diff options
Diffstat (limited to 'compat/waitpid.c')
| -rw-r--r-- | compat/waitpid.c | 170 |
1 files changed, 0 insertions, 170 deletions
diff --git a/compat/waitpid.c b/compat/waitpid.c deleted file mode 100644 index 1069f56..0000000 --- a/compat/waitpid.c +++ /dev/null @@ -1,170 +0,0 @@ -/* - * waitpid.c -- - * - * This procedure emulates the POSIX waitpid kernel call on - * BSD systems that don't have waitpid but do have wait3. - * This code is based on a prototype version written by - * Mark Diekhans and Karl Lehenbauer. - * - * Copyright (c) 1993 The Regents of the University of California. - * Copyright (c) 1994 Sun Microsystems, Inc. - * - * See the file "license.terms" for information on usage and redistribution - * of this file, and for a DISCLAIMER OF ALL WARRANTIES. - * - * RCS: @(#) $Id: waitpid.c,v 1.2 1998/09/14 18:39:45 stanton Exp $ - */ - -#include "tclInt.h" -#include "tclPort.h" - -/* - * A linked list of the following structures is used to keep track - * of processes for which we received notification from the kernel, - * but the application hasn't waited for them yet (this can happen - * because wait may not return the process we really want). We - * save the information here until the application finally does - * wait for the process. - */ - -typedef struct WaitInfo { - int pid; /* Pid of process that exited. */ - WAIT_STATUS_TYPE status; /* Status returned when child exited - * or suspended. */ - struct WaitInfo *nextPtr; /* Next in list of exited processes. */ -} WaitInfo; - -static WaitInfo *deadList = NULL; /* First in list of all dead - * processes. */ - -/* - *---------------------------------------------------------------------- - * - * waitpid -- - * - * This procedure emulates the functionality of the POSIX - * waitpid kernel call, using the BSD wait3 kernel call. - * Note: it doesn't emulate absolutely all of the waitpid - * functionality, in that it doesn't support pid's of 0 - * or < -1. - * - * Results: - * -1 is returned if there is an error in the wait kernel call. - * Otherwise the pid of an exited or suspended process is - * returned and *statusPtr is set to the status value of the - * process. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -#ifdef waitpid -# undef waitpid -#endif - -int -waitpid(pid, statusPtr, options) - int pid; /* The pid to wait on. Must be -1 or - * greater than zero. */ - int *statusPtr; /* Where to store wait status for the - * process. */ - int options; /* OR'ed combination of WNOHANG and - * WUNTRACED. */ -{ - register WaitInfo *waitPtr, *prevPtr; - int result; - WAIT_STATUS_TYPE status; - - if ((pid < -1) || (pid == 0)) { - errno = EINVAL; - return -1; - } - - /* - * See if there's a suitable process that has already stopped or - * exited. If so, remove it from the list of exited processes and - * return its information. - */ - - for (waitPtr = deadList, prevPtr = NULL; waitPtr != NULL; - prevPtr = waitPtr, waitPtr = waitPtr->nextPtr) { - if ((pid != waitPtr->pid) && (pid != -1)) { - continue; - } - if (!(options & WUNTRACED) && (WIFSTOPPED(waitPtr->status))) { - continue; - } - result = waitPtr->pid; - *statusPtr = *((int *) &waitPtr->status); - if (prevPtr == NULL) { - deadList = waitPtr->nextPtr; - } else { - prevPtr->nextPtr = waitPtr->nextPtr; - } - ckfree((char *) waitPtr); - return result; - } - - /* - * Wait for any process to stop or exit. If it's an acceptable one - * then return it to the caller; otherwise store information about it - * in the list of exited processes and try again. On systems that - * have only wait but not wait3, there are several situations we can't - * handle, but we do the best we can (e.g. can still handle some - * combinations of options by invoking wait instead of wait3). - */ - - while (1) { -#if NO_WAIT3 - if (options & WNOHANG) { - return 0; - } - if (options != 0) { - errno = EINVAL; - return -1; - } - result = wait(&status); -#else - result = wait3(&status, options, 0); -#endif - if ((result == -1) && (errno == EINTR)) { - continue; - } - if (result <= 0) { - return result; - } - - if ((pid != result) && (pid != -1)) { - goto saveInfo; - } - if (!(options & WUNTRACED) && (WIFSTOPPED(status))) { - goto saveInfo; - } - *statusPtr = *((int *) &status); - return result; - - /* - * Can't return this info to caller. Save it in the list of - * stopped or exited processes. Tricky point: first check for - * an existing entry for the process and overwrite it if it - * exists (e.g. a previously stopped process might now be dead). - */ - - saveInfo: - for (waitPtr = deadList; waitPtr != NULL; waitPtr = waitPtr->nextPtr) { - if (waitPtr->pid == result) { - waitPtr->status = status; - goto waitAgain; - } - } - waitPtr = (WaitInfo *) ckalloc(sizeof(WaitInfo)); - waitPtr->pid = result; - waitPtr->status = status; - waitPtr->nextPtr = deadList; - deadList = waitPtr; - - waitAgain: continue; - } -} |