x/tools/gopls: deadlock opening many files at once

[muirdm]

While testing a different issue I ran into a new deadlock. I think it boils down to a different lock acquisition order in these two code paths:

Path 1:

1. loadParseTypecheck acquires mcache mutex
2. eventually gets into lsp/cache.(*fileBase).Handle which acquires f.handleMu

Path 2:

1. lsp/cache.(*goFile).invalidateContent acquires f.handleMu and then tries acquiring mcache mutex.

Here is the full goroutine trace:

goroutine profile: total 100
91 @ 0x1030c0f 0x10078aa 0x1007880 0x100756b 0x131ad28 0x105d841
#	0x131ad27	golang.org/x/tools/internal/jsonrpc2.(*Conn).Run.func1+0x37	/Users/muir/projects/tools/internal/jsonrpc2/jsonrpc2.go:429

1 @ 0x1030c0f 0x10078aa 0x1007880 0x100756b 0x1525c69 0x1525968 0x138755a 0x1388d99 0x1367907 0x15269bc 0x15269ab 0x1525f40 0x1525968 0x138755a 0x1388d99 0x1367907 0x15269bc 0x15269ab 0x1525f40 0x105d841
#	0x1525c68	golang.org/x/tools/internal/lsp/cache.(*importer).getPkg+0x1a8		/Users/muir/projects/tools/internal/lsp/cache/check.go:59
#	0x1525967	golang.org/x/tools/internal/lsp/cache.(*importer).Import+0x87		/Users/muir/projects/tools/internal/lsp/cache/check.go:41
#	0x1387559	go/types.(*Checker).importPackage+0x6e9					/usr/local/go/src/go/types/resolver.go:161
#	0x1388d98	go/types.(*Checker).collectObjects+0x15f8				/usr/local/go/src/go/types/resolver.go:256
#	0x1367906	go/types.(*Checker).checkFiles+0x96					/usr/local/go/src/go/types/check.go:252
#	0x15269bb	go/types.(*Checker).Files+0x9db						/usr/local/go/src/go/types/check.go:245
#	0x15269aa	golang.org/x/tools/internal/lsp/cache.(*importer).typeCheck+0x9ca	/Users/muir/projects/tools/internal/lsp/cache/check.go:187
#	0x1525f3f	golang.org/x/tools/internal/lsp/cache.(*importer).getPkg+0x47f		/Users/muir/projects/tools/internal/lsp/cache/check.go:68
#	0x1525967	golang.org/x/tools/internal/lsp/cache.(*importer).Import+0x87		/Users/muir/projects/tools/internal/lsp/cache/check.go:41
#	0x1387559	go/types.(*Checker).importPackage+0x6e9					/usr/local/go/src/go/types/resolver.go:161
#	0x1388d98	go/types.(*Checker).collectObjects+0x15f8				/usr/local/go/src/go/types/resolver.go:256
#	0x1367906	go/types.(*Checker).checkFiles+0x96					/usr/local/go/src/go/types/check.go:252
#	0x15269bb	go/types.(*Checker).Files+0x9db						/usr/local/go/src/go/types/check.go:245
#	0x15269aa	golang.org/x/tools/internal/lsp/cache.(*importer).typeCheck+0x9ca	/Users/muir/projects/tools/internal/lsp/cache/check.go:187
#	0x1525f3f	golang.org/x/tools/internal/lsp/cache.(*importer).getPkg+0x47f		/Users/muir/projects/tools/internal/lsp/cache/check.go:68

