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)
27 int readPipe[2]; int writePipe[2];
28 assert(pipe(readPipe) == 0);
29 assert(pipe(writePipe) == 0);
34 close(readPipe[0]); //close end that parent reads from
35 close(writePipe[1]); //close end that parent writes to
37 //TODO: Fix possible bug here if the process is already a daemon
38 assert(writePipe[0] != 0 && readPipe[1] != 1);
39 dup2(writePipe[0],0); close(writePipe[0]); //pipe end child reads from goes to STDIN
40 dup2(readPipe[1], 1); close(readPipe[1]); //pipe end child writes to goes to STDOUT
42 //TODO: Somehow force the exec'd process to be unbuffered
43 setbuf(stdin, NULL); //WARNING: These lines don't appear to have any affect
44 setbuf(stdout, NULL); //You should add them at the start of the wrapped program.
45 //If your wrapped program is not written in C/C++, you will probably have a problem
49 execl(executablePath, executablePath, (char*)(NULL)); ///Replace process with desired executable
50 fprintf(stderr, "Program::Program - Could not run program \"%s\"!\n", executablePath);
51 exit(EXIT_FAILURE); //We will probably have to terminate the whole program if this happens
55 close(writePipe[0]); //close end that child writes to
56 close(readPipe[1]); //close end that child reads from
58 input = fdopen(readPipe[0],"r"); output = fdopen(writePipe[1],"w");
67 * Writes EOF to the wrapped program and then closes all streams
68 * Kills the wrapped program if it does not exit within 1 second.
72 if (kill(pid, 0) == 0) //Check if the process created is still running...
74 fputc(EOF, output); //If it was, tell it to stop with EOF
75 usleep(500000); //Give it 1/2 a second to respond...
76 if (kill(pid, 0) == 0) //Check if its still running
78 kill(pid, 9); //Slay the infidel mercilessly!
91 * Sends a message to the wrapped AI program
92 * WARNING: Always prints a new line after the message (so don't include a new line)
93 * This is because everything is always line buffered.
94 * @returns true if the message was successfully sent; false if it was not (ie: the process was not running!)
96 bool Program::SendMessage(const char * print, ...)
98 if (kill(pid, 0) != 0) //Is the process running...
104 if (vfprintf(output, print, ap) < 0 || fprintf(output, "\n") < 0)
119 * Retrieves a message from the wrapped AI program, waiting a maximum amount of time
120 * @param buffer - C++ string to store the resultant message in
121 * @param timeout - Maximum amount of time to wait before failure. If timeout <= 0, then GetMessage will wait indefinately.
122 * @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.
124 bool Program::GetMessage(string & buffer, double timeout)
126 if (kill(pid, 0) != 0)
129 assert(&buffer != NULL);
130 GetterThread getterThread(input, buffer);
131 assert(&(getterThread.buffer) != NULL);
132 TimerThread timerThread(timeout*1000000);
134 getterThread.Start();
139 while (!getterThread.Finished())
141 if (timeout > 0 && timerThread.Finished())
154 if (buffer.size() == 1 && buffer[0] == EOF)
162 * Returns true iff the process is running
163 * @returns what I just said, fool
165 bool Program::Running() const
167 return (kill(pid,0) == 0);