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| 1 // Copyright 2014 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "mojo/edk/embedder/platform_channel_utils_posix.h" | |
| 6 | |
| 7 #include <sys/socket.h> | |
| 8 #include <sys/uio.h> | |
| 9 #include <unistd.h> | |
| 10 | |
| 11 #include "base/logging.h" | |
| 12 #include "base/posix/eintr_wrapper.h" | |
| 13 #include "build/build_config.h" | |
| 14 | |
| 15 namespace mojo { | |
| 16 namespace embedder { | |
| 17 | |
| 18 // On Linux, |SIGPIPE| is suppressed by passing |MSG_NOSIGNAL| to | |
| 19 // |send()|/|sendmsg()|. (There is no way of suppressing |SIGPIPE| on | |
| 20 // |write()|/|writev().) On Mac, |SIGPIPE| is suppressed by setting the | |
| 21 // |SO_NOSIGPIPE| option on the socket. | |
| 22 // | |
| 23 // Performance notes: | |
| 24 // - On Linux, we have to use |send()|/|sendmsg()| rather than | |
| 25 // |write()|/|writev()| in order to suppress |SIGPIPE|. This is okay, since | |
| 26 // |send()| is (slightly) faster than |write()| (!), while |sendmsg()| is | |
| 27 // quite comparable to |writev()|. | |
| 28 // - On Mac, we may use |write()|/|writev()|. Here, |write()| is considerably | |
| 29 // faster than |send()|, whereas |sendmsg()| is quite comparable to | |
| 30 // |writev()|. | |
| 31 // - On both platforms, an appropriate |sendmsg()|/|writev()| is considerably | |
| 32 // faster than two |send()|s/|write()|s. | |
| 33 // - Relative numbers (minimum real times from 10 runs) for one |write()| of | |
| 34 // 1032 bytes, one |send()| of 1032 bytes, one |writev()| of 32+1000 bytes, | |
| 35 // one |sendmsg()| of 32+1000 bytes, two |write()|s of 32 and 1000 bytes, two | |
| 36 // |send()|s of 32 and 1000 bytes: | |
| 37 // - Linux: 0.81 s, 0.77 s, 0.87 s, 0.89 s, 1.31 s, 1.22 s | |
| 38 // - Mac: 2.21 s, 2.91 s, 2.98 s, 3.08 s, 3.59 s, 4.74 s | |
| 39 | |
| 40 // Flags to use with calling |send()| or |sendmsg()| (see above). | |
| 41 #if defined(OS_MACOSX) | |
| 42 const int kSendFlags = 0; | |
| 43 #else | |
| 44 const int kSendFlags = MSG_NOSIGNAL; | |
| 45 #endif | |
| 46 | |
| 47 ssize_t PlatformChannelWrite(PlatformHandle h, | |
| 48 const void* bytes, | |
| 49 size_t num_bytes) { | |
| 50 DCHECK(h.is_valid()); | |
| 51 DCHECK(bytes); | |
| 52 DCHECK_GT(num_bytes, 0u); | |
| 53 | |
| 54 #if defined(OS_MACOSX) | |
| 55 return HANDLE_EINTR(write(h.fd, bytes, num_bytes)); | |
| 56 #else | |
| 57 return send(h.fd, bytes, num_bytes, kSendFlags); | |
| 58 #endif | |
| 59 } | |
| 60 | |
| 61 ssize_t PlatformChannelWritev(PlatformHandle h, | |
| 62 struct iovec* iov, | |
| 63 size_t num_iov) { | |
| 64 DCHECK(h.is_valid()); | |
| 65 DCHECK(iov); | |
| 66 DCHECK_GT(num_iov, 0u); | |
| 67 | |
| 68 #if defined(OS_MACOSX) | |
| 69 return HANDLE_EINTR(writev(h.fd, iov, static_cast<int>(num_iov))); | |
| 70 #else | |
| 71 struct msghdr msg = {}; | |
| 72 msg.msg_iov = iov; | |
| 73 msg.msg_iovlen = num_iov; | |
| 74 return HANDLE_EINTR(sendmsg(h.fd, &msg, kSendFlags)); | |
| 75 #endif | |
| 76 } | |
| 77 | |
| 78 ssize_t PlatformChannelSendmsgWithHandles(PlatformHandle h, | |
| 79 struct iovec* iov, | |
| 80 size_t num_iov, | |
| 81 PlatformHandle* platform_handles, | |
| 82 size_t num_platform_handles) { | |
| 83 DCHECK(iov); | |
| 84 DCHECK_GT(num_iov, 0u); | |
| 85 DCHECK(platform_handles); | |
| 86 DCHECK_GT(num_platform_handles, 0u); | |
| 87 DCHECK_LE(num_platform_handles, kPlatformChannelMaxNumHandles); | |
| 88 | |
| 89 char cmsg_buf[CMSG_SPACE(kPlatformChannelMaxNumHandles * sizeof(int))]; | |
| 90 struct msghdr msg = {}; | |
| 91 msg.msg_iov = iov; | |
| 92 msg.msg_iovlen = num_iov; | |
| 93 msg.msg_control = cmsg_buf; | |
| 94 msg.msg_controllen = CMSG_LEN(num_platform_handles * sizeof(int)); | |
