diff options
Diffstat (limited to 'tcl8.6/unix/tclUnixPipe.c')
| -rw-r--r-- | tcl8.6/unix/tclUnixPipe.c | 1327 |
1 files changed, 1327 insertions, 0 deletions
diff --git a/tcl8.6/unix/tclUnixPipe.c b/tcl8.6/unix/tclUnixPipe.c new file mode 100644 index 0000000..8b26694 --- /dev/null +++ b/tcl8.6/unix/tclUnixPipe.c @@ -0,0 +1,1327 @@ +/* + * tclUnixPipe.c -- + * + * This file implements the UNIX-specific exec pipeline functions, the + * "pipe" channel driver, and the "pid" Tcl command. + * + * Copyright (c) 1991-1994 The Regents of the University of California. + * Copyright (c) 1994-1997 Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution of + * this file, and for a DISCLAIMER OF ALL WARRANTIES. + */ + +#include "tclInt.h" + +#ifdef USE_VFORK +#define fork vfork +#endif + +/* + * The following macros convert between TclFile's and fd's. The conversion + * simple involves shifting fd's up by one to ensure that no valid fd is ever + * the same as NULL. + */ + +#define MakeFile(fd) ((TclFile) INT2PTR(((int) (fd)) + 1)) +#define GetFd(file) (PTR2INT(file) - 1) + +/* + * This structure describes per-instance state of a pipe based channel. + */ + +typedef struct PipeState { + Tcl_Channel channel; /* Channel associated with this file. */ + TclFile inFile; /* Output from pipe. */ + TclFile outFile; /* Input to pipe. */ + TclFile errorFile; /* Error output from pipe. */ + int numPids; /* How many processes are attached to this + * pipe? */ + Tcl_Pid *pidPtr; /* The process IDs themselves. Allocated by + * the creator of the pipe. */ + int isNonBlocking; /* Nonzero when the pipe is in nonblocking + * mode. Used to decide whether to wait for + * the children at close time. */ +} PipeState; + +/* + * Declarations for local functions defined in this file: + */ + +static int PipeBlockModeProc(ClientData instanceData, int mode); +static int PipeClose2Proc(ClientData instanceData, + Tcl_Interp *interp, int flags); +static int PipeGetHandleProc(ClientData instanceData, + int direction, ClientData *handlePtr); +static int PipeInputProc(ClientData instanceData, char *buf, + int toRead, int *errorCode); +static int PipeOutputProc(ClientData instanceData, + const char *buf, int toWrite, int *errorCode); +static void PipeWatchProc(ClientData instanceData, int mask); +static void RestoreSignals(void); +static int SetupStdFile(TclFile file, int type); + +/* + * This structure describes the channel type structure for command pipe based + * I/O: + */ + +static const Tcl_ChannelType pipeChannelType = { + "pipe", /* Type name. */ + TCL_CHANNEL_VERSION_5, /* v5 channel */ + TCL_CLOSE2PROC, /* Close proc. */ + PipeInputProc, /* Input proc. */ + PipeOutputProc, /* Output proc. */ + NULL, /* Seek proc. */ + NULL, /* Set option proc. */ + NULL, /* Get option proc. */ + PipeWatchProc, /* Initialize notifier. */ + PipeGetHandleProc, /* Get OS handles out of channel. */ + PipeClose2Proc, /* close2proc. */ + PipeBlockModeProc, /* Set blocking or non-blocking mode.*/ + NULL, /* flush proc. */ + NULL, /* handler proc. */ + NULL, /* wide seek proc */ + NULL, /* thread action proc */ + NULL /* truncation */ +}; + +/* + *---------------------------------------------------------------------- + * + * TclpMakeFile -- + * + * Make a TclFile from a channel. + * + * Results: + * Returns a new TclFile or NULL on failure. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +TclFile +TclpMakeFile( + Tcl_Channel channel, /* Channel to get file from. */ + int direction) /* Either TCL_READABLE or TCL_WRITABLE. */ +{ + ClientData data; + + if (Tcl_GetChannelHandle(channel, direction, &data) != TCL_OK) { + return NULL; + } + + return MakeFile(PTR2INT(data)); +} + +/* + *---------------------------------------------------------------------- + * + * TclpOpenFile -- + * + * Open a file for use in a pipeline. + * + * Results: + * Returns a new TclFile handle or NULL on failure. + * + * Side effects: + * May cause a file to be created on the file system. + * + *---------------------------------------------------------------------- + */ + +TclFile +TclpOpenFile( + const char *fname, /* The name of the file to open. */ + int mode) /* In what mode to open the file? */ +{ + int fd; + const char *native; + Tcl_DString ds; + + native = Tcl_UtfToExternalDString(NULL, fname, -1, &ds); + fd = TclOSopen(native, mode, 0666); /* INTL: Native. */ + Tcl_DStringFree(&ds); + if (fd != -1) { + fcntl(fd, F_SETFD, FD_CLOEXEC); + + /* + * If the file is being opened for writing, seek to the end so we can + * append to any data already in the file. + */ + + if ((mode & O_WRONLY) && !