+++ /dev/null
-/*
- * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#define _LGPL_SOURCE
-#include <fcntl.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-
-#include <common/common.h>
-
-#include "pipe.h"
-
-/*
- * Lock read side of a pipe.
- */
-static void lock_read_side(struct lttng_pipe *pipe)
-{
- pthread_mutex_lock(&pipe->read_mutex);
-}
-
-/*
- * Unlock read side of a pipe.
- */
-static void unlock_read_side(struct lttng_pipe *pipe)
-{
- pthread_mutex_unlock(&pipe->read_mutex);
-}
-
-/*
- * Lock write side of a pipe.
- */
-static void lock_write_side(struct lttng_pipe *pipe)
-{
- pthread_mutex_lock(&pipe->write_mutex);
-}
-
-/*
- * Unlock write side of a pipe.
- */
-static void unlock_write_side(struct lttng_pipe *pipe)
-{
- pthread_mutex_unlock(&pipe->write_mutex);
-}
-
-/*
- * Internal function. Close read side of pipe WITHOUT locking the mutex.
- *
- * Return 0 on success else a negative errno from close(2).
- */
-static int _pipe_read_close(struct lttng_pipe *pipe)
-{
- int ret, ret_val = 0;
-
- LTTNG_ASSERT(pipe);
-
- if (!lttng_pipe_is_read_open(pipe)) {
- goto end;
- }
-
- do {
- ret = close(pipe->fd[0]);
- } while (ret < 0 && errno == EINTR);
- if (ret < 0) {
- PERROR("close lttng read pipe");
- ret_val = -errno;
- }
- pipe->r_state = LTTNG_PIPE_STATE_CLOSED;
-
-end:
- return ret_val;
-}
-
-/*
- * Internal function. Close write side of pipe WITHOUT locking the mutex.
- *
- * Return 0 on success else a negative errno from close(2).
- */
-static int _pipe_write_close(struct lttng_pipe *pipe)
-{
- int ret, ret_val = 0;
-
- LTTNG_ASSERT(pipe);
-
- if (!lttng_pipe_is_write_open(pipe)) {
- goto end;
- }
-
- do {
- ret = close(pipe->fd[1]);
- } while (ret < 0 && errno == EINTR);
- if (ret < 0) {
- PERROR("close lttng write pipe");
- ret_val = -errno;
- }
- pipe->w_state = LTTNG_PIPE_STATE_CLOSED;
-
-end:
- return ret_val;
-}
-
-static struct lttng_pipe *_pipe_create(void)
-{
- int ret;
- struct lttng_pipe *p;
-
- p = zmalloc(sizeof(*p));
- if (!p) {
- PERROR("zmalloc pipe create");
- goto end;
- }
- p->fd[0] = p->fd[1] = -1;
-
- ret = pthread_mutex_init(&p->read_mutex, NULL);
- if (ret) {
- PERROR("pthread_mutex_init read lock pipe create");
- goto error_destroy;
- }
- ret = pthread_mutex_init(&p->write_mutex, NULL);
- if (ret) {
- PERROR("pthread_mutex_init write lock pipe create");
- goto error_destroy_rmutex;
- }
-end:
- return p;
-error_destroy_rmutex:
- (void) pthread_mutex_destroy(&p->read_mutex);
-error_destroy:
- free(p);
- return NULL;
-}
-
-static int _pipe_set_flags(struct lttng_pipe *pipe, int flags)
-{
- int i, ret = 0;
-
- if (!flags) {
- goto end;
- }
-
- for (i = 0; i < 2; i++) {
- if (flags & O_NONBLOCK) {
- ret = fcntl(pipe->fd[i], F_SETFL, O_NONBLOCK);
- if (ret < 0) {
- PERROR("fcntl lttng pipe %d", flags);
- goto end;
- }
- }
- if (flags & FD_CLOEXEC) {
- ret = fcntl(pipe->fd[i], F_SETFD, FD_CLOEXEC);
- if (ret < 0) {
- PERROR("fcntl lttng pipe %d", flags);
- goto end;
- }
- }
- /*
- * We only check for O_NONBLOCK or FD_CLOEXEC, if another flag is
- * needed, we can add it, but for now just make sure we don't make
- * mistakes with the parameters we pass.
