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diff --git a/doc/go1.9.html b/doc/go1.9.html deleted file mode 100644 index 86ee257d03..0000000000 --- a/doc/go1.9.html +++ /dev/null @@ -1,1024 +0,0 @@ -<!--{ - "Title": "Go 1.9 Release Notes", - "Path": "/doc/go1.9", - "Template": true -}--> - -<!-- -NOTE: In this document and others in this directory, the convention is to -set fixed-width phrases with non-fixed-width spaces, as in -<code>hello</code> <code>world</code>. -Do not send CLs removing the interior tags from such phrases. ---> - -<style> - main ul li { margin: 0.5em 0; } -</style> - -<h2 id="introduction">Introduction to Go 1.9</h2> - -<p> - The latest Go release, version 1.9, arrives six months - after <a href="go1.8">Go 1.8</a> and is the tenth release in - the <a href="https://golang.org/doc/devel/release.html">Go 1.x - series</a>. - There are two <a href="#language">changes to the language</a>: - adding support for type aliases and defining when implementations - may fuse floating point operations. - Most of the changes are in the implementation of the toolchain, - runtime, and libraries. - As always, the release maintains the Go 1 - <a href="/doc/go1compat.html">promise of compatibility</a>. - We expect almost all Go programs to continue to compile and run as - before. -</p> - -<p> - The release - adds <a href="#monotonic-time">transparent monotonic time support</a>, - <a href="#parallel-compile">parallelizes compilation of functions</a> within a package, - better supports <a href="#test-helper">test helper functions</a>, - includes a new <a href="#math-bits">bit manipulation package</a>, - and has a new <a href="#sync-map">concurrent map type</a>. -</p> - -<h2 id="language">Changes to the language</h2> - -<p> - There are two changes to the language. -</p> -<p> - Go now supports type aliases to support gradual code repair while - moving a type between packages. - The <a href="https://golang.org/design/18130-type-alias">type alias - design document</a> - and <a href="https://talks.golang.org/2016/refactor.article">an - article on refactoring</a> cover the problem in detail. - In short, a type alias declaration has the form: -</p> - -<pre> -type T1 = T2 -</pre> - -<p> - This declaration introduces an alias name <code>T1</code>—an - alternate spelling—for the type denoted by <code>T2</code>; that is, - both <code>T1</code> and <code>T2</code> denote the same type. -</p> - -<p> <!-- CL 40391 --> - A smaller language change is that the - <a href="/ref/spec#Floating_point_operators">language specification - now states</a> when implementations are allowed to fuse floating - point operations together, such as by using an architecture's "fused - multiply and add" (FMA) instruction to compute <code>x*y</code> <code>+</code> <code>z</code> - without rounding the intermediate result <code>x*y</code>. - To force the intermediate rounding, write <code>float64(x*y)</code> <code>+</code> <code>z</code>. -</p> - -<h2 id="ports">Ports</h2> - -<p> - There are no new supported operating systems or processor - architectures in this release. -</p> - -<h3 id="power8">ppc64x requires POWER8</h3> - -<p> <!-- CL 36725, CL 36832 --> - Both <code>GOARCH=ppc64</code> and <code>GOARCH=ppc64le</code> now - require at least POWER8 support. In previous releases, - only <code>GOARCH=ppc64le</code> required POWER8 and the big - endian <code>ppc64</code> architecture supported older - hardware. -<p> - -<h3 id="freebsd">FreeBSD</h3> - -<p> - Go 1.9 is the last release that will run on FreeBSD 9.3, - which is already - <a href="https://www.freebsd.org/security/unsupported.html">unsupported by FreeBSD</a>. - Go 1.10 will require FreeBSD 10.3+. -</p> - -<h3 id="openbsd">OpenBSD 6.0</h3> - -<p> <!-- CL 40331 --> - Go 1.9 now enables PT_TLS generation for cgo binaries and thus - requires OpenBSD 6.0 or newer. Go 1.9 no longer supports - OpenBSD 5.9. -<p> - -<h3 id="known_issues">Known Issues</h3> - -<p> - There are some instabilities on FreeBSD that are known but not understood. - These can lead to program crashes in rare cases. - See <a href="https://golang.org/issue/15658">issue 15658</a>. - Any help in solving this FreeBSD-specific issue would be appreciated. -</p> - -<p> - Go stopped running NetBSD builders during the Go 1.9 development - cycle due to NetBSD kernel crashes, up to and including NetBSD 7.1. - As Go 1.9 is being released, NetBSD 7.1.1 is being released with a fix. - However, at this time we have no NetBSD builders passing our test suite. - Any help investigating the - <a href="https://github.com/golang/go/labels/OS-NetBSD">various NetBSD issues</a> - would be appreciated. -</p> - -<h2 id="tools">Tools</h2> - -<h3 id="parallel-compile">Parallel Compilation</h3> - -<p> - The Go compiler now supports compiling a package's functions in parallel, taking - advantage of multiple cores. This is in addition to the <code>go</code> command's - existing support for parallel compilation of separate packages. - Parallel compilation is on by default, but it can be disabled by setting the - environment variable <code>GO19CONCURRENTCOMPILATION</code> to <code>0</code>. -</p> - -<h3 id="vendor-dotdotdot">Vendor matching with ./...