diff options
author | ltabb <devnull@localhost> | 1998-03-28 02:44:19 +0000 |
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committer | ltabb <devnull@localhost> | 1998-03-28 02:44:19 +0000 |
commit | f37da7c8c6b5efa19577e626dc75420498c35077 (patch) | |
tree | 0bf3e03b605ef5c66d9e56e70c0d9276587a1115 /pr/src/md/unix/uxproces.c | |
download | nspr-hg-f37da7c8c6b5efa19577e626dc75420498c35077.tar.gz |
Free the lizard
Diffstat (limited to 'pr/src/md/unix/uxproces.c')
-rw-r--r-- | pr/src/md/unix/uxproces.c | 715 |
1 files changed, 715 insertions, 0 deletions
diff --git a/pr/src/md/unix/uxproces.c b/pr/src/md/unix/uxproces.c new file mode 100644 index 00000000..7f8ab887 --- /dev/null +++ b/pr/src/md/unix/uxproces.c @@ -0,0 +1,715 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* + * The contents of this file are subject to the Netscape Public License + * Version 1.0 (the "NPL"); you may not use this file except in + * compliance with the NPL. You may obtain a copy of the NPL at + * http://www.mozilla.org/NPL/ + * + * Software distributed under the NPL is distributed on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL + * for the specific language governing rights and limitations under the + * NPL. + * + * The Initial Developer of this code under the NPL is Netscape + * Communications Corporation. Portions created by Netscape are + * Copyright (C) 1998 Netscape Communications Corporation. All Rights + * Reserved. + */ + +#include "primpl.h" + +#include <sys/types.h> +#include <unistd.h> +#include <fcntl.h> +#include <signal.h> +#include <sys/wait.h> + +/* + ********************************************************************** + * + * The Unix process routines + * + ********************************************************************** + */ + +#define _PR_SIGNALED_EXITSTATUS 256 + +typedef enum pr_PidState { + _PR_PID_DETACHED, + _PR_PID_REAPED, + _PR_PID_WAITING +} pr_PidState; + +typedef struct pr_PidRecord { + pid_t pid; + int exitStatus; + pr_PidState state; + PRCondVar *reapedCV; + struct pr_PidRecord *next; +} pr_PidRecord; + +/* + * Irix sprocs and LinuxThreads are actually a kind of processes + * that can share the virtual address space and file descriptors. + */ +#if (defined(IRIX) && !defined(_PR_PTHREADS)) \ + || (defined(LINUX) && defined(_PR_PTHREADS)) +#define _PR_SHARE_CLONES +#endif + +/* + * The macro _PR_NATIVE_THREADS indicates that we are + * using native threads only, so waitpid() blocks just the + * calling thread, not the process. In this case, the waitpid + * daemon thread can safely block in waitpid(). So we don't + * need to catch SIGCHLD, and the pipe to unblock PR_Poll() is + * also not necessary. + */ + +#if defined(_PR_GLOBAL_THREADS_ONLY) \ + || (defined(_PR_PTHREADS) && !defined(LINUX)) +#define _PR_NATIVE_THREADS +#endif + +/* + * All the static variables used by the Unix process routines are + * collected in this structure. + */ + +static struct { + PRCallOnceType once; + PRThread *thread; + PRLock *ml; +#if defined(_PR_NATIVE_THREADS) + PRInt32 numProcs; + PRCondVar *cv; +#else + int pipefd[2]; +#endif + pr_PidRecord **pidTable; + +#ifdef _PR_SHARE_CLONES + struct pr_CreateProcOp *opHead, *opTail; +#endif +} pr_wp; + +#ifdef _PR_SHARE_CLONES +static int pr_waitpid_daemon_exit; + +void +_MD_unix_terminate_waitpid_daemon(void) +{ + if (pr_wp.thread) { + pr_waitpid_daemon_exit = 1; + write(pr_wp.pipefd[1], "", 1); + PR_JoinThread(pr_wp.thread); + } +} +#endif + +static PRStatus _MD_InitProcesses(void); +#if !defined(_PR_NATIVE_THREADS) +static void pr_InstallSigchldHandler(void); +#endif + +static PRProcess * +ForkAndExec( + const char *path, + char *const *argv, + char *const *envp, + const PRProcessAttr *attr) +{ + PRProcess *process; + + process = PR_NEW(PRProcess); + if (!process) { + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0); + return NULL; + } + + process->md.pid = fork(); + if ((pid_t) -1 == process->md.pid) { + PR_SetError(PR_INSUFFICIENT_RESOURCES_ERROR, errno); + PR_DELETE(process); + return NULL; + } else if (0 == process->md.pid) { /* the child process */ + /* + * If the child process needs to exit, it must call _exit(). + * Do not call exit(), because exit() will flush and close + * the standard I/O file descriptors, and hence corrupt + * the parent process's standard I/O data structures. + */ + + if (attr) { + if (attr->stdinFd + && attr->stdinFd->secret->md.osfd != 0) { + if (dup2(attr->stdinFd->secret->md.osfd, 0) != 0) { + _exit(1); /* failed */ + } + close(attr->stdinFd->secret->md.osfd); + } + if (attr->stdoutFd + && attr->stdoutFd->secret->md.osfd != 1) { + if (dup2(attr->stdoutFd->secret->md.osfd, 1) != 1) { + _exit(1); /* failed */ + } + close(attr->stdoutFd->secret->md.osfd); + } + if (attr->stderrFd + && attr->stderrFd->secret->md.osfd != 2) { + if (dup2(attr->stderrFd->secret->md.osfd, 2) != 2) { + _exit(1); /* failed */ + } + close(attr->stderrFd->secret->md.osfd); + } + } + + (void)execve(path, argv, envp); + /* Whoops! It returned. That's a bad sign. */ + _exit(1); + } + +#if defined(_PR_NATIVE_THREADS) + PR_Lock(pr_wp.ml); + if (0 == pr_wp.numProcs++) { + PR_NotifyCondVar(pr_wp.cv); + } + PR_Unlock(pr_wp.ml); +#endif + return process; +} + +#ifdef _PR_SHARE_CLONES + +struct pr_CreateProcOp { + const char *path; + char *const *argv; + char *const *envp; + const PRProcessAttr *attr; + PRProcess *process; + PRErrorCode prerror; + PRInt32 oserror; + PRBool done; + PRCondVar *doneCV; + struct pr_CreateProcOp *next; +}; + +PRProcess * +_MD_CreateUnixProcess( + const char *path, + char *const *argv, + char *const *envp, + const PRProcessAttr *attr) +{ + struct pr_CreateProcOp *op; + PRProcess *proc; + int rv; + + if (PR_CallOnce(&pr_wp.once, _MD_InitProcesses) == PR_FAILURE) { + return NULL; + } + + op = PR_NEW(struct pr_CreateProcOp); + if (NULL == op) { + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0); + return NULL; + } + op->path = path; + op->argv = argv; + op->envp = envp; + op->attr = attr; + op->done = PR_FALSE; + op->doneCV = PR_NewCondVar(pr_wp.ml); + if (NULL == op->doneCV) { + PR_DELETE(op); + return NULL; + } + PR_Lock(pr_wp.ml); + + /* add to the tail of op queue */ + op->next = NULL; + if (pr_wp.opTail) { + pr_wp.opTail->next = op; + pr_wp.opTail = op; + } else { + PR_ASSERT(NULL == pr_wp.opHead); + pr_wp.opHead = pr_wp.opTail = op; + } + + /* wake up the daemon thread */ + do { + rv = write(pr_wp.pipefd[1], "", 1); + } while (-1 == rv && EINTR == errno); + + while (op->done == PR_FALSE) { + PR_WaitCondVar(op->doneCV, PR_INTERVAL_NO_TIMEOUT); + } + PR_Unlock(pr_wp.ml); + PR_DestroyCondVar(op->doneCV); + proc = op->process; + if (!proc) { + PR_SetError(op->prerror, op->oserror); + } + PR_DELETE(op); + return