(mode & O_APPEND)) { + TclOSseek(fd, (Tcl_SeekOffset) 0, SEEK_END); + } + + /* + * Increment the fd so it can't be 0, which would conflict with the + * NULL return for errors. + */ + + return MakeFile(fd); + } + return NULL; +} + +/* + *---------------------------------------------------------------------- + * + * TclpCreateTempFile -- + * + * This function creates a temporary file initialized with an optional + * string, and returns a file handle with the file pointer at the + * beginning of the file. + * + * Results: + * A handle to a file. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +TclFile +TclpCreateTempFile( + const char *contents) /* String to write into temp file, or NULL. */ +{ + int fd = TclUnixOpenTemporaryFile(NULL, NULL, NULL, NULL); + + if (fd == -1) { + return NULL; + } + fcntl(fd, F_SETFD, FD_CLOEXEC); + if (contents != NULL) { + Tcl_DString dstring; + char *native; + + native = Tcl_UtfToExternalDString(NULL, contents, -1, &dstring); + if (write(fd, native, Tcl_DStringLength(&dstring)) == -1) { + close(fd); + Tcl_DStringFree(&dstring); + return NULL; + } + Tcl_DStringFree(&dstring); + TclOSseek(fd, (Tcl_SeekOffset) 0, SEEK_SET); + } + return MakeFile(fd); +} + +/* + *---------------------------------------------------------------------- + * + * TclpTempFileName -- + * + * This function returns unique filename. + * + * Results: + * Returns a valid Tcl_Obj* with refCount 0, or NULL on failure. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclpTempFileName(void) +{ + Tcl_Obj *retVal, *nameObj = Tcl_NewObj(); + int fd; + + Tcl_IncrRefCount(nameObj); + fd = TclUnixOpenTemporaryFile(NULL, NULL, NULL, nameObj); + if (fd == -1) { + Tcl_DecrRefCount(nameObj); + return NULL; + } + + fcntl(fd, F_SETFD, FD_CLOEXEC); + TclpObjDeleteFile(nameObj); + close(fd); + retVal = Tcl_DuplicateObj(nameObj); + Tcl_DecrRefCount(nameObj); + return retVal; +} + +/* + *---------------------------------------------------------------------------- + * + * TclpTempFileNameForLibrary -- + * + * Constructs a file name in the native file system where a dynamically + * loaded library may be placed. + * + * Results: + * Returns the constructed file name. If an error occurs, returns NULL + * and leaves an error message in the interpreter result. + * + * On Unix, it works to load a shared object from a file of any name, so this + * function is merely a thin wrapper around TclpTempFileName(). + * + *---------------------------------------------------------------------------- + */ + +Tcl_Obj * +TclpTempFileNameForLibrary( + Tcl_Interp *interp, /* Tcl interpreter. */ + Tcl_Obj *path) /* Path name of the library in the VFS. */ +{ + Tcl_Obj *retval = TclpTempFileName(); + + if (retval == NULL) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't create temporary file: %s", + Tcl_PosixError(interp))); + } + return retval; +} + +/* + *---------------------------------------------------------------------- + * + * TclpCreatePipe -- + * + * Creates a pipe - simply calls the pipe() function. + * + * Results: + * Returns 1 on success, 0 on failure. + * + * Side effects: + * Creates a pipe. + * + *---------------------------------------------------------------------- + */ + +int +TclpCreatePipe( + TclFile *readPipe, /* Location to store file handle for read side + * of pipe. */ + TclFile *writePipe) /* Location to store file handle for write + * side of pipe. */ +{ + int pipeIds[2]; + + if (pipe(pipeIds) != 0) { + return 