</h3> - -<p><!-- CL 38745 --> - By popular request, <code>./...</code> no longer matches packages - in <code>vendor</code> directories in tools accepting package names, - such as <code>go</code> <code>test</code>. To match vendor - directories, write <code>./vendor/...</code>. -</p> - -<h3 id="goroot">Moved GOROOT</h3> - -<p><!-- CL 42533 --> - The <a href="/cmd/go/">go tool</a> will now use the path from which it - was invoked to attempt to locate the root of the Go install tree. - This means that if the entire Go installation is moved to a new - location, the go tool should continue to work as usual. - This may be overridden by setting <code>GOROOT</code> in the environment, - which should only be done in unusual circumstances. - Note that this does not affect the result of - the <a href="/pkg/runtime/#GOROOT">runtime.GOROOT</a> function, which - will continue to report the original installation location; - this may be fixed in later releases. -</p> - -<h3 id="compiler">Compiler Toolchain</h3> - -<p><!-- CL 37441 --> - Complex division is now C99-compatible. This has always been the - case in gccgo and is now fixed in the gc toolchain. -</p> - -<p> <!-- CL 36983 --> - The linker will now generate DWARF information for cgo executables on Windows. -</p> - -<p> <!-- CL 44210, CL 40095 --> - The compiler now includes lexical scopes in the generated DWARF if the - <code>-N -l</code> flags are provided, allowing - debuggers to hide variables that are not in scope. The <code>.debug_info</code> - section is now DWARF version 4. -</p> - -<p> <!-- CL 43855 --> - The values of <code>GOARM</code> and <code>GO386</code> now affect a - compiled package's build ID, as used by the <code>go</code> tool's - dependency caching. -</p> - -<h3 id="asm">Assembler</h3> - -<p> <!-- CL 42028 --> - The four-operand ARM <code>MULA</code> instruction is now assembled correctly, - with the addend register as the third argument and the result - register as the fourth and final argument. - In previous releases, the two meanings were reversed. - The three-operand form, in which the fourth argument is implicitly - the same as the third, is unaffected. - Code using four-operand <code>MULA</code> instructions - will need to be updated, but we believe this form is very rarely used. - <code>MULAWT</code> and <code>MULAWB</code> were already - using the correct order in all forms and are unchanged. -</p> - -<p> <!-- CL 42990 --> - The assembler now supports <code>ADDSUBPS/PD</code>, completing the - two missing x86 SSE3 instructions. -</p> - -<h3 id="go-doc">Doc</h3> - -<p><!-- CL 36031 --> - Long lists of arguments are now truncated. This improves the readability - of <code>go</code> <code>doc</code> on some generated code. -</p> - -<p><!-- CL 38438 --> - Viewing documentation on struct fields is now supported. - For example, <code>go</code> <code>doc</code> <code>http.Client.Jar</code>. -</p> - -<h3 id="go-env-json">Env</h3> - -<p> <!-- CL 38757 --> - The new <code>go</code> <code>env</code> <code>-json</code> flag - enables JSON output, instead of the default OS-specific output - format. -</p> - -<h3 id="go-test-list">Test</h3> - -<p> <!-- CL 41195 --> - The <a href="/cmd/go/#hdr-Description_of_testing_flags"><code>go</code> <code>test</code></a> - command accepts a new <code>-list</code> flag, which takes a regular - expression as an argument and prints to stdout the name of any - tests, benchmarks, or examples that match it, without running them. -</p> - - -<h3 id="go-tool-pprof">Pprof</h3> - -<p> <!-- CL 34192 --> - Profiles produced by the <code>runtime/pprof</code> package now - include symbol information, so they can be viewed - in <code>go</code> <code>tool</code> <code>pprof</code> - without the binary that produced the profile. -</p> - -<p> <!-- CL 38343 --> - The <code>go</code> <code>tool</code> <code>pprof</code> command now - uses the HTTP proxy information defined in the environment, using - <a href="/pkg/net/http/#ProxyFromEnvironment"><code>http.ProxyFromEnvironment</code></a>. -</p> - -<h3 id="vet">Vet</h3> - -<!