X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fuserprog.texi;h=c4bd9e137bd2c93d4b4c47494d0a581f616d299f;hb=0450759c86862c1aae5fb8416630b1eb89302046;hp=7322dd52946c2c9b601063bc717dbd2f38d245cf;hpb=68bad31062d1a3196a9e4d8550d561c22ae5e9cb;p=pintos-anon diff --git a/doc/userprog.texi b/doc/userprog.texi index 7322dd5..c4bd9e1 100644 --- a/doc/userprog.texi +++ b/doc/userprog.texi @@ -481,6 +481,12 @@ The @code{write} system call for writing to fd 1, the system console. All of our test programs write to the console (the user process version of @func{printf} is implemented this way), so they will all malfunction until @code{write} is available. + +@item +For now, change @func{process_wait} to an infinite loop (one that waits +forever). The provided implementation returns immediately, so Pintos +will power off before any processes actually get to run. You will +eventually need to provide a correct implementation. @end itemize After the above are implemented, user processes should work minimally. @@ -593,8 +599,8 @@ the program cannot load or run for any reason. @deftypefn {System Call} int wait (pid_t @var{pid}) Waits for process @var{pid} to die and returns the status it passed to @code{exit}. Returns -1 if @var{pid} -was terminated by the kernel (i.e.@: killed due to an exception). If -@var{pid} is invalid or if it was not a child of the +was terminated by the kernel (e.g.@: killed due to an exception). If +@var{pid} is does not refer to a child of the calling thread, or if @code{wait} has already been successfully called for the given @var{pid}, returns -1 immediately, without waiting.