1 @ 0x1030c0f 0x10078aa 0x1007880 0x100756b 0x1525c69 0x1525968 0x138755a 0x1388d99 0x1367907 0x15269bc 0x15269ab 0x1525f40 0x152acd5 0x1529983 0x1529cac 0x152a2f4 0x14c85be 0x1517a38 0x1523677 0x105d841
#	0x1525c68	golang.org/x/tools/internal/lsp/cache.(*importer).getPkg+0x1a8			/Users/muir/projects/tools/internal/lsp/cache/check.go:59
#	0x1525967	golang.org/x/tools/internal/lsp/cache.(*importer).Import+0x87			/Users/muir/projects/tools/internal/lsp/cache/check.go:41
#	0x1387559	go/types.(*Checker).importPackage+0x6e9						/usr/local/go/src/go/types/resolver.go:161
#	0x1388d98	go/types.(*Checker).collectObjects+0x15f8					/usr/local/go/src/go/types/resolver.go:256
#	0x1367906	go/types.(*Checker).checkFiles+0x96						/usr/local/go/src/go/types/check.go:252
#	0x15269bb	go/types.(*Checker).Files+0x9db							/usr/local/go/src/go/types/check.go:245
#	0x15269aa	golang.org/x/tools/internal/lsp/cache.(*importer).typeCheck+0x9ca		/Users/muir/projects/tools/internal/lsp/cache/check.go:187
#	0x1525f3f	golang.org/x/tools/internal/lsp/cache.(*importer).getPkg+0x47f			/Users/muir/projects/tools/internal/lsp/cache/check.go:68
#	0x152acd4	golang.org/x/tools/internal/lsp/cache.(*view).loadParseTypecheck+0x1e4		/Users/muir/projects/tools/internal/lsp/cache/load.go:49
#	0x1529982	golang.org/x/tools/internal/lsp/cache.(*goFile).GetPackages+0x322		/Users/muir/projects/tools/internal/lsp/cache/gofile.go:112
#	0x1529cab	golang.org/x/tools/internal/lsp/cache.(*goFile).GetPackage+0x4b			/Users/muir/projects/tools/internal/lsp/cache/gofile.go:137
#	0x152a2f3	golang.org/x/tools/internal/lsp/cache.(*goFile).GetActiveReverseDeps+0x73	/Users/muir/projects/tools/internal/lsp/cache/gofile.go:198
#	0x14c85bd	golang.org/x/tools/internal/lsp/source.Diagnostics+0x2ad			/Users/muir/projects/tools/internal/lsp/source/diagnostics.go:88
#	0x1517a37	golang.org/x/tools/internal/lsp.(*Server).Diagnostics+0x267			/Users/muir/projects/tools/internal/lsp/diagnostics.go:27
#	0x1523676	golang.org/x/tools/internal/lsp.(*Server).didOpen.func1+0x66			/Users/muir/projects/tools/internal/lsp/text_synchronization.go:29

1 @ 0x1030c0f 0x102c3da 0x102b9c6 0x10bb88b 0x10bdeca 0x10bdeab 0x114bee2 0x1166b52 0x1165728 0x12e78fd 0x1512856 0x1512803 0x105d841
#	0x102b9c5	internal/poll.runtime_pollWait+0x55			/usr/local/go/src/runtime/netpoll.go:182
#	0x10bb88a	internal/poll.(*pollDesc).wait+0x9a			/usr/local/go/src/internal/poll/fd_poll_runtime.go:87
#	0x10bdec9	internal/poll.(*pollDesc).waitRead+0x1b9		/usr/local/go/src/internal/poll/fd_poll_runtime.go:92
#	0x10bdeaa	internal/poll.(*FD).Accept+0x19a			/usr/local/go/src/internal/poll/fd_unix.go:384
#	0x114bee1	net.(*netFD).accept+0x41				/usr/local/go/src/net/fd_unix.go:238
#	0x1166b51	net.(*TCPListener).accept+0x31				/usr/local/go/src/net/tcpsock_posix.go:139
#	0x1165727	net.(*TCPListener).Accept+0x47				/usr/local/go/src/net/tcpsock.go:260
#	0x12e78fc	net/http.(*Server).Serve+0x22c				/usr/local/go/src/net/http/server.go:2859
#	0x1512855	net/http.Serve+0x4c5					/usr/local/go/src/net/http/server.go:2456
#	0x1512802	golang.org/x/tools/internal/lsp/debug.Serve.func1+0x472	/Users/muir/projects/tools/internal/lsp/debug/serve.go:232