0; + } + + fcntl(pipeIds[0], F_SETFD, FD_CLOEXEC); + fcntl(pipeIds[1], F_SETFD, FD_CLOEXEC); + + *readPipe = MakeFile(pipeIds[0]); + *writePipe = MakeFile(pipeIds[1]); + return 1; +} + +/* + *---------------------------------------------------------------------- + * + * TclpCloseFile -- + * + * Implements a mechanism to close a UNIX file. + * + * Results: + * Returns 0 on success, or -1 on error, setting errno. + * + * Side effects: + * The file is closed. + * + *---------------------------------------------------------------------- + */ + +int +TclpCloseFile( + TclFile file) /* The file to close. */ +{ + int fd = GetFd(file); + + /* + * Refuse to close the fds for stdin, stdout and stderr. + */ + + if ((fd == 0) || (fd == 1) || (fd == 2)) { + return 0; + } + + Tcl_DeleteFileHandler(fd); + return close(fd); +} + +/* + *--------------------------------------------------------------------------- + * + * TclpCreateProcess -- + * + * Create a child process that has the specified files as its standard + * input, output, and error. The child process runs asynchronously and + * runs with the same environment variables as the creating process. + * + * The path is searched to find the specified executable. + * + * Results: + * The return value is TCL_ERROR and an error message is left in the + * interp's result if there was a problem creating the child process. + * Otherwise, the return value is TCL_OK and *pidPtr is filled with the + * process id of the child process. + * + * Side effects: + * A process is created. + * + *--------------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +TclpCreateProcess( + Tcl_Interp *interp, /* Interpreter in which to leave errors that + * occurred when creating the child process. + * Error messages from the child process + * itself are sent to errorFile. */ + int argc, /* Number of arguments in following array. */ + const char **argv, /* Array of argument strings in UTF-8. + * argv[0] contains the name of the executable + * translated using Tcl_TranslateFileName + * call). Additional arguments have not been + * converted. */ + TclFile inputFile, /* If non-NULL, gives the file to use as input + * for the child process. If inputFile file is + * not readable or is NULL, the child will + * receive no standard input. */ + TclFile outputFile, /* If non-NULL, gives the file that receives + * output from the child process. If + * outputFile file is not writeable or is + * NULL, output from the child will be + * discarded. */ + TclFile errorFile, /* If non-NULL, gives the file that receives + * errors from the child process. If errorFile + * file is not writeable or is NULL, errors + * from the child will be discarded. errorFile + * may be the same as outputFile. */ + Tcl_Pid *pidPtr) /* If this function is successful, pidPtr is + * filled with the process id of the child + * process. */ +{ + TclFile errPipeIn, errPipeOut; + int count, status, fd; + char errSpace[200 + TCL_INTEGER_SPACE]; + Tcl_DString *dsArray; + char **newArgv; + int pid, i; + + errPipeIn = NULL; + errPipeOut = NULL; + pid = -1; + + /* + * Create a pipe that the child can use to return error information if + * anything goes wrong. + */ + + if (TclpCreatePipe(&errPipeIn, &errPipeOut) == 0) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't create pipe: %s", Tcl_PosixError(interp))); + goto error; + } + + /* + * We need to allocate and convert this before the fork so it is properly + * deallocated later + */ + + dsArray = TclStackAlloc(interp, argc * sizeof(Tcl_DString)); + newArgv = TclStackAlloc(interp, (argc+1) * sizeof(char *)); + newArgv[argc] = NULL; + for (i = 0; i < argc; i++) { + newArgv[i] = Tcl_UtfToExternalDString(NULL, argv[i], -1, &dsArray[i]); + } + +#ifdef USE_VFORK + /* + * After vfork(), do not call code in the child that changes global state, + * because it is using the parent's memory space at that point and writes + * might corrupt the parent: so ensure standard channels are initialized + * in the parent, otherwise SetupStdFile() might initialize them in the + * child. + */ + + if (!inputFile) { + Tcl_GetStdChannel(TCL_STDIN); + } + if (!outputFile) { + Tcl_GetStdChannel(TCL_STDOUT); + } + if (!errorFile) { + Tcl_GetStdChannel(TCL_STDERR); + } +#endif + + pid = fork(); + if (pid == 0) { + size_t len; + int joinThisError = errorFile && (errorFile == outputFile); + + fd = GetFd(errPipeOut); + + /* + * Set up stdio file handles for the child process. + */ + + if (!SetupStdFile(inputFile, TCL_STDIN) + || !SetupStdFile(outputFile, TCL_STDOUT) + || (!joinThisError && !SetupStdFile(errorFile, TCL_STDERR)) + || (joinThisError && + ((dup2(1,2) == -1) || (fcntl(2, F_SETFD, 0) != 0)))) { + sprintf(errSpace, + "%dforked process couldn't set up input/output", errno); + len = strlen(errSpace); + if (len != (size_t) write(fd, errSpace, len)) { + Tcl_Panic("TclpCreateProcess: unable to write to errPipeOut"); + } + _exit(1); + } + + /* + * Close the input side of the error pipe. + */ + + RestoreSignals(); + execvp(newArgv[0], newArgv); /* INTL: Native. */ + sprintf(errSpace, "%dcouldn't execute \"%.150s\"", errno, argv[0]); + len = strlen(errSpace); + if (len != (size_t) write(fd, errSpace, len)) { + Tcl_Panic("TclpCreateProcess: unable to write to errPipeOut"); + } + _exit(1); + } + + /* + * Free the mem we used for the fork + */ + + for (i = 0; i < argc; i++) { + Tcl_DStringFree(&dsArray[i]); + } + TclStackFree(interp, newArgv); + TclStackFree(interp, dsArray); + + if (pid == -1) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "couldn't fork child process: %s", Tcl_PosixError(interp))); + goto error; + } + + /* + * Read back from the error pipe to see if the child started up OK. The + * info in the pipe (if any) consists of a decimal errno value followed by + * an error message. + */ + + TclpCloseFile(errPipeOut); + errPipeOut = NULL; + + fd = GetFd(errPipeIn); + count = read(fd, errSpace, (size_t) (sizeof(errSpace) - 1)); + if (count > 0) { + char *end; + + errSpace[count] = 0; + errno = strtol(errSpace, &end, 10); + Tcl_SetObjResult(interp, Tcl_ObjPrintf("%s: %s", + end, Tcl_PosixError(interp))); + goto error; + } + + TclpCloseFile(errPipeIn); + *pidPtr = (Tcl_Pid) INT2PTR(pid); + return TCL_OK; + + error: + if (pid != -1) { + /* + * Reap the child process now if an error occurred during its startup. + * We don't call this with WNOHANG because that can lead to defunct + * processes on an MP system. We shouldn't have to worry about hanging + * here, since this is the error case. [Bug: 6148] + */ + + Tcl_WaitPid((Tcl_Pid) INT2PTR(pid), &status, 0); + } + + if (errPipeIn) { + TclpCloseFile(errPipeIn); + } + if (errPipeOut) { + TclpCloseFile(errPipeOut); + } + return TCL_ERROR; +} + +/* + *---------------------------------------------------------------------- + * + * RestoreSignals -- + * + * This function is invoked in a forked child process just before + * exec-ing a new program to restore all signals to their default + * settings. + * + * Results: + * None. + * + * Side effects: + * Signal settings get changed. + * + *---------------------------------------------------------------------- + */ + +static void +RestoreSignals(void) +{ +#ifdef SIGABRT + signal(SIGABRT, SIG_DFL); +#endif +#ifdef SIGALRM + signal(SIGALRM, SIG_DFL); +#endif +#ifdef SIGFPE + signal(SIGFPE, SIG_DFL); +#endif +#ifdef SIGHUP + signal(SIGHUP, SIG_DFL); +#endif +#ifdef SIGILL + signal(SIGILL, SIG_DFL); +#endif +#ifdef SIGINT + signal(SIGINT, SIG_DFL); +#endif +#ifdef SIGPIPE + signal(SIGPIPE, SIG_DFL); +#endif +#ifdef SIGQUIT + signal(SIGQUIT, SIG_DFL); +#endif +#ifdef SIGSEGV + signal(SIGSEGV, SIG_DFL); +#endif +#ifdef SIGTERM + signal(SIGTERM, SIG_DFL); +#endif +#ifdef SIGUSR1 + signal(SIGUSR1, SIG_DFL); +#endif +#ifdef SIGUSR2 + signal(SIGUSR2, SIG_DFL); +#endif +#ifdef SIGCHLD + signal(SIGCHLD, SIG_DFL); +#endif +#ifdef SIGCONT + signal(SIGCONT, SIG_DFL); +#endif +#ifdef SIGTSTP + signal(SIGTSTP, SIG_DFL); +#endif +#ifdef SIGTTIN + signal(SIGTTIN, SIG_DFL); +#endif +#ifdef SIGTTOU + signal(SIGTTOU, SIG_DFL); +#endif +} + +/* + *---------------------------------------------------------------------- + * + * SetupStdFile -- + * + * Set up stdio file handles for the child process, using the current + * standard channels if no other files are specified. If no standard + * channel is defined, or if no file is associated with the channel, then + * the corresponding standard fd is closed. + * + * Results: + * Returns 1 on success, or 0 on failure. + * + * Side effects: + * Replaces stdio fds. + * + *---------------------------------------------------------------------- + */ + +static int +SetupStdFile( + TclFile file, /* File to dup, or NULL. */ + int type) /* One of TCL_STDIN, TCL_STDOUT, TCL_STDERR */ +{ + Tcl_Channel channel; + int fd; + int targetFd = 0; /* Initializations here needed only to */ + int direction = 0; /* prevent warnings about using uninitialized + * variables. */ + + switch (type) { + case TCL_STDIN: + targetFd = 0; + direction = TCL_READABLE; + break; + case TCL_STDOUT: + targetFd = 1; + direction = TCL_WRITABLE; + break; + case TCL_STDERR: + targetFd = 2; + direction = TCL_WRITABLE; + break; + } + + if (!file) { + channel = Tcl_GetStdChannel(type); + if (channel) { + file = TclpMakeFile(channel, direction); + } + } + if (file) { + fd = GetFd(file); + if (fd != targetFd) { + if (dup2(fd, targetFd) == -1) { + return 0; + } + + /* + * Must clear the close-on-exec flag for the target FD, since some + * systems (e.g. Ultrix) do not clear the CLOEXEC flag on the + * target FD. + */ + + fcntl(targetFd, F_SETFD, 0); + } else { + /* + * Since we aren't dup'ing the file, we need to explicitly clear + * the close-on-exec flag. + */ + + fcntl(fd, F_SETFD, 0); + } + } else { + close(targetFd); + } + return 1; +} + +/* + *---------------------------------------------------------------------- + * + * TclpCreateCommandChannel -- + * + * This function is called by the generic IO level to perform the + * platform specific channel initialization for a command channel. + * + * Results: + * Returns a new channel or NULL on failure. + * + * Side effects: + * Allocates a new channel. + * + *---------------------------------------------------------------------- + */ + +Tcl_Channel +TclpCreateCommandChannel( + TclFile readFile, /* If non-null, gives the file for reading. */ + TclFile writeFile, /* If non-null, gives the file for writing. */ + TclFile errorFile, /* If non-null, gives the file where errors + * can be read. */ + int numPids, /* The number of pids in the pid array. */ + Tcl_Pid *pidPtr) /* An array of process identifiers. Allocated + * by the caller, freed when the channel is + * closed or the processes are detached (in a + * background exec). */ +{ + char channelName[16 + TCL_INTEGER_SPACE]; + int channelId; + PipeState *statePtr = ckalloc(sizeof(PipeState)); + int mode; + + statePtr->inFile = readFile; + statePtr->outFile = writeFile; + statePtr->errorFile = errorFile; + statePtr->numPids = numPids; + statePtr->pidPtr = pidPtr; + statePtr->isNonBlocking = 0; + + mode = 0; + if (readFile) { + mode |= TCL_READABLE; + } + if (writeFile) { + mode |= TCL_WRITABLE; + } + + /* + * Use one of the fds associated with the channel as the channel id. + */ + + if (readFile) { + channelId = GetFd(readFile); + } else if (writeFile) { + channelId = GetFd(writeFile); + } else if (errorFile) { + channelId = GetFd(errorFile); + } else { + channelId = 0; + } + + /* + * For backward compatibility with previous versions of Tcl, we use + * "file%d" as the base name for pipes even though it would be more + * natural to use "pipe%d". + */ + + sprintf(channelName, "file%d", channelId); + statePtr->channel = Tcl_CreateChannel(&pipeChannelType, channelName, + statePtr, mode); + return statePtr->channel; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_CreatePipe -- + * + * System dependent interface to create a pipe for the [chan pipe] + * command. Stolen from TclX. + * + * Results: + * TCL_OK or TCL_ERROR. + * + * Side effects: + * Registers two channels. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_CreatePipe( + Tcl_Interp *interp, /* Errors returned in result. */ + Tcl_Channel *rchan, /* Returned read side. */ + Tcl_Channel *wchan, /* Returned write side. */ + int flags) /* Reserved for future use. */ +{ + int fileNums[2]; + + if (pipe(fileNums) < 0) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf("pipe creation failed: %s", + Tcl_PosixError(interp))); + return TCL_ERROR; + } + + fcntl(fileNums[0], F_SETFD, FD_CLOEXEC); + fcntl(fileNums[1], F_SETFD, FD_CLOEXEC); + + *rchan = Tcl_MakeFileChannel(INT2PTR(fileNums[0]), TCL_READABLE); + Tcl_RegisterChannel(interp, *rchan); + *wchan = Tcl_MakeFileChannel(INT2PTR(fileNums[1]), TCL_WRITABLE); + Tcl_RegisterChannel(interp, *wchan); + + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * TclGetAndDetachPids -- + * + * This function is invoked in the generic implementation of a + * background "exec" (an exec when invoked with a terminating "&") to + * store a list of the PIDs for processes in a command pipeline in the + * interp's result and to detach the processes. + * + * Results: + * None. + * + * Side effects: + * Modifies the interp's result. Detaches processes. + * + *---------------------------------------------------------------------- + */ + +void +TclGetAndDetachPids( + Tcl_Interp *interp, /* Interpreter to append the PIDs to. */ + Tcl_Channel chan) /* Handle for the pipeline. */ +{ + PipeState *pipePtr; + const Tcl_ChannelType *chanTypePtr; + Tcl_Obj *pidsObj; + int i; + + /* + * Punt if the channel is not a command channel. + */ + + chanTypePtr = Tcl_GetChannelType(chan); + if (chanTypePtr != &pipeChannelType) { + return; + } + + pipePtr = Tcl_GetChannelInstanceData(chan); + TclNewObj(pidsObj); + for (i = 0; i < pipePtr->numPids; i++) { + Tcl_ListObjAppendElement(NULL, pidsObj, Tcl_NewIntObj( + PTR2INT(pipePtr->pidPtr[i]))); + Tcl_DetachPids(1, &pipePtr->pidPtr[i]); + } + Tcl_SetObjResult(interp, pidsObj); + if (pipePtr->numPids > 0) { + ckfree(pipePtr->pidPtr); + pipePtr->numPids = 0; + } +} + +/* + *---------------------------------------------------------------------- + * + * PipeBlockModeProc -- + * + * Helper function to set blocking and nonblocking modes on a pipe based + * channel. Invoked by generic IO level code. + * + * Results: + * 0 if successful, errno when failed. + * + * Side effects: + * Sets the device into blocking or non-blocking mode. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +static int +PipeBlockModeProc( + ClientData instanceData, /* Pipe state. */ + int mode) /* The mode to set. Can be one of + * TCL_MODE_BLOCKING or + * TCL_MODE_NONBLOCKING. */ +{ + PipeState *psPtr = instanceData; + + if (psPtr->inFile + && TclUnixSetBlockingMode(GetFd(psPtr->inFile), mode) < 0) { + return errno; + } + if (psPtr->outFile + && TclUnixSetBlockingMode(GetFd(psPtr->outFile), mode) < 0) { + return errno; + } + + psPtr->isNonBlocking = (mode == TCL_MODE_NONBLOCKING); + + return 0; +} + +/* + *---------------------------------------------------------------------- + * + * PipeClose2Proc + * + * This function is invoked by the generic IO level to perform + * pipeline-type-specific half or full-close. + * + * Results: + * 0 on success, errno otherwise. + * + * Side effects: + * Closes the command pipeline channel. + * + *---------------------------------------------------------------------- + */ + +static int +PipeClose2Proc( + ClientData instanceData, /* The pipe to close. */ + Tcl_Interp *interp, /* For error reporting. */ + int flags) /* Flags that indicate which side to close. */ +{ + PipeState *pipePtr = instanceData; + Tcl_Channel errChan; + int errorCode, result; + + errorCode = 0; + result = 0; + + if (((!flags) || (flags & TCL_CLOSE_READ)) && (pipePtr->inFile != NULL)) { + if (TclpCloseFile(pipePtr->inFile) < 0) { + errorCode = errno; + } else { + pipePtr->inFile = NULL; + } + } + if (((!flags) || (flags & TCL_CLOSE_WRITE)) && (pipePtr->outFile != NULL) + && (errorCode == 0)) { + if (TclpCloseFile(pipePtr->outFile) < 0) { + errorCode = errno; + } else { + pipePtr->outFile = NULL; + } + } + + /* + * If