source: tests/io/many_read.cfa@ ca2feff

//
// Cforall Version 1.0.0 Copyright (C) 2021 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// many_read.cfa -- Make sure that multiple concurrent reads don't mess up.
//
// Author           : Thierry Delisle
// Created On       : Thu Feb 18 15:26:05 2021
// Last Modified By :
// Last Modified On :
// Update Count     :
//

extern "C" {
        #include <sys/types.h>
        #include <sys/stat.h>
        #include <fcntl.h>
        #include <unistd.h>
}

#include <string.h>

#include <fstream.hfa>
#include <iofwd.hfa>

#include <thread.hfa>
#include <kernel.hfa>

#define xstr(s) str(s)
#define str(s) #s

const char * file = xstr(IN_DIR) "many_read.data";
int fd;
off_t size;

const char * content;

thread reader {};
void ?{}(reader & this) {}
void ^?{}(reader & mutex this) {}
void main(reader & this);

int main() {
        fd = open(file, 0);
        if(fd < 0) {
                serr | "Failed to open file: " | file;
                exit(1);
        }

        struct stat sb;
        int ret = fstat(fd, &sb);
        if(ret < 0) {
                serr | "Failed to stat file: " | file;
                exit(1);
        }

        size = sb.st_size;
        sout | "File has size: " | size | "bytes";

        char data[size+1];
        {
                size_t left = size;
                char * it = data;

                while(left) {
                        ret = read(fd, it, left);
                        if(ret < 0) {
                                serr | "Failed to read file: " | file | " (the first time)";
                                exit(1);
                        }
                        it += ret;
                        left -= ret;
                }
        }
        data[size] = 0;
        content = data;
        sout | content;

        {
                processor proc[2];
                {
                        reader readers[17];
                }
        }

        sout | "Yup, it all matches.";
}

#ifdef CFA_HAVE_PREADV2
        extern "C" {
                #include <sys/uio.h>
        }
#endif

void main(reader & this) {
        for(50) {
                char data[size];
                char * it = data;
                size_t left = size;
                off_t offset = 0;

                #ifdef CFA_HAVE_PREADV2
                        while(left) {
                                struct iovec vec;
                                vec.iov_base = (void*)it;
                                vec.iov_len = left;
                                int ret = cfa_preadv2(fd, &vec, 1, offset, 0, 0);
                                if(ret < 0) {
                                        serr | "Failed to read file: " | file | " (NOT the first time)";
                                        exit(1);
                                }
                                it += ret;
                                left -= ret;
                                offset += ret;
                        }

                        if(strncmp(content, data, size) != 0) {
                                serr | "Subsequent read of file '" | file | "' return different content";
                                exit(1);
                        }
                #endif
        }
}