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Diffstat (limited to 'Utilities/cmlibuv/src/win/signal.c')
| -rw-r--r-- | Utilities/cmlibuv/src/win/signal.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/Utilities/cmlibuv/src/win/signal.c b/Utilities/cmlibuv/src/win/signal.c new file mode 100644 index 0000000..2c64a55 --- /dev/null +++ b/Utilities/cmlibuv/src/win/signal.c @@ -0,0 +1,356 @@ +/* Copyright Joyent, Inc. and other Node contributors. All rights reserved. + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include <assert.h> +#include <signal.h> + +#include "uv.h" +#include "internal.h" +#include "handle-inl.h" +#include "req-inl.h" + + +RB_HEAD(uv_signal_tree_s, uv_signal_s); + +static struct uv_signal_tree_s uv__signal_tree = RB_INITIALIZER(uv__signal_tree); +static ssize_t volatile uv__signal_control_handler_refs = 0; +static CRITICAL_SECTION uv__signal_lock; + + +void uv_signals_init() { + InitializeCriticalSection(&uv__signal_lock); +} + + +static int uv__signal_compare(uv_signal_t* w1, uv_signal_t* w2) { + /* Compare signums first so all watchers with the same signnum end up */ + /* adjacent. */ + if (w1->signum < w2->signum) return -1; + if (w1->signum > w2->signum) return 1; + + /* Sort by loop pointer, so we can easily look up the first item after */ + /* { .signum = x, .loop = NULL } */ + if ((uintptr_t) w1->loop < (uintptr_t) w2->loop) return -1; + if ((uintptr_t) w1->loop > (uintptr_t) w2->loop) return 1; + + if ((uintptr_t) w1 < (uintptr_t) w2) return -1; + if ((uintptr_t) w1 > (uintptr_t) w2) return 1; + + return 0; +} + + +RB_GENERATE_STATIC(uv_signal_tree_s, uv_signal_s, tree_entry, uv__signal_compare); + + +/* + * Dispatches signal {signum} to all active uv_signal_t watchers in all loops. + * Returns 1 if the signal was dispatched to any watcher, or 0 if there were + * no active signal watchers observing this signal. + */ +int uv__signal_dispatch(int signum) { + uv_signal_t lookup; + uv_signal_t* handle; + int dispatched = 0; + + EnterCriticalSection(&uv__signal_lock); + + lookup.signum = signum; + lookup.loop = NULL; + + for (handle = RB_NFIND(uv_signal_tree_s, &uv__signal_tree, &lookup); + handle != NULL && handle->signum == signum; + handle = RB_NEXT(uv_signal_tree_s, &uv__signal_tree, handle)) { + unsigned long previous = InterlockedExchange( + (volatile LONG*) &handle->pending_signum, signum); + + if (!previous) { + POST_COMPLETION_FOR_REQ(handle->loop, &handle->signal_req); + } + + dispatched = 1; + } + + LeaveCriticalSection(&uv__signal_lock); + + return dispatched; +} + + +static BOOL WINAPI uv__signal_control_handler(DWORD type) { + switch (type) { + case CTRL_C_EVENT: + return uv__signal_dispatch(SIGINT); + + case CTRL_BREAK_EVENT: + return uv__signal_dispatch(SIGBREAK); + + case CTRL_CLOSE_EVENT: + if (uv__signal_dispatch(SIGHUP)) { + /* Windows will terminate the process after the control handler */ + /* returns. After that it will just terminate our process. Therefore */ + /* block the signal handler so the main loop has some time to pick */ + /* up the signal and do something for a few seconds. */ + Sleep(INFINITE); + return TRUE; + } + return FALSE; + + case CTRL_LOGOFF_EVENT: + case CTRL_SHUTDOWN_EVENT: + /* These signals are only sent to services. Services have their own */ + /* notification mechanism, so there's no point in handling these. */ + + default: + /* We don't handle these. */ + return FALSE; + } +} + + +static int uv__signal_register_control_handler() { + /* When this function is called, the uv__signal_lock must be held. */ + + /* If the console control handler has already been hooked, just add a */ + /* reference. */ + if (uv__signal_control_handler_refs > 0) { + uv__signal_control_handler_refs++; + return 0; + } + + if (!SetConsoleCtrlHandler(uv__signal_control_handler, TRUE)) + return GetLastError(); + + uv__signal_control_handler_refs++; + + return 0; +} + + +static void uv__signal_unregister_control_handler() { + /* When this function is called, the uv__signal_lock must be held. */ + BOOL r; + + /* Don't unregister if the number of console control handlers exceeds one. */ + /* Just remove a reference in that case. */ + if (uv__signal_control_handler_refs > 1) { + uv__signal_control_handler_refs--; + return; + } + + assert(uv__signal_control_handler_refs == 1); + + r = SetConsoleCtrlHandler(uv__signal_control_handler, FALSE); + /* This should never fail; if it does it is probably a bug in libuv. */ + assert(r); + + uv__signal_control_handler_refs--; +} + + +static int uv__signal_register(int signum) { + switch (signum) { + case SIGINT: + case SIGBREAK: + case SIGHUP: + return uv__signal_register_control_handler(); + + case SIGWINCH: + /* SIGWINCH is generated in tty.c. No need to register anything. */ + return 0; + + case SIGILL: + case SIGABRT_COMPAT: + case SIGFPE: + case SIGSEGV: + case SIGTERM: + case SIGABRT: + /* Signal is never raised. */ + return 0; + + default: + /* Invalid signal. */ + return ERROR_INVALID_PARAMETER; + } +} + + +static void uv__signal_unregister(int signum) { + switch (signum) { + case SIGINT: + case SIGBREAK: + case SIGHUP: + uv__signal_unregister_control_handler(); + return; + + case SIGWINCH: + /* SIGWINCH is generated in tty.c. No need to unregister anything. */ + return; + + case SIGILL: + case SIGABRT_COMPAT: + case SIGFPE: + case SIGSEGV: + case SIGTERM: + case SIGABRT: + /* Nothing is registered for this signal. */ + return; + + default: + /* Libuv bug. */ + assert(0 && "Invalid signum"); + return; + } +} + + +int uv_signal_init(uv_loop_t* loop, uv_signal_t* handle) { + uv_req_t* req; + + uv__handle_init(loop, (uv_handle_t*) handle, UV_SIGNAL); + handle->pending_signum = 0; + handle->signum = 0; + handle->signal_cb = NULL; + + req = &handle->signal_req; + uv_req_init(loop, req); + req->type = UV_SIGNAL_REQ; + req->data = handle; + + return 0; +} + + +int uv_signal_stop(uv_signal_t* handle) { + uv_signal_t* removed_handle; + + /* If the watcher wasn't started, this is a no-op. */ + if (handle->signum == 0) + return 0; + + EnterCriticalSection(&uv__signal_lock); + + uv__signal_unregister(handle->signum); + + removed_handle = RB_REMOVE(uv_signal_tree_s, &uv__signal_tree, handle); + assert(removed_handle == handle); + + LeaveCriticalSection(&uv__signal_lock); + + handle->signum = 0; + uv__handle_stop(handle); + + return 0; +} + + +int uv_signal_start(uv_signal_t* handle, uv_signal_cb signal_cb, int signum) { + int err; + + /* If the user supplies signum == 0, then return an error already. If the */ + /* signum is otherwise invalid then uv__signal_register will find out */ + /* eventually. */ + if (signum == 0) { + return UV_EINVAL; + } + + /* Short circuit: if the signal watcher is already watching {signum} don't */ + /* go through the process of deregistering and registering the handler. */ + /* Additionally, this avoids pending signals getting lost in the (small) */ + /* time frame that handle->signum == 0. */ + if (signum == handle->signum) { + handle->signal_cb = signal_cb; + return 0; + } + + /* If the signal handler was already active, stop it first. */ + if (handle->signum != 0) { + int r = uv_signal_stop(handle); + /* uv_signal_stop is infallible. */ + assert(r == 0); + } + + EnterCriticalSection(&uv__signal_lock); + + err = uv__signal_register(signum); + if (err) { + /* Uh-oh, didn't work. */ + LeaveCriticalSection(&uv__signal_lock); + return uv_translate_sys_error(err); + } + + handle->signum = signum; + RB_INSERT(uv_signal_tree_s, &uv__signal_tree, handle); + + LeaveCriticalSection(&uv__signal_lock); + + handle->signal_cb = signal_cb; + uv__handle_start(handle); + + return 0; +} + + +void uv_process_signal_req(uv_loop_t* loop, uv_signal_t* handle, + uv_req_t* req) { + long dispatched_signum; + + assert(handle->type == UV_SIGNAL); + assert(req->type == UV_SIGNAL_REQ); + + dispatched_signum = InterlockedExchange( + (volatile LONG*) &handle->pending_signum, 0); + assert(dispatched_signum != 0); + + /* Check if the pending signal equals the signum that we are watching for. */ + /* These can get out of sync when the handler is stopped and restarted */ + /* while the signal_req is pending. */ + if (dispatched_signum == handle->signum) + handle->signal_cb(handle, dispatched_signum); + + if (handle->flags & UV__HANDLE_CLOSING) { + /* When it is closing, it must be stopped at this point. */ + assert(handle->signum == 0); + uv_want_endgame(loop, (uv_handle_t*) handle); + } +} + + +void uv_signal_close(uv_loop_t* loop, uv_signal_t* handle) { + uv_signal_stop(handle); + uv__handle_closing(handle); + + if (handle->pending_signum == 0) { + uv_want_endgame(loop, (uv_handle_t*) handle); + } +} + + +void uv_signal_endgame(uv_loop_t* loop, uv_signal_t* handle) { + assert(handle->flags & UV__HANDLE_CLOSING); + assert(!(handle->flags & UV_HANDLE_CLOSED)); + + assert(handle->signum == 0); + assert(handle->pending_signum == 0); + + handle->flags |= UV_HANDLE_CLOSED; + + uv__handle_close(handle); +} |