| 95 struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg); | |
| 96 cmsg->cmsg_level = SOL_SOCKET; | |
| 97 cmsg->cmsg_type = SCM_RIGHTS; | |
| 98 cmsg->cmsg_len = CMSG_LEN(num_platform_handles * sizeof(int)); | |
| 99 for (size_t i = 0; i < num_platform_handles; i++) { | |
| 100 DCHECK(platform_handles[i].is_valid()); | |
| 101 reinterpret_cast<int*>(CMSG_DATA(cmsg))[i] = platform_handles[i].fd; | |
| 102 } | |
| 103 | |
| 104 return HANDLE_EINTR(sendmsg(h.fd, &msg, kSendFlags)); | |
| 105 } | |
| 106 | |
| 107 bool PlatformChannelSendHandles(PlatformHandle h, | |
| 108 PlatformHandle* handles, | |
| 109 size_t num_handles) { | |
| 110 DCHECK(handles); | |
| 111 DCHECK_GT(num_handles, 0u); | |
| 112 DCHECK_LE(num_handles, kPlatformChannelMaxNumHandles); | |
| 113 | |
| 114 // Note: |sendmsg()| fails on Mac if we don't write at least one character. | |
| 115 struct iovec iov = {const_cast<char*>(""), 1}; | |
| 116 char cmsg_buf[CMSG_SPACE(kPlatformChannelMaxNumHandles * sizeof(int))]; | |
| 117 struct msghdr msg = {}; | |
| 118 msg.msg_iov = &iov; | |
| 119 msg.msg_iovlen = 1; | |
| 120 msg.msg_control = cmsg_buf; | |
| 121 msg.msg_controllen = CMSG_LEN(num_handles * sizeof(int)); | |
| 122 struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg); | |
| 123 cmsg->cmsg_level = SOL_SOCKET; | |
| 124 cmsg->cmsg_type = SCM_RIGHTS; | |
| 125 cmsg->cmsg_len = CMSG_LEN(num_handles * sizeof(int)); | |
| 126 for (size_t i = 0; i < num_handles; i++) { | |
| 127 DCHECK(handles[i].is_valid()); | |
| 128 reinterpret_cast<int*>(CMSG_DATA(cmsg))[i] = handles[i].fd; | |
| 129 } | |
| 130 | |
| 131 ssize_t result = HANDLE_EINTR(sendmsg(h.fd, &msg, kSendFlags)); | |
| 132 if (result < 1) { | |
| 133 DCHECK_EQ(result, -1); | |
| 134 return false; | |
| 135 } | |
| 136 | |
| 137 for (size_t i = 0; i < num_handles; i++) | |
| 138 handles[i].CloseIfNecessary(); | |
| 139 return true; | |
| 140 } | |
| 141 | |
| 142 ssize_t PlatformChannelRecvmsg(PlatformHandle h, | |
| 143 void* buf, | |
| 144 size_t num_bytes, | |
| 145 std::deque<PlatformHandle>* platform_handles) { | |
| 146 DCHECK(buf); | |
| 147 DCHECK_GT(num_bytes, 0u); | |
| 148 DCHECK(platform_handles); | |
| 149 | |
| 150 struct iovec iov = {buf, num_bytes}; | |
| 151 char cmsg_buf[CMSG_SPACE(kPlatformChannelMaxNumHandles * sizeof(int))]; | |
| 152 struct msghdr msg = {}; | |
| 153 msg.msg_iov = &iov; | |
| 154 msg.msg_iovlen = 1; | |
| 155 msg.msg_control = cmsg_buf; | |
| 156 msg.msg_controllen = sizeof(cmsg_buf); | |
| 157 | |
| 158 ssize_t result = HANDLE_EINTR(recvmsg(h.fd, &msg, MSG_DONTWAIT)); | |
| 159 if (result < 0) | |
| 160 return result; | |
| 161 | |
| 162 // Success; no control messages. | |
| 163 if (msg.msg_controllen == 0) | |
| 164 return result; | |
| 165 | |
| 166 DCHECK(!(msg.msg_flags & MSG_CTRUNC)); | |
| 167 | |
| 168 for (cmsghdr* cmsg = CMSG_FIRSTHDR(&msg); cmsg; | |
| 169 cmsg = CMSG_NXTHDR(&msg, cmsg)) { | |
| 170 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { | |
| 171 size_t payload_length = cmsg->cmsg_len - CMSG_LEN(0); | |
| 172 DCHECK_EQ(payload_length % sizeof(int), 0u); | |
| 173 size_t num_fds = payload_length / sizeof(int); | |
| 174 const int* fds = reinterpret_cast<int*>(CMSG_DATA(cmsg)); | |
| 175 for (size_t i = 0; i < num_fds; i++) { | |
| 176 platform_handles->push_back(PlatformHandle(fds[i])); | |
| 177 DCHECK(platform_handles->back().is_valid()); | |
| 178 } | |
| 179 } | |
| 180 } | |
| 181 | |
| 182 return result; | |
| 183 } | |
| 184 | |
| 185 } // namespace embedder | |
| 186 } // namespace mojo | |
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Chromium Code Reviews
Issue 814543006:
Move //mojo/{public, edk} underneath //third_party (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@master