| // Copyright 2018 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "textflag.h" |
| |
| // blockingPoll makes the poll() syscall while calling the version of |
| // entersyscall that relinquishes the P so that other Gs can run. This is meant |
| // to be called in cases when the syscall is expected to block. |
| // |
| // func blockingPoll(fds *pollEvent, nfds int, timeout int64) (n int, err syscall.Errno) |
| TEXT ·blockingPoll(SB),NOSPLIT,$0-40 |
| CALL runtime·entersyscallblock(SB) |
| MOVQ fds+0(FP), DI |
| MOVQ nfds+8(FP), SI |
| MOVQ timeout+16(FP), DX |
| MOVQ $0x7, AX // SYS_POLL |
| SYSCALL |
| CMPQ AX, $0xfffffffffffff001 |
| JLS ok |
| MOVQ $-1, n+24(FP) |
| NEGQ AX |
| MOVQ AX, err+32(FP) |
| CALL runtime·exitsyscall(SB) |
| RET |
| ok: |
| MOVQ AX, n+24(FP) |
| MOVQ $0, err+32(FP) |
| CALL runtime·exitsyscall(SB) |
| RET |