half-closing, stop here. + */ + + if (flags) { + return errorCode; + } + + if (pipePtr->isNonBlocking || TclInExit()) { + /* + * If the channel is non-blocking or Tcl is being cleaned up, just + * detach the children PIDs, reap them (important if we are in a + * dynamic load module), and discard the errorFile. + */ + + Tcl_DetachPids(pipePtr->numPids, pipePtr->pidPtr); + Tcl_ReapDetachedProcs(); + + if (pipePtr->errorFile) { + TclpCloseFile(pipePtr->errorFile); + } + } else { + /* + * Wrap the error file into a channel and give it to the cleanup + * routine. + */ + + if (pipePtr->errorFile) { + errChan = Tcl_MakeFileChannel( + INT2PTR(GetFd(pipePtr->errorFile)), + TCL_READABLE); + } else { + errChan = NULL; + } + result = TclCleanupChildren(interp, pipePtr->numPids, pipePtr->pidPtr, + errChan); + } + + if (pipePtr->numPids != 0) { + ckfree(pipePtr->pidPtr); + } + ckfree(pipePtr); + if (errorCode == 0) { + return result; + } + return errorCode; +} + +/* + *---------------------------------------------------------------------- + * + * PipeInputProc -- + * + * This function is invoked from the generic IO level to read input from + * a command pipeline based channel. + * + * Results: + * The number of bytes read is returned or -1 on error. An output + * argument contains a POSIX error code if an error occurs, or zero. + * + * Side effects: + * Reads input from the input device of the channel. + * + *---------------------------------------------------------------------- + */ + +static int +PipeInputProc( + ClientData instanceData, /* Pipe state. */ + char *buf, /* Where to store data read. */ + int toRead, /* How much space is available in the + * buffer? */ + int *errorCodePtr) /* Where to store error code. */ +{ + PipeState *psPtr = instanceData; + int bytesRead; /* How many bytes were actually read from the + * input device? */ + + *errorCodePtr = 0; + + /* + * Assume there is always enough input available. This will block + * appropriately, and read will unblock as soon as a short read is + * possible, if the channel is in blocking mode. If the channel is + * nonblocking, the read will never block. Some OSes can throw an + * interrupt error, for which we should immediately retry. [Bug #415131] + */ + + do { + bytesRead = read(GetFd(psPtr->inFile), buf, (size_t) toRead); + } while ((bytesRead < 0) && (errno == EINTR)); + + if (bytesRead < 0) { + *errorCodePtr = errno; + return -1; + } + return bytesRead; +} + +/* + *---------------------------------------------------------------------- + * + * PipeOutputProc-- + * + * This function is invoked from the generic IO level to write output to + * a command pipeline based channel. + * + * Results: + * The number of bytes written is returned or -1 on error. An output + * argument contains a POSIX error code if an error occurred, or zero. + * + * Side effects: + * Writes output on the output device of the channel. + * + *---------------------------------------------------------------------- + */ + +static int +PipeOutputProc( + ClientData instanceData, /* Pipe state. */ + const char *buf, /* The data buffer. */ + int toWrite, /* How many bytes to write? */ + int *errorCodePtr) /* Where to store error code. */ +{ + PipeState *psPtr = instanceData; + int written; + + *errorCodePtr = 0; + + /* + * Some OSes can throw an interrupt error, for which we should immediately + * retry. [Bug #415131] + */ + + do { + written = write(GetFd(psPtr->outFile), buf, (size_t) toWrite); + } while ((written < 0) && (errno == EINTR)); + + if (written < 0) { + *errorCodePtr = errno; + return -1; + } + return written; +} + +/* + *---------------------------------------------------------------------- + * + * PipeWatchProc -- + * + * Initialize the notifier to watch the fds from this channel. + * + * Results: + * None. + * + * Side effects: + * Sets up the notifier so that a future event on the channel will be + * seen by Tcl. + * + *---------------------------------------------------------------------- + */ + +static void +PipeWatchProc( + ClientData