我一直在研究 this Go 的 SQLite 库，在做一些压力测试时，遇到了一些奇怪的错误。

我正在尝试运行这段代码:

package main

import "code.google.com/p/go-sqlite/go1/sqlite3"
import "fmt"
import "sync"

func main() {
    var wg sync.WaitGroup
    wg.Add(100)
    for i := 0; i < 100; i++ {
        query(&wg, i)
    }
    wg.Wait()
}

func query(wg *sync.WaitGroup, id int) {
    defer wg.Done()
    c, _ := sqlite3.Open("sqlite.db")
    for i := 0; i < 100; i++{
        args := sqlite3.NamedArgs{"$bval": "demo"}
        sql := "SELECT rowid, * FROM x WHERE b = $bval"
        row := make(sqlite3.RowMap)
        for s, err := c.Query(sql, args); err == nil; err = s.Next() {
                var rowid int64
                s.Scan(&rowid, row)     // Assigns 1st column to rowid, the rest to row
                fmt.Println(rowid, row) // Prints "1 map[a:1 b:demo c:<nil>]"
        }
    }
    c.Close()
    fmt.Println("Worker ", id, " is done")
}

默认情况下没有问题；但是当我将 GOMAXPROCS 增加到超过 1 时，程序在任意点崩溃，并给出错误:

fatal error: unexpected signal during runtime execution
[signal 0xb code=0x1 addr=0xc0000000d pc=0x4100b9]

runtime stack:
runtime.gothrow(0x5a1610, 0x2a)
    /usr/lib/go/src/runtime/panic.go:503 +0x8e fp=0x7f4bd5ffa830 sp=0x7f4bd5ffa818
runtime.sigpanic()
    /usr/lib/go/src/runtime/sigpanic_unix.go:14 +0x5e fp=0x7f4bd5ffa880 sp=0x7f4bd5ffa830

goroutine 1 [syscall, locked to thread]:
runtime.cgocall_errno(0x408043, 0xc20808fcf8, 0x0)
    /usr/lib/go/src/runtime/cgocall.go:130 +0xf5 fp=0xc20808fcd8 sp=0xc20808fcb0
code.google.com/p/go-sqlite/go1/sqlite3._Cfunc_sqlite3_prepare_v2(0x7f4bc00023b8, 0xc2080483f0, 0xffffffff, 0xc20808fd30, 0xc20808fd28, 0x0)
    /home/eumen/Programming/gocode/src/code.google.com/p/go-sqlite/go1/sqlite3/:534 +0x43 fp=0xc20808fcf8 sp=0xc20808fcd8
code.google.com/p/go-sqlite/go1/sqlite3.newStmt(0xc2080482d0, 0x599e90, 0x26, 0xc20804b8c8, 0x0, 0x0)
    /home/eumen/Programming/gocode/src/code.google.com/p/go-sqlite/go1/sqlite3/sqlite3.go:583 +0xe4 fp=0xc20808fdb0 sp=0xc20808fcf8
code.google.com/p/go-sqlite/go1/sqlite3.(*Conn).Query(0xc2080482d0, 0x599e90, 0x26, 0xc20808fee0, 0x1, 0x1, 0xc20807a000, 0x0, 0x0)
    /home/eumen/Programming/gocode/src/code.google.com/p/go-sqlite/go1/sqlite3/sqlite3.go:276 +0xc3 fp=0xc20808fe00 sp=0xc20808fdb0
main.query(0xc208022020, 0x16)
    /home/eumen/Programming/Go/practice/sqlite-sync.go:26 +0x261 fp=0xc20808ff70 sp=0xc20808fe00
main.main()
    /home/eumen/Programming/Go/practice/sqlite-sync.go:11 +0x66 fp=0xc20808ff98 sp=0xc20808ff70
runtime.main()
    /usr/lib/go/src/runtime/proc.go:63 +0xf3 fp=0xc20808ffe0 sp=0xc20808ff98
runtime.goexit()
    /usr/lib/go/src/runtime/asm_amd64.s:2232 +0x1 fp=0xc20808ffe8 sp=0xc20808ffe0

goroutine 2 [force gc (idle)]:
runtime.gopark(0x496870, 0x831d30, 0x583f70, 0xf)
    /usr/lib/go/src/runtime/proc.go:130 +0x105 fp=0xc20801e798 sp=0xc20801e768
runtime.goparkunlock(0x831d30, 0x583f70, 0xf)
    /usr/lib/go/src/runtime/proc.go:136 +0x48 fp=0xc20801e7c0 sp=0xc20801e798
runtime.forcegchelper()
    /usr/lib/go/src/runtime/proc.go:99 +0xce fp=0xc20801e7e0 sp=0xc20801e7c0
runtime.goexit()
    /usr/lib/go/src/runtime/asm_amd64.s:2232 +0x1 fp=0xc20801e7e8 sp=0xc20801e7e0
created by runtime.init·4
    /usr/lib/go/src/runtime/proc.go:87 +0x25

goroutine 3 [GC sweep wait]:
runtime.gopark(0x496870, 0x838ff8, 0x580b50, 0xd)
    /usr/lib/go/src/runtime/proc.go:130 +0x105 fp=0xc208021f98 sp=0xc208021f68
runtime.goparkunlock(0x838ff8, 0x580b50, 0xd)
    /usr/lib/go/src/runtime/proc.go:136 +0x48 fp=0xc208021fc0 sp=0xc208021f98
runtime.bgsweep()
    /usr/lib/go/src/runtime/mgc0.go:98 +0xbc fp=0xc208021fe0 sp=0xc208021fc0
runtime.goexit()
    /usr/lib/go/src/runtime/asm_amd64.s:2232 +0x1 fp=0xc208021fe8 sp=0xc208021fe0
created by gc
    /usr/lib/go/src/runtime/mgc0.c:1386

goroutine 4 [finalizer wait]:
runtime.gopark(0x496870, 0x838ff0, 0x583ad0, 0xe)
    /usr/lib/go/src/runtime/proc.go:130 +0x105 fp=0xc20801d730 sp=0xc20801d700
runtime.goparkunlock(0x838ff0, 0x583ad0, 0xe)
    /usr/lib/go/src/runtime/proc.go:136 +0x48 fp=0xc20801d758 sp=0xc20801d730
runtime.runfinq()
    /usr/lib/go/src/runtime/malloc.go:727 +0xba fp=0xc20801d7e0 sp=0xc20801d758
runtime.goexit()
    /usr/lib/go/src/runtime/asm_amd64.s:2232 +0x1 fp=0xc20801d7e8 sp=0xc20801d7e0
created by runtime.createfing
    /usr/lib/go/src/runtime/malloc.go:707 +0x5e

goroutine 17 [syscall, locked to thread]:
runtime.goexit()
    /usr/lib/go/src/runtime/asm_amd64.s:2232 +0x1 fp=0xc208032fe8 sp=0xc208032fe0
signal: aborted (core dumped)

这个错误只会在我增加 GOMAXPROCS 时发生，如果我使用 go query(&wg, i) 也会发生。奇怪的是，如果不使用循环，或者如果 i 设置为足够小的数字，也不会发生错误。有人能够阐明这里发生的事情吗？

最佳答案

根据 https://code.google.com/p/go-sqlite/source/browse/go1/sqlite3/doc.go#29，您正在使用的库不支持并发-

Concurrency

A single connection instance and all of its derived objects (prepared statements, backup operations, etc.) may NOT be used concurrently from multiple goroutines without external synchronization. The only exception is Conn.Interrupt(), which may be called from another goroutine to abort a long-running operation. It is safe to use separate connection instances concurrently, even if they are accessing the same database file.

由于 sqlite3 是一个基于文件的数据库，驱动程序需要管理来自多个线程的并发访问。

https://github.com/mattn/go-sqlite3图书馆 should support thread-safe前提是你的 sqlite3 被编译为这样做。

关于Go SQlite 并发问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31107290/