proc; +} + +#else /* ! _PR_SHARE_CLONES */ + +PRProcess * +_MD_CreateUnixProcess( + const char *path, + char *const *argv, + char *const *envp, + const PRProcessAttr *attr) +{ + if (PR_CallOnce(&pr_wp.once, _MD_InitProcesses) == PR_FAILURE) { + return NULL; + } + return ForkAndExec(path, argv, envp, attr); +} /* _MD_CreateUnixProcess */ + +#endif /* _PR_SHARE_CLONES */ + +/* + * The pid table is a hashtable. + * + * The number of buckets in the hashtable (NBUCKETS) must be a power of 2. + */ +#define NBUCKETS_LOG2 6 +#define NBUCKETS (1 << NBUCKETS_LOG2) +#define PID_HASH_MASK ((pid_t) (NBUCKETS - 1)) + +static pr_PidRecord * +FindPidTable(pid_t pid) +{ + pr_PidRecord *pRec; + int keyHash = (int) (pid & PID_HASH_MASK); + + pRec = pr_wp.pidTable[keyHash]; + while (pRec) { + if (pRec->pid == pid) { + break; + } + pRec = pRec->next; + } + return pRec; +} + +static void +InsertPidTable(pr_PidRecord *pRec) +{ + int keyHash = (int) (pRec->pid & PID_HASH_MASK); + + pRec->next = pr_wp.pidTable[keyHash]; + pr_wp.pidTable[keyHash] = pRec; +} + +static void +DeletePidTable(pr_PidRecord *pRec) +{ + int keyHash = (int) (pRec->pid & PID_HASH_MASK); + + if (pr_wp.pidTable[keyHash] == pRec) { + pr_wp.pidTable[keyHash] = pRec->next; + } else { + pr_PidRecord *pred, *cur; /* predecessor and current */ + + pred = pr_wp.pidTable[keyHash]; + cur = pred->next; + while (cur) { + if (cur == pRec) { + pred->next = cur->next; + break; + } + pred = cur; + cur = cur->next; + } + PR_ASSERT(cur != NULL); + } +} + +static int +ExtractExitStatus(int rawExitStatus) +{ + /* + * We did not specify the WCONTINUED and WUNTRACED options + * for waitpid, so these two events should not be reported. + */ + PR_ASSERT(!WIFSTOPPED(rawExitStatus)); +#ifdef WIFCONTINUED + PR_ASSERT(!WIFCONTINUED(rawExitStatus)); +#endif + if (WIFEXITED(rawExitStatus)) { + return WEXITSTATUS(rawExitStatus); + } else { + PR_ASSERT(WIFSIGNALED(rawExitStatus)); + return _PR_SIGNALED_EXITSTATUS; + } +} + +static void +ProcessReapedChildInternal(pid_t pid, int status) +{ + pr_PidRecord *pRec; + + pRec = FindPidTable(pid); + if (NULL == pRec) { + pRec = PR_NEW(pr_PidRecord); + pRec->pid = pid; + pRec->state = _PR_PID_REAPED; + pRec->exitStatus = ExtractExitStatus(status); + pRec->reapedCV = NULL; + InsertPidTable(pRec); + } else { + PR_ASSERT(pRec->state != _PR_PID_REAPED); + if (_PR_PID_DETACHED == pRec->state) { + PR_ASSERT(NULL == pRec->reapedCV); + DeletePidTable(pRec); + PR_DELETE(pRec); + } else { + PR_ASSERT(_PR_PID_WAITING == pRec->state); + PR_ASSERT(NULL != pRec->reapedCV); + pRec->exitStatus = ExtractExitStatus(status); + pRec->state = _PR_PID_REAPED; + PR_NotifyCondVar(pRec->reapedCV); + } + } +} + +#if defined(_PR_NATIVE_THREADS) + +/* + * If all the threads are native threads, the daemon thread is + * simpler. We don't need to catch the SIGCHLD signal. We can + * just have the daemon thread block in waitpid(). + */ + +static void WaitPidDaemonThread(void *unused) +{ + pid_t pid; + int status; + + while (1) { + PR_Lock(pr_wp.ml); + while (0 == pr_wp.numProcs) { + PR_WaitCondVar(pr_wp.cv, PR_INTERVAL_NO_TIMEOUT); + } + PR_Unlock(pr_wp.ml); + + while (1) { + do { + pid = waitpid((pid_t) -1, &status, 0); + } while ((pid_t) -1 == pid && EINTR == errno); + + /* + * waitpid() cannot return 0 because we did not invoke it + * with the WNOHANG option. + */ + PR_ASSERT(0 != pid); + + /* + * The only possible error code is ECHILD. But if we do + * our accounting correctly, we should only call waitpid() + * when there is a child process to wait for. + */ + PR_ASSERT((pid_t) -1 != pid); + if ((pid_t) -1 == pid) { + break; + } + + PR_Lock(pr_wp.ml); + ProcessReapedChildInternal(pid, status); + pr_wp.numProcs--; + while (0 == pr_wp.numProcs) { + PR_WaitCondVar(pr_wp.cv, PR_INTERVAL_NO_TIMEOUT); + } + PR_Unlock(pr_wp.ml); + } + } +} + +#else /* _PR_NATIVE_THREADS */ + +static void WaitPidDaemonThread(void *unused) +{ + PRPollDesc pd; + PRFileDesc *fd; + int rv; + char buf[128]; + pid_t pid; + int status; +#ifdef _PR_SHARE_CLONES + struct pr_CreateProcOp *op; +#endif + +#ifdef _PR_SHARE_CLONES + pr_InstallSigchldHandler(); +#endif + + fd = PR_ImportFile(pr_wp.pipefd[0]); + PR_ASSERT(NULL != fd); + pd.fd = fd; + pd.in_flags = PR_POLL_READ; + + while (1) { + rv = PR_Poll(&pd, 1, PR_INTERVAL_NO_TIMEOUT); + PR_ASSERT(1 == rv); + +#ifdef _PR_SHARE_CLONES + if (pr_waitpid_daemon_exit) { + return; + } + PR_Lock(pr_wp.ml); +#endif + + do { + rv = read(pr_wp.pipefd[0], buf, sizeof(buf)); + } while (sizeof(buf) == rv || (-1 == rv && EINTR == errno)); + +#ifdef _PR_SHARE_CLONES + PR_Unlock(pr_wp.ml); + while ((op = pr_wp.opHead) != NULL) { + op->process = ForkAndExec(op->path, op->argv, + op->envp, op->attr); + if (NULL == op->process) { + op->prerror = PR_GetError(); + op->oserror = PR_GetOSError(); + } + PR_Lock(pr_wp.ml); + pr_wp.opHead = op->next; + if (NULL == pr_wp.opHead) { + pr_wp.opTail = NULL; + } + op->done = PR_TRUE; + PR_NotifyCondVar(op->doneCV); + PR_Unlock(pr_wp.ml); + } +#endif + + while (1) { + do { + pid = waitpid((pid_t) -1, &status, WNOHANG); + } while ((pid_t) -1 == pid && EINTR == errno); + if (0 == pid) break; + if ((pid_t) -1 == pid) { + /* must be because we have no child processes */ + PR_ASSERT(ECHILD == errno); + break; + } + + PR_Lock(pr_wp.ml); + ProcessReapedChildInternal(pid, status); + PR_Unlock(pr_wp.ml); + } + } +} + +static void pr_SigchldHandler(int sig) +{ + int errnoCopy; + int rv; + + errnoCopy = errno; + + do { + rv = write(pr_wp.pipefd[1], "", 1); + } while (-1 == rv && EINTR == errno); + +#ifdef DEBUG + if (-1 == rv && EAGAIN != errno && EWOULDBLOCK != errno) { + char *msg = "cannot write to pipe\n"; + write(2, msg, strlen(msg) + 1); + _exit(1); + } +#endif + + errno = errnoCopy; +} + +static void pr_InstallSigchldHandler() +{ +#if defined(HPUX) && defined(_PR_DCETHREADS) +#error "HP-UX DCE threads have their own SIGCHLD handler" +#endif + + struct sigaction act, oact; + int rv; + + act.sa_handler = pr_SigchldHandler; + sigemptyset(&act.sa_mask); + act.sa_flags = SA_NOCLDSTOP | SA_RESTART; + rv = sigaction(SIGCHLD, &act, &oact); + PR_ASSERT(0 == rv); + /* Make sure we are not overriding someone else's SIGCHLD handler */ +#ifndef _PR_SHARE_CLONES + PR_ASSERT(oact.sa_handler == SIG_DFL); +#endif +} + +#endif /* !defined(_PR_NATIVE_THREADS) */ + +static PRStatus _MD_InitProcesses() +{ +#if !defined(_PR_NATIVE_THREADS) + int rv; + int flags; +#endif +#ifdef SUNOS4 +#define _PR_NBIO_FLAG FNDELAY +#else +#define _PR_NBIO_FLAG O_NONBLOCK +#endif + + pr_wp.ml = PR_NewLock(); + PR_ASSERT(NULL != pr_wp.ml); + +#if defined(_PR_NATIVE_THREADS) + pr_wp.numProcs = 0; + pr_wp.cv = PR_NewCondVar(pr_wp.ml); + PR_ASSERT(NULL != pr_wp.cv); +#else + rv = pipe(pr_wp.pipefd); + PR_ASSERT(0 == rv); + flags = fcntl(pr_wp.pipefd[0], F_GETFL, 0); + fcntl(pr_wp.pipefd[0], F_SETFL, flags | _PR_NBIO_FLAG); + flags = fcntl(pr_wp.pipefd[1], F_GETFL, 0); + fcntl(pr_wp.pipefd[1], F_SETFL, flags | _PR_NBIO_FLAG); + +#ifndef _PR_SHARE_CLONES + pr_InstallSigchldHandler(); +#endif +#endif /* !