- */
- if (!(flags & O_NONBLOCK) && !(flags & FD_CLOEXEC)) {
- fprintf(stderr, "Unsupported flag\n");
- ret = -1;
- goto end;
- }
- }
-end:
- return ret;
-}
-
-/*
- * Open a new lttng pipe and set flags using fcntl().
- *
- * Return a newly allocated lttng pipe on success or else NULL.
- */
-struct lttng_pipe *lttng_pipe_open(int flags)
-{
- int ret;
- struct lttng_pipe *p;
-
- p = _pipe_create();
- if (!p) {
- goto error;
- }
-
- ret = pipe(p->fd);
- if (ret < 0) {
- PERROR("lttng pipe");
- goto error;
- }
- p->r_state = LTTNG_PIPE_STATE_OPENED;
- p->w_state = LTTNG_PIPE_STATE_OPENED;
-
- ret = _pipe_set_flags(p, flags);
- if (ret) {
- goto error;
- }
-
- p->flags = flags;
-
- return p;
-error:
- lttng_pipe_destroy(p);
- return NULL;
-}
-
-/*
- * Open a new lttng pipe at path and set flags using fcntl().
- *
- * Return a newly allocated lttng pipe on success or else NULL.
- */
-struct lttng_pipe *lttng_pipe_named_open(const char *path, mode_t mode,
- int flags)
-{
- int ret, fd_r, fd_w;
- struct lttng_pipe *pipe;
-
- pipe = _pipe_create();
- if (!pipe) {
- goto error;
- }
-
- ret = mkfifo(path, mode);
- if (ret) {
- PERROR("mkfifo");
- goto error;
- }
-
- fd_r = open(path, O_RDONLY | O_NONBLOCK);
- if (fd_r < 0) {
- PERROR("open fifo");
- goto error;
- }
- pipe->fd[0] = fd_r;
- pipe->r_state = LTTNG_PIPE_STATE_OPENED;
-
- fd_w = open(path, O_WRONLY | O_NONBLOCK);
- if (fd_w < 0) {
- PERROR("open fifo");
- goto error;
- }
- pipe->fd[1] = fd_w;
- pipe->w_state = LTTNG_PIPE_STATE_OPENED;
-
- ret = _pipe_set_flags(pipe, flags);
- if (ret) {
- goto error;
- }
- pipe->flags = flags;
-
- return pipe;
-error:
- lttng_pipe_destroy(pipe);
- return NULL;
-}
-
-/*
- * Close read side of a lttng pipe.
- *
- * Return 0 on success else a negative value.
- */
-int lttng_pipe_read_close(struct lttng_pipe *pipe)
-{
- int ret;
-
- LTTNG_ASSERT(pipe);
-
- /* Handle read side first. */
- lock_read_side(pipe);
- ret = _pipe_read_close(pipe);
- unlock_read_side(pipe);
-
- return ret;
-}
-
-/*
- * Close write side of a lttng pipe.
- *
- * Return 0 on success else a negative value.
- */
-int lttng_pipe_write_close(struct lttng_pipe *pipe)
-{
- int ret;
-
- LTTNG_ASSERT(pipe);
-
- lock_write_side(pipe);
- ret = _pipe_write_close(pipe);
- unlock_write_side(pipe);
-
- return ret;
-}
-
-/*
- * Close both read and write side of a lttng pipe.
- *
- * Return 0 on success else a negative value.
- */
-int lttng_pipe_close(struct lttng_pipe *pipe)
-{
- int ret, ret_val = 0;
-
- LTTNG_ASSERT(pipe);
-
- ret = lttng_pipe_read_close(pipe);
- if (ret < 0) {
- ret_val = ret;
- }
-
- ret = lttng_pipe_write_close(pipe);
- if (ret < 0) {
- ret_val = ret;
- }
-
- return ret_val;
-}
-
-/*
- * Close and destroy a lttng pipe object. Finally, pipe is freed.