-- CL 40112 --> -<p> - The <a href="/cmd/vet/"><code>vet</code> command</a> - has been better integrated into the - <a href="/cmd/go/"><code>go</code> tool</a>, - so <code>go</code> <code>vet</code> now supports all standard build - flags while <code>vet</code>'s own flags are now available - from <code>go</code> <code>vet</code> as well as - from <code>go</code> <code>tool</code> <code>vet</code>. -</p> - -<h3 id="gccgo">Gccgo</h3> - -<p> -Due to the alignment of Go's semiannual release schedule with GCC's -annual release schedule, -GCC release 7 contains the Go 1.8.3 version of gccgo. -We expect that the next release, GCC 8, will contain the Go 1.10 -version of gccgo. -</p> - -<h2 id="runtime">Runtime</h2> - -<h3 id="callersframes">Call stacks with inlined frames</h3> - -<p> - Users of - <a href="/pkg/runtime#Callers"><code>runtime.Callers</code></a> - should avoid directly inspecting the resulting PC slice and instead use - <a href="/pkg/runtime#CallersFrames"><code>runtime.CallersFrames</code></a> - to get a complete view of the call stack, or - <a href="/pkg/runtime#Caller"><code>runtime.Caller</code></a> - to get information about a single caller. - This is because an individual element of the PC slice cannot account - for inlined frames or other nuances of the call stack. -</p> - -<p> - Specifically, code that directly iterates over the PC slice and uses - functions such as - <a href="/pkg/runtime#FuncForPC"><code>runtime.FuncForPC</code></a> - to resolve each PC individually will miss inlined frames. - To get a complete view of the stack, such code should instead use - <code>CallersFrames</code>. - Likewise, code should not assume that the length returned by - <code>Callers</code> is any indication of the call depth. - It should instead count the number of frames returned by - <code>CallersFrames</code>. -</p> - -<p> - Code that queries a single caller at a specific depth should use - <code>Caller</code> rather than passing a slice of length 1 to - <code>Callers</code>. -</p> - -<p> - <a href="/pkg/runtime#CallersFrames"><code>runtime.CallersFrames</code></a> - has been available since Go 1.7, so code can be updated prior to - upgrading to Go 1.9. -</p> - -<h2 id="performance">Performance</h2> - -<p> - As always, the changes are so general and varied that precise - statements about performance are difficult to make. Most programs - should run a bit faster, due to speedups in the garbage collector, - better generated code, and optimizations in the core library. -</p> - -<h3 id="gc">Garbage Collector</h3> - -<p> <!-- CL 37520 --> - Library functions that used to trigger stop-the-world garbage - collection now trigger concurrent garbage collection. - - Specifically, <a href="/pkg/runtime/#GC"><code>runtime.GC</code></a>, - <a href="/pkg/runtime/debug/#SetGCPercent"><code>debug.SetGCPercent</code></a>, - and - <a href="/pkg/runtime/debug/#FreeOSMemory"><code>debug.FreeOSMemory</code></a>, - now trigger concurrent garbage collection, blocking only the calling - goroutine until the garbage collection is done. -</p> - -<p> <!-- CL 34103, CL 39835 --> - The - <a href="/pkg/runtime/debug/#SetGCPercent"><code>debug.SetGCPercent</code></a> - function only triggers a garbage collection if one is immediately - necessary because of the new GOGC value. - This makes it possible to adjust GOGC on-the-fly. -</p> - -<p> <!-- CL 38732 --> - Large object allocation performance is significantly improved in - applications using large (>50GB) heaps containing many large - objects. -</p> - -<p> <!-- CL 34937 --> - The <a href="/pkg/runtime/#ReadMemStats"><code>runtime.ReadMemStats</code></a> - function now takes less than 100µs even for very large heaps. -</p> - -<h2 id="library">Core library</h2> - -<h3 id="monotonic-time">Transparent Monotonic Time support</h3> - -<p> <!-- CL 36255 --> - The <a href="/pkg/time/"><code>time</code></a> package now transparently - tracks monotonic time in each <a href="/pkg/time/#Time"><code>Time</code></a> - value, making computing durations between two <code>Time</code> values - a safe operation in the presence of wall clock adjustments. - See the <a href="/pkg/time/#hdr-Monotonic_Clocks">package docs</a> and - <a href="https://golang.org/design/12914-monotonic">design document</a> - for details. -</p> - -<h3 id="math-bits">New bit manipulation package</h3> - -<p> <!