_PR_NATIVE_THREADS */ + + pr_wp.thread = PR_CreateThread(PR_SYSTEM_THREAD, + WaitPidDaemonThread, NULL, PR_PRIORITY_NORMAL, +#ifdef _PR_SHARE_CLONES + PR_GLOBAL_THREAD, +#else + PR_LOCAL_THREAD, +#endif + PR_JOINABLE_THREAD, 0); + PR_ASSERT(NULL != pr_wp.thread); + + pr_wp.pidTable = (pr_PidRecord**)PR_CALLOC(NBUCKETS * sizeof(pr_PidRecord *)); + PR_ASSERT(NULL != pr_wp.pidTable); + return PR_SUCCESS; +} + +PRStatus _MD_DetachUnixProcess(PRProcess *process) +{ + PRStatus retVal = PR_SUCCESS; + pr_PidRecord *pRec; + + PR_Lock(pr_wp.ml); + pRec = FindPidTable(process->md.pid); + if (NULL == pRec) { + pRec = PR_NEW(pr_PidRecord); + if (NULL == pRec) { + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0); + retVal = PR_FAILURE; + goto done; + } + pRec->pid = process->md.pid; + pRec->state = _PR_PID_DETACHED; + pRec->reapedCV = NULL; + InsertPidTable(pRec); + } else { + PR_ASSERT(_PR_PID_REAPED == pRec->state); + if (_PR_PID_REAPED != pRec->state) { + PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0); + retVal = PR_FAILURE; + } else { + DeletePidTable(pRec); + PR_ASSERT(NULL == pRec->reapedCV); + PR_DELETE(pRec); + } + } + +done: + PR_Unlock(pr_wp.ml); + return retVal; +} + +PRStatus _MD_WaitUnixProcess( + PRProcess *process, + PRInt32 *exitCode) +{ + pr_PidRecord *pRec; + PRStatus retVal = PR_SUCCESS; + PRBool interrupted = PR_FALSE; + + PR_Lock(pr_wp.ml); + pRec = FindPidTable(process->md.pid); + if (NULL == pRec) { + pRec = PR_NEW(pr_PidRecord); + if (NULL == pRec) { + PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0); + retVal = PR_FAILURE; + goto done; + } + pRec->pid = process->md.pid; + pRec->state = _PR_PID_WAITING; + pRec->reapedCV = PR_NewCondVar(pr_wp.ml); + if (NULL == pRec->reapedCV) { + PR_DELETE(pRec); + retVal = PR_FAILURE; + goto done; + } + InsertPidTable(pRec); + while (!interrupted && _PR_PID_REAPED != pRec->state) { + if (PR_WaitCondVar(pRec->reapedCV, + PR_INTERVAL_NO_TIMEOUT) == PR_FAILURE + && PR_GetError() == PR_PENDING_INTERRUPT_ERROR) { + interrupted = PR_TRUE; + } + } + if (_PR_PID_REAPED == pRec->state) { + if (exitCode) { + *exitCode = pRec->exitStatus; + } + } else { + PR_ASSERT(interrupted); + retVal = PR_FAILURE; + } + DeletePidTable(pRec); + PR_DestroyCondVar(pRec->reapedCV); + PR_DELETE(pRec); + } else { + PR_ASSERT(_PR_PID_REAPED == pRec->state); + PR_ASSERT(NULL == pRec->reapedCV); + DeletePidTable(pRec); + if (exitCode) { + *exitCode = pRec->exitStatus; + } + PR_DELETE(pRec); + } + +done: + PR_Unlock(pr_wp.ml); + return retVal; +} /* _MD_WaitUnixProcess */ + +PRStatus _MD_KillUnixProcess(PRProcess *process) +{ + PRErrorCode prerror; + PRInt32 oserror; + + if (kill(process->md.pid, SIGKILL) == 0) { + return PR_SUCCESS; + } + oserror = errno; + switch (oserror) { + case EPERM: + prerror = PR_NO_ACCESS_RIGHTS_ERROR; + break; + case ESRCH: + prerror = PR_INVALID_ARGUMENT_ERROR; + break; + default: + prerror = PR_UNKNOWN_ERROR; + break; + } + PR_SetError(prerror, oserror); + return PR_FAILURE; +} /* _MD_KillUnixProcess */ |