- */
-void lttng_pipe_destroy(struct lttng_pipe *pipe)
-{
- int ret;
-
- if (!pipe) {
- return;
- }
-
- /*
- * Destroy should *never* be called with a locked mutex. These must always
- * succeed so we unlock them after the close pipe below.
- */
- ret = pthread_mutex_trylock(&pipe->read_mutex);
- LTTNG_ASSERT(!ret);
- ret = pthread_mutex_trylock(&pipe->write_mutex);
- LTTNG_ASSERT(!ret);
-
- /* Close pipes WITHOUT trying to lock the pipes. */
- (void) _pipe_read_close(pipe);
- (void) _pipe_write_close(pipe);
-
- unlock_read_side(pipe);
- unlock_write_side(pipe);
-
- (void) pthread_mutex_destroy(&pipe->read_mutex);
- (void) pthread_mutex_destroy(&pipe->write_mutex);
-
- free(pipe);
-}
-
-/*
- * Read on a lttng pipe and put the data in buf of at least size count.
- *
- * Return "count" on success. Return < count on error. errno can be used
- * to check the actual error.
- */
-ssize_t lttng_pipe_read(struct lttng_pipe *pipe, void *buf, size_t count)
-{
- ssize_t ret;
-
- LTTNG_ASSERT(pipe);
- LTTNG_ASSERT(buf);
-
- lock_read_side(pipe);
- if (!lttng_pipe_is_read_open(pipe)) {
- ret = -1;
- errno = EBADF;
- goto error;
- }
- ret = lttng_read(pipe->fd[0], buf, count);
-error:
- unlock_read_side(pipe);
- return ret;
-}
-
-/*
- * Write on a lttng pipe using the data in buf and size of count.
- *
- * Return "count" on success. Return < count on error. errno can be used
- * to check the actual error.
- */
-ssize_t lttng_pipe_write(struct lttng_pipe *pipe, const void *buf,
- size_t count)
-{
- ssize_t ret;
-
- LTTNG_ASSERT(pipe);
- LTTNG_ASSERT(buf);
-
- lock_write_side(pipe);
- if (!lttng_pipe_is_write_open(pipe)) {
- ret = -1;
- errno = EBADF;
- goto error;
- }
- ret = lttng_write(pipe->fd[1], buf, count);
-error:
- unlock_write_side(pipe);
- return ret;
-}
-
-/*
- * Return and release the read end of the pipe.
- *
- * This call transfers the ownership of the read fd of the underlying pipe
- * to the caller if it is still open.
- *
- * Returns the fd of the read end of the pipe, or -1 if it was already closed or
- * released.
- */
-int lttng_pipe_release_readfd(struct lttng_pipe *pipe)
-{
- int ret;
-
- if (!pipe) {
- ret = -1;
- goto end;
- }
-
- lock_read_side(pipe);
- if (!lttng_pipe_is_read_open(pipe)) {
- ret = -1;
- goto end_unlock;
- }
- ret = pipe->fd[0];
- pipe->fd[0] = -1;
- pipe->r_state = LTTNG_PIPE_STATE_CLOSED;
-end_unlock:
- unlock_read_side(pipe);
-end:
- return ret;
-}
-
-/*
- * Return and release the write end of the pipe.
- *
- * This call transfers the ownership of the write fd of the underlying pipe
- * to the caller if it is still open.
- *
- * Returns the fd of the write end of the pipe, or -1 if it was alwritey closed
- * or released.
- */
-int lttng_pipe_release_writefd(struct lttng_pipe *pipe)
-{
- int ret;
-
- if (!pipe) {
- ret = -1;
- goto end;
- }
-
- lock_write_side(pipe);
- if (!lttng_pipe_is_write_open(pipe)) {
- ret = -1;
- goto end_unlock;
- }
- ret = pipe->fd[1];
- pipe->fd[1] = -1;
- pipe->w_state = LTTNG_PIPE_STATE_CLOSED;
-end_unlock:
- unlock_write_side(pipe);
-end:
- return ret;
-}
projects / lttng-tools.git / blobdiff