-- CL 36315 --> - Go 1.9 includes a new package, - <a href="/pkg/math/bits/"><code>math/bits</code></a>, with optimized - implementations for manipulating bits. On most architectures, - functions in this package are additionally recognized by the - compiler and treated as intrinsics for additional performance. -</p> - -<h3 id="test-helper">Test Helper Functions</h3> - -<p> <!-- CL 38796 --> - The - new <a href="/pkg/testing/#T.Helper"><code>(*T).Helper</code></a> - and <a href="/pkg/testing/#B.Helper"><code>(*B).Helper</code></a> - methods mark the calling function as a test helper function. When - printing file and line information, that function will be skipped. - This permits writing test helper functions while still having useful - line numbers for users. -</p> - -<h3 id="sync-map">Concurrent Map</h3> - -<p> <!-- CL 36617 --> - The new <a href="/pkg/sync/#Map"><code>Map</code></a> type - in the <a href="/pkg/sync/"><code>sync</code></a> package - is a concurrent map with amortized-constant-time loads, stores, and - deletes. It is safe for multiple goroutines to call a <code>Map</code>'s methods - concurrently. -</p> - -<h3 id="pprof-labels">Profiler Labels</h3> - -<p><!-- CL 34198 --> - The <a href="/pkg/runtime/pprof"><code>runtime/pprof</code> package</a> - now supports adding labels to <code>pprof</code> profiler records. - Labels form a key-value map that is used to distinguish calls of the - same function in different contexts when looking at profiles - with the <a href="/cmd/pprof/"><code>pprof</code> command</a>. - The <code>pprof</code> package's - new <a href="/pkg/runtime/pprof/#Do"><code>Do</code> function</a> - runs code associated with some provided labels. Other new functions - in the package help work with labels. -</p> - -</dl><!-- runtime/pprof --> - - -<h3 id="minor_library_changes">Minor changes to the library</h3> - -<p> - As always, there are various minor changes and updates to the library, - made with the Go 1 <a href="/doc/go1compat">promise of compatibility</a> - in mind. -</p> - -<dl id="archive/zip"><dt><a href="/pkg/archive/zip/">archive/zip</a></dt> - <dd> - <p><!-- CL 39570 --> - The - ZIP <a href="/pkg/archive/zip/#Writer"><code>Writer</code></a> - now sets the UTF-8 bit in - the <a href="/pkg/archive/zip/#FileHeader.Flags"><code>FileHeader.Flags</code></a> - when appropriate. - </p> - -</dl><!-- archive/zip --> - -<dl id="crypto/rand"><dt><a href="/pkg/crypto/rand/">crypto/rand</a></dt> - <dd> - <p><!-- CL 43852 --> - On Linux, Go now calls the <code>getrandom</code> system call - without the <code>GRND_NONBLOCK</code> flag; it will now block - until the kernel has sufficient randomness. On kernels predating - the <code>getrandom</code> system call, Go continues to read - from <code>/dev/urandom</code>. - </p> - -</dl><!-- crypto/rand --> - -<dl id="crypto/x509"><dt><a href="/pkg/crypto/x509/">crypto/x509</a></dt> - <dd> - <p><!-- CL 36093 --> - - On Unix systems the environment - variables <code>SSL_CERT_FILE</code> - and <code>SSL_CERT_DIR</code> can now be used to override the - system default locations for the SSL certificate file and SSL - certificate files directory, respectively. - </p> - - <p>The FreeBSD file <code>/usr/local/etc/ssl/cert.pem</code> is - now included in the certificate search path. - </p> - - <p><!-- CL 36900 --> - - The package now supports excluded domains in name constraints. - In addition to enforcing such constraints, - <a href="/pkg/crypto/x509/#CreateCertificate"><code>CreateCertificate</code></a> - will create certificates with excluded name constraints - if the provided template certificate has the new - field - <a href="/pkg/crypto/x509/#Certificate.ExcludedDNSDomains"><code>ExcludedDNSDomains</code></a> - populated. - </p> - - <p><!-- CL 36696 --> - - If any SAN extension, including with no DNS names, is present - in the certificate, then the Common Name from - <a href="/pkg/crypto/x509/#Certificate.Subject"><code>Subject</code></a> is ignored. - In previous releases, the code tested only whether DNS-name SANs were - present in a certificate. - </p> - -</dl><!-- crypto/x509 --> - -<dl id="database/sql"><dt><a href="/pkg/database/sql/">database/sql</a></dt> - <dd> - <p><!-- CL 35476 --> - The package will now use a cached <a href="/pkg/database/sql/#Stmt"><code>Stmt</code></a> if - available in <a href="/pkg/database/sql/#Tx.Stmt"><code>Tx.Stmt</code></a>. - This prevents statements from being re-prepared each time - <a href="/pkg/database/sql/#Tx.Stmt"><code>Tx.Stmt</code></a> is called. - </p> - - <p><!