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annotate framework/env/execute/command.lua @ 487:91d0c8304d74

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Do not execute abortable command if termination has already been requested
author jbe
date Mon Jun 12 03:18:54 2017 +0200 (2017-06-12)
parents 7d53e12f0804
children 5b1c4f76e44f
rev   line source
jbe@486 1 --[[--
jbe@486 2 output, -- collected data from stdout if process exited successfully
jbe@486 3 errmsg = -- error message if execution failed or if process didn't exit successfully
jbe@486 4 execute.command{
jbe@486 5 command = { filename, arg1, arg2, ... }, -- command and arguments
jbe@486 6 stdin_data = stdin_data, -- optional data to be sent to process via stdin
jbe@486 7 stdout_result_handler = stdout_result_handler, -- callback receiving: stdout data, success boolean, optional error message
jbe@486 8 stderr_line_handler = stderr_line_handler, -- callback for processing stderr line-wise
jbe@486 9 exit_handler = exit_handler, -- callback when process exited
jbe@486 10 signal_handler = signal_handler, -- callback when process terminated due to signal
jbe@486 11 timeout_handler = timeout_handler, -- callback when process gets killed due to timeout
jbe@486 12 abort_handler = abort_handler, -- callback when process gets killed due to request by poll function
jbe@486 13 abortable = abortable, -- set to true if process shall be terminated if poll function requests termination
jbe@486 14 poll = poll, -- alternative poll command with moonbridge_io.poll(...) semantics
jbe@486 15 db = db, -- database handle for waiting for notifies
jbe@486 16 db_notify_handler = db_notify_handler -- handler for database notifications which may return true to kill process
jbe@486 17 }
jbe@486 18
jbe@486 19 --]]--
jbe@486 20
jbe@486 21 function execute.command(args)
jbe@486 22
jbe@486 23 local moonbridge_io = require("moonbridge_io")
jbe@486 24 local poll = args.poll or moonbridge_io.poll
jbe@486 25
jbe@486 26 local stdout_chunks, stderr_chunks = {}, {}
jbe@486 27
jbe@486 28 local function return_error(errmsg)
jbe@486 29 if args.stdout_result_handler then
jbe@486 30 args.stdout_result_handler(table.concat(stdout_chunks), false, errmsg)
jbe@486 31 end
jbe@486 32 return nil, errmsg
jbe@486 33 end
jbe@486 34
jbe@487 35 if args.abortable then
jbe@487 36 local pollready, pollmsg, pollterm = poll(nil, nil, 0, true)
jbe@487 37 if pollterm then
jbe@487 38 if args.abort_handler then args.abort_handler() end
jbe@487 39 return_error(pollmsg)
jbe@487 40 end
jbe@487 41 end
jbe@487 42
jbe@487 43 local start = moonbridge_io.timeref()
jbe@487 44 local process, errmsg = moonbridge_io.exec(table.unpack(args.command))
jbe@487 45 if not process then return nil, errmsg end
jbe@487 46
jbe@487 47 local read_fds = {[process.stdout] = true, [process.stderr] = true}
jbe@487 48 local write_fds = {[process.stdin] = true}
jbe@487 49 if args.db then
jbe@487 50 read_fds[args.db.fd] = true
jbe@487 51 end
jbe@487 52
jbe@486 53 local function write(...)
jbe@486 54 if write_fds[process.stdin] then
jbe@486 55 local buffered = process.stdin:flush_nb(...)
jbe@486 56 if not buffered or buffered == 0 then
jbe@486 57 process.stdin:close()
jbe@486 58 write_fds[process.stdin] = nil
jbe@486 59 end
jbe@486 60 end
jbe@486 61 end
jbe@486 62 write(args.stdin_data or "")
jbe@486 63
jbe@486 64 while
jbe@486 65 read_fds[process.stdout] or read_fds[process.stderr] or
jbe@486 66 write_fds[process.stdin]
jbe@486 67 do
jbe@486 68 local timeout = args.timeout and args.timeout-moonbridge_io.timeref(start)
jbe@487 69 local pollready, pollmsg, pollterm =
jbe@486 70 poll(read_fds, write_fds, timeout, args.abortable)
jbe@487 71 if not pollready then
jbe@486 72 process:kill():wait()
jbe@486 73 if pollterm then
jbe@486 74 if args.abort_handler then args.abort_handler() end
jbe@486 75 else
jbe@486 76 if args.timeout_handler then args.timeout_handler() end
jbe@486 77 end
jbe@486 78 return return_error(pollmsg)
jbe@486 79 end
jbe@486 80 if args.db then
jbe@486 81 local channel, payload, pid = db:wait(0)
jbe@486 82 if channel then
jbe@486 83 if args.db_notify_handler(channel, payload, pid) then
jbe@486 84 process:kill():wait()
jbe@486 85 return return_error("Database event received")
jbe@486 86 end
jbe@486 87 end
jbe@486 88 end
jbe@486 89 if read_fds[process.stdout] then
jbe@486 90 local chunk, status = process.stdout:read_nb()
jbe@486 91 if not chunk or status == "eof" then
jbe@486 92 process.stdout:close()
jbe@486 93 read_fds[process.stdout] = nil
jbe@486 94 end
jbe@486 95 if chunk and chunk ~= "" then
jbe@486 96 stdout_chunks[#stdout_chunks+1] = chunk
jbe@486 97 end
jbe@486 98 end
jbe@486 99 if read_fds[process.stderr] then
jbe@486 100 local chunk, status = process.stderr:read_nb()
jbe@486 101 if not chunk or status == "eof" then
jbe@486 102 process.stderr:close()
jbe@486 103 read_fds[process.stderr] = nil
jbe@486 104 end
jbe@486 105 if chunk and args.stderr_line_handler then
jbe@486 106 while true do
jbe@486 107 local chunk1, chunk2 = string.match(chunk, "(.-)\n(.*)")
jbe@486 108 if not chunk1 then break end
jbe@486 109 stderr_chunks[#stderr_chunks+1] = chunk1
jbe@486 110 args.stderr_line_handler(table.concat(stderr_chunks))
jbe@486 111 stderr_chunks = {}
jbe@486 112 chunk = chunk2
jbe@486 113 end
jbe@486 114 if chunk ~= "" then
jbe@486 115 stderr_chunks[#stderr_chunks+1] = chunk
jbe@486 116 end
jbe@486 117 if status == "eof" then
jbe@486 118 local line = table.concat(stderr_chunks)
jbe@486 119 if #line > 0 then args.stderr_line_handler(line) end
jbe@486 120 end
jbe@486 121 end
jbe@486 122 end
jbe@486 123 write()
jbe@486 124 end
jbe@486 125
jbe@486 126 local status = process:wait()
jbe@486 127
jbe@486 128 if status < 0 then
jbe@486 129 if args.signal_handler then
jbe@486 130 args.signal_handler(-status)
jbe@486 131 end
jbe@486 132 return return_error("Command terminated by signal " .. -status)
jbe@486 133 elseif status > 0 then
jbe@486 134 if args.exit_handler then
jbe@486 135 args.exit_handler(status)
jbe@486 136 end
jbe@486 137 return return_error("Command returned exit code " .. status)
jbe@486 138 elseif args.stdout_result_handler then
jbe@486 139 args.stdout_result_handler(table.concat(stdout_chunks), true)
jbe@486 140 return true
jbe@486 141 else
jbe@486 142 return table.concat(stdout_chunks)
jbe@486 143 end
jbe@486 144
jbe@486 145 end

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