1 @ 0x1030c0f 0x1040f89 0x1040f5f 0x1040cfd 0x1073419 0x1528b22 0x1526dad 0x1525f40 0x1525968 0x138755a 0x1388d99 0x1367907 0x15269bc 0x15269ab 0x1525f40 0x1525968 0x138755a 0x1388d99 0x1367907 0x15269bc 0x15269ab 0x1525f40 0x105d841
#	0x1040cfc	sync.runtime_SemacquireMutex+0x3c					/usr/local/go/src/runtime/sema.go:71
#	0x1073418	sync.(*Mutex).Lock+0x108						/usr/local/go/src/sync/mutex.go:134
#	0x1528b21	golang.org/x/tools/internal/lsp/cache.(*fileBase).Handle+0x41		/Users/muir/projects/tools/internal/lsp/cache/file.go:60
#	0x1526dac	golang.org/x/tools/internal/lsp/cache.(*importer).typeCheck+0xdcc	/Users/muir/projects/tools/internal/lsp/cache/check.go:126
#	0x1525f3f	golang.org/x/tools/internal/lsp/cache.(*importer).getPkg+0x47f		/Users/muir/projects/tools/internal/lsp/cache/check.go:68
#	0x1525967	golang.org/x/tools/internal/lsp/cache.(*importer).Import+0x87		/Users/muir/projects/tools/internal/lsp/cache/check.go:41
#	0x1387559	go/types.(*Checker).importPackage+0x6e9					/usr/local/go/src/go/types/resolver.go:161
#	0x1388d98	go/types.(*Checker).collectObjects+0x15f8				/usr/local/go/src/go/types/resolver.go:256
#	0x1367906	go/types.(*Checker).checkFiles+0x96					/usr/local/go/src/go/types/check.go:252
#	0x15269bb	go/types.(*Checker).Files+0x9db						/usr/local/go/src/go/types/check.go:245
#	0x15269aa	golang.org/x/tools/internal/lsp/cache.(*importer).typeCheck+0x9ca	/Users/muir/projects/tools/internal/lsp/cache/check.go:187
#	0x1525f3f	golang.org/x/tools/internal/lsp/cache.(*importer).getPkg+0x47f		/Users/muir/projects/tools/internal/lsp/cache/check.go:68
#	0x1525967	golang.org/x/tools/internal/lsp/cache.(*importer).Import+0x87		/Users/muir/projects/tools/internal/lsp/cache/check.go:41
#	0x1387559	go/types.(*Checker).importPackage+0x6e9					/usr/local/go/src/go/types/resolver.go:161
#	0x1388d98	go/types.(*Checker).collectObjects+0x15f8				/usr/local/go/src/go/types/resolver.go:256
#	0x1367906	go/types.(*Checker).checkFiles+0x96					/usr/local/go/src/go/types/check.go:252
#	0x15269bb	go/types.(*Checker).Files+0x9db						/usr/local/go/src/go/types/check.go:245
#	0x15269aa	golang.org/x/tools/internal/lsp/cache.(*importer).typeCheck+0x9ca	/Users/muir/projects/tools/internal/lsp/cache/check.go:187
#	0x1525f3f	golang.org/x/tools/internal/lsp/cache.(*importer).getPkg+0x47f		/Users/muir/projects/tools/internal/lsp/cache/check.go:68

1 @ 0x1030c0f 0x1040f89 0x1040f5f 0x1040cfd 0x1073419 0x15296c4 0x1529cac 0x152a2f4 0x14c85be 0x1517a38 0x1523677 0x105d841
#	0x1040cfc	sync.runtime_SemacquireMutex+0x3c						/usr/local/go/src/runtime/sema.go:71
#	0x1073418	sync.(*Mutex).Lock+0x108							/usr/local/go/src/sync/mutex.go:134
#	0x15296c3	golang.org/x/tools/internal/lsp/cache.(*goFile).GetPackages+0x63		/Users/muir/projects/tools/internal/lsp/cache/gofile.go:108
#	0x1529cab	golang.org/x/tools/internal/lsp/cache.(*goFile).GetPackage+0x4b			/Users/muir/projects/tools/internal/lsp/cache/gofile.go:137
#	0x152a2f3	golang.org/x/tools/internal/lsp/cache.(*goFile).GetActiveReverseDeps+0x73	/Users/muir/projects/tools/internal/lsp/cache/gofile.go:198
#	0x14c85bd	golang.org/x/tools/internal/lsp/source.Diagnostics+0x2ad			/Users/muir/projects/tools/internal/lsp/source/diagnostics.go:88
#	0x1517a37	golang.org/x/tools/internal/lsp.(*Server).Diagnostics+0x267			/Users/muir/projects/tools/internal/lsp/diagnostics.go:27
#	0x1523676	golang.org/x/tools/internal/lsp.(*Server).didOpen.func1+0x66			/Users/muir/projects/tools/internal/lsp/text_synchronization.go:29

