crashpad/handler/crashpad_handler.ad

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:doctype: manpage

= crashpad_handler(8)

== Name

crashpad_handler - Crashpad’s exception handler server

== Synopsis

[verse]
*crashpad_handler* ['OPTION…']

== Description

This program is Crashpad’s main exception-handling server. It is responsible for
catching exceptions, writing crash reports, and uploading them to a crash report
collection server. Uploads are disabled by default, and can only be enabled by a
Crashpad client using the Crashpad client library, typically in response to a
user requesting this behavior.

On OS X, this server may be started by its initial client, in which case it
performs a handshake with this client via a pipe established by the client that
is inherited by the server, referenced by the *--handshake-fd* argument. During
the handshake, the server furnishes the client with a send right that the client
may use as an exception port. The server retains the corresponding receive
right, which it monitors for exception messages. When the receive right loses
all senders, the server exits after allowing any upload in progress to complete.

Alternatively, on OS X, this server may be started from launchd(8), where it
receives the Mach service name in a *--mach-service* argument. It checks in with
the bootstrap server under this service name, and clients may look it up with
the bootstrap server under this service name. It monitors this service for
exception messages. Upon receipt of +SIGTERM+, the server exits after allowing
any upload in progress to complete. +SIGTERM+ is normally sent by launchd(8)
when it determines that the server should exit.

On Windows, clients register with this server by communicating with it via the
named pipe identified by the *--pipe-name* argument. Alternatively, the server
can create a new pipe with a random name and inform a client of this name via
the *--handshake-handle* mechanism; clients may then register by communicating
with it via that named pipe. During registration, a client provides the server
with an OS event object that it will signal should it crash. The server obtains
the client’s process handle and waits on the crash event object for a crash, as
well as the client’s process handle for the client to exit cleanly without
crashing. When a server started via the *--handshake-handle* mechanism loses all
of its clients, it exits after allowing any upload in progress to complete.

On Windows, this executable is built by default as a Windows GUI app, so no
console will appear in normal usage. This is the version that will typically be
used. A second copy is also made with a +.com+ extension, rather than +.exe+. In
this second copy, the PE header is modified to indicate that it's a console app.
This is useful because the +.com+ is found in the path before the +.exe+, so
when run normally from a shell using only the basename (without an explicit
+.com+ or +.exe+ extension), the +.com+ console version will be chosen, and so
stdio will be hooked up as expected to the parent console so that logging output
will be visible.

It is not normally appropriate to invoke this program directly. Usually, it will
be invoked by a Crashpad client using the Crashpad client library, or started by
another system service. On OS X, arbitrary programs may be run with a Crashpad
handler by using man_link:run_with_crashpad[1] to establish the Crashpad client
environment before running a program.

== Options
*--annotation*='KEY=VALUE'::
Sets a process-level annotation mapping 'KEY' to 'VALUE' in each crash report
that is written. This option may appear zero, one, or multiple times.
+
Most annotations should be provided by the Crashpad client as module-level
annotations instead of process-level annotations. Module-level annotations are
more flexible in that they can be modified and cleared during the client
program’s lifetime. Module-level annotations can be set via the Crashpad client
library. Process-level annotations are useful for annotations that the
collection server requires be present, that have fixed values, and for cases
where a program that does not use the Crashpad client library is being
monitored.
+
Breakpad-type collection servers only require the +"prod"+ and +"ver"+
annotations, which should be set to the product name or identifier and product
version, respectively. It is unusual to specify other annotations as
process-level annotations via this argument.

*--database*='PATH'::
Use 'PATH' as the path to the Crashpad crash report database. This option is
required. Crash reports are written to this database, and if uploads are
enabled, uploaded from this database to a crash report collection server. If the
database does not exist, it will be created, provided that the parent directory
of 'PATH' exists.

*--handshake-fd*='FD'::
Perform the handshake with the initial client on the file descriptor at 'FD'.
Either this option or *--mach-service*, but not both, is required. This option
is only valid on OS X.

*--handshake-handle*='HANDLE'::
Perform the handshake with the initial client on the HANDLE at 'HANDLE'. Either
this option or *--pipe-name*, but not both, is required. This option is only
valid on Windows.
+
When this option is present, the server creates a new named pipe at a random
name and informs its client of the name. The server waits for at least one
client to register, and exits when all clients have exited, after waiting for
any uploads in progress to complete.

*--mach-service*='SERVICE'::
Check in with the bootstrap server under the name 'SERVICE'. Either this option
or *--handshake-fd*, but not both, is required. This option is only valid on OS
X.
+
'SERVICE' may already be reserved with the bootstrap server in cases where this
tool is started by launchd(8) as a result of a message being sent to a service
declared in a job’s +MachServices+ dictionary (see launchd.plist(5)). The
service name may also be completely unknown to the system.

*--no-rate-limit*::
Do not rate limit the upload of crash reports. By default uploads are throttled
to one per hour. Using this option disables that behavior, and Crashpad will
attempt to upload all captured reports.

*--pipe-name*='PIPE'::
Listen on the given pipe name for connections from clients. 'PIPE' must be of
the form +\\.\pipe\<somename>+. Either this option or *--handshake-handle*, but
not both, is required. This option is only valid on Windows.
+
When this option is present, the server creates a named pipe at 'PIPE', a name
known to both the server and its clients. The server continues running even
after all clients have exited.

*--reset-own-crash-exception-port-to-system-default*::
Causes the exception handler server to set its own crash handler to the system
default before beginning operation. This is only expected to be useful in cases
where the server inherits an inappropriate crash handler from its parent
process. This option is only valid on OS X. Use of this option is discouraged.
It should not be used absent extraordinary circumstances.

*--url*='URL'::
If uploads are enabled, sends crash reports to the Breakpad-type crash report
collection server at 'URL'. Uploads are disabled by default, and can only be
enabled for a database by a Crashpad client using the Crashpad client library,
typically in response to a user requesting this behavior. If this option is not
specified, this program will behave as if uploads are disabled.

*--help*::
Display help and exit.

*--version*::
Output version information and exit.

== Exit Status

*0*::
Success.

*1*::
Failure, with a message printed to the standard error stream.

== See Also

man_link:catch_exception_tool[1],
man_link:crashpad_database_util[1],
man_link:generate_dump[1],
man_link:run_with_crashpad[1]

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