7 #include "thread_util.h"
16 * @param executablePath - path to the program that will be run
18 * Creates two pipes - one for each direction between the parent process and the AI program
20 * The child process closes unused sides of the pipe, and then calls exec to replace itself with the AI program
21 * The parent process closes unused sides of the pipe, and sets up member variables - associates streams with the pipe fd's for convenience.
23 Program::Program(const char * executablePath) : input(NULL), output(NULL), pid(0)
25 //See if file exists...
26 FILE * file = fopen(executablePath, "r");
37 int readPipe[2]; int writePipe[2];
38 assert(pipe(readPipe) == 0);
39 assert(pipe(writePipe) == 0);
44 close(readPipe[0]); //close end that parent reads from
45 close(writePipe[1]); //close end that parent writes to
47 //TODO: Fix possible bug here if the process is already a daemon
48 assert(writePipe[0] != 0 && readPipe[1] != 1);
49 dup2(writePipe[0],0); close(writePipe[0]); //pipe end child reads from goes to STDIN
50 dup2(readPipe[1], 1); close(readPipe[1]); //pipe end child writes to goes to STDOUT
52 //TODO: Somehow force the exec'd process to be unbuffered
53 setbuf(stdin, NULL); //WARNING: These lines don't appear to have any affect
54 setbuf(stdout, NULL); //You should add them at the start of the wrapped program.
55 //If your wrapped program is not written in C/C++, you will probably have a problem
59 execl(executablePath, executablePath, (char*)(NULL)); ///Replace process with desired executable
60 //fprintf(stderr, "Program::Program - Could not run program \"%s\"!\n", executablePath);
61 //exit(EXIT_FAILURE); //We will probably have to terminate the whole program if this happens
65 close(writePipe[0]); //close end that child writes to
66 close(readPipe[1]); //close end that child reads from
68 input = fdopen(readPipe[0],"r"); output = fdopen(writePipe[1],"w");
77 * Writes EOF to the wrapped program and then closes all streams
78 * Kills the wrapped program if it does not exit within 1 second.
82 if (Running()) //Check if the process created is still running...
84 fputc(EOF, output); //If it was, tell it to stop with EOF
86 TimerThread timer(2); //Wait for 2 seconds
88 while (!timer.Finished())
112 * Sends a message to the wrapped AI program
113 * WARNING: Always prints a new line after the message (so don't include a new line)
114 * This is because everything is always line buffered.
115 * @returns true if the message was successfully sent; false if it was not (ie: the process was not running!)
117 bool Program::SendMessage(const char * print, ...)
119 if (!Running()) //Is the process running...
125 if (vfprintf(output, print, ap) < 0 || fprintf(output, "\n") < 0)
140 * Retrieves a message from the wrapped AI program, waiting a maximum amount of time
141 * @param buffer - C++ string to store the resultant message in
142 * @param timeout - Maximum amount of time to wait before failure. If timeout <= 0, then GetMessage will wait indefinately.
143 * @returns true if the response was recieved within the specified time, false if it was not, or an EOF was recieved, or the process was not running.
145 bool Program::GetMessage(string & buffer, double timeout)
150 assert(&buffer != NULL);
151 GetterThread getterThread(input, buffer);
152 assert(&(getterThread.buffer) != NULL);
153 TimerThread timerThread(timeout*1000000);
155 getterThread.Start();
160 while (!getterThread.Finished())
162 if (timeout > 0 && timerThread.Finished())
175 if (buffer.size() == 1 && buffer[0] == EOF)
183 * Returns true iff the process is running
184 * @returns what I just said, fool
186 bool Program::Running() const
188 return (pid > 0 && kill(pid,0) == 0);