuffer); + return rwb->wrflush(rwb->dev, startblock, nblocks, wrbuffer); #endif } |