1 /*
2 *
3 * Copyright 2016 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #include <grpc/support/port_platform.h>
20
21 #include "src/core/lib/iomgr/port.h"
22
23 #ifdef GRPC_POSIX_WAKEUP_FD
24
25 #include "src/core/lib/iomgr/wakeup_fd_cv.h"
26
27 #include <errno.h>
28 #include <string.h>
29
30 #include <grpc/support/alloc.h>
31 #include <grpc/support/log.h>
32 #include <grpc/support/sync.h>
33 #include <grpc/support/time.h>
34
35 #include "src/core/lib/gpr/useful.h"
36 #include "src/core/lib/gprpp/thd.h"
37
38 #define MAX_TABLE_RESIZE 256
39
40 extern grpc_cv_fd_table g_cvfds;
41
cv_fd_init(grpc_wakeup_fd * fd_info)42 static grpc_error* cv_fd_init(grpc_wakeup_fd* fd_info) {
43 unsigned int i, newsize;
44 int idx;
45 gpr_mu_lock(&g_cvfds.mu);
46 if (!g_cvfds.free_fds) {
47 newsize = GPR_MIN(g_cvfds.size * 2, g_cvfds.size + MAX_TABLE_RESIZE);
48 g_cvfds.cvfds = static_cast<grpc_fd_node*>(
49 gpr_realloc(g_cvfds.cvfds, sizeof(grpc_fd_node) * newsize));
50 for (i = g_cvfds.size; i < newsize; i++) {
51 g_cvfds.cvfds[i].is_set = 0;
52 g_cvfds.cvfds[i].cvs = nullptr;
53 g_cvfds.cvfds[i].next_free = g_cvfds.free_fds;
54 g_cvfds.free_fds = &g_cvfds.cvfds[i];
55 }
56 g_cvfds.size = newsize;
57 }
58
59 idx = static_cast<int>(g_cvfds.free_fds - g_cvfds.cvfds);
60 g_cvfds.free_fds = g_cvfds.free_fds->next_free;
61 g_cvfds.cvfds[idx].cvs = nullptr;
62 g_cvfds.cvfds[idx].is_set = 0;
63 fd_info->read_fd = GRPC_IDX_TO_FD(idx);
64 fd_info->write_fd = -1;
65 gpr_mu_unlock(&g_cvfds.mu);
66 return GRPC_ERROR_NONE;
67 }
68
cv_fd_wakeup(grpc_wakeup_fd * fd_info)69 static grpc_error* cv_fd_wakeup(grpc_wakeup_fd* fd_info) {
70 grpc_cv_node* cvn;
71 gpr_mu_lock(&g_cvfds.mu);
72 g_cvfds.cvfds[GRPC_FD_TO_IDX(fd_info->read_fd)].is_set = 1;
73 cvn = g_cvfds.cvfds[GRPC_FD_TO_IDX(fd_info->read_fd)].cvs;
74 while (cvn) {
75 gpr_cv_signal(cvn->cv);
76 cvn = cvn->next;
77 }
78 gpr_mu_unlock(&g_cvfds.mu);
79 return GRPC_ERROR_NONE;
80 }
81
cv_fd_consume(grpc_wakeup_fd * fd_info)82 static grpc_error* cv_fd_consume(grpc_wakeup_fd* fd_info) {
83 gpr_mu_lock(&g_cvfds.mu);
84 g_cvfds.cvfds[GRPC_FD_TO_IDX(fd_info->read_fd)].is_set = 0;
85 gpr_mu_unlock(&g_cvfds.mu);
86 return GRPC_ERROR_NONE;
87 }
88
cv_fd_destroy(grpc_wakeup_fd * fd_info)89 static void cv_fd_destroy(grpc_wakeup_fd* fd_info) {
90 if (fd_info->read_fd == 0) {
91 return;
92 }
93 gpr_mu_lock(&g_cvfds.mu);
94 // Assert that there are no active pollers
95 GPR_ASSERT(!g_cvfds.cvfds[GRPC_FD_TO_IDX(fd_info->read_fd)].cvs);
96 g_cvfds.cvfds[GRPC_FD_TO_IDX(fd_info->read_fd)].next_free = g_cvfds.free_fds;
97 g_cvfds.free_fds = &g_cvfds.cvfds[GRPC_FD_TO_IDX(fd_info->read_fd)];
98 gpr_mu_unlock(&g_cvfds.mu);
99 }
100
cv_check_availability(void)101 static int cv_check_availability(void) { return 1; }
102
103 const grpc_wakeup_fd_vtable grpc_cv_wakeup_fd_vtable = {
104 cv_fd_init, cv_fd_consume, cv_fd_wakeup, cv_fd_destroy,
105 cv_check_availability};
106
107 #endif /* GRPC_POSIX_WAKUP_FD */
108