instanceData, /* The pipe state. */ + int mask) /* Events of interest; an OR-ed combination of + * TCL_READABLE, TCL_WRITABLE and + * TCL_EXCEPTION. */ +{ + PipeState *psPtr = instanceData; + int newmask; + + if (psPtr->inFile) { + newmask = mask & (TCL_READABLE | TCL_EXCEPTION); + if (newmask) { + Tcl_CreateFileHandler(GetFd(psPtr->inFile), newmask, + (Tcl_FileProc *) Tcl_NotifyChannel, psPtr->channel); + } else { + Tcl_DeleteFileHandler(GetFd(psPtr->inFile)); + } + } + if (psPtr->outFile) { + newmask = mask & (TCL_WRITABLE | TCL_EXCEPTION); + if (newmask) { + Tcl_CreateFileHandler(GetFd(psPtr->outFile), newmask, + (Tcl_FileProc *) Tcl_NotifyChannel, psPtr->channel); + } else { + Tcl_DeleteFileHandler(GetFd(psPtr->outFile)); + } + } +} + +/* + *---------------------------------------------------------------------- + * + * PipeGetHandleProc -- + * + * Called from Tcl_GetChannelHandle to retrieve OS handles from inside a + * command pipeline based channel. + * + * Results: + * Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if there is no + * handle for the specified direction. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static int +PipeGetHandleProc( + ClientData instanceData, /* The pipe state. */ + int direction, /* TCL_READABLE or TCL_WRITABLE */ + ClientData *handlePtr) /* Where to store the handle. */ +{ + PipeState *psPtr = instanceData; + + if (direction == TCL_READABLE && psPtr->inFile) { + *handlePtr = INT2PTR(GetFd(psPtr->inFile)); + return TCL_OK; + } + if (direction == TCL_WRITABLE && psPtr->outFile) { + *handlePtr = INT2PTR(GetFd(psPtr->outFile)); + return TCL_OK; + } + return TCL_ERROR; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_WaitPid -- + * + * Implements the waitpid system call on Unix systems. + * + * Results: + * Result of calling waitpid. + * + * Side effects: + * Waits for a process to terminate. + * + *---------------------------------------------------------------------- + */ + +Tcl_Pid +Tcl_WaitPid( + Tcl_Pid pid, + int *statPtr, + int options) +{ + int result; + pid_t real_pid = (pid_t) PTR2INT(pid); + + while (1) { + result = (int) waitpid(real_pid, statPtr, options); + if ((result != -1) || (errno != EINTR)) { + return (Tcl_Pid) INT2PTR(result); + } + } +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_PidObjCmd -- + * + * This function is invoked to process the "pid" Tcl command. See the + * user documentation for details on what it does. + * + * Results: + * A standard Tcl result. + * + * Side effects: + * See the user documentation. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_PidObjCmd( + ClientData dummy, /* Not used. */ + Tcl_Interp *interp, /* Current interpreter. */ + int objc, /* Number of arguments. */ + Tcl_Obj *const *objv) /* Argument strings. */ +{ + Tcl_Channel chan; + PipeState *pipePtr; + int i; + Tcl_Obj *resultPtr; + + if (objc > 2) { + Tcl_WrongNumArgs(interp, 1, objv, "?channelId?"); + return TCL_ERROR; + } + + if (objc == 1) { + Tcl_SetObjResult(interp, Tcl_NewLongObj((long) getpid())); + } else { + /* + * Get the channel and make sure that it refers to a pipe. + */ + + chan = Tcl_GetChannel(interp, Tcl_GetString(objv[1]), NULL); + if (chan == NULL) { + return TCL_ERROR; + } + if (Tcl_GetChannelType(chan) != &pipeChannelType) { + return TCL_OK; + } + + /* + * Extract the process IDs from the pipe structure. + */ + + pipePtr = Tcl_GetChannelInstanceData(chan); + resultPtr = Tcl_NewObj(); + for (i = 0; i < pipePtr->numPids; i++) { + Tcl_ListObjAppendElement(NULL, resultPtr, + Tcl_NewIntObj(PTR2INT(TclpGetPid(pipePtr->pidPtr[i])))); + } + Tcl_SetObjResult(interp, resultPtr); + } + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * TclpFinalizePipes -- + * + * Cleans up the pipe subsystem from Tcl_FinalizeThread + * + * Results: + * None. + * + * Notes: + * This function carries out no operation on Unix. + * + *---------------------------------------------------------------------- + */ + +void +TclpFinalizePipes(void) +{ +} + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |