diff options
Diffstat (limited to 'src/core/lib/iomgr/fd_posix.h')
| -rw-r--r-- | src/core/lib/iomgr/fd_posix.h | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/src/core/lib/iomgr/fd_posix.h b/src/core/lib/iomgr/fd_posix.h new file mode 100644 index 0000000000..69d09ef5e3 --- /dev/null +++ b/src/core/lib/iomgr/fd_posix.h @@ -0,0 +1,192 @@ +/* + * + * Copyright 2015-2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#ifndef GRPC_CORE_LIB_IOMGR_FD_POSIX_H +#define GRPC_CORE_LIB_IOMGR_FD_POSIX_H + +#include <grpc/support/atm.h> +#include <grpc/support/sync.h> +#include <grpc/support/time.h> +#include "src/core/lib/iomgr/iomgr_internal.h" +#include "src/core/lib/iomgr/pollset.h" + +typedef struct grpc_fd grpc_fd; + +typedef struct grpc_fd_watcher { + struct grpc_fd_watcher *next; + struct grpc_fd_watcher *prev; + grpc_pollset *pollset; + grpc_pollset_worker *worker; + grpc_fd *fd; +} grpc_fd_watcher; + +struct grpc_fd { + int fd; + /* refst format: + bit0: 1=active/0=orphaned + bit1-n: refcount + meaning that mostly we ref by two to avoid altering the orphaned bit, + and just unref by 1 when we're ready to flag the object as orphaned */ + gpr_atm refst; + + gpr_mu mu; + int shutdown; + int closed; + int released; + + /* The watcher list. + + The following watcher related fields are protected by watcher_mu. + + An fd_watcher is an ephemeral object created when an fd wants to + begin polling, and destroyed after the poll. + + It denotes the fd's interest in whether to read poll or write poll + or both or neither on this fd. + + If a watcher is asked to poll for reads or writes, the read_watcher + or write_watcher fields are set respectively. A watcher may be asked + to poll for both, in which case both fields will be set. + + read_watcher and write_watcher may be NULL if no watcher has been + asked to poll for reads or writes. + + If an fd_watcher is not asked to poll for reads or writes, it's added + to a linked list of inactive watchers, rooted at inactive_watcher_root. + If at a later time there becomes need of a poller to poll, one of + the inactive pollers may be kicked out of their poll loops to take + that responsibility. */ + grpc_fd_watcher inactive_watcher_root; + grpc_fd_watcher *read_watcher; + grpc_fd_watcher *write_watcher; + + grpc_closure *read_closure; + grpc_closure *write_closure; + + struct grpc_fd *freelist_next; + + grpc_closure *on_done_closure; + + grpc_iomgr_object iomgr_object; +}; + +/* Create a wrapped file descriptor. + Requires fd is a non-blocking file descriptor. + This takes ownership of closing fd. */ +grpc_fd *grpc_fd_create(int fd, const char *name); + +/* Return the wrapped fd, or -1 if it has been released or closed. */ +int grpc_fd_wrapped_fd(grpc_fd *fd); + +/* Releases fd to be asynchronously destroyed. + on_done is called when the underlying file descriptor is definitely close()d. + If on_done is NULL, no callback will be made. + If release_fd is not NULL, it's set to fd and fd will not be closed. + Requires: *fd initialized; no outstanding notify_on_read or + notify_on_write. + MUST NOT be called with a pollset lock taken */ +void grpc_fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd, grpc_closure *on_done, + int *release_fd, const char *reason); + +/* Begin polling on an fd. + Registers that the given pollset is interested in this fd - so that if read + or writability interest changes, the pollset can be kicked to pick up that + new interest. + Return value is: + (fd_needs_read? read_mask : 0) | (fd_needs_write? write_mask : 0) + i.e. a combination of read_mask and write_mask determined by the fd's current + interest in said events. + Polling strategies that do not need to alter their behavior depending on the + fd's current interest (such as epoll) do not need to call this function. + MUST NOT be called with a pollset lock taken */ +uint32_t grpc_fd_begin_poll(grpc_fd *fd, grpc_pollset *pollset, + grpc_pollset_worker *worker, uint32_t read_mask, + uint32_t write_mask, grpc_fd_watcher *rec); +/* Complete polling previously started with grpc_fd_begin_poll + MUST NOT be called with a pollset lock taken + if got_read or got_write are 1, also does the become_{readable,writable} as + appropriate. */ +void grpc_fd_end_poll(grpc_exec_ctx *exec_ctx, grpc_fd_watcher *rec, + int got_read, int got_write); + +/* Return 1 if this fd is orphaned, 0 otherwise */ +int grpc_fd_is_orphaned(grpc_fd *fd); + +/* Cause any current callbacks to error out with GRPC_CALLBACK_CANCELLED. */ +void grpc_fd_shutdown(grpc_exec_ctx *exec_ctx, grpc_fd *fd); + +/* Register read interest, causing read_cb to be called once when fd becomes + readable, on deadline specified by deadline, or on shutdown triggered by + grpc_fd_shutdown. + read_cb will be called with read_cb_arg when *fd becomes readable. + read_cb is Called with status of GRPC_CALLBACK_SUCCESS if readable, + GRPC_CALLBACK_TIMED_OUT if the call timed out, + and CANCELLED if the call was cancelled. + + Requires:This method must not be called before the read_cb for any previous + call runs. Edge triggered events are used whenever they are supported by the + underlying platform. This means that users must drain fd in read_cb before + calling notify_on_read again. Users are also expected to handle spurious + events, i.e read_cb is called while nothing can be readable from fd */ +void grpc_fd_notify_on_read(grpc_exec_ctx *exec_ctx, grpc_fd *fd, + grpc_closure *closure); + +/* Exactly the same semantics as above, except based on writable events. */ +void grpc_fd_notify_on_write(grpc_exec_ctx *exec_ctx, grpc_fd *fd, + grpc_closure *closure); + +/* Notification from the poller to an fd that it has become readable or + writable. + If allow_synchronous_callback is 1, allow running the fd callback inline + in this callstack, otherwise register an asynchronous callback and return */ +void grpc_fd_become_readable(grpc_exec_ctx *exec_ctx, grpc_fd *fd); +void grpc_fd_become_writable(grpc_exec_ctx *exec_ctx, grpc_fd *fd); + +/* Reference counting for fds */ +/*#define GRPC_FD_REF_COUNT_DEBUG*/ +#ifdef GRPC_FD_REF_COUNT_DEBUG +void grpc_fd_ref(grpc_fd *fd, const char *reason, const char *file, int line); +void grpc_fd_unref(grpc_fd *fd, const char *reason, const char *file, int line); +#define GRPC_FD_REF(fd, reason) grpc_fd_ref(fd, reason, __FILE__, __LINE__) +#define GRPC_FD_UNREF(fd, reason) grpc_fd_unref(fd, reason, __FILE__, __LINE__) +#else +void grpc_fd_ref(grpc_fd *fd); +void grpc_fd_unref(grpc_fd *fd); +#define GRPC_FD_REF(fd, reason) grpc_fd_ref(fd) +#define GRPC_FD_UNREF(fd, reason) grpc_fd_unref(fd) +#endif + +void grpc_fd_global_init(void); +void grpc_fd_global_shutdown(void); + +#endif /* GRPC_CORE_LIB_IOMGR_FD_POSIX_H */ |