-- CL 38533 --> - The package now allows drivers to implement their own argument checkers by implementing - <a href="/pkg/database/sql/driver/#NamedValueChecker"><code>driver.NamedValueChecker</code></a>. - This also allows drivers to support <code>OUTPUT</code> and <code>INOUT</code> parameter types. - <a href="/pkg/database/sql/#Out"><code>Out</code></a> should be used to return output parameters - when supported by the driver. - </p> - - <p><!-- CL 39031 --> - <a href="/pkg/database/sql/#Rows.Scan"><code>Rows.Scan</code></a> can now scan user-defined string types. - Previously the package supported scanning into numeric types like <code>type</code> <code>Int</code> <code>int64</code>. It now also supports - scanning into string types like <code>type</code> <code>String</code> <code>string</code>. - </p> - - <p><!-- CL 40694 --> - The new <a href="/pkg/database/sql/#DB.Conn"><code>DB.Conn</code></a> method returns the new - <a href="/pkg/database/sql/#Conn"><code>Conn</code></a> type representing an - exclusive connection to the database from the connection pool. All queries run on - a <a href="/pkg/database/sql/#Conn"><code>Conn</code></a> will use the same underlying - connection until <a href="/pkg/database/sql/#Conn.Close"><code>Conn.Close</code></a> is called - to return the connection to the connection pool. - </p> - -</dl><!-- database/sql --> - -<dl id="encoding/asn1"><dt><a href="/pkg/encoding/asn1/">encoding/asn1</a></dt> - <dd> - <p><!-- CL 38660 --> - The new - <a href="/pkg/encoding/asn1/#NullBytes"><code>NullBytes</code></a> - and - <a href="/pkg/encoding/asn1/#NullRawValue"><code>NullRawValue</code></a> - represent the ASN.1 NULL type. - </p> - -</dl><!-- encoding/asn1 --> - -<dl id="encoding/base32"><dt><a href="/pkg/encoding/base32/">encoding/base32</a></dt> - <dd> - <p><!-- CL 38634 --> - The new <a href="/pkg/encoding/base32/#Encoding.WithPadding">Encoding.WithPadding</a> - method adds support for custom padding characters and disabling padding. - </p> - -</dl><!-- encoding/base32 --> - -<dl id="encoding/csv"><dt><a href="/pkg/encoding/csv/">encoding/csv</a></dt> - <dd> - <p><!-- CL 41730 --> - The new field - <a href="/pkg/encoding/csv/#Reader.ReuseRecord"><code>Reader.ReuseRecord</code></a> - controls whether calls to - <a href="/pkg/encoding/csv/#Reader.Read"><code>Read</code></a> - may return a slice sharing the backing array of the previous - call's returned slice for improved performance. - </p> - -</dl><!-- encoding/csv --> - -<dl id="fmt"><dt><a href="/pkg/fmt/">fmt</a></dt> - <dd> - <p><!-- CL 37051 --> - The sharp flag ('<code>#</code>') is now supported when printing - floating point and complex numbers. It will always print a - decimal point - for <code>%e</code>, <code>%E</code>, <code>%f</code>, <code>%F</code>, <code>%g</code> - and <code>%G</code>; it will not remove trailing zeros - for <code>%g</code> and <code>%G</code>. - </p> - -</dl><!-- fmt --> - -<dl id="hash/fnv"><dt><a href="/pkg/hash/fnv/">hash/fnv</a></dt> - <dd> - <p><!-- CL 38356 --> - The package now includes 128-bit FNV-1 and FNV-1a hash support with - <a href="/pkg/hash/fnv/#New128"><code>New128</code></a> and - <a href="/pkg/hash/fnv/#New128a"><code>New128a</code></a>, respectively. - </p> - -</dl><!-- hash/fnv --> - -<dl id="html/template"><dt><a href="/pkg/html/template/">html/template</a></dt> - <dd> - <p><!-- CL 37880, CL 40936 --> - The package now reports an error if a predefined escaper (one of - "html", "urlquery" and "js") is found in a pipeline and does not match - what the auto-escaper would have decided on its own. - This avoids certain security or correctness issues. - Now use of one of these escapers is always either a no-op or an error. - (The no-op case eases migration from <a href="/pkg/text/template/">text/template</a>.) - </p> - -</dl><!-- html/template --> - -<dl id="image"><dt><a href="/pkg/image/">image</a></dt> - <dd> - <p><!-- CL 36734 --> - The <a href="/pkg/image/#Rectangle.Intersect"><code>Rectangle.Intersect</code></a> - method now returns a zero <code>Rectangle</code> when called on - adjacent but non-overlapping rectangles, as documented. In - earlier releases it would incorrectly return an empty but - non-zero <code>Rectangle</code>. - </p> - -</dl><!-- image --> - -<dl id="image/color"><dt><a href="/pkg/image/color/">image/color</a></dt> - <dd> - <p><!-- CL 36732 --> - The YCbCr to RGBA conversion formula has been tweaked to ensure - that rounding adjustments span the complete [0, 0xffff] RGBA - range. - </p> - -</dl><!-- image/color --> - -<dl id="image/png"><dt><a href="/pkg/image/png/">image/png</a></dt> - <dd> - <p><!