--- /dev/null
+/*
+ * An experiment with parallel reading and writing of files using ASIO.
+ */
+
+#include "lib/lib.h"
+#include "lib/lfs.h"
+#include "lib/asio.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#define COPY
+#define DIRECT O_DIRECT
+
+#define P_INIT do { cnt = 0; cnt_rep = 0; cnt_ms = 1; } while(0)
+#define P_UPDATE(cc) do { \
+ cnt += cc; \
+ if (cnt >= cnt_rep) { cnt_ms += get_timer(); \
+ printf("%d of %d MB (%.2f MB/sec)\r", (int)(cnt >> 20), (int)(total_size >> 20), (double)cnt / 1048576 * 1000 / cnt_ms); \
+ fflush(stdout); cnt_rep += 1<<26; } } while(0)
+#define P_FINAL do { \
+ cnt_ms += get_timer(); \
+ log(L_INFO, "Spent %.3f sec (%.2f MB/sec)", (double)cnt_ms/1000, (double)cnt / 1048576 * 1000 / cnt_ms); \
+} while(0)
+
+static struct asio_queue io_queue;
+
+int main(int argc, char **argv)
+{
+ ASSERT(argc == 4);
+ uns files = atol(argv[1]);
+ uns bufsize = atol(argv[2]) * 1024; // Kbytes
+ u64 total_size = (u64)atol(argv[3]) * 1024*1024*1024; // Gbytes
+ u64 cnt, cnt_rep;
+ uns cnt_ms;
+ int fd[files];
+ byte name[files][16];
+
+ init_timer();
+
+ io_queue.buffer_size = bufsize;
+ io_queue.max_writebacks = 2;
+ asio_init_queue(&io_queue);
+
+#ifdef COPY
+ log(L_INFO, "Creating input file");
+ int in_fd = sh_open("tmp/ft-in", O_RDWR | O_CREAT | O_TRUNC | DIRECT, 0666);
+ ASSERT(in_fd >= 0);
+ ASSERT(!(total_size % bufsize));
+ P_INIT;
+ for (uns i=0; i<total_size/bufsize; i++)
+ {
+ struct asio_request *r = asio_get(&io_queue);
+ r->op = ASIO_WRITE_BACK;
+ r->fd = in_fd;
+ r->len = bufsize;
+ byte *xbuf = r->buffer;
+ for (uns j=0; j<bufsize; j++)
+ xbuf[j] = i+j;
+ asio_submit(r);
+ P_UPDATE(bufsize);
+ }
+ asio_sync(&io_queue);
+ lseek(in_fd, 0, SEEK_SET);
+ sync();
+ P_FINAL;
+#endif
+
+ log(L_INFO, "Initializing output files");
+ for (uns i=0; i<files; i++)
+ {
+ sprintf(name[i], "tmp/ft-%d", i);
+ fd[i] = sh_open(name[i], O_RDWR | O_CREAT | O_TRUNC | DIRECT, 0666);
+ if (fd[i] < 0)
+ die("Cannot create %s: %m", name[i]);
+ }
+ sync();
+ get_timer();
+
+ log(L_INFO, "Writing %d MB to %d files in parallel with %d byte buffers", (int)(total_size >> 20), files, bufsize);
+ P_INIT;
+ for (uns round=0; round<total_size/bufsize/files; round++)
+ {
+ for (uns i=0; i<files; i++)
+ {
+ struct asio_request *r = asio_get(&io_queue);
+#ifdef COPY
+ r->op = ASIO_READ;
+ r->fd = in_fd;
+ r->len = bufsize;
+ asio_submit(r);
+ struct asio_request *rr = asio_wait(&io_queue);
+ ASSERT(rr == r && r->status == (int)r->len);
+#else
+ for (uns j=0; j<bufsize; j++)
+ r->buffer[j] = round+i+j;
+#endif
+ r->op = ASIO_WRITE_BACK;
+ r->fd = fd[i];
+ r->len = bufsize;
+ asio_submit(r);
+ P_UPDATE(bufsize);
+ }
+ }
+ asio_sync(&io_queue);
+#ifdef COPY
+ close(in_fd);
+#endif
+ log(L_INFO, "Syncing");
+ sync();
+ P_FINAL;
+
+ log(L_INFO, "Reading the files sequentially");
+ P_INIT;
+ for (uns i=0; i<files; i++)
+ {
+ lseek(fd[i], 0, SEEK_SET);
+ for (uns round=0; round<total_size/bufsize/files; round++)
+ {
+ struct asio_request *rr, *r = asio_get(&io_queue);
+ r->op = ASIO_READ;
+ r->fd = fd[i];
+ r->len = bufsize;
+ asio_submit(r);
+ rr = asio_wait(&io_queue);
+ ASSERT(rr == r && r->status == (int)bufsize);
+ asio_put(r);
+ P_UPDATE(bufsize);
+ }
+ close(fd[i]);
+ }
+ P_FINAL;
+
+ for (uns i=0; i<files; i++)
+ unlink(name[i]);
+#ifdef COPY
+ unlink("tmp/ft-in");
+#endif
+
+ asio_cleanup_queue(&io_queue);
+ log(L_INFO, "Done");
+ return 0;
+}