Allow synchronous proxying of async JS functions #26000
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Still a WIP, especially the name for this new mode.. |
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I found that combining |
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Non-function change split out from emscripten-core#26000.
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Non-function change split out from #26000.
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This new mode allows the proxied work itself to be asynchronous (i.e. return a promise). The new behaviour is triggered by marking a functions as both `__proxy: 'sync'` and also `__async: true`. We can use this new mode to replace the bespoke proxying code that exists for `dlsync` as well as the `poll` system call. For the poll system call this bespoke code was added in emscripten-core#25523 and emscripten-core#25990, but can now be completely removed. In addition to this, because the `poll` syscall is now marked as `__async` it automatically works under JSPI too. One downside of this new mode is that the proxied work requires the main thread event loop to run. Unlike the synchronous proxied work that can complete even when we are deeply nested. Fixes: emscripten-core#25970
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This new mode allows the proxied work itself to be asynchronous (i.e.
return a promise). The new behaviour is triggered by marking a
functions as both
__proxy: 'sync'and also__async: true.We can use this new mode to replace the bespoke proxying code that
exists for
dlsyncas well as thepollsystem call. For the pollsystem call this bespoke code was added in #25523 and #25990, but can
now be completely removed.
In addition to this, because the
pollsyscall is now marked as__asyncit automatically works under JSPI too.One downside of this new mode is that the proxied work requires the main
thread event loop to run. Unlike the synchronous proxied work that can
complete even when we are deeply nested.
Fixes: #25970