-- CL 34150 --> - The new <a href="/pkg/image/png/#Encoder.BufferPool"><code>Encoder.BufferPool</code></a> - field allows specifying an <a href="/pkg/image/png/#EncoderBufferPool"><code>EncoderBufferPool</code></a>, - that will be used by the encoder to get temporary <code>EncoderBuffer</code> - buffers when encoding a PNG image. - - The use of a <code>BufferPool</code> reduces the number of - memory allocations performed while encoding multiple images. - </p> - - <p><!-- CL 38271 --> - The package now supports the decoding of transparent 8-bit - grayscale ("Gray8") images. - </p> - -</dl><!-- image/png --> - -<dl id="math/big"><dt><a href="/pkg/math/big/">math/big</a></dt> - <dd> - <p><!-- CL 36487 --> - The new - <a href="/pkg/math/big/#Int.IsInt64"><code>IsInt64</code></a> - and - <a href="/pkg/math/big/#Int.IsUint64"><code>IsUint64</code></a> - methods report whether an <code>Int</code> - may be represented as an <code>int64</code> or <code>uint64</code> - value. - </p> - -</dl><!-- math/big --> - -<dl id="mime/multipart"><dt><a href="/pkg/mime/multipart/">mime/multipart</a></dt> - <dd> - <p><!-- CL 39223 --> - The new - <a href="/pkg/mime/multipart/#FileHeader.Size"><code>FileHeader.Size</code></a> - field describes the size of a file in a multipart message. - </p> - -</dl><!-- mime/multipart --> - -<dl id="net"><dt><a href="/pkg/net/">net</a></dt> - <dd> - <p><!-- CL 32572 --> - The new - <a href="/pkg/net/#Resolver.StrictErrors"><code>Resolver.StrictErrors</code></a> - provides control over how Go's built-in DNS resolver handles - temporary errors during queries composed of multiple sub-queries, - such as an A+AAAA address lookup. - </p> - - <p><!-- CL 37260 --> - The new - <a href="/pkg/net/#Resolver.Dial"><code>Resolver.Dial</code></a> - allows a <code>Resolver</code> to use a custom dial function. - </p> - - <p><!-- CL 40510 --> - <a href="/pkg/net/#JoinHostPort"><code>JoinHostPort</code></a> now only places an address in square brackets if the host contains a colon. - In previous releases it would also wrap addresses in square brackets if they contained a percent ('<code>%</code>') sign. - </p> - - <p><!-- CL 37913 --> - The new methods - <a href="/pkg/net/#TCPConn.SyscallConn"><code>TCPConn.SyscallConn</code></a>, - <a href="/pkg/net/#IPConn.SyscallConn"><code>IPConn.SyscallConn</code></a>, - <a href="/pkg/net/#UDPConn.SyscallConn"><code>UDPConn.SyscallConn</code></a>, - and - <a href="/pkg/net/#UnixConn.SyscallConn"><code>UnixConn.SyscallConn</code></a> - provide access to the connections' underlying file descriptors. - </p> - - <p><!-- 45088 --> - It is now safe to call <a href="/pkg/net/#Dial"><code>Dial</code></a> with the address obtained from - <code>(*TCPListener).String()</code> after creating the listener with - <code><a href="/pkg/net/#Listen">Listen</a>("tcp", ":0")</code>. - Previously it failed on some machines with half-configured IPv6 stacks. - </p> - -</dl><!-- net --> - -<dl id="net/http"><dt><a href="/pkg/net/http/">net/http</a></dt> - <dd> - - <p><!-- CL 37328 --> - The <a href="/pkg/net/http/#Cookie.String"><code>Cookie.String</code></a> method, used for - <code>Cookie</code> and <code>Set-Cookie</code> headers, now encloses values in double quotes - if the value contains either a space or a comma. - </p> - - <p>Server changes:</p> - <ul> - <li><!-- CL 38194 --> - <a href="/pkg/net/http/#ServeMux"><code>ServeMux</code></a> now ignores ports in the host - header when matching handlers. The host is matched unmodified for <code>CONNECT</code> requests. - </li> - - <li><!-- CL 44074 --> - The new <a href="/pkg/net/http/#Server.ServeTLS"><code>Server.ServeTLS</code></a> method wraps - <a href="/pkg/net/http/#Server.Serve"><code>Server.Serve</code></a> with added TLS support. - </li> - - <li><!-- CL 34727 --> - <a href="/pkg/net/http/#Server.WriteTimeout"><code>Server.WriteTimeout</code></a> - now applies to HTTP/2 connections and is enforced per-stream. - </li> - - <li><!-- CL 43231 --> - HTTP/2 now uses the priority write scheduler by default. - Frames are scheduled by following HTTP/2 priorities as described in - <a href="https://tools.ietf.org/html/rfc7540#section-5.3">RFC 7540 Section 5.3</a>. - </li> - - <li><!-- CL 36483 --> - The HTTP handler returned by <a href="/pkg/net/http/#StripPrefix"><code>StripPrefix</code></a> - now calls its provided handler with a modified clone of the original <code>*http.Request</code>. - Any code storing per-request state in maps keyed by <code>*http.Request</code> should - use - <a href="/pkg/net/http/#Request.Context"><code>Request.Context</code></a>, - <a href="/pkg/net/http/#Request.WithContext"><code>Request.WithContext</code></a>, - and - <a href="/pkg/context/#WithValue"><code>context.WithValue</code></a> instead. - </li> - - <li><!