1 /* 2 * Test pipe operations. 3 * 4 * Copyright (C) 2020, 2021 Paul Boddie <paul@boddie.org.uk> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA 20 */ 21 22 #include <l4/re/env.h> 23 #include <l4/sys/err.h> 24 25 #include <thread> 26 27 #include <stdio.h> 28 #include <string.h> 29 #include <stdlib.h> 30 #include <unistd.h> /* sleep */ 31 32 #include <fsclient/client.h> 33 #include <fsclient/file.h> 34 #include <mem/memory_utils.h> 35 36 37 38 /* Minimum pipe region size in pages. */ 39 40 const unsigned int PIPE_PAGES = 2; 41 42 /* Use the writer to fill the pipe with data. */ 43 44 static void write_pipe(file_t *writer, int number) 45 { 46 offset_t size = 600; 47 char buffer[size]; 48 long err; 49 50 /* Make writers blocking to permit synchronisation. */ 51 52 if ((err = client_set_blocking(writer, NOTIFY_SPACE_AVAILABLE))) 53 { 54 printf("Could not set pipe #%d as blocking: %s\n", number, l4sys_errtostr(err)); 55 return; 56 } 57 58 for (int loop = 0; loop < 3; loop++) 59 { 60 for (int region = 0; region < 26; region++) 61 { 62 memset(buffer, (int) 'a' + region, size); 63 64 offset_t nwritten = client_write(writer, buffer, size); 65 66 printf("Written %ld/%ld in #%d of %d/%d to pipe #%d...\n", nwritten, size, region, loop, 2, number); 67 } 68 69 sleep(1); 70 } 71 72 /* Flush to make the final output available. */ 73 74 client_flush(writer); 75 76 file_close(writer); 77 } 78 79 /* Use the reader to obtain data from the pipe. */ 80 81 static void read_pipes(file_t *reader1, file_t *reader2) 82 { 83 offset_t size = 600, totals[] = {0, 0}; 84 bool active[] = {true, true}; 85 int num_active = 2; 86 long err; 87 file_t *reader; 88 89 /* Register the readers for notification. */ 90 91 // NOTE: Use the flags to detect initial conditions! 92 93 if ((err = client_subscribe(reader1, NOTIFY_CONTENT_AVAILABLE | NOTIFY_PEER_CLOSED)) || 94 (err = client_subscribe(reader2, NOTIFY_CONTENT_AVAILABLE | NOTIFY_PEER_CLOSED))) 95 { 96 printf("Could not subscribe to notifications: %s\n", l4sys_errtostr(err)); 97 return; 98 } 99 100 while (1) 101 { 102 char buffer[size]; 103 offset_t nread; 104 105 /* Wait for notification of content. */ 106 107 err = client_wait_files(&reader); 108 109 if (err) 110 { 111 printf("Error waiting for notifications: %s\n", l4sys_errtostr(err)); 112 return; 113 } 114 115 if ((reader != reader1) && (reader != reader2)) 116 { 117 printf("Spurious notification received for %p versus %p, %p.\n", reader, reader1, reader2); 118 continue; 119 } 120 121 nread = client_read(reader, buffer, size); 122 123 // NOTE: Should really be testing for the condition somehow. 124 125 int p = reader == reader1 ? 0 : 1; 126 127 if (!nread) 128 { 129 if (active[p]) 130 { 131 active[p] = false; 132 num_active--; 133 134 if (!num_active) 135 break; 136 } 137 } 138 139 while (nread) 140 { 141 totals[p] += nread; 142 143 printf("Read %ld/%ld, total %ld, first %c, last %c, from pipe #%d...\n", nread, size, totals[p], *buffer, *(buffer + nread - 1), p + 1); 144 #if 0 145 for (offset_t i = 0; i < nread; i += 60) 146 { 147 fwrite(buffer + i, sizeof(char), nread - i > 60 ? 60 : nread - i, stdout); 148 fputs("\n", stdout); 149 } 150 #endif 151 nread = client_read(reader, buffer, size); 152 } 153 } 154 155 printf("Data shown.\n"); 156 } 157 158 int main(void) 159 { 160 /* Obtain access to the filesystem. */ 161 162 l4_cap_idx_t server = l4re_env_get_cap("server"); 163 164 /* Invoke the open method to receive the file reference. */ 165 166 file_t reader1, reader2, writer1, writer2; 167 long err = pipe_open(page(PIPE_PAGES), &reader1, &writer1, server) || 168 pipe_open(page(PIPE_PAGES), &reader2, &writer2, server); 169 170 if (err) 171 { 172 printf("Could not obtain pipes: %s\n", l4sys_errtostr(err)); 173 return 1; 174 } 175 176 /* Schedule reader and writer threads. */ 177 178 std::thread *activities[3]; 179 180 activities[0] = new std::thread(read_pipes, &reader1, &reader2); 181 activities[1] = new std::thread(write_pipe, &writer1, 1); 182 activities[2] = new std::thread(write_pipe, &writer2, 2); 183 184 for (int i = 0; i < 3; i++) 185 activities[i]->join(); 186 } 187 188 // vim: tabstop=2 expandtab shiftwidth=2