X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/7271198cf0eb4714fba706605ab8170363012cfa..dd51571cc3092d40c5f16c2fece874e288ea3395:/src/syncio.c?ds=sidebyside diff --git a/src/syncio.c b/src/syncio.c index 9958363b..b0c2969e 100644 --- a/src/syncio.c +++ b/src/syncio.c @@ -36,50 +36,79 @@ * of the SYNC command where the slave does it in a blocking way, and * the MIGRATE command that must be blocking in order to be atomic from the * point of view of the two instances (one migrating the key and one receiving - * the key). This is why need the following blocking I/O functions. */ + * the key). This is why need the following blocking I/O functions. + * + * All the functions take the timeout in milliseconds. */ + +#define REDIS_SYNCIO_RESOLUTION 10 /* Resolution in milliseconds */ -int syncWrite(int fd, char *ptr, ssize_t size, int timeout) { +/* Write the specified payload to 'fd'. If writing the whole payload will be done + * within 'timeout' milliseconds the operation succeeds and 'size' is returned. + * Otherwise the operation fails, -1 is returned, and an unspecified partial write + * could be performed against the file descriptor. */ +ssize_t syncWrite(int fd, char *ptr, ssize_t size, long long timeout) { ssize_t nwritten, ret = size; - time_t start = time(NULL); + long long start = mstime(); + long long remaining = timeout; - timeout++; - while(size) { - if (aeWait(fd,AE_WRITABLE,1000) & AE_WRITABLE) { + while(1) { + long long wait = (remaining > REDIS_SYNCIO_RESOLUTION) ? + remaining : REDIS_SYNCIO_RESOLUTION; + long long elapsed; + + if (aeWait(fd,AE_WRITABLE,wait) & AE_WRITABLE) { nwritten = write(fd,ptr,size); if (nwritten == -1) return -1; ptr += nwritten; size -= nwritten; + if (size == 0) return ret; } - if ((time(NULL)-start) > timeout) { + elapsed = mstime() - start; + if (elapsed >= timeout) { errno = ETIMEDOUT; return -1; } + remaining = timeout - elapsed; } - return ret; } -int syncRead(int fd, char *ptr, ssize_t size, int timeout) { +/* Read the specified amount of bytes from 'fd'. If all the bytes are read within + * 'timeout' milliseconds the operation succeed and 'size' is returned. + * Otherwise the operation fails, -1 is returned, and an unspecified amount of + * data could be read from the file descriptor. */ +ssize_t syncRead(int fd, char *ptr, ssize_t size, long long timeout) { ssize_t nread, totread = 0; - time_t start = time(NULL); + long long start = mstime(); + long long remaining = timeout; - timeout++; - while(size) { - if (aeWait(fd,AE_READABLE,1000) & AE_READABLE) { + while(1) { + long long wait = (remaining > REDIS_SYNCIO_RESOLUTION) ? + remaining : REDIS_SYNCIO_RESOLUTION; + long long elapsed; + + if (aeWait(fd,AE_READABLE,wait) & AE_READABLE) { nread = read(fd,ptr,size); if (nread <= 0) return -1; ptr += nread; size -= nread; totread += nread; + if (size == 0) return totread; } - if ((time(NULL)-start) > timeout) { + elapsed = mstime() - start; + if (elapsed >= timeout) { errno = ETIMEDOUT; return -1; } + remaining = timeout - elapsed; } - return totread; } -int syncReadLine(int fd, char *ptr, ssize_t size, int timeout) { +/* Read a line making sure that every char will not require more than 'timeout' + * milliseconds to be read. + * + * On success the number of bytes read is returned, otherwise -1. + * On success the string is always correctly terminated with a 0 byte. */ +ssize_t syncReadLine(int fd, char *ptr, ssize_t size, long long timeout) { ssize_t nread = 0; size--;