-- CL 35490 --> - <a href="/pkg/net/http/#LocalAddrContextKey"><code>LocalAddrContextKey</code></a> now contains - the connection's actual network address instead of the interface address used by the listener. - </li> - </ul> - - <p>Client & Transport changes:</p> - <ul> - <li><!-- CL 35488 --> - The <a href="/pkg/net/http/#Transport"><code>Transport</code></a> - now supports making requests via SOCKS5 proxy when the URL returned by - <a href="/pkg/net/http/#Transport.Proxy"><code>Transport.Proxy</code></a> - has the scheme <code>socks5</code>. - </li> - </ul> - -</dl><!-- net/http --> - -<dl id="net/http/fcgi"><dt><a href="/pkg/net/http/fcgi/">net/http/fcgi</a></dt> - <dd> - <p><!-- CL 40012 --> - The new - <a href="/pkg/net/http/fcgi/#ProcessEnv"><code>ProcessEnv</code></a> - function returns FastCGI environment variables associated with an HTTP request - for which there are no appropriate - <a href="/pkg/net/http/#Request"><code>http.Request</code></a> - fields, such as <code>REMOTE_USER</code>. - </p> - -</dl><!-- net/http/fcgi --> - -<dl id="net/http/httptest"><dt><a href="/pkg/net/http/httptest/">net/http/httptest</a></dt> - <dd> - <p><!-- CL 34639 --> - The new - <a href="/pkg/net/http/httptest/#Server.Client"><code>Server.Client</code></a> - method returns an HTTP client configured for making requests to the test server. - </p> - - <p> - The new - <a href="/pkg/net/http/httptest/#Server.Certificate"><code>Server.Certificate</code></a> - method returns the test server's TLS certificate, if any. - </p> - -</dl><!-- net/http/httptest --> - -<dl id="net/http/httputil"><dt><a href="/pkg/net/http/httputil/">net/http/httputil</a></dt> - <dd> - <p><!-- CL 43712 --> - The <a href="/pkg/net/http/httputil/#ReverseProxy"><code>ReverseProxy</code></a> - now proxies all HTTP/2 response trailers, even those not declared in the initial response - header. Such undeclared trailers are used by the gRPC protocol. - </p> - -</dl><!-- net/http/httputil --> - -<dl id="os"><dt><a href="/pkg/os/">os</a></dt> - <dd> - <p><!-- CL 36800 --> - The <code>os</code> package now uses the internal runtime poller - for file I/O. - This reduces the number of threads required for read/write - operations on pipes, and it eliminates races when one goroutine - closes a file while another is using the file for I/O. - </p> - - <dd> - <p><!-- CL 37915 --> - On Windows, - <a href="/pkg/os/#Args"><code>Args</code></a> - is now populated without <code>shell32.dll</code>, improving process start-up time by 1-7 ms. - </p> - -</dl><!-- os --> - -<dl id="os/exec"><dt><a href="/pkg/os/exec/">os/exec</a></dt> - <dd> - <p><!-- CL 37586 --> - The <code>os/exec</code> package now prevents child processes from being created with - any duplicate environment variables. - If <a href="/pkg/os/exec/#Cmd.Env"><code>Cmd.Env</code></a> - contains duplicate environment keys, only the last - value in the slice for each duplicate key is used. - </p> - -</dl><!-- os/exec --> - -<dl id="os/user"><dt><a href="/pkg/os/user/">os/user</a></dt> - <dd> - <p><!-- CL 37664 --> - <a href="/pkg/os/user/#Lookup"><code>Lookup</code></a> and - <a href="/pkg/os/user/#LookupId"><code>LookupId</code></a> now - work on Unix systems when <code>CGO_ENABLED=0</code> by reading - the <code>/etc/passwd</code> file. - </p> - - <p><!-- CL 33713 --> - <a href="/pkg/os/user/#LookupGroup"><code>LookupGroup</code></a> and - <a href="/pkg/os/user/#LookupGroupId"><code>LookupGroupId</code></a> now - work on Unix systems when <code>CGO_ENABLED=0</code> by reading - the <code>/etc/group</code> file. - </p> - -</dl><!-- os/user --> - -<dl id="reflect"><dt><a href="/pkg/reflect/">reflect</a></dt> - <dd> - <p><!-- CL 38335 --> - The new - <a href="/pkg/reflect/#MakeMapWithSize"><code>MakeMapWithSize</code></a> - function creates a map with a capacity hint. - </p> - -</dl><!-- reflect --> - -<dl id="pkg-runtime"><dt><a href="/pkg/runtime/">runtime</a></dt> - <dd> - <p><!-- CL 37233, CL 37726 --> - Tracebacks generated by the runtime and recorded in profiles are - now accurate in the presence of inlining. - To retrieve tracebacks programmatically, applications should use - <a href="/pkg/runtime/#CallersFrames"><code>runtime.CallersFrames</code></a> - rather than directly iterating over the results of - <a href="/pkg/runtime/#Callers"><code>runtime.Callers</code></a>. - </p> - - <p><!-- CL 38403 --> - On Windows, Go no longer forces the system timer to run at high - resolution when the program is idle. - This should reduce the impact of Go programs on battery life. - </p> - - <p><!-- CL 29341 --> - On FreeBSD, <code>GOMAXPROCS</code> and - <a href="/pkg/runtime/#NumCPU"><code>runtime.NumCPU</code></a> - are now based on the process' CPU mask, rather than the total - number of CPUs. - </p> - - <p><!-- CL 43641 --> - The runtime has preliminary support for Android O. - </p> - -</dl><!-- runtime --> - -<dl id="runtime/debug"><dt><a href="/pkg/runtime/debug/">runtime/debug</a></dt> - <dd> - <p><!-- CL 34013 --> - Calling - <a href="/pkg/runtime/debug/#SetGCPercent"><code>SetGCPercent</code></a> - with a negative value no longer runs an immediate garbage collection. - </p> - -</dl><!-- runtime/debug --> - -<dl id="runtime/trace"><dt><a href="/pkg/runtime/trace/">runtime/trace</a></dt> - <dd> - <p><!-- CL 36015 --> - The execution trace now displays mark assist events, which - indicate when an application goroutine is forced to assist - garbage collection because it is allocating too quickly. - </p> - - <p><!-- CL 40810 --> - "Sweep" events now encompass the entire process of finding free - space for an allocation, rather than recording each individual - span that is swept. - This reduces allocation latency when tracing allocation-heavy - programs. - The sweep event shows how many bytes were swept and how many - were reclaimed. - </p> - -</dl><!-- runtime/trace --> - -<dl id="sync"><dt><a href="/pkg/sync/">sync</a></dt> - <dd> - <p><!-- CL 34310 --> - <a href="/pkg/sync/#Mutex"><code>Mutex</code></a> is now more fair. - </p> - -</dl><!-- sync --> - -<dl id="syscall"><dt><a href="/pkg/syscall/">syscall</a></dt> - <dd> - <p><!-- CL 36697 --> - The new field - <a href="/pkg/syscall/#Credential.NoSetGroups"><code>Credential.NoSetGroups</code></a> - controls whether Unix systems make a <code>setgroups</code> system call - to set supplementary groups when starting a new process. - </p> - - <p><!-- CL 43512 --> - The new field - <a href="/pkg/syscall/#SysProcAttr.AmbientCaps"><code>SysProcAttr.AmbientCaps</code></a> - allows setting ambient capabilities on Linux 4.3+ when creating - a new process. - </p> - - <p><!-- CL 37439 --> - On 64-bit x86 Linux, process creation latency has been optimized with - use of <code>CLONE_VFORK</code> and <code>CLONE_VM</code>. - </p> - - <p><!-- CL 37913 --> - The new - <a href="/pkg/syscall/#Conn"><code>Conn</code></a> - interface describes some types in the - <a href="/pkg/net/"><code>net</code></a> - package that can provide access to their underlying file descriptor - using the new - <a href="/pkg/syscall/#RawConn"><code>RawConn</code></a> - interface. - </p> - -</dl><!-- syscall --> - - -<dl id="testing/quick"><dt><a href="/pkg/testing/quick/">testing/quick</a></dt> - <dd> - <p><!-- CL 39152 --> - The package now chooses values in the full range when - generating <code>int64</code> and <code>uint64</code> random - numbers; in earlier releases generated values were always - limited to the [-2<sup>62</sup>, 2<sup>62</sup>) range. - </p> - - <p> - In previous releases, using a nil - <a href="/pkg/testing/quick/#Config.Rand"><code>Config.Rand</code></a> - value caused a fixed deterministic random number generator to be used. - It now uses a random number generator seeded with the current time. - For the old behavior, set <code>Config.Rand</code> to <code>rand.New(rand.NewSource(0))</code>. - </p> - -</dl><!-- testing/quick --> - -<dl id="text/template"><dt><a href="/pkg/text/template/">text/template</a></dt> - <dd> - <p><!-- CL 38420 --> - The handling of empty blocks, which was broken by a Go 1.8 - change that made the result dependent on the order of templates, - has been fixed, restoring the old Go 1.7 behavior. - </p> - -</dl><!-- text/template --> - -<dl id="time"><dt><a href="/pkg/time/">time</a></dt> - <dd> - <p><!-- CL 36615 --> - The new methods - <a href="/pkg/time/#Duration.Round"><code>Duration.Round</code></a> - and - <a href="/pkg/time/#Duration.Truncate"><code>Duration.Truncate</code></a> - handle rounding and truncating durations to multiples of a given duration. - </p> - - <p><!-- CL 35710 --> - Retrieving the time and sleeping now work correctly under Wine. - </p> - - <p> - If a <code>Time</code> value has a monotonic clock reading, its - string representation (as returned by <code>String</code>) now includes a - final field <code>"m=±value"</code>, where <code>value</code> is the - monotonic clock reading formatted as a decimal number of seconds. - </p> - - <p><!-- CL 44832 --> - The included <code>tzdata</code> timezone database has been - updated to version 2017b. As always, it is only used if the - system does not already have the database available. - </p> - -</dl><!-- time --> |