1 @ 0x1030c0f 0x1040f89 0x1040f5f 0x1040cfd 0x1073419 0x153371f 0x153615e 0x1535116 0x1535cd0 0x153158a 0x1530a2e 0x1521630 0x151ea39 0x13265c4 0x131ae07 0x105d841
#	0x1040cfc	sync.runtime_SemacquireMutex+0x3c					/usr/local/go/src/runtime/sema.go:71
#	0x1073418	sync.(*Mutex).Lock+0x108						/usr/local/go/src/sync/mutex.go:134
#	0x153371e	golang.org/x/tools/internal/lsp/cache.(*goFile).invalidateContent+0x7e	/Users/muir/projects/tools/internal/lsp/cache/view.go:231
#	0x153615d	golang.org/x/tools/internal/lsp/cache.(*view).getFile.func1+0x4d	/Users/muir/projects/tools/internal/lsp/cache/view.go:354
#	0x1535115	golang.org/x/tools/internal/lsp/cache.(*WatchMap).Notify+0xd5		/Users/muir/projects/tools/internal/lsp/cache/watcher.go:54
#	0x1535ccf	golang.org/x/tools/internal/lsp/cache.(*session).openOverlay.func1+0x6f	/Users/muir/projects/tools/internal/lsp/cache/session.go:267
#	0x1531589	golang.org/x/tools/internal/lsp/cache.(*session).openOverlay+0x389	/Users/muir/projects/tools/internal/lsp/cache/session.go:283
#	0x1530a2d	golang.org/x/tools/internal/lsp/cache.(*session).DidOpen+0xfd		/Users/muir/projects/tools/internal/lsp/cache/session.go:191
#	0x152162f	golang.org/x/tools/internal/lsp.(*Server).didOpen+0xcf			/Users/muir/projects/tools/internal/lsp/text_synchronization.go:23
#	0x151ea38	golang.org/x/tools/internal/lsp.(*Server).DidOpen+0x48			/Users/muir/projects/tools/internal/lsp/server.go:138
#	0x13265c3	golang.org/x/tools/internal/lsp/protocol.serverHandler.func1+0x20c3	/Users/muir/projects/tools/internal/lsp/protocol/tsserver.go:104
#	0x131ae06	golang.org/x/tools/internal/jsonrpc2.(*Conn).Run.func1+0x116		/Users/muir/projects/tools/internal/jsonrpc2/jsonrpc2.go:441

1 @ 0x104c81e 0x10a5637 0x10bc62f 0x10bc609 0x10c2020 0x10c1ff3 0x11cf69f 0x11d03ed 0x11d0890 0x13197d9 0x13197cb 0x1318c92 0x15426a1 0x154267b 0x1539f87 0x1538dd3 0x153c5bc 0x1539f87 0x1538dd3 0x154ba9a 0x103081c 0x105d841
#	0x104c81d	syscall.syscall+0x2d						/usr/local/go/src/runtime/sys_darwin.go:63
#	0x10a5636	syscall.read+0x66						/usr/local/go/src/syscall/zsyscall_darwin_amd64.go:1169
#	0x10bc62e	syscall.Read+0x12e						/usr/local/go/src/syscall/syscall_unix.go:172
#	0x10bc608	internal/poll.(*FD).Read+0x108					/usr/local/go/src/internal/poll/fd_unix.go:165
#	0x10c201f	os.(*File).read+0x6f						/usr/local/go/src/os/file_unix.go:263
#	0x10c1ff2	os.(*File).Read+0x42						/usr/local/go/src/os/file.go:108
#	0x11cf69e	bufio.(*Reader).fill+0x10e					/usr/local/go/src/bufio/bufio.go:100
#	0x11d03ec	bufio.(*Reader).ReadSlice+0x3c					/usr/local/go/src/bufio/bufio.go:356
#	0x11d088f	bufio.(*Reader).ReadBytes+0x6f					/usr/local/go/src/bufio/bufio.go:434
#	0x13197d8	bufio.(*Reader).ReadString+0x98					/usr/local/go/src/bufio/bufio.go:474
#	0x13197ca	golang.org/x/tools/internal/jsonrpc2.(*headerStream).Read+0x8a	/Users/muir/projects/tools/internal/jsonrpc2/stream.go:97
#	0x1318c91	golang.org/x/tools/internal/jsonrpc2.(*Conn).Run+0xa1		/Users/muir/projects/tools/internal/jsonrpc2/jsonrpc2.go:396
#	0x15426a0	golang.org/x/tools/internal/lsp.(*Server).Run+0x540		/Users/muir/projects/tools/internal/lsp/server.go:61
#	0x154267a	golang.org/x/tools/internal/lsp/cmd.(*Serve).Run+0x51a		/Users/muir/projects/tools/internal/lsp/cmd/serve.go:95
#	0x1539f86	golang.org/x/tools/internal/tool.Main.func2+0xb6		/Users/muir/projects/tools/internal/tool/tool.go:130
#	0x1538dd2	golang.org/x/tools/internal/tool.Main+0x242			/Users/muir/projects/tools/internal/tool/tool.go:131
#	0x153c5bb	golang.org/x/tools/internal/lsp/cmd.(*Application).Run+0x4ab	/Users/muir/projects/tools/internal/lsp/cmd/cmd.go:106
#	0x1539f86	golang.org/x/tools/internal/tool.Main.func2+0xb6		/Users/muir/projects/tools/internal/tool/tool.go:130
#	0x1538dd2	golang.org/x/tools/internal/tool.Main+0x242			/Users/muir/projects/tools/internal/tool/tool.go:131
#	0x154ba99	main.main+0x119							/Users/muir/projects/tools/cmd/gopls/main.go:22
#	0x103081b	runtime.main+0x20b						/usr/local/go/src/runtime/proc.go:200

1 @ 0x104c81e 0x10a5637 0x10bc62f 0x10bc609 0x114b5cf 0x115db39 0x12dd378 0x105d841
#	0x104c81d	syscall.syscall+0x2d				/usr/local/go/src/runtime/sys_darwin.go:63
#	0x10a5636	syscall.read+0x66				/usr/local/go/src/syscall/zsyscall_darwin_amd64.go:1169
#	0x10bc62e	syscall.Read+0x12e				/usr/local/go/src/syscall/syscall_unix.go:172
#	0x10bc608	internal/poll.(*FD).Read+0x108			/usr/local/go/src/internal/poll/fd_unix.go:165
#	0x114b5ce	net.(*netFD).Read+0x4e				/usr/local/go/src/net/fd_unix.go:202
#	0x115db38	net.(*conn).Read+0x68				/usr/local/go/src/net/net.go:177
#	0x12dd377	net/http.(*connReader).backgroundRead+0x57	/usr/local/go/src/net/http/server.go:677

1 @ 0x1505550 0x1505370 0x1501f40 0x150ece6 0x150f747 0x12e4244 0x12e6146 0x12e7518 0x12e3201 0x105d841
#	0x150554f	runtime/pprof.writeRuntimeProfile+0x8f	/usr/local/go/src/runtime/pprof/pprof.go:708
#	0x150536f	runtime/pprof.writeGoroutine+0x9f	/usr/local/go/src/runtime/pprof/pprof.go:670
#	0x1501f3f	runtime/pprof.(*Profile).WriteTo+0x38f	/usr/local/go/src/runtime/pprof/pprof.go:329
#	0x150ece5	net/http/pprof.handler.ServeHTTP+0x355	/usr/local/go/src/net/http/pprof/pprof.go:245
#	0x150f746	net/http/pprof.Index+0x6f6		/usr/local/go/src/net/http/pprof/pprof.go:268
#	0x12e4243	net/http.HandlerFunc.ServeHTTP+0x43	/usr/local/go/src/net/http/server.go:1995
#	0x12e6145	net/http.(*ServeMux).ServeHTTP+0x1d5	/usr/local/go/src/net/http/server.go:2375
#	0x12e7517	net/http.serverHandler.ServeHTTP+0xa7	/usr/local/go/src/net/http/server.go:2774
#	0x12e3200	net/http.(*conn).serve+0x850		/usr/local/go/src/net/http/server.go:1878

/cc @stamblerre

[muirdm]

@ianthehat while testing out a fix for above deadlock I hit a different deadlock involving the watcher. Basically one codepath tries adding a file to the watcher while holding the view's mutex, and another codepath is invoking a watcher callback (which holds the watcher mutex) and the callback acquires the view mutex. I have annotated the relevant stack traces below with @@mutex.

Do you think we should make the watcher not hold the mutex while invoking the callbacks (i.e. copy the slice of callbacks before invoking), or perhaps invoke the callbacks in a goroutine (or something else)?

          1 @ 0x1030c0f 0x1040f89 0x1040f5f 0x1040cfd 0x1073419 0x1532dac 0x153582e 0x15347e6 0x15353a0 0x1530c5a 0x15300fe 0x1520d30 0x151e139 0x13265c4 0x131ae07 0x105d841
          #	0x1040cfc	sync.runtime_SemacquireMutex+0x3c					/usr/local/go/src/runtime/sema.go:71
          #	0x1073418	sync.(*Mutex).Lock+0x108						/usr/local/go/src/sync/mutex.go:134
@@view    #	0x1532dab	golang.org/x/tools/internal/lsp/cache.(*goFile).invalidateContent+0x3b	/Users/muir/projects/tools/internal/lsp/cache/view.go:230
          #	0x153582d	golang.org/x/tools/internal/lsp/cache.(*view).getFile.func1+0x4d	/Users/muir/projects/tools/internal/lsp/cache/view.go:356
@@watcher #	0x15347e5	golang.org/x/tools/internal/lsp/cache.(*WatchMap).Notify+0xd5		/Users/muir/projects/tools/internal/lsp/cache/watcher.go:54
          #	0x153539f	golang.org/x/tools/internal/lsp/cache.(*session).openOverlay.func1+0x6f	/Users/muir/projects/tools/internal/lsp/cache/session.go:267
          #	0x1530c59	golang.org/x/tools/internal/lsp/cache.(*session).openOverlay+0x389	/Users/muir/projects/tools/internal/lsp/cache/session.go:283
          #	0x15300fd	golang.org/x/tools/internal/lsp/cache.(*session).DidOpen+0xfd		/Users/muir/projects/tools/internal/lsp/cache/session.go:191
          #	0x1520d2f	golang.org/x/tools/internal/lsp.(*Server).didOpen+0xcf			/Users/muir/projects/tools/internal/lsp/text_synchronization.go:23
          #	0x151e138	golang.org/x/tools/internal/lsp.(*Server).DidOpen+0x48			/Users/muir/projects/tools/internal/lsp/server.go:138
          #	0x13265c3	golang.org/x/tools/internal/lsp/protocol.serverHandler.func1+0x20c3	/Users/muir/projects/tools/internal/lsp/protocol/tsserver.go:104
          #	0x131ae06	golang.org/x/tools/internal/jsonrpc2.(*Conn).Run.func1+0x116		/Users/muir/projects/tools/internal/jsonrpc2/jsonrpc2.go:441

          1 @ 0x1030c0f 0x1040f89 0x1040f5f 0x1040cfd 0x1073419 0x153448e 0x1533aca 0x152bb3d 0x152af68 0x152a2b5 0x1529053 0x152937c 0x14c7a76 0x1517138 0x1522d47 0x105d841
          #	0x1040cfc	sync.runtime_SemacquireMutex+0x3c					/usr/local/go/src/runtime/sema.go:71
          #	0x1073418	sync.(*Mutex).Lock+0x108						/usr/local/go/src/sync/mutex.go:134
@@watcher #	0x153448d	golang.org/x/tools/internal/lsp/cache.(*WatchMap).Watch+0x4d		/Users/muir/projects/tools/internal/lsp/cache/watcher.go:26
          #	0x1533ac9	golang.org/x/tools/internal/lsp/cache.(*view).getFile+0x229		/Users/muir/projects/tools/internal/lsp/cache/view.go:351
          #	0x152bb3c	golang.org/x/tools/internal/lsp/cache.(*view).link+0x19c		/Users/muir/projects/tools/internal/lsp/cache/load.go:217
          #	0x152af67	golang.org/x/tools/internal/lsp/cache.(*view).checkMetadata+0x487	/Users/muir/projects/tools/internal/lsp/cache/load.go:109
@@mcache  #	0x152a2b4	golang.org/x/tools/internal/lsp/cache.(*view).loadParseTypecheck+0xf4	/Users/muir/projects/tools/internal/lsp/cache/load.go:29
@@view    #	0x1529052	golang.org/x/tools/internal/lsp/cache.(*goFile).GetPackages+0x322	/Users/muir/projects/tools/internal/lsp/cache/gofile.go:112
          #	0x152937b	golang.org/x/tools/internal/lsp/cache.(*goFile).GetPackage+0x4b		/Users/muir/projects/tools/internal/lsp/cache/gofile.go:137
          #	0x14c7a75	golang.org/x/tools/internal/lsp/source.Diagnostics+0x65			/Users/muir/projects/tools/internal/lsp/source/diagnostics.go:62
          #	0x1517137	golang.org/x/tools/internal/lsp.(*Server).Diagnostics+0x267		/Users/muir/projects/tools/internal/lsp/diagnostics.go:27
          #	0x1522d46	golang.org/x/tools/internal/lsp.(*Server).didOpen.func1+0x66		/Users/muir/projects/tools/internal/lsp/text_synchronization.go:29

[gopherbot]

Change https://golang.org/cl/184880 mentions this issue: internal/lsp: